>Your exhaust needs backpressure to make torque!

>>13863032
I just removed my headers and I use diamond valves now

File: 1311241807074.jpg (6KB, 157x153px) Image search: [Google]

6KB, 157x153px

>I6's make more torque

You do but a 12" tube off the exhaust port provides enough. Scavenging is important for power and economy though. That's why people run siamesed exhaust instead of individual pipes.

File: 507.jpg (76KB, 600x709px)

76KB, 600x709px

>pushrods make more torque

File: 1311222662015.jpg (4KB, 137x176px) Image search: [Google]

4KB, 137x176px

>making power at high rpm is better!

File: 65066.jpg (70KB, 330x319px) Image search: [Google]

70KB, 330x319px

>>13863090
>making power at low rpm is better

>>13863090
>>13863111

Neither is better as long as the same power is produced.

>>13863119
with the same displacement, you will be making more powerthe faster your engine spins

>>13863129
>with the same displacement, you will be making more powerthe faster your engine spins

That's wrong. Displacement and rpm is not the sole determining factors for how much power is made.

And the point is for equivalent amounts of power, high RPM or low RPM does not matter at all.

>>13863119

Either one can be better than the other depending on the application.

File: 1397777706456.jpg (31KB, 433x419px)

31KB, 433x419px

>>13863138
>That's wrong.

kek, say that to LMP and F1 motor engineers

>>13863144
If you think how fast an engine spins and how much volume it displaces are the only things that determine how much power an engine produce, you're a fool.

>>13863032
>if you get rid of your cat you'll break your exhaust valves!

lol

i love boomer myths

too large of an exhaust can hurt power tho

File: 286542036.jpg (11KB, 250x241px) Image search: [Google]

11KB, 250x241px

>>13863151
thats irrelevant, no one is discussing that

the architecture of an engine that makes power at high rpms is better for motorsports than a diesel truck-tier engine that makes power down low

>>13863170
That has everything to do with flow velocity for scavenging and nothing to do with "back pressure".

>>13863177
Weight is the issue. You could gear the trans and final drive to get the same speeds @3krpm as you could at 13k.

>>13863138
>he doesn't know power is work (torque) over time!
>laughing girls

>>13863177
>thats irrelevant, no one is discussing that
Yes. That is exactly what was said.

see:
>>13863129
>with the same displacement, you will be making more powerthe faster your engine spins

This is fucking wrong.
For a given displacement, simply spinning an engine faster does not necessarily create more power.

>the architecture of an engine that makes power at high rpms is better for motorsports
Motorsports are displacement limited 95% of the time. thus the only way to make power within a given displacement constraint once flow limits have been eliminated it to increase the operating speed of the engine.

Nothing about making power at high rpm is intrinsically better for motorsport than making that same amount of power at a lower rpm.

>>13863188
I know how horsepower is calculated retard.
That still doesn't mean displacement and rpm dictate power you fucking idiot.

File: 1431112832914.png (946KB, 912x905px)

946KB, 912x905px

>>13863185
and bore and stroke lenght, in which an engine with a longer stroke has a higher center of gravity, and smaller valve area, an engine with a longer stroke is harder to balance, crank is bigger, its wider, etc etc

I rather take racing engineers knowledge, who make high revving racing engines over a cunt in 4chan kek

>>13863151
hmm it's most of it though ho

File: Girls.png (477KB, 560x500px)

477KB, 560x500px

>>13863032
>His car needs 3rd gear to reach 60

>>13863189
>Motorsports are displacement limited 95% of the time.
irrelevant, they dont regulate the bore and stroke lenght
racing engines rev high inteads of having a longer stroke and making power down low

>Nothing about making power at high rpm is intrinsically better for motorsport than making that same amount of power at a lower rpm.
kek, racing engineers know otherwise

File: loser.png (256KB, 354x486px)

256KB, 354x486px

>LS swapped rx7 are better

>>13863199
>nd bore and stroke lenght, in which an engine with a longer stroke has a higher center of gravity
>what are flat engines
>what are OHV heads on V engines.
The LS is shorter than the equivalent displacement power OHC engine. And even shorter of smaller displacement equivelent power OHC V8's.

>and smaller valve area
Valve curtain area is a product of valve lift and valve area. Lower RPM engines can lift a valve further equating the same valve curtain without valvetrain float issues.

>engine with a longer stroke is harder to balance, crank is bigger, its wider, etc etc

Which is not as critical because said engine is rotating at a lower rpm anyways.

>I rather take racing engineers knowledge, who make high revving racing engines
As has been explained, race engines rev high because they are displacement limited and high revs are one of the few ways in which to pull maximum power out of a limited displacement.

And again, nothing about making power at higher rpm is inherently better for motorsport than making power at low rpm.

File: 1311643569662.png (246KB, 521x620px)

246KB, 521x620px

>>13863201
>He uses 0-60 times as a credible metric of performance.

>>13863199
Stroke has nothing to do with valve area, bore and combustion chamber design are what limits size. width has to do with number of cylinder banks, bank separation angle (if multi bank), head design, material thickness and manufacturing methods.

If I bore and stroke my engine for another 2 liters of displacement. It's physical size hasn't changed.

What limits long stroke engines it piston speeds and side load. Of course this is dependant on rod/stroke ratio.

>Reasons most race engines are built the way they are is class limitations faggot.

File: 1445051152856.jpg (26KB, 393x700px) Image search: [Google]

26KB, 393x700px

can't get above 80% volumetric efficiency using natural aspiration

>>13863210
>irrelevant, they dont regulate the bore and stroke lenght
They regulate displacement, which has direct implications on bore and stroke.

>racing engines rev high inteads of having a longer stroke and making power down low
No, racing engines rev high because that's the only way to make power within a limited displacement regulation.

Nothing about actually making the power at high rpm (as opposed to low rpm) is beneficial to performance in and of itself. It's the fact that high rpm is required to make the power that necessitates racing engine design.

>kek, racing engineers know otherwise
Yet you cannot explain how or what simply making power at higher rpm is somehow better.

Take a 3 liter inline 6 that makes 300hp at 6000rpm
Then take another 3 liter inline 6 that makes 300hp at 8000rpm.

Explain to me how one of these engines is better than the other.

File: 1311927508802.jpg (25KB, 204x182px)

25KB, 204x182px

>>13863214
>Rotaries aren't unreliable gutless piles of garbage.

>>13863267
Oh god.
inb4 full force autism triggering from dorritofags.

>>13863235
>The LS is shorter than the equivalent displacement power OHC engine. And even shorter of smaller displacement equivelent power OHC V8's.
irrelevant

>Valve curtain area is a product of valve lift and valve area. Lower RPM engines can lift a valve further equating the same valve curtain without valvetrain float issues.
> Lower RPM engines can lift a valve further
kek if you actually belive you will lift a valve higher just because of longer stroke

what, are you going to lift a valve 3 inches?

>Which is not as critical because said engine is rotating at a lower rpm anyways.
at the same speed, the engine with the longer stroke will be harder to balance

> race engines rev high because they are displacement limited and high revs are one of the few ways in which to pull maximum power out of a limited displacement.
yup
because making power at higher revs is an advantage

glad you get it

>nothing about making power at higher rpm is inherently better for motorsport than making power at low rpm.
tell that to engine makers who decide to have a shorter stroke over a longer stroke

>>13863247
>Stroke has nothing to do with valve are
>bore and combustion chamber design are what limits size.

given the same displacement, you will have bigger valves the bigger the bore is

>If I bore and stroke my engine for another 2 liters of displacement. It's physical size hasn't changed.
irrelevant to the discussion

>>Reasons most race engines are built the way they are is class limitations faggot.
name a racing class that regulates bore and stroke length faggot

>>13863274
>irrelevant
It is relevant to your claim that longer stroke equates to a higher center of gravity. More than just stroke length dictates center of gravity as evidenced by my examples.

>kek if you actually belive you will lift a valve higher just because of longer stroke
No, a longer stroke equating to a higher rod:stroke ratio means the engines operating range will be naturally lower.
Lower rpm engines can reliable have higher valve lift due to less limitations in valvetrain at high rp,.
More valve lift effectively negates any imposed valve area limitations by bore dimension on valve curtain area.

>what, are you going to lift a valve 3 inches?
No, that would be stupid, like you.

>at the same speed, the engine with the longer stroke will be harder to balance

Balance is critical at lower rpm anyway.

>because making power at higher revs is an advantage
[citation needed]

>tell that to engine makers who decide to have a shorter stroke over a longer stroke
You tell that to engine makers who decide to have a longer stroke over a shorter stroke.

File: 1440303732756.jpg (44KB, 960x539px) Image search: [Google]

44KB, 960x539px

>>13863243
His car even reaches 60. Mine just skips it altogether and jumps to 140 immediately

>>13863300
>given the same displacement, you will have bigger valves the bigger the bore is
Valve curtain area, the dimension critical to flow, is not only dictated by valve area, but also valve lift.

More valve lift is possible at lower rpm given the same valvetrain limitations.

>name a racing class that regulates bore and stroke length faggot
Most regulate displacement.

Displacement limitations necessitate making power at higher rpm to maximize specific output. This dictates stroke, bore, and rod:stroke ratio to maximize power for that displacement.

This does not prove your point that making XYZ power at high rpm is somehow better than makign that same power at low rpm.

Once again:
Take a 3 liter inline 6 that makes 300hp at 6000rpm
Then take another 3 liter inline 6 that makes 300hp at 8000rpm.

Explain to me how one of these engines is better than the other.

>>13863261
>They regulate displacement, which has direct implications on bore and stroke.
nope

you can have an undersquare and oversquare 2 liter engine, for some reasons, (unknown by you obv) racing engines have a shorter stroke

>No, racing engines rev high because that's the only way to make power within a limited displacement regulation.
kek
you could have a longer stroke, since several racing classes do not regulate bore and stroke lenght, and make power down low


according to you, it wouldnt matter, since an engine with a longer stroke makes more torque, it would make the same power at lower rpms

sadly its not that simple

>Yet you cannot explain how or what simply making power at higher rpm is somehow better.
I already did

>Take a 3 liter inline 6 that makes 300hp at 6000rpm
Then take another 3 liter inline 6 that makes 300hp at 8000rpm.
the one that revs higher probably has a shorter stroke, the crank is smaller, the block is shorter the bore is bigger, its easier to balance therefore it is lighter and smaller

>>13863274
7/10

Displacement limits do have an impact on bore/stroke.

You can't fit big valves into a small bore engine therefore you must run a large bore, displacement is limited so you must run a short stroke to meet regulations.

Bore x Stroke = cylinder volume.
Cylinder volume x # of cyls= engine displacement.

Now where does a big valve short stroke large bore engine make its power? The fucking moon Alice.

If the class limits induction cfm, valve size, camshaft lift or duration you see a lot of longer stroke engines to take advantage of that rule set.

>You're fucking dense m8.

>>13863138
>sole
>only

You guys are arguing over something that was never said.

>>13863129
>with the same displacement, you will be making more powerthe faster your engine spins

This statement is true.

>>13863090
>>making power at high rpm is better!
>>13863111
>>making power at low rpm is better

And those depend on the function.

For a lighweight car, high RPM power is better. Think how the McLaren F1 is easy to drive without TC while every other 600 hp car requires TC for unexperienced drivers.

On the other side, buses and trucks use diesel engines exactly because of the low rpm power, since it won't require the driver to rev the engine to get moving.

Sorry for making sense.

>>13863309

>It is relevant to your claim that longer stroke equates to a higher center of gravity.
no it isnt

>More than just stroke length dictates center of gravity as evidenced by my examples
given the same head design, an engine with a shorter block will be lower
how stupid are you that you think this is an argument?

>No, a longer stroke equating to a higher rod:stroke ratio means the engines operating range will be naturally lower.
doesnt mean you can lift a valve more

>Lower rpm engines can reliable have higher valve lift due to less limitations in valvetrain at high rpm
nope, since a shorter valve is lighter, and it travels a smaller distance, the forces that are applied to the spings, cams, camshaft and rollers themselves are not the same
just because a valve is moving faster doesnt mean its less reliable

>More valve lift effectively negates any imposed valve area limitations by bore dimension on valve curtain area.
you can have exactly the same valve lift in a higher revving engine, besides, lifting a valve higher involes a more aggressive camshaft which can create valvefloat
there is a point where the lift of a valve and duration are dictated by the compression ratio


>No, that would be stupid, like you.
nice butthurt, sadly its the whole basis of your argument, there is a point where you wont be able to lift a valve anymore

>[citation needed]
L!, LMP GT, moto GP and other motorposrt that regulate displacement but not bore and stroke

>You tell that to engine makers who decide to have a longer stroke over a shorter stroke.
pigfat truck engines, dont care

>>13863325
>Valve curtain area, the dimension critical to flow, is not only dictated by valve area, but also valve lift.
you can have the same valve lift in a valve with bigger are

>>13863325
>Most regulate displacement.
irrelevant
you can have an undersquare and oversquare 2 liter engine, for example

>Displacement limitations necessitate making power at higher rpm to maximize specific output. This dictates stroke, bore, and rod:stroke ratio to maximize power for that displacement.
I dont see you dont understand how this proves your whole point wrong
engineers chose the optimum engine velocity for the application, according to you, increasing stroke and reducing bore, in order to make the same power, but at lowe rpms, yield better results, yet, engineers chose not to, and decided that the optimum rev range, in lmp, f1, moto gp st stc
is actually quite high

for the sake of the argument, any engine that revs higher than 5252 rpms is an engine that revs high, because at this point, the goal was not torque, but horsepower

your point is, that by increasing torque, you make the same power at lower rpms, yet racing engineers do no make long stroke engines, that rev below 5252

>b-but those are arbitrary numbers
no they arent, you decided to start san argument here >>13863090 without dictating at what point an engine rpm is connsidered high or low
>This does not prove your point that making XYZ power at high rpm is somehow better than makign that same power at low rpm.
yes it does
engineered chose an optimum engine velocity, and the engine velocity in most motorsport engines is quite high

>Once again:
>Take a 3 liter inline 6 that makes 300hp at 6000rpm
>Then take another 3 liter inline 6 that makes 300hp at 8000rpm.
see >>13863330

>>13863345
according to this dumb anon, valve area doesnt matter, since you can lift a valve higher on an engine with a longer stroke

of course the dumb ass doesnt know that for higher lift you need to avoid valves from hitting eachother, and have to decrease valve angle r to avoid them from hitting eachother, since you would need higher duration to avoid valvefloat by having a camshaft with high lift but low duration

>>13863330
>nope
>you can have an undersquare and oversquare 2 liter engine, for some reasons, (unknown by you obv) racing engines have a shorter stroke

Yes, you tard.

Displacement limitations mean engine builders must build engines for higher rpm in order to make the most power for that displacement. That means building undersquare engines.

>you could have a longer stroke, since several racing classes do not regulate bore and stroke lenght, and make power down low
You would make less power doing that.

This has nothing to do with the fact that making a given EQUAL amount of power at higher rpm is no better than making that same equal amount of power at low rpm.

Just because displacement limited racing engines have to make power at high rpm to be competitive does not mean higher rpm power is inherently better to performance compared to an equal amount of lower rpm power.

>according to you, it wouldnt matter, since an engine with a longer stroke makes more torque, it would make the same power at lower rpms
Strawman, I never said that. I've consistently said displacement limited racing engines must rev higher to make the most power within their rule limitations. You just can't read.

>I already did
No, you're pointing to displacement limited racing as evidence that makign power at high rpm is evidence that making a given amount of power at high rpm is "better".

This is ignoring the fact that these displacement limited engine MUST make power at high rpm to be competitive, and has no implications on the relative merits of high rpm power compared to an equal amount of low rpm power.

even nascar engines rev high and never ever ever run around at a low rpm
this kid is retarded

File: 1447384162821.png (218KB, 500x339px)

218KB, 500x339px

>>13863090
Making power at higher RPM is better, because low RPM power requires supercharging which is leeching and really heavy, or high displacement which is going to be heavier than a small displacement. There's no real advantage to low RPM power if your gearing and redline are good enough, so it's better to only have power at high RPM, because you can make the engine smaller/lighter while making the same power. That's why the fastest F1 cars were tiny 1.5l V6s with huge turbos that revved to 15k or whatever insanity.

Same reason why the new Ford GT has a V6 Turbo, and Audi dominates LMP with turbo V6s, it's just better for racing than a big hueg V12 or V8.

File: bmw-hp4-08.jpg (142KB, 2000x1333px)

142KB, 2000x1333px

>>13863445
>DISPLACEMENT LIMITED RACING ENGINES WAAH WAAH
what about production vehicles then, such as motorcycles?

>>13863330
>the one that revs higher probably has a shorter stroke, the crank is smaller, the block is shorter the bore is bigger, its easier to balance therefore it is lighter and smaller
This has no bearing on at what rpm the engine makes power. You are drawing conclusions that were not given in the example.

It is perfectly reasonable to have two 3 liter I6 engines of an equal weight/size, each making 300hp. With one making 300hp at 6000rpm and the other making 300hp at 8000rpm.

You cannot demonstrate how making 300hp at 8000rpm is any better than making 300hp at 6000rpm.

That is my point, that has been my point since the begining.

There is no inherent performance advantage to making a given amount of horsepower at high rpm alone. This is fact.

In fact the rpm two engines of equal power operate at have no bearing on performance, all else being equal.

>>13863459
The thing is tho t.bh engines dont make power at a low rpm. They all make their peak power towards the end. Even muh LiteralShit engines you gotta get dat high rpm to take advantage of all the power.
So this guy faggot nigger cukc saying its better to make power down low roflmao engines dont even make power down low

>>13863144
>>13863177
Have you seen LeMans the last 10 years?

>>13863373
>You guys are arguing over something that was never said.
>>with the same displacement, you will be making more powerthe faster your engine spins
>This statement is true.

No it is not. RPM and displacement are not the only things that determine power output. You can easily spin a 5 liter motor faster and not make any more power than if you left it at it's stock redline.

>For a lighweight car, high RPM power is better.
No.

>On the other side, buses and trucks use diesel engines exactly because of the low rpm power, since it won't require the driver to rev the engine to get moving.
No.

Gearing exists. The rpm at which a given amount of horsepower is made doesn't matter because gearing differences equalizes engine speed to wheel speed.

>>13863463
>You cannot demonstrate how making 300hp at 8000rpm is any better than making 300hp at 6000rpm
The engine that revs to 8k will get more speed out of each gear, meaning its faster.

File: befa8af669310a7eecf3945ddb73e7c3341cf833_hq.jpg (77KB, 960x648px)

77KB, 960x648px

>>13863445
>Displacement limitations mean engine builders must build engines for higher rpm in order to make the most power for that displacement. That means building undersquare engines.
nope

according to you, you can have a longer stroke, that makes the same power down low and fix top speed with gearing

yet they dont do that

>You would make less power doing that.
yes, because revving higger is an advantage

>This has nothing to do with the fact that making a given EQUAL amount of power at higher rpm is no better than making that same equal amount of power at low rpm.
sorry but in order to make the same power with a bigger stroke and a longer stroke, you would need bigger displacement, bigger valve lift, bigger camlobe duration and other advantages

>Just because displacement limited racing engines have to make power at high rpm to be competitive
they dont regulate bore and stroke

>does not mean higher rpm power is inherently better to performance compared to an equal amount of lower rpm power.
in order to make the same power you would need bigger displacement, bigger valve lift and duriation (since according to you, makes up for the smaller area)

these are advantages that you cannot ask for because your dumb ass decided to make an engine with a longer stroke

or perhaps you do understand that a higher rpm limit equals advantages such as higher valve lift and rudartion and bigger displacement, in which case, you just labeled higher rpm as an advantge aswel

>No, you're pointing to displacement limited racing as evidence that makign power at high rpm is evidence that making a given amount of power at high rpm is "better".
because it is

engineers dont chose to give the engine a longer stroke, because they would need more displacement and a higher lift, (something you typed)

at this point, you just labeled a higher rpm an advantage similar to more displacement and higher valve lift

GG no re

2-0 today because rotary powered RX7s are faster :-V

>>13863476
yes

lmp2 and toyota v8 engines rev quite high

>>13863470
>What is torque

>>13863490
another dumb ass spaying "muh torq"

enginners dont make racing engines with a long stroke and short bore for a reason,

>>13863490
Power makes a car go fast not torque

>>13863498
small bore*

File: 1375064866059.jpg (346KB, 1280x853px)

346KB, 1280x853px

>>13863498
>>13863501
I came into this argument late. Is it purely about racing engines? If not, torque is a good thing in a street car.

Also depends on the type of racing
>inb4 drag race shitposting
Like it or not, drag racing is still racing

>>13863525
> Is it purely about racing engines? If not, torque is a good thing in a street car.
it depends on the definition of high revving desu, but even on street cars a 6k redline is better than a 3k redline, for example

>>13863477
>RPM and displacement are not the ONLY things that determine power output.

Nobody said they are the ONLY things, but that they AFFECT.

>>13863477
>You can easily spin a 5 liter motor faster and not make any more power than if you left it at it's stock redline.

If you're just spinning the engine faster without making it able to deal with the increased flow, it wont.
If you deal with the flow limitation and change the cam profile to deal with higher revs, it will make more power.

Nobody said "spin it faster and gain power", but "a engine that spins faster (a.k.a. is engineered to spin faster) will make more power".

>>13863389
>no it isnt
Yes it is.
You claimed longer stroke equates to a higher CoG. This is bullshit because stroke is not the only determine factor for an engine's CoG. And in some engines CoG is not effected by an engine's stroke at all.

>given the same head design, an engine with a shorter block will be lower
You never said anything about a given head design. You said shorter stroke= lower CoG.

This is not the case as stroke is not the only thing that determines an engine's CoG.

>doesnt mean you can lift a valve more
Lower rpm allows more valve lift for a given amount of valvetrain limitaiton without float. So higher lift cams can be fitted to allow more valve curtain area to make up for losses in valve surface area.

>nope, since a shorter valve is lighter
We're not talking about shorter valves or valve length at all, we're talking about smaller/larger diameter valves. A larger diameter valve allowed by a larger bore has more mass.

>the forces that are applied to the spings, cams, camshaft and rollers themselves are not the same
No, they're not. The forces applied by a heavier valve at high RPM are much higher.

>just because a valve is moving faster doesnt mean its less reliable
Nobody said anything about reliability. we're talking about valve float.

And for a given amount of valvetrain limitation, more valve lift is possible at lower rpm which allows a larger valve curtain area and can equalize flow between larger, yet shorter lift valves with equal valve lift area.

>you can have exactly the same valve lift in a higher revving engine
Not for the same valvetrain limitations. To have the same valve lift at higher rpm you must have stronger components and higher tension springs to control the valves and prevent float.

>lifting a valve higher involes a more aggressive camshaft which can create valvefloat
Valve float is rpm dependent retard. If an engine doesn't spin fast enough, higher lift cams can be used.

>>13863389
> sadly its the whole basis of your argument
No. I never said anything about lifting a valve 3". Your retarded ass said that.

>there is a point where you wont be able to lift a valve anymore

There is, just like there's a point where you cannot make a valve any larger.

Valve lift can equalize valve diameter in creating valve curtain area and thus flow. Negating the benefits of having larger diameter valves in a higher revving engine by compensating with increased lift.

>L!, LMP GT, moto GP and other motorposrt that regulate displacement but not bore and stroke
Saying racing classes does not provide a citation that making power at higher rpm is better than makign power at lower rpm.

As I've already explained, displacement limited engines must make power at higher rpm to be competitive within their ruleset. This has nothing to do with advantages of making power at high rpm vs low rpm and it's impact on performance.

>pigfat truck engines, dont care
Just because your dumbass doesn't care doesn't mean it's not relevant to the discussion.

>you can have the same valve lift in a valve with bigger are
You can also have more lift on a valve with a smaller area.

And your more lift at higher rpm equates to more valvetrain stress and a propensity for valve float which would not necessarily be an issue on the same amount of valve lift on a smaller valve at lower rpm to equate the same valve curtain area and thus flow.

>>13863552
Yes more peak hp but less peak tq and less avg power and tq.

A 2jz that makes 1200hp on the dyno will be slower than a 800hp engine around a technical course since the ported high rev big turbo motor only makes peak hp in a very narrow rpm range.

More power? Yes. More usable power???

By designing the engine to be efficient at high operating speeds you make it inefficient at lower speeds because the volume of air passing through doesn't have enough velocity for proper cylinder fill.

>>13863416
>you can have an undersquare and oversquare 2 liter engine, for example
As I said:
Displacement limitations mean engine builders must build engines for higher rpm in order to make the most power for that displacement. That means building undersquare engines.

>I dont see you dont understand how this proves your whole point wrong
because you don't understand my point you fucking retard.

>engineers chose the optimum engine velocity for the application
Correct. However this does not mean that making a given amount of horsepower at higher rpm is better in all situations as has been claimed.

Just because displacement limited classes NEED to make power at high rpm does not mean making power at high rpm is better than making a given amount of power at lower rpm.

>yet racing engineers do no make long stroke engines, that rev below 5252
Because racing engineers work within displacement limits and are trying to pull the maximum horsepower for a given displacement while being reliable enough to finish a race/season.

>you decided to start san argument here >>13863090 (You) without dictating at what point an engine rpm is connsidered high or low
I didn't start any argument. I pointed out the absurdity of the idea that claiming that making power at higher rpm is somehow better. it doesn't matter what RPM you arbitrarily set as the baseline at. Simply making an engine spi nfaster to produce the same amount of power is of no net benefit to performance.

>the engine velocity in most motorsport engines is quite high
>motorsport
Cool moving the goalposts
My initial post had nothing to do with motorsport, you're the one who started talking about displacement limited engines necessitating me explaining to you why displacement limited racing engines must rev high.

>see >>13863330

No. I've set the the example.
Two equal size/weight I6's making equal amount of power.

Explain to me how one of those engines making that amount of power at a higher rpm is better

>>13863119
7 posts until someone took an obvious troll thread seriously.

You suck, /o/.

>>13863449
NASCAR engines are displacement limited idiot.

So basically this faggot is crying "waah waah they only rev higher because of regulations!" when like every race engine regardless of displacement makes all their power high. Like whats he crying about seriously.

Like do nascars really run around the oval at 4000rpm? Fuck no.
Race engines rev high and make all their power up high for a reason, and it has nothing to do with not being able to throw more displacement at it. Fucking mongoloid.

>>13863675
So you're telling me if the teams could add an extra 2l of displacement they wouldn't rev to 10k? Like they're already running with 800hp 5.7l engines, more displacement isnt gonna do much.

File: 06TrkSS-5.jpg (76KB, 802x602px)

76KB, 802x602px

>>13863461
>what about production vehicles then, such as motorcycles?
Performance production motorcycles conform to displacement limiting racing rulesets for homogation purposes. Hence the 600cc class, 1000cc class, etc.

Motorcycle are actually a prime example.
Ducati's make pretty much equal amounts of power at significantly lower RPM and are competitive and have been even dominant in their respective classes.

A prime example where equal power at lower rpm is made no difference in vehicle performance.

>>13863478
This is wrong.

Both engine's can be geared to hit the same wheel speeds at redline in each gear.

You don't know how gearing works.

>>13863486
>according to you, you can have a longer stroke, that makes the same power down low and fix top speed with gearing

Strawman. Show me exactly where I said that.

>yes, because revving higger is an advantage
No it isn't. Revving higher is necessary to make competitive power in displacement limited classes, this does not mean revving higher itself is a benefit to performance, it's a necessity of being competitive within the ruleset.

>sorry but in order to make the same power with a bigger stroke and a longer stroke, you would need bigger displacement, bigger valve lift, bigger camlobe duration and other advantages
You've completely missed the point. Again.

>they dont regulate bore and stroke
Never said they did.
I explained exactly why racing engines must make power at high rpm within displacement limited classes to be competitive.

>in order to make the same power you would need bigger displacement
No. Displacement is not the only determining factor for output, You have no idea how engines work.

>rhaps you do understand that a higher rpm limit equals advantages such as higher valve lift and rudartion and bigger displacement
No it fucking doesn't.

>because it is
No it isn't. It's evidence that high rpm is necessary to get the most out of a limited displacement. It doesn't say anything about how making power at higher rpm alone is in any way beneficial to net performance.

>at this point, you just labeled a higher rpm an advantage
Wrong.

The operating RPM does not dictate performance. Only horsepower. The operating rpm literally does not matter once you know the horsepower.

>2-0 today because rotary powered RX7s are faster :-V
Kinda funny because you're the one who ran away from the RX-7 thread crying after you got BTFO by me, Just like you will in this thread, pussy.

>>13863470
"high rpm" and "low rpm" are relative terms retard.

There is no benefit to making 300hp at 6000rpm compared to making 300hp at 8000rpm compared to making 300hp at 10,000rpm.

300hp is 300hp. Revving higher to make 300hp is of no performance advantage.

>>13863525
>Like it or not, drag racing is still racing
And ironic shitposting is still shitposting

>>13863552
>Nobody said they are the ONLY things, but that they AFFECT.
And?

>If you're just spinning the engine faster without making it able to deal with the increased flow, it wont.
Right.

>If you deal with the flow limitation and change the cam profile to deal with higher revs, it will make more power.

You could just as easily deal with flow limitations without effecting it's rpm limit and make more torque, and thus more horsepower within it's preexisting rpm limit.

Making power at a higher rpm has no advantage. If making more power is the goal you can make more power via pushing the torque curve to higher rpm, or just making more torque, either way is literally the same if the final horsepower numbers are the same.

>>13863762
>There is no benefit to making 300hp at 6000rpm compared to making 300hp at 8000rpm compared to making 300hp at 10,000rpm
There is if the higher revving engines make that 3000hp at 6000rpm and continue making more power until their respective rev limits while the 6000rpm engine is already at its limiter. So in this case revving higher is extremely beneficial to performance :^)

>>13863719
>Both engine's can be geared to hit the same wheel speeds at redline in each gear.
>You don't know how gearing works.
First off, the other guy was right. He just had a simplistic view.
Secondly, the engines can be geared?
And you say he doesn't know how gearing works.

>>13863777
I wasn't shitposting though.

>>13863692
>>Like do nascars really run around the oval at 4000rpm? Fuck no.
NASCAR is a displacement limited racing series retard. All the same rules apply.

>Race engines rev high and make all their power up high for a reason
And you cannot tell me what that reason is.

>>13863707
>So you're telling me if the teams could add an extra 2l of displacement
If they added 2 liters of displacement they wouldn't be able to rev as high.

Even if they were they wouldn't need to, they would be able to make more power simply making more torque throughout the rev range.

>>13863785
>There is if the higher revving engines make that 3000hp at 6000rpm and continue making more power
No, we're talking about 300hp motors here. Not "makes 300hp until it makes more than 300hp" or whatever the fuck you're trying to say.

>>13863790
>First off, the other guy was right. He just had a simplistic view.
NO he wasn't. A higher redline does not equate to more speed in each gear. a 8000rpm 300hp motor would have 25% shorter gearing equating to equal acceleration and equal redline wheel speed to a 300hp 6000rpm motor.

>Secondly, the engines can be geared?
Engines are hooked up to transmissions and final drives/differentials, not sure if you're aware of this.

>And you say he doesn't know how gearing works.
He doesn't. And neither do you.

>>13863799
Gearing is the entire reason nascar engines rev so high. Go learn something about nascar faggot.
They can easily make 800hp without revving to 10k, even with their current displacement limits. But they need that 10k rpm for a massive powerband to take advantage of gearing suited to running around a fucking oval at 200mph.

>>13863816
>Gearing is the entire reason nascar engines rev so high.
Explain.

>Go learn something about nascar faggot.
I know about physics. That trumps your hillbilly racing knowledge.

>They can easily make 800hp without revving to 10k, even with their current displacement limits.
Who said they can't?

>But they need that 10k rpm for a massive powerband to take advantage of gearing suited to running around a fucking oval at 200mph.
You have no idea how gearing works.

>>13863762
The performance advantage comes from having the smaller engine; but, that's hardly a certainty.

Smaller engine that revs higher can take advantage of air speeds in the throttle to increase volumetric efficiency.

Larger, lower rpm engines have low piston speeds, thereby lowering lower air speeds and lower volumetric efficiency.

IIRC the s2k's engine has something like 120% volumetric efficiency near redline. So it's 2L engine at 9k is actually burning 2.4L of fuel/air. This, and other factors is why it makes 240ish hp, despite being a small engine.

The other end of things is the 3v 05 mustang GT engine, which IIRC is something like 70% VE. So in it's power band, the 4.6L engine is only burning 3.22L of fuel/air which is why despite being over 2x the size of the s2ks engine, it only makes 300hp.

>>13863814
He, and I, were talking about engines, not the drivetrain.

>>13863831
>>IIRC the s2k's engine has something like 120% volumetric efficiency near redline

That's impossible.

Also, peak VE% always occurs at the torque peak.

>The other end of things is the 3v 05 mustang GT engine, which IIRC is something like 70% VE
Your VE% numbers are way off.

>>13863144
>What is camshaft profile
>What is fuel type
>etc.

YOU are the dumb one. Yes I took the bait.

>PS friendly reminder that arabs aren't human, they're subhuman savages.

>>13863845
No engine has a fixed 1:1 ratio in anything modern automotive related.

So we're always talking about gearing.

>>13863846
>That's impossible.
What is fluid hammer
What is timing

>peak VE% at torque peak.
What is friction losses.

idiots. an engine that spins higher allows use of a shorter gear ratio.

>>13863863
When you isolate a variable to discuss the pros and cons of changing the variable, you assume everything else is the same.
Otherwise, there is no point.

>>13863893
>That's impossible.
Not him but its actually impossible for an f20c to have a VE of 120% unless its modified to hell and back
if youre going to make such outrageous claims at least try back them up

>>13863893
>What is fluid hammer
I know what can increase VE% tard.

>What is timing
Hope you're not talking about ignition timing. Because in automotive circles that's what "timing" refers to.

But yes, cam timing has a large impact on VE% numbers

But no, the S2000 does not have anywhere near 120% VE% near redline.

>What is friction losses.
Friction losses have no effect on VE%.

Unless you're calling boundary layer drag "friction losses" which literally no one does.

And even then boundary layer drag only serves to reduce VE%

The S2000 does not make 120% VE%. Even coming close to 100% VE% on an N/A engine is the stuff only experimental racing engines could dream of with things like ram induction.

>>13863895
And the engine that spins slower and produces the same amount of horsepower, also makes more torque, and thus does not need a shorter axle ratio.

>>13863898
You cannot isolate gearing from considering an engine's benefits.

If gearing didn't matter/wasn't considered, horsepower would not matter.

If every engine was assumed to have a 1:1 output. Peak acceleration would occur at the torque peak in all cases which would occur at all different output speeds and the data would be meaningless.

>>13863940
>And the engine that spins slower and produces the same amount of horsepower, also makes more torque, and thus does not need a shorter axle ratio
So it makes the same horsepower and has taller gearing, so it doesnt accelerate as fast.

>>13863599
Would that be solvable by a fictional ideal b variable valve lift/duration system? >>13863955

>>13863955
That's not how horsepower or gearing works.

Equal torque and taller gearing equates to slower acceleration.

Equal horsepower but at lower rpm means taller gearing and equal acceleration.

Consider
500hp at 5000rpm through a 2:1 ratio
500hp at 10,000rpm through a 4:1 ratio.

Both engines would put the same torque to the ground despite one of those engines having a half as short a ratio.

That's how gearing works.

>>13863090
You know, this was a good thread before you ruined it.

File: 1311732617161.jpg (16KB, 447x444px) Image search: [Google]

16KB, 447x444px

>>13863981
>yfw I started it.

>>13863980
Same horsepower+taller gearing=slower. End of story.

>>13863987
you two dont look like the same people but makeup is a wonderful thing

>>13863916
F20C has a peak volumetric efficiency of like 110%

>>13864138
I don't know the exact numbers, but it is over 100%. Not 120 though, 110 sounds about right. I wonder what Honda could do with DI and I-VTEC. We probably won't see another performance n/a Honda engine though unfortunately.

>>13863709
>dat extra 150cc's though

>>13864019
>Same horsepower+taller gearing=slower. End of story.
not when torque has increased proportionate to gearing

>>13863111
This is true for everyday "drivability" but not necessarily true for a performance car.

ITT: we all talk out of our ass

>>13863970
Manufacturers have used variable length intake runners and variable cam timing and lift for quite some time to increase port velocity and optimize valve timing at low rpms for improved driveability.
While having the flow needed to make power at high rpm.

If i chop the muffler off my truck will it do anything to its power output?
Also im just trying to be an annoying faggot for a month or two before putting it back on

all this bench engineering is hilarious because nobody here makes over 200hp i bet.

>>13863477
>Gearing exists.

You're fucking stupid bro. Why dont you take your little epiphany out of your moms basement and revolutionize the industry? I'm sure you can make millions selling your

>>13867027
No, it will just be loud

>>13863167

Hah, I've never heard that one. What's the (boomer) logic behind it?

>>13863214
Most everyone who has driven both LS swapped, and equal powered doritos agree that it is in fact better with the LS

>>13868225
I do. Frosty does. Baby Dick Nova does. Every single person that have a V8 mustang or truck does.

But yes, this thread is fucking cancer.

>>13864019
>Same horsepower+taller gearing=slower. End of story.
That is factually incorrect.

You don't know how horsepower or gearing works.

>>13868271
Don't be mad because you're wrong fag. kek.

>>13865865
>not when torque has increased proportionate to gearing
shorter gearing further multiplies torque, retard
acceleration is dependent on horsepower anyway

>>13868557
sure thing buddy, keep telling yourself a car will be faster if you throw longer gears at it. fucking retard.

>>13868417
Most everyone who has driven both LS swapped, and equal powered doritos agree that it is in fact vastly inferior with the LS.

>>13868307
probably because back when leaded fuel was still in circulation if you ran without an exhaust manifold burning valves was a legitimate concern.

Nowerdays though its a different matter, valve seats, springs and valves themslves are made of sterner stuff.

>>13863032
>>Your exhaust needs backpressure to make torque!
Yes it does actually, thanks for reafirming

>exhaust back pressure
dont make me trip up and humiliate you

>>13868894
Unless you have a two stroke motorcycle, I'm pretty damn sure back pressure ain't good.

Hey guys is this the shitposting general?

>>13868867
>shorter gearing further multiplies torque, retard

Horsepower is a product of RPM and torque. Gearing modifies RPM and torque in ratios.

For two engines of equal power. One making power at high rpm, the other at low rpm. The higher rpm engine will have shorter gearing to put the same torque output to the wheels.

>acceleration is dependent on horsepower anyway
Yes. And horsepower is horsepower regardles of the RPM it is made at. A higher rpm motor with a given amount of torque will have shorter gearing than a lower rpm motor with the same amount of horsepower.

Just because the lower RPM motor with equal horsepower has taller gearing doesn't mean it's slower.

>sure thing buddy, keep telling yourself a car will be faster if you throw longer gears at it. fucking retard.
That's not what I said at all.
You claimed for equal horsepower, taller gearing will equate to a slower acceleration. This is completely wrong.

As in my example:
>500hp at 5000rpm through a 2:1 ratio
This engine is making 525.5lb-ft to produce 500hp
(500*5252)/5000=525.5lb-ft
>500hp at 10,000rpm through a 4:1 ratio.
This engine is making 262.6lb-ftto produce 500hp.
(500*5252)/10,000=262.6lb-ft

The 5000rpm engine has gearing TWICE as tall as the 10,000rpm engine. But it also makes TWICE as much torque because it makes the same horsepower spinning half as fast.

So if you put these motors through their respective ratios both engines are putting the same torque to the wheels. ~1050lb-ft
525.5lb-ft through 2:1 ratio:
(525.5*2)=~1050lb-ft
262.6lb-ft through 4:1 ratio:
(262.6*4)=1050lb-ft

>Same horsepower+taller gearing=slower. End of story.
So once again, this statement is factually incorrect.

>>13868894
Hahaha. No. You're a faggot.

www.youtube.com/watch?v=RWTARjxiqlo

>>13868923
Please do. So I can laugh at your sad attempts to justify this retarded old myth.

>>13863032
It's not nice to post Eric Shavers picture on 4chan

>>13868984
>Just because the lower RPM motor with equal horsepower has taller gearing doesn't mean it's slower
Yeah it pretty much does.

>This is completely wrong
Nope. Its a correct statement.
You have a 300hp car that weighs 1200kg with 3.08, throw a 4.10 in and it will accelerate faster. This is a fact. Deal with it.

>The 5000rpm engine has gearing TWICE as tall as the 10,000rpm engine
So its slower accelerating.

>But it also makes TWICE as much torque because it makes the same horsepower spinning half as fast
Wrong. The shorter gearing on the 10,000rpm engine multiplies the torque at the wheels. Not that torque matters outside of towing shit anyway, your point is irrelevant.

>So once again, this statement is factually incorrect
You've yet to disprove my statement, a statement which is 100% factually correct to anyone not desperately trying to damage control and squirm out of a broken argument they got themselves into like over 24 hours ago.

All you've managed to do is say that shorter gearing does not equate to faster acceleration. Which is wrong.
And that an engine making similar power to another engine but revving higher means it makes less torque at the fly wheel. Which is an irrelevant point for the discussion we are having as we are talking about horsepower and acceleration, not how easy it is to tow a boat.

You really want to keep going on with your "SHORTER GEARING DOESNT MEAN ANYTHING!!!" bullshit?

>>13869042
>Yeah it pretty much does.
No it doesn't.

>You have a 300hp car that weighs 1200kg with 3.08, throw a 4.10 in and it will accelerate faster. This is a fact. Deal with it.
Because you've simply added taller geargin without the corresponging shit in rpm where power is produced retard.

We're not talking about regearing a car with the same engine and same rpm power peak. we're talking about two different rpm power peaks. The higher rpm power peak necessitates shorter gearing while the lower rpm power peak necessitates taller gearing to net the same torque at the wheels which then equates to equivelent acceleration.

>Wrong. The shorter gearing on the 10,000rpm engine multiplies the torque at the wheels.
No. You're an idiot.

The 5000rpm engine is producing TWICE as much torque as the 10,000rpm engine. I even broke it down mathematically for you you fucking idiot:

>500hp at 5000rpm through a 2:1 ratio
>This engine is making 525.5lb-ft to produce 500hp
>(500*5252)/5000=525.5lb-ft
>500hp at 10,000rpm through a 4:1 ratio.
>This engine is making 262.6lb-ftto produce 500hp.
>(500*5252)/10,000=262.6lb-ft

525.5lb-ft is roughly twice as much as 262.6lb-ft.

>The shorter gearing on the 10,000rpm engine multiplies the torque at the wheels.
it spins twice as fast so it's ratios can be twice as short. This equates to a 4:1 ratio and 1050lb-ft to the wheels.

The 5000rpm motor also gets to multiply it's torque, but by HALF as much through a 2:1 ratio but because it has twice as much torque to begin with it ends up with the same amount of torque after gearing (~1050lb-ft), despite having taller gears.

>Not that torque matters outside of towing shit anyway, your point is irrelevant.
Torque absolutely matters in calculating horsepower.

>You've yet to disprove my statement, a statement which is 100% factually correct
I've mathematically proven your point completely incorrect. You are just have no idea how horsepower, torque, or gearing works so you don't understand.

>>13869042
>And that an engine making similar power to another engine but revving higher means it makes less torque at the fly wheel.

You seriously don't understand how making less torque at higher rpm equates to the necessity for shorter ratios to multiply that torque the same level as a lower rpm motor with taller gears making the same more torque and yet the same horsepower?

Come on anon, this is like horsepower 101

>>13869097
Your calculations are worthless
Purely showing the difference between torque of two equally powered engines at the flywheel, an irrelevant point that isn't serving to prove anything. Basically at this point you're just repeating the same shit over and over for no reason.

> torque matters in calculating power
And we already have the horsepower figures so it's no longer relevant, unless you're driving a pigfat American piece of shit

>
I've mathematically proven your point completely incorrect. You are just have no idea how horsepower, torque, or gearing works so you don't understand.
again, formula for horsepower isn't proving anything. You're just repeating yourself like a parrot who just learned something new. Not relevant to what we're discussing in anyway outside of you thinking you're smart for repeating common knowledge.

and now you're projecting

same power+shorter gearing=faster acceleration

Bbbut muh equal wheel speed at redline because of gearing!!!
, yea the shorter geared car gets there faster. Deal with it.

>>13869103
You don't throw shorter gears on the higher rpm engine to make up the difference in torque, you throw short gears on the higher rpm engine because it allows for faster acceleration while maintaining the same speed at top of the gear as it would with lower redline and longer gear. You have no idea what you're talking about

>>13869160
>Your calculations are worthless
My calculations show exactly that what you are claiming is wrong.

>Purely showing the difference between torque of two equally powered engines at the flywheel
Yes, where do you think torque comes from? Outer space?

>an irrelevant point that isn't serving to prove anything.
Explain to me how flywheel torque is not relevant.

Flywheel torque matter becaust gear ratios determine how much of that flywheel torque ends up at the wheels through torque multiplication/division.

>Basically at this point you're just repeating the same shit over and over for no reason.
Yes, I'm explaining a basic concept to someone over and over who simply cannot grasp how horsepower, torque, and gearing works.

>And we already have the horsepower figures so it's no longer relevant,
You cannot determine how much torque (the acceleration force) is at the wheels without extrapolating torque through the gear ratios.

If you want to ignore torque then yes, there is 500hp in both cases of motive force at the wheels (ignoring drivetrain losses). Meaning both cars would accelerate equally tall or short gearing.

>unless you're driving a pigfat American piece of shit
Ironic that you're talking shit on Americans but you don't understand basic physics concepts or mathematics.

>same power+shorter gearing=faster acceleration
Again, I've mathematically proven this wrong.

>yea the shorter geared car gets there faster. Deal with it.
Wrong, the shorter gearing car had less torque than the lower rpm higher torque car. Thus the additional torque multiplication serves to equalize torque at the wheels between cars.

You don't seem to understand how horsepower is calculated or that a higher rpm engine with the same power will be producing less torque, thus shorter gearing is needed to equalize torque at the wheels for a given amount of power.

>>13869220
> my mathematics of how horsepower is calculated disproves your claim that shorter gearing allows for faster acceleration
Okay so I'm actually having a discussion with a brain dead sea lion. I'm getting the fuck out of here before your retardation rubs off on me. Seriously you are one dumb mother fucker.

Shorter gearing=faster
Deal with it

>>13869205
>You don't throw shorter gears on the higher rpm engine to make up the difference in torque
That's exactly what you do... Jesus you don't know anything.

>you throw short gears on the higher rpm engine because it allows for faster acceleration
How does shorter gears on the higher rpm engine allow better acceleration?

The engine starts off with less torque, torque is then multiplied to a greater extent because of the shorter gears. This in turn reduces the rpm by a proportional amount.

>while maintaining the same speed
Yes, you are sacrificing RPM for the multiplication of torque. Just like a high torque engine of equal horsepower would be sacrificing torque for the multiplication of RPM.

Either way it serves the same purpose:
to produce equal output wheel torque for an equal output wheel speed.

>You have no idea what you're talking about
Ironic.

You literally do not understand how horsepower and gearing interrelate.

>>13869205
>>13869248

Bro, seriously. Please tell me you're trolling.

No one is this stupid. Right?

>>13869272
I'm not the one using formula for calculation of horsepower as a reason why shorter gearing doesn't allow for faster acceleration
Like how brain dead do you have to be to do that srsly

File: graphic lel.jpg (126KB, 433x419px)

126KB, 433x419px

>>13863709
>ducati is competitive
KEK
and ducati engines are bigger than 1000cc

>>13863753
>pls pls dont leave me alone ;_;
KEK that stockholm syndrome

by implying you need a higher lift to achieve the same flow as a bigger valve you are directly implying an oversquare design has an advantage over an undersquare design its bigger valve area

by design, an oversquare engine will flow better given the same valve lift and duration

making power at high rpm is not an advantage per se, the advantage is the bore/stroke ratio of engines that make power at high rpms

>>13869248
>Okay so I'm actually having a discussion with a brain dead sea lion.
Irony.

You're arguing concepts you literally don't even have an elementary understanding of.

Did you ever go to highschool? This is highschool level physics that you're completely shitting the bed on.

>I'm getting the fuck out of here before your retardation rubs off on me.
Translation:
>Your scary highschool math equations and physics concepts hurt my brain so I'm going to abandon thread before I make an even bigger idiot of myself.

>Seriously you are one dumb mother fucker.
Asshurt projection: The Post

>Shorter gearing=faster
This is factually incorrect and far too general/simple of a statement to be even remotely true.

>>13869292
>I'm not the one using formula for calculation of horsepower as a reason why shorter gearing doesn't allow for faster acceleration

The formula for horsepower is exactly applicable.

The same horsepower and higher rpm equate to less torque produced. Less torque produced and a higher rpm equate to shorter gearing being needed to net the same torque to the output.

Meaning the shorter gearing is simply compensating for the less torque produced and sacrificing the additional rpm to equalize the playing field.

It is directly related, you're just too stupid to understand.

Shorter gearing on a higher revving engine of equal power does not equate to faster acceleration.

>>13869298
Wow didn't expect this much ass mad from the retard

In almost all instances shorter gearing will accelerate the car faster
I thought I already made that point with the 300hp 1200kg csr with a 3.08 and 4.10, a point you've failed to disprove no matter how much you regurgitate the same irrelevant shit about muh torkz.

> shorter gearing allows for faster acceleration
> all race engineers prioritize High rpm performance over low rpm performance for a reason, and it's not "muh displacement limited classes!!!"
Trip up kid I've seen you spreading your shit across multiple threads and quite frankly to be honest I'm sick of it.

> 13brew makes 200whp in lowest trim at 6000rpm
> f20c makes 150whp at 6000rpm
Top kek jhst to triple trigger you

>>13869297
>and ducati engines are bigger than 1000cc
And? we weren't talking about the relative merits of displacement. We were talking about the relative merits of making the same horsepower at different RPM.

>by implying you need a higher lift to achieve the same flow as a bigger valve you are directly implying an oversquare design has an advantage over an undersquare design its bigger valve area
That is not true at all.

Higher lift is not somehow inferior to larger valve area simply because you say so.

>by design, an oversquare engine will flow better given the same valve lift and duration
>given the same valve lift
Why would you limit the undersquare engines valve lift to that of the oversquare engine?

The undersquare engine can achieve higher valve lift for the same valvetrain limitation because it theoretically revs lower and doesn't have to worry about valve float at higher rpm equating to the same valve curtain area and thus flow.

>>13869328
>Wow didn't expect this much ass mad from the retard
Why would I be mad that you are too stupid to understand basic physics concepts?

>In almost all instances shorter gearing will accelerate the car faster
This is wrong.

>I thought I already made that point with the 300hp 1200kg csr with a 3.08 and 4.10
Once again, we are not talking about swapping final drives on a car with the same engine. We are talking about shorter/taller gearing compensating for higher/lower rpm engines of the same horsepower output.

Which means taller gearing does not equate to a slower car if the taller gearing corresponds to a lower rpm that power is made at and a consequentially higher output torque.

>a point you've failed to disprove
I've mathematically disproven your bullshit a few times now. You're just too stupid to understand the simple concepts being discussed.

>I've seen you spreading your shit across multiple threads and quite frankly to be honest I'm sick of it.
I don't care if you don't like factually true statements and want to continue to believe the retarded bullshit you keep saying.

>>13869313
Again you keep on with muh torkz
Shorter gearing IS NOT used purely to make up a difference in wheel torque, it's used because it allows for faster acceleration you dumb shit
You'd have a point if we were talking utility vehicles but we aren't.

The engine that revs higher can go with shorter gearing because it will still keep the same wheel speed at redline while having quicker acceleration. You can throw shorter gearing for same rate of acceleration on the low rpm engine but it will hit the ceiling too soon and need more gears to make up for difference in speed.

Shorter gearing allows for faster acceleration
super cars don't have super long gears do they, fucking spas

>>13868417
Most people who say that are retards that can't maintain a rotary so they swap it

>>13869337
>And? we weren't talking about the relative merits of displacement. We were talking about the relative merits of making the same horsepower at different RPM.
more displacement is an advantage in the same way a higher redline is an advantage

>Higher lift is not somehow inferior to larger valve area simply because you say so.
nice lack of reading comprehension
read it again, you might understand what that means

>Why would you limit the undersquare engines valve lift to that of the oversquare engine?
i am not limiting anything
same lift and duration, the engine with a bigger valve are will flow better

>The undersquare engine can achieve higher valve lift for the same valvetrain limitation because it theoretically revs lower
nope
you can have the same valve profile at both engines

you are not going to lift the valve 3 inches, your point is moot

>equating to the same valve curtain area and thus flow.
because it has the advantage if higher valve lift and longer duration, as opposed to the other engine that has the advantage of a higher rev limit

given the same lift and duration, the engine with the bigger bore will flow better, meaning its a desired design in high-performance engines

dummy

ill check the thread in a couple of hours to see if you finally grasped the concept

>>13869361
> I've mathematically disproven your bullshit a few times now. You're just too stupid to understand the simple concepts being discussed
you haven't disproven anything with anything. If you think the formula for horsepower is calculated disproves my claim that shorter gearing allows for faster acceleration then I don't know what to say... You're literally autistic.

Keep regurgitating the same shit over and over with that holier than thou attitude tho f, am. Totally helping your cause


Shorter gearing = better than long gearing
A fact you can't deal with :^)

>>13869363
>Again you keep on with muh torkz
Torque is a critical variable in calculating output torque, and thus acceleration potential. You're just too stupid to understand that.

>Shorter gearing IS NOT used purely to make up a difference in wheel torque
Gearing is PRIMARILY used to equalize output torque to a design operating range (wheel speed) among equal or similar horsepower engines. You're just too stupid to understand that.

>it's used because it allows for faster acceleration you dumb shit
This is true for higher rpm and lower rpm engines.

This doesn't change the fact that for equal horsepower on a lower rpm engine, taller gearing does not equate to slower acceleration as you claim.

You are wrong.

>The engine that revs higher can go with shorter gearing because it will still keep the same wheel speed at redline while having quicker acceleration.
This is wrong.

The engine with the higher rpm power will be producing less torque, thus the shorter gearing is necessary to bring output torque up high enough to compete with the lower rpm engine that has more torque and taller gearing.

This is a simple concept that you are too stupid to understand.

>Shorter gearing allows for faster acceleration
This is factually incorrect and too general of a statement to have any meaning at all.

>super cars don't have super long gears do they
Depends on the car.
A 650hp 6500rpm high torque Corvette or a Viper will have taller gears than a high rpm, lower torque, equivalent horsepower Ferrari.

Your statements and the entire premise behind your arguments is factually incorrect.

>>13869373
>more displacement is an advantage in the same way a higher redline is an advantage
And?

I fail to see how this equates to higher rpm power being somehow better than the same power being produced at lower rpm. As with Ducati making the same power as a Japanese bike but at a lower rpm yet still being competitive.

>read it again, you might understand what that means
I've read it. The implication you've drawn from my statement is incorrect.

>same lift and duration, the engine with a bigger valve are will flow better
And?

A lower rpm engine will be able to support higher lift for a smaller valve given the same valvetrain limitations in turn equalizing flow.

>you can have the same valve profile at both engines

Valvetrain limitations make this untrue.

For a given valvetrain you can achieve higher lift at lower rpm. As rpm rises, lift must be reduced to prevent valve float without modifying the valvetrain.

>you are not going to lift the valve 3 inches, your point is moot
Strawman. No one ever said anyhting about 3" of valve lift other than you.

Higher valve lift on a smaller valve can flow the same as lower valve lift on a larger valve.

Higher valve lift is easier to achieve at lower rpm because of valve float as rpm increases.

You are wrong.

>given the same lift and duration, the engine with the bigger bore will flow better, meaning its a desired design in high-performance engines
You are trying to set valve lift and duration at a set point across all engines to make your point.
This is incorrect. For an undersquare engine lower operating speeds means higher valve lift is possible with the same valvetrain limitation without valve float. More valve lift easily compensates for smaller valve area and thus flow.

>ill check the thread in a couple of hours to see if you finally grasped the concept
Why would I grasp a concept that is flatly incorrect?

>>13863325

One can BRAP more than the other.

>>13869379
>you haven't disproven anything with anything.
I have. I'm sorry you are just too stupid to understand basic physics concepts.

> If you think the formula for horsepower is calculated disproves my claim that shorter gearing allows for faster acceleration
It does.

Horsepower is a product of torque and rpm.
If a given amount of power is made at higher rpm less torque is produced.
If less torque is produced shorter gearing is necessary for equal torque output at the wheels.

For equal power at different RPM. Shorter gearing does not equate to faster acceleration. It serves only to equalize acceleration against a higher torque motor with taller gears for a give operating range.

This is fact.

>If you think the formula for horsepower is calculated disproves my claim that shorter gearing allows for faster acceleration then I don't know what to say.
You don't know what to say because you don't know what you're talking about and don't understand the basic concepts being discussed.

>You're literally autistic.
You're literally an idiot that doesn't understand highschool physics.

>Keep regurgitating the same shit over and over
I will, until your dumb ass finally gets it.

>with that holier than thou attitude
I'm sorry that you think someone being smarter than you, and right, makes you feel this way. It doesn't change the fact that you are wrong and do not understand the concepts being discussed.

>Totally helping your cause
Aww is wittle baby upset at da way big mean internet man is tawking to him?

>Shorter gearing = better than long gearing
You keep saying it and it still remains wrong each time.

File: 1441832639861.jpg (194KB, 1072x714px)

194KB, 1072x714px

>>13869431
>I fail to see how this equates to higher rpm power being somehow better than the same power being produced at lower rpm.
cant be this stupid
in order to make the same power you need more displacement, as in the case of that ducati, or higher lift and longer duration to make up for the smaller valve area as you are claiming

>A lower rpm engine will be able to support higher lift for a smaller valve
>Valvetrain limitations make this untrue.
>For a given valvetrain you can achieve higher lift at lower rpm. As rpm rises, lift must be reduced to prevent valve float without modifying the valvetrain.
valve lift and duration limit is dictated by piston shape, combustion chamber design, valve angle and compression ratio, not by stroke alone, you are retarded

>You are trying to set valve lift and duration at a set point across all engines to make your point.
because otherwise, you are giving an engine with the longer stroke, an advantage, higher lift and longer duration camshaft

im going to add a positive displacement supercharger to the short stroke engine to make up for the smaller displacement, as in the ducati vs literbikes example

see how stupid your point is?

the advantage of a bigger valve in an undersquare design is what makes it desireable for high performance, and why its better to make power at high rpms, this advantage is inherent to it, similar to the advatnage of a 4 valve head vs a 2 valve one

>For an undersquare engine lower operating speeds means higher valve lift is possible with the same valvetrain limitation without valve float.
valvefloat is not dictated only by camshaft profilealone

Nascar engines have up to .600 in lift
http://www.stangtv.com/tech-stories/comp-cams-new-4-pattern-cam-boasts-advanced-nascar-technology/
your point is moot

>tl;dr
>american education
just please tell me your mechanical engineering degree, if you have one, did not put you in massive debt pls

>>13869364
I'm pretty sure Matt Farrah can maintain a rotary.

>le dorito so hard to maintain maymay

>>13869509
Lol still going with the I'm right you're wrong holier than thou shit. Doesn't help try prove your points it just makes you look silly grasping for anything as you fall Into pit of despair.

> muh torkz
Again, irrelevant. We are not towing boats here mister.
Horsepower is horsepower and horsepower is the main factor in acceleration of a vehicle.
> bbbut you need to tork to calculate horsepower!
Yes everyone knows this go back to Wikipedia kid it's irrelevant after the fact

Same horsepower+shorter gearing+retaining same wheel speed at top of gear(thanks to higher rpm)=faster acceleration
end of story. Go read some actual articles on gearijg in drag racing instead of reading Wikipedia or whatever and coming to your own retarded bumble fuck conclusions on what you think is happening

And your "calculations" are worthless for the hundredth time
It's not a matter of me not understanding your retarded shit like you say, but more a matter of you actually having no understand what you're talking about

so for the final time hopefully...
Shorter gearing allows for faster acceleration than taller gearing. End of story you literally cannot argue that

>>13869526
>in order to make the same power you need more displacement, as in the case of that ducati, or higher lift and longer duration to make up for the smaller valve area as you are claiming
Right.

And this has everything to do with how to MAKE power within certain constraints and nothing to do with what exactly the performance benefit from making power at higher rpm is.

>valve lift and duration limit is dictated by piston shape, combustion chamber design, valve angle and compression ratio, not by stroke alone, you are retarded
Where exactly did I imply otherwise?

>because otherwise, you are giving an engine with the longer stroke, an advantage, higher lift and longer duration camshaft

Just like giving a larger bore engine larger valves is an advantage.
You play to the strengths of teach relative design. Larger bore (oversquare) means you can rev higher with larger area valves and lower lift to get the same flow.
Longer stroke (underquare) means you can use larger lift because of the lower rpm operating range (and not having to worry about valve float with large lift at high rpm) to get the same flow with the necessarily smaller area valves.

>im going to add a positive displacement supercharger to the short stroke engine to make up for the smaller displacement
That is not an equivalent argument at all.

>see how stupid your point is?
No, we are talking about engine design decisions that best take advantage of each type of engines strengths and operate withing their limitations. You are attempting to ignore the strengths of a undersquare engine (like the ability to run more valve lift) while harping on it's limitations (like valve size).

>valvefloat is not dictated only by camshaft profilealone
You're right, it's dictated by valvetrain mass and valve spring tension. Which is why I said for similar valvetrain limitations to eliminate these variable and have something to compare.

>your point is moot
Exactly how does this negate anything I said?

>>13869552
>Lol still going with the I'm right you're wrong holier than thou shit.
Yes, because I am.

>Again, irrelevant. We are not towing boats here mister.
You're an idiot if you think torque only relates to towing. Torque is the actual force that accelerates a vehicle. Of course it's relevant when talking about acceleration.

>Horsepower is horsepower and horsepower is the main factor in acceleration of a vehicle.
Horsepower is useful because it dictates how much torque can be put to the wheels through gearing. That is why it is useful and you do not understand this basic concept.

>Yes everyone knows this go back to Wikipedia kid it's irrelevant after the fact
No it isn't.
Once you know how much horsepower you have, you can then calculate torque to the wheels.
If you calculate torque to the wheels after gearing you just end up with your original horsepower number (ignoring losses), which means nothing.

Torque is the force that determines the rate at which a car is accelerated.
The calculation for acceleration is Force=mass*accleration or for our purposes acceleration=mass/Force.
The force is torque, the mass is the mass of the vehicle. Do you see horsepower (power) anywhere in that formula?
This is literally basic newtonian physics here kid.

>Same horsepower+shorter gearing+retaining same wheel speed at top of gear(thanks to higher rpm)=faster acceleration
Again, this is wrong.
If you have the same horsepower at an rpm. If you equalize wheel speed at that rpm you are also equalizing torque at that rpm.
You know torque, the force that accelerates the car.

>Go read some actual articles on gearijg in drag racing
I don't have to read some retarded consumer level articles on racing to understand basic physics lel.
If that's where you get your physics knowledge double lel.

>And your "calculations" are worthless for the hundredth time
>hurr physics calculations are worthless
You're an idiot

>you actually having no understand what you're talking about
Irony

>>13869630
Horsepower is the rate at which work is done. It is the main factor in acceleration and speed at the end of the day
You are literally fucking retarded

> muh physics calculations
again the only calculation you've done is copy paste the formula for how horsepower is calculated. and repeated it a dozen times in an attempt to disprove my 1000% factually correct claim that shorter gearing allows for faster acceleration

you're just another retarded /o/ shit who spends all day reading about things you really have no understanding of and coming to fucked conclusions of what you think is happening in your mind
keep at it bench physicist, you're hopeless

so, to finish up
horsepower is main factor in how fast a car can go
shorter gearing allows faster acceleration than linger gearing
now shut up and deal with it cunt

>>13869692
>Horsepower is the rate at which work is done.
Correct.

>It is the main factor in acceleration
WRONG. Learn some basic physics.
Force and mass are the main factors in acceleration:
>a=F/m

Horsepower does not dictate the rate of acceleration. Power/work and impulse have to do with how FAR or LONG something will accelerate.

>You are literally fucking retarded
You literally are failing basic highschool level physics here. You are a fucking retard.

>again the only calculation you've done is copy paste the formula for how horsepower is calculated
Which directly dictates how much torque is output to the wheels which directly impacts how quickly a vehicle accelerates.

I'm sorry the big scary equations are bullying you. Go start a tumblr about it fag.

>in an attempt to disprove my 1000% factually correct claim that shorter gearing allows for faster acceleration
Just because you don't understand the basic math involved in proving how you are completely incorrect does not change the fact that you are completely incorrect and have been mathematically proven to be incorrect.

See:
>500hp at 5000rpm through a 2:1 ratio
This engine is making 525.5lb-ft to produce 500hp
(500*5252)/5000=525.5lb-ft
>500hp at 10,000rpm through a 4:1 ratio.
This engine is making 262.6lb-ftto produce 500hp.
(500*5252)/10,000=262.6lb-ft

The 5000rpm engine has gearing TWICE as tall as the 10,000rpm engine. But it also makes TWICE as much torque because it makes the same horsepower spinning half as fast.

So if you put these motors through their respective ratios both engines are putting the same torque to the wheels. ~1050lb-ft
525.5lb-ft through 2:1 ratio:
(525.5*2)=~1050lb-ft
262.6lb-ft through 4:1 ratio:
(262.6*4)=1050lb-ft

The taller gearing is resulting in equal accelerative force for equal amounts of horsepower. This directly proves this statement factually incorrect:
>>13864019
>Same horsepower+taller gearing=slower.

>>13869692
>>13869692
>horsepower is main factor in how fast a car can go
>how fast a car can go
We're not talking about top speed here retard.

>shorter gearing allows faster acceleration than linger gearing
Factually incorrect and proven so, see:
>>13870505

>now shut up and deal with it cunt
I can't deal with the fact that someone as dumb as you exists and someone as dumb as you is so militantly incorrect about something as basic as highschool physics.

So I'm taking time out of my schedule to school you on basic highschool physics. You should be thanking me.

>>13869692
>https://danielmiessler.com/study/horsepower/

Here, read this faggot.

>>13869692
How can you know so little about horsepower?

You'd think you would actually take your own advice and go real wikipedia or something to at least have a basic understanding before you start arguing.

>>13863389
Displacement regulations are bore/stroke regulations.

>does gearing effect acceleration
How is this even an argument on /o/.