explain how displacement isnt always better cause there are

>>14090413
you're just begging for a murica v europeen thread here dude

Go and drive cars with large and small engines and find out for yourself, stop playing fucking video games.

>>14090440

>driving simulations
>video games

>Forza

>>14090413
>smaller displacement are more HP and better output especially after you add turbos
>not knowing the same thing works for larger displacement.

>>14090464

>thinking the fully upgraded turbo options of the hemi/7 liter engines dont result in less HP/Torque and speeds

>yfw your 4 cylinder tin can engine strains to make half the horsepower of a bone stock crate truck engine geared for towing

>yfw your megasquirt meme ecu leans out and blows up grandma's civic

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>This thread again

adding displacement means adding more weight and stroke, both of which limit your rev range, which limits the amount of power you can draw out of the engine.

happy now?

>>14090508
is that why the fastest drag cars in the world have engines the size of your grandma's civic?

>>14090456
>driving simulations
>forza

>mfw i can only get a single turbo LS1 to 990kw on the dyno on Automation
They need a dual turb/Supercharger option

>>14090495

why do the I4 turbo engines have a M shaped torque line?

do engines in real life have this??

how do you correct it IRL?

>>14090508
Diesels go like 3k rpm and leave you behind in soot. Big engines have torque and allows taller gears.

>>14090540
>why do the I4 turbo engines have a M shaped torque line?

lolwat

>>14090540
that's easy

they weren't made in america

>>14090560

sorry its specifically a I4 Rally/Turbo engine

it has a torque curve that crescents twice like 2 arches

>>14090547
>>14090514
torque means nothing if you have no top end to keep up in the long run. hence why drag strips don't go past 1/4 mile lol.

forced induction and variable valve timing have made possible dynamic compression ratios. The computer is the replacement for displacement.

Want your inline-4 to have the punch of a V6?
you just have to build the engine strong enough to take 20+ lbs of boost all day erryday, which in turn adds weight just like building a high displacement engine, but in different areas.

>>14090609
>my 50hp civic can't win so the rules are unfair

should everyone get a participation ribbon, too?

>>14090609
Are you forgetting about the mile long races?

>>14090630
what's that? i can't hear you because i have to rev my civic to 8000 to make any horsepower

>>14090638
what's that i can't hear you. i have to replace my roush because i blipped the throttle too hard.

>>14090647
but the thing i said is true and your thing is made up nonsense

>>14090540
>>14090560
Its called variable valve timing. It is only possible in DOHC engines, unless you are Honda.
>Americlap OHV pushrod fags would never understand

>>14090615
>using buzz words to sound intelligent but not actually be intelligent.

For shame.

>>14090676

what are the pro/cons

>>14090720
none

he's ignoring the many quad cam v8s

anything a 4 cylinder engine can do for gains, a v8 can do better

>>14090732
>anything a 4 cylinder engine can do for gains, a v8 can do better
It has little to do with cylinder config and more to do with overall displacement.

>2.0 I4 will make more torque than a 1.0 V8

>>14090753
This isn't true.

It has the potential to.

Potential is the lost word in every argument here.

>>14090753

i should mention that the 7L hemi engines are beat out by 6.2L engines in Forza

which make it odd, its not as clearly cut major difference as you guys with 4 vs 8

>>14090753
who the fuck makes a 1 liter v8 you fucking idiot

wow if they only made 500 liter i4 that could fit in my civic!!! that'd show you fucking displacemnt guys!!!

If your limiting factor in building an engine is the vaporization of gasoline and oxygen in the cylinder, then it's better to have high pressure, high displacement engines because those engines can produce substantial power and if paired with large tires for maximum traction and gearboxes with high gear ratio's. This is why Lambroghini's have V12 engines with upwards of 6-8 Liters of displacement. You can't just squirt fuel in, detonate it, and cycle an engine at 8000+ RPM, things get enough energy in them they tend to fly apart or wear against each other and seize.

If you are able to preheat and premix the gasoline and oxygen without causing backfiring and detonation into the gas tank or other equipment, and you solve the problem of friction, then your engine is going to be built around the hardest and strongest metal you can find with the lowest possible weight as it always make more sense to move weight into the chassis, suspension, electronics, fuel delivery and capacity, and tires than it does to put weight into the engine. This is why high octane is important in performance engines, it reduces the propensity for premature detonation of the fuel.

>>14090514
> drag cars

ok bud
have fun with that straight line

>>14090767
No, a 1.0V8 might be able to make much more horsepower by way of having tiny reciprocating parts and can probably redline at 25k RPM, but being a V8 doesn't help it make torque like the 2.0L.

>>14090779
>REEEEEEEEEEEEEEEEEEEE
The point remains that "V8" doesn't automatically mean HEUG KEWBS KERCHUNK KERCHUNK it's just a cylinder configuration.

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>>14090514
>mfw my mee maw doesn't own a 500ci civic

>>14090720
stuff like VVT and VTEC don't really have any cons other than more things to break.

>>14090686
>forced induction is a buzzword
>vvt is a buzzword

ok fine i shoulda used variable displacement instead of dynamic.
you're still wrong

>>14090832

the car's momentum is still the only way the air is being inducted

its not like theres a vaccum sucking the air

so forced induction is stupid

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>>14090894

>>14090732
>OHV
>DOHC
These are not the same

>>14090915
Get OHVer it

>>14090676
>Tfw my OHV engine has VVT

>>14090832
I was actually going with dynamic vs static compression. You don't understand it.

>>14090941
I'll cut you

>>14090479
dude it's a video game, I don't think max hp output is exactly realistic in forza.

>>14090946
Do it.

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Forza doesn't take things like reliability and realistic build budget into consideration. For hobbyists on limited budgets (be they $5,000 or $100,000) the big displacement engines will get you more hp/$ AND will be more reliable so the only argument for high-rev is weight i.e. le ebin "Murrican cars can't turn" meme

>>14090413
>forza

>>14090508
>not understanding power bands
Faggot

adding displacement is usually more expensive than other methods of addnigpower, and offers faaar less gains

but huur duur muh chebby big block makes more power than muh chebby small block whatever

>>14090413
>same amount of cylinders
larger diameter bore = more friction, slower relative propagation
larger stroke = increased piston speeds and more inertia
larger cylinder displacement = harder to get optimum ve
>adding more cylinder
adds more parts, cost, weight, still friction and inertia. but takes care of pistons speeds, rod fatigue, and issues with ve and fuel burn

>>14090413
All of you retards are forgetting compression ratios

>>14091588
good thing compression and total displacement aren't related.

>>14090464
mad reading comprehension bro

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>forza
Please stop posting.

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>>14092938

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>>14092945

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>>14092946

>>14090413
>Forza
>>>/v/

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>>14092951

>>14090787
This is an engine thread, not a suspension thread friend

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>>14090801
>What is weight
>What is rotating mass
>What is cost

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>>14090753
>>14090792
>2.0 I4 will make more torque than a 1.0 V8

No fucking shit.

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>>14090413
>hp/L

Way to prove how much you don't know about cars in the first post.

>>14090787

>What is a Race.
>noun: Competition between two individuals to reach a goal first.

>Race to Europoors.
>IT HAS TO HAVE AT LEAST 100 CURVES BECAUSE OUR ENGINES ARE TINY AND THATS THE ONLY WAY WE CAN WIN A RACE GUYS LOL KEK V8 MORE LIKE VGAY XDDDDDDD PLEASE DONT TAX ME FOR MAKING A LAUGH ILLEGALLY ON THE INTERNET

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>>14090787
>m-my autocross lot h-has a lot of c-corners, they take m-more skill and I c-can do it in my M-m-miata

Stay lame

>>14090508
but drilling a bigger hole makes it lighter!

Also the engine design of performance vs cost/reliability has a huge impact on it. Small high-strung engines can be faster than big low-strung engines, but big high-strung engines usually have the most potential.

>trying to make sense of forza

Kekd

>>14093285
whhat thhe fuck is that

>>14090413
bigger motor gives broader power band
small motors are useless at less than half rev limit

>>14090514
Lolol no. Look at any top fuel car and see what I mean. The winningest engines are all massive aluminum block race Hemis that spin to 10k and make thousands of horsepower and torque. They would munch any 4 banger in existence if the reaction of the drivers are identical. That's just a fact.

>>14090534
Do what? Last time I checked you could only twin turbo V8s in automation did this change?

>>14090456
>"simulations"
>actually driving

Fucking millenials..

>>14090894
An engine is a vacuum pump you uneducated fuck. Jesus /o/.

>>14090413
>baiting this hard
>people actually biting

Damn it /o/

>>14090540
>why do the I4 turbo engines have a M shaped torque line?
In the past, engines could only have one torque peak. The designer chose which RPM should have that peak - high for sporty cars, low for trucks, in between for commuters.

Then DOHC came along and allowed variable valve timing and TWO torque peaks. Honda used it to give its small engines a decent amount of low-end torque (decent for a small engine) and a dose of high-end torque. That's one reason it could use such a high rev limit.

Nowadays manufacturers are getting "infinite" torque peaks which smoothens out the torque curve. But in the '90s, two peaks was impressive.

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>>14093285
This guy wasn't very fast, but the sound was great.

>>14091300
But that's not true. A full overbore with new pistons, rings, and bearings is about 900 for a 440. Add another 350 for gaskets, freeze plugs, and oil and I'm making more power than a $1000 turbo kit and 250 in extras on a 4 banger. Turboing the carbd engine would be way more expensive than a bore stroke and cam and converting to EFI would about equal a blow through setup.

Source: I have big V8s and have turbod 4 cylinders in the past.

>>14093437
You are close, but even with VVT and VVL, you may not have a second torque hump on a graph, it depends on the cam grinds. As well, new cars do not have infinite torque peaks but rather have cam profiles and VVT settings that keep it at 90% max torque for more of the rev range. The only engine that could feasibly have a nearly constant torque band would be something using Fiat's Multiair on both cams. Same as what Koeniggsegg is researching.

>>14093408

so wait, are you seriously trying to claim that cars prior to computer mechanics are better?

someone ITT already broken down that the racing chips do more to optimize a car's performance than any garagefag could with a wrench

>>14093444
>looking good in the process is an excuse to fail in a competitive environment
Waiting for the day when someone says "I failed the job interview, but my suit looked good".

>>14094345

you mean every nigger?

>>14094333
No, I think he was saying that a simulation and real driving are not the same at all. I agree with him and I have Fanatec Clubsport and CSR wheel setups, CSR on a stand, Clubsport on a frame with attached Corbeau seat. Nowhere near the same feel even with pedal and wheel feedback.

Technically V8s are completely out of balance from an engineering point of veiw. But that's why they sound sooooooo good!

>>14093452
way to cherry pick a certain shitty situation cunt

>have na 1600c 4cyl
>stroke/bore to 1800cc for a 10hp gain
>or turbo for 400hp gain
you tell me

>>14094643
Then at the same point what's the cost per hp and what did your turbo setup actually cost? You will need lower compression pistons, new cams, rings, possibly a fully forged bottom end to hold the boost reliably. Add in the cost of a bore and hone, the exhaust, headwork, and ecu tuning on top of a new clutch as 400 hp to a factory clutch will shred it after a few good launches. You aren't going to be putting 400 to the wheels turbo that way. Setting the same budget on the same engine, your 400hp turbo engine (which you said 1.6 so ill say a D16Z6 Honda 4) will grenade wayyy sooner than an NA. Btw, 240-250 can be had power wise from an NA D16, and yes you can get to 400 with boost, but at a much higher initial investment and with a shorter overall lifespan.

And did I cherry pick? I was giving an example of something I actually did do and continue to do, same as the example listed above. Go back to the benchracing containment thread faggot and leave bang for buck to people that have see cam bearings in an engine.

>>14094760
>your 400hp turbo engine (which you said 1.6 so ill say a D16Z6 Honda 4) will grenade wayyy sooner than an NA
but the na cant make 400hp

>Btw, 240-250 can be had power wise from an NA D16
and at a much higher cost than a turbo build, while being less reliable and offering vastly inferior power delivery

>but at a much higher initial investment and with a shorter overall lifespan
you are literally describing making na power compared to making turbo power, not the other way around

>try do this without the superior method of increasing power, faggot
http://www.dragzine.com/features/car-features/matt-happels-newest-9-second-junkyard-fairmont-sleeper/

>>14094826
In what world do you live in where a set of internals costs the same as a set of internals, turbo, intercooler, injectors, fuel pump, tuning, etc on the same engine?


>Cherry picking
It's what you just did with the 5.3. Show me the same thing with a 1.6L as you said above. They also had a fully stocked shop with extra parts from previous builds laying around and got the engine from a yard. I'm talking about putting new parts in a new engine build. What you linked also mentions they used Nitrous as well as a Turbo so there is that.

I got it anon, I got it. We each get a 1.6L 4 cylinder shitbox engine. We then have a $1000 budget and you go turbo, ill go NA and we see which engine explodes first: The NA that was built right or the Haggard garage eBay turbo kit running 20lbs and dumping fuel to get anywhere near 400hp.


And before we continue, building NA is NOT more expensive than a turbo setup. Just ask, a friend has a 5.3 turbo Camaro, full cage,minitub, etc. He lays 740 horses to the crank and spent a total of 9k getting there before even talking about a trans and rear end. I, by contrast am 7k in engine and making 630ish to the crank and 660 lb/ft. If I didn't want to street the car at all, id have went for an even more aggressive cam and would be in the 700 range but I wanted street/strip. My bottom end is proven to 1500hp in other known builds meaning if I wanted, I could go even larger NA, or add a 2 stage 250/500 nitrous setup for under a grand and ram 1200hp to my transmission. I know which way I'd go.

>>14094964
so he spend less on his turbo build thats making more power than your na build?
thanks for proving me right

>>14094981
No. He spent more on just his engine than I did on just my engine. A difference of ~$2000 more that he spent and got 100 more horses. Read it again.

>>14094345
You can go to have fun, that's what I do. Deliberately get the tail out for shits and giggles.

>>14094964
NA just can't compete
>Think of it: atmosphere of boost will double the horsepower but the supercharged engine's pressure is nonetheless only 8 percent higher. And 100 percent of the added load is compressive through the connecting rod against the crankshaft.
>If redline increases from say, 6,000 to 7,000 rpm, loading increases not 17 percent-like engine speed- but 36 percent! Compare this to the 8 percent increased rod loading from 15 psi boost.
>Bottom line, considering the nature of the way turbocharging increases cylinder pressure versus the exponential nature of increased rod loading from higher engine speeds, turbocharging is clearly far easier on an engine than increasing the redline.
http://keystoneturbollc.com/id78.html

>>14093361
an aussie burnout

>>14095118
Funny, I thought different engine configurations had different cam profiles depending on the application. And my higher compression over the turbo engine makes that power at a lower RPM. Rev to rev, I make more power than he does until 5600 to his redline of 7300 RPM. I redline at 6600 but shift at 6300 to put me near peak power. And I would have to spin my engine much, much faster to break my rods or ruin my crankshaft as the same bottom end at the same stroke has been tested at 8500 rpm before rapid part degredation occurred. If I swapped cams, lost some of my low down torque, and went for HP, id be above where he is power wise with a more linear delivery and at a lower RPM.

>>14095118
>exponential nature of increased rod loading from higher engine speeds, turbocharging is clearly far easier on an engine than increasing the redline.
This is horseshit, absolute horseshit.

>>14095309
>>14095209
here's the source

https://books.google.co.uk/books?id=8bSYNEWaRfYC&pg=PA34

>>14095309
Not him, but it's true in terms of reaching a specific power output. If you want to get 300hp out of your 2.0 engine you're going to use a turbo instead of going formula 1 tier on the redline. It's far less stressful

>>14095472
Torque stresses an engine in reality, not so much RPM. The engine making more torque and at a lower RPM experiences the highest stresses.

More friction is lost in high RPM and yes inertial forces of individual parts increase exponentially, but the net forces from inertia alone pales in comparison to combustion pressures (torque).

Example, If you tried to apply 400ft/lbs @ 1200rpm through a B18C1 all rods would immediately bend and the engine would literally grenade (rods through block, open aluminum deck would crack). However the B18C rods and block *might* survive with 400ftlbs of torque at 6000rpm, considering that the torque is being distributed among 5 times as many power strokes@6000rpm vs 1200rpm.

>>14095118
You are assuming he has to raise his revs to make more power when in reality, a cam swap that moves the power away from low down torque and more towards top end horsepower. It is the essential difference between an LS1 in a truck and an LS1 in a corvette. I do realize they use a different set of heads, but swapping cams shows the main difference.

>>14095118
>>14095340
damn this is actually really good bait, can't believe this guy made a book with this shit

>>14095658
>confusing toque with horsepower
lol!

>>14090413

Because there are ways to fit more in each cylinder without needing a larger displacement and achieving greater power/weight ratio.

>>14095658
You couldn't possibly be more wrong if you were trying.

In a perfect engine torque would be flat from 1rpm to max rpm. it isnt spread out between revolutions.. s m h dude

>>14095933
>being so dumb that you dont understand compression vs tension
I question why you trip almost every time I see you post.

>>14095993
what the fuck are you talking about you fucking fuck? read the links and you'll see the guy is full of shit

>Suppose normal charged cranking compression yields 185 psi, and a turbo compressor adds an additional 15 psi of boost pressure. The total compression component of cylinder pressure would be 200 psi exerted against a 4-inch piston of 12.57 square inch crown area. Multiplying the 200 psi by 12.57 indicates a total compression loading on the connecting rod of 2,514 pounds at top dead center CTDC) for the supercharged engine. But this is only 8 percent higher than the 2,324 pound loading of a similar normal-charged powerplant.
>Obviously, this is small compared to combustion loading, which could easily quadruple pressure in the combustion chamber to 740 psi in the normal-charged engine and 800 psi in the boosted engine, resulting in total loading of 9,301 and 10;056 pounds for the two powerplants. Think of it: atmosphere of boost will double the horsepower but the supercharged engine's pressure is nonetheless only 8 percent higher. And 100 percent of the added load is compressive through the connecting rod against the crankshaft.

i don't care who he is and if he's written a book, this is complete bullshit

the tensile forces near BDC due to increase in rpm are much higher than the net compressive forces at TDC due to increase in cylinder pressure. if you're gonna throw a rod it's going to be on a an exhaust or intake stroke. the rod is much safer during combustion than it is during any other part of the stroke.

the tensile forces from rapid deceleration and acceleration of the piston at TDC is canceled out by the compression forces of combustion and cylinder pressure during a compression and power stroke.

the kind of rpm you need to get 200hp out of a 100hp engine would stress the road 1000 times more than the increased pressure of boosting to 200hp

>>14096214
i.e. the rod in a 1.2 liter engine boosted to 200hp sees much less stress than a 200hp 1.2 liter n/a engine.

in general torque breaks cranks, rpm breaks rods, pressure and heat breaks pistons. within reasonable realistic parameters anyway.

>>14096214
>if you're gonna throw a rod it's going to be on a an exhaust or intake stroke.
no
>the rod is much safer during combustion than it is during any other part of the stroke.
no
>the tensile forces from rapid deceleration and acceleration of the piston at TDC is canceled out by the compression forces
no
>the kind of rpm you need to get 200hp out of a 100hp engine would stress the road 1000 times more than the increased pressure of boosting to 200hp
congrats you managed to be completely wrong

>>14096245
>in general torque breaks cranks, rpm breaks rods, pressure and heat breaks pistons. within reasonable realistic parameters anyway.
no.

you followed up to be more wrong. impressive

>>14096247
https://www.steel.org/~/media/Files/Autosteel/Programs/LongProducts/bar_connecting_rod_thesis.pdf

educate yourself

>>14090787
How do most people race?
Street race
What are all street races prrimarily?
Straight line races of a distance of usually 2-4 blocks.

>HURF DURF CAR CAN'T TAKE HARD RIGHTS AT 80 MPH
Congratulations. Your car can do something that you will never use in a street race. Then you wonder why you always lose.

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>>14090413

It's not all about displacement. It is all about bore and stroke.

>>14096257
it may be counter-intuitive to you, but it's right.

>>14090801
VTEC is just an alternating valve train system. Literally EVERY car uses one these days. There is nothing special about Honda's. Only JDM retards actually think it's something special.

>>14096272
drop all the links you want, it doesn't work the way you described. what you wrote it ridiculous in fact.

>torque breaks cranks
>rpm breaks rods
You're way out to lunch bro. Build and race an engine some time.

>>14096307
I'm right.. your failure to educate yourself is your own fault.

All the information is there.
Scroll to look at the graphs if you're too lazy to read.
Look at the combined compression tension loads in relation to the crankshaft degree.

>>14096307
>im an engineer because i put together an engine (adult legos)
ok

>>14090413
At the end of the day more displacement = more air and fuel = more power potential
not saying because an engine has more displacement it's better, because that's far from the truth.

>>14096336
>I'm right
You are not. You want to be right, but you're not.
>>14096348
>I have no experience but I read a paper and I think I comprehended it correctly (no conception).

>>14096350
bigger engines are less thermal and volumetrically efficient. That's why you see 6 liter v12s making 70hp/l and 2 liter i4s making 120hp/l with the same development.

excluding reliability as a variable, only reason to use more displacement is if its financially or materially impossible to get to a power output using less displacement.

>>14096390
I was just saying that larger displacement will always have more potential for power. Efficiency and reliability has nothing to do with it.
A gallon of gas has more energy than a liter is pretty much what I'm getting at.
None of this really matters to me since I have a car that MAY put 100 at the wheels.

>>14096214
According to you, all of these rods should have snapped.

In the realm of your old wives tales, with the combustion/compression "keeping engines together", "rpms break rods, not torque" and "cancelling out inertial forces" bullshit, THIS RIGHT HERE IS A WORST CASE SCENARIO
https://www.youtube.com/watch?v=j8gvgISVHak
This Rover 2.0L is being mechanically spun to 10K + with NO head. No magical compression pressure to keep the pistons from flying to mars. But shit, THAT NEVER FUCKING HAPPENS. The bottom end siezes instead.

What happened?

>>14096386
You're wrong and you have no facts to back it up.
I'm right and have a thesis to back it up, there's also another good site that explains the same thing, but I can't find it.
You can educate yourself and accept it or continue being wrong. The first conclusion of someone looking at a bent rod is over rev. Because over rev breaks rods. This thesis tells you why.

>I have no experience
I've built engines. Building an engine teaches you nothing about the engineering.

>>14096416
>Building an engine teaches you nothing about the engineering.
>Building, tuning and racing engines teaches you nothing
You truly are the daft cunt they've spoken of. All hail the supreme autism.

>>14096390
no one ever bought a car because thermal and volumetric efficiency you pretentious fuck.
it doesn't matter, no one cares - and rightly so.

>>14096415
because the rods are strong enough for 10k rpm with that stroke length.. obviously

>>14096451
>im a race car engineer and a race car driver
this sounds believable, tell us more

>>14096461
>no one cares
then why does this thread exist

>>14090508
Or you could add cylinders.

6.5L V12 will rev more than a 2.5L I4.

>>14096473
>because the rods are strong enough for 10k rpm with that stroke length.. obviously
Wait a fucking minute, are you sugesting that the Rover 2.0L rods are considerably stronger than every other engine's rods?

Are you backpeddling and moving goalposts to salvage your failed theory!?

>>14096473
>>im a race car engineer and a race car driver
>this sounds believable, tell us more
So when all else fails, like your interpretation of technical documentation, lack of experience and own personal theories, let's just default to condescension and sarcasm, does that sound about right?

>>14090508

you are wrong you fucking retard

>>14096415
How do you know the rods aren't bent?

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>>14096488
lmao
>b-b-b-but how do you know
You lost. We're done.

>>14096476
this is 4chan we argue about anything

>>14096482
10k rpm is not that high for a short stroke engine.

>But in high- revving engines, increased tensile strength is an absolute must for the rods to survive at high rpm
straight from engine builder magazine.

I don't know why you're debating this.. most of the stress on a rod is tensile force from rpm.
Can you just fuck off and go read a book?

>let's just default to condescension and sarcasm
That's what you've been doing this entire time. You have no evidence whatsoever. Which is understandable because you're wrong. And you're claiming your a race car engineer.

Idk why you're so against just learning something.

>>14096482
>"Over revving is the main cause of connecting rod failures in new and high performance engines. If the tachometer hits the red--even briefly--the connection rods are in danger of breaking. This is because the forces acting on a connecting rod increase dramatically at high revolutions."

Same reason rod bearings take such a beating on 2 strokes.

>>14096529
>I don't know why you're debating this.. most of the stress on a rod is tensile force from rpm.
>Can you just fuck off and go read a book?
You're still wrong. Theory a little less hard, nuber. You're literally

>>14096571
>>"Over revving is the main cause of connecting rod failures in new and high performance engines. If the tachometer hits the red--even briefly--the connection rods are in danger of breaking. This is because the forces acting on a connecting rod increase dramatically at high revolutions."
Hilarious!
"rods will last forever as long as they dont go too fast, you'll break a crank before you ever break a rod."

Oh shit all these people changing their rods to push 45psi of boost, when they don't have to do that thy just need a new crank. Wow, everyone is stupid except that retard that wrote the quoted, and the stupid nuber kid who read it.

Shit guys! CALL CROWER, CALL PAUTER, CALL EAGLE, CALL CARILLO, CALL MANLEY, CALL TODA, THEY'RE ALL WRONG. DONT UPGRADE YOUR RODS FOR ALL THAT BOOST JUST UPGRADE YOUR CRANK. AN AUTISTIC SAVANT ON /o/ JUST BROKE THE CODE, CAN SAVE THE INDUSTRY BILLIONS!!!!!

>>14096607
>You're still wrong.
I'm right.

>changing their rods to push 45psi of boost
obviously you need stronger rods at extreme pressure levels.. are you retarded? is that what you have been thinking im argueing against this entire time? lmao you're dumb as fuck.

the compression forces from 45psi are insane.. that's why I said reasonable levels literally in my very first post. improve your comprehension.

btw you still aren't a race engine builder.

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>>14096646
>obviously you need stronger rods at extreme pressure levels.. are you retarded?
I thought torque doesnt break rods, RPM does.
And what about upgrading the crankshaft to accept the torque?

Funny, most people are REALLY stupid and never change their crank, but they're changing their rods to push more torque on boost, with the same redline.

Yeah, they're all stupid. Why don't they go 'educate themselves', maybe put read an article on the internet and get overwhelmed with Dunning-Kruger feels.

They're all so dumb, they don't know they should be keeping the stock rods and changing their crankshaft instead. DUHHHHHHHHHHHH

>GRAB THE PHONE WE GOT MORE CALLS TO MAKE

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>>14096501
>being this jumpy about winning a pointless argument on some japanese anime screenshot file repository

you turbo charged retard

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>>14096698

Different anon here. You really are silly, and aren't doing yourself any favours by carrying on like a twat. If you cannot comprehend the reality of metallurgy and the physics at work inside an IC engine that's okay, not everyone can. But this behavior is more fitting for the clients I worked with in Disability Employment in a previous life.

As an aside point, every engine manufacturer I have either contracted engines from or been an agent for suffers from rod failure in an over-rev situation. Throwing a leg out of bed is a pretty classic symptom.

>>14096698
torque doesnt break rods. rods aren't torqued. they are compressed and pulled.
torque twists cranks.

>and never change their crank
because the stock crank is strong enough. most stock cranks are already forged and hardened.
but really high power builds absolutely use aftermarket 4130 hardened cranks.

you've been arguing against nothing this entire time.. at 45psi you will need strong rods, but not at less than 2.5 bar no matter how much power you're making with most stock rods. it all depends on rpm and stroke length if you're within reasonable cylinder pressures for the stock rods. (like my original post said).

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I'm so sick of this stupid debate on /o/.

Yes, a 4 cylinder with a turbo charger and thousands of dollars in aftermarket parts will outperform a smug era big block on the track. It's really comparing apples to oranges.

Simply put, engines with a higher displacement have a larger potential to create power and in most cases will have better specs. Are some 4s and 6s better then some V8s for power? Yes, of course but the vast majority are not. Each engine platform has it's pros and cons and some are better for different vehicles and different uses.

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>>14096805

No point saying it, the type of users who post the most have the least potential to learn new information or discriminate between fact and fiction.

Just look and laugh man, look and laugh.

>>14094760
240-250 NA D series. I wouldnt be surprised if its been done but i'll have to see it to believe it

>>14096607
Dude youre a fuckin tard

heres a different question an/o/ns

when setting up gear ratios in Forza, almost every car has a REDLINE on the speedometer, but the point at which the engine starts to auto-throttle itself is usually about 1-1.5 maybe even 2 thousand RPMs past that point

which is the correct powerband shift point, right at the speedometer redline? (which i assume doesnt change as you add on new parts and upgrades)

or that point in which the engine self-throttles?

>>14097041
>Forza


I'm starting to think most of the benchracers on this board think Forza is an accurate depiction of real life.

>>14097041
>REDLINE on the speedometer,
u wot m8?
sorry i don't play video games

>>14090676
You do realize that the LT1 and Ecotec3 pushrod GM V8s have variable valve timing?

>>14097049

every fucking car has a red area of the RPM in real life

>>14096776
>torque doesnt break rods. rods aren't torqued.
no one said rods were torqued
"engine torque" is directly proportional to the relative torsional severity experienced by the rod beam of a given engine[geometry] and beam design.

>torque twists cranks.
torque twists badly designed cranks
we don't worry about crankshafts anymore. most are forged and definitely forged on most any engine worth building. even a good ductile iron cast crank with proper main and rod diameters, and proper fillets is nothing to worry about in those cases. Balance her up, re-harden any cut journals- maybe correct oiling issues in rare cases and it's ready to go. I don't worry about shit engines, and I don't worry about cranks when I'm looking for power.

>the stock crank is strong enough.
Yeah, read above. Maybe if you didn't read so many hot rod books from the 60's in such naive earnest, you'd know that.

> at 45psi you will need strong rods
oh you think so?
> but not at less than 2.5 bar no matter how much power you're making with most stock rods
lol wut 36ish psi on stock rods? that's definitely not a rule of thumb or even good advice. jesus.
>depends on rpm and stroke length if you're within reasonable ***cylinder pressures*** for the stock rods
yeah, major fucking caveat there bro, and most common cam profiles will allow EASILY for that rod bending torque level to be achieved.
If the boost is available too early in the RPM range, and the combustion is normal the rods will bend from torsion. Over torsion is in fact the most common cause of bent rods in automotive performance engines, at least in the last 5 decades.

rarely ever would an automotive engine's connecting rod beam be the principle mode of failure from an over-rev. The rod bolts would much more likely stretch than the rod beam being affected by tension.

>>14097238

I think this post truly shows how little you are in touch with the automotive sector, or any engine sector really. Do you honestly believe the text you have written down the bottom of your dribble? Can you verify with any source that it would be more likely to stretch a rod bolt than to deform a connecting rod in an overspeed situation? I invite you to search, for I feel very strongly that you will find only information that counters your own.

Has your own experience shown this? Can you relate and verify your own experience? I can only speak for my experience with engines that I have destroyed or have arranged refits for, but in my experience throwing a leg out of bed is by far the most common symptom of an overspeed condition.

A quick heads up too, torsion is a twisting force. Connecting rods and pistons do not experience much in the way of torsion, as force is applied almost entirely in a reciprocating manner over the central point of the piston and the fulcrum present in the piston-rod-crank connection.

I think you may have meant tension, but then again I doubt that you think.

Another quick heads up, since the introduction of widespread compression ratios above nine and a half to one in petrol automotive engines the most common source of connecting rod failure, according to Ward's, is hydraulic lock.

Stop making things up to sound good. You are not achieving that aim very well.

>all these turbocharged benchracers

Enjoy your heatsoak.

>>14097085
redline? on the speedometer? post pictures pls.

>>14094333
>My hondata came!
>Look desu! The box says 10HP!

>>14097428

any analog speedometer has it

>>14097460

You sure? Plenty of tachometers have a redline. Pretty uncommon to see a redline on a speedo.

>>14090413
Is this what happens when videogame faggots think they know everything about cars because they play videogames?


Sit the fuck down, kiddo, i am gonna teach you something.


Turbos and superchargers works by simulating bigger displacement on the engine by compressing and forcing more fuel and air into the cylinder than what it would be able to hold uncompressed. This means that a 2.0 NA engine running in normal atmospheric pressure will work as a 4.0 when the turbo spins up if its set to take twice the atmospheric pressure. Most turbos however usually take at least 3 times the displacement at top power, tho.


Whenever you want to compare bigger engine NA to smaller FI, compare the smaller engine in the displacement it has when its turbo its working.

>>14097334
>replying to 'most common mode of rod beam failure in *performance* engines' with "b-but Ward's says..."
Ward's is synonymous with the racing scene and SURELY they poll professional and independent performance engine builder worldwide, about cylinder pressure induced compressive rod deformation.........

>TORSION
I should have specified THE BENDING PARALLEL TO THE BEAMS AXIS
Torsion is a misappropriation, and that was my hasty mistake.
Nevertheless, it remains that tensile failures not much an issue in auto engines. COMPRESSIVE LOADS ARE. Even your wards example of hydrolock comes down to rod beam failure by compressive load. Tension, not so much.

It must be said I have been made to feel shame by this reply, no doubt- shame for blaming my mildly abrasive tone previously for the difficulty with you. I didn't think I would get trolled so hard by someone's intense Dunning-Kruger syndrome.

I mean, thanks for the basic as fuck fulcrum bit pal. It really is obvious who's trying to sound smart. I allowed myself to get trolled. It is my fault for thinking you were anything but a benchracer, a novice fucking benchracer at that.


CHEERS BLOKE

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>>14097537
I think him saying tension was just him mocking you saying torsion my man

>>14090792
>can probably redline at 25k RPM
Nah mate, way too much vibration from a V configuration. Plus still too big. Highest for a commercial engine is old 250cc i4 sportsbikes with 20k

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>>14097610
Yep. It was.
>>14097537

Whooe man you have arced up. I'm impressed how many science words you can fit in a sentence without making much sense at all.

You need to relax man. Always allowing yourself to be trolled on a japanese image board must be an interesting afternoon for you.

I'm glad you are just words on a screen. I imagine you'd be quite the cunt to be around.

>>14090508
Adding stroke=more torque=more power. Fagglord

>>14099157
Increasing stroke = more displacement, - compression = less power

wtf are you playing forza for
its an absolute shitty wannabe of a simulator that is trumped in every aspect by nearly every racing game

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this is some quality cancer