Why do people build high horsepower cars but never dyno it? That's

>>13928109
Ignorance is bliss. Besides its better than being bench racing number faggots

high horsepower cars have all been dyno'd
it's the only reliable way to tune them unless you have off the shelf kits.

>>13928155
>tfw so many tried and true combos to get 450 rampaging stallions from a 440.
>tfw you are going to a 543 build and everything will be near custom specs.
>Cheapest Dynapro dyno is 75/pull for tuning.

It will be worth it but still....

>>13928109
I don't have to weigh myself to see my face looking less fat, I don't have to dyno my truck to feel it pull harder above 4000.

But yeah, with a fueli, you'd better get it dyno tuned.
>>13928155

>>13928210
$75 a PULL? I've gotta drive an hour, but the dyno closest to me is $60 an HOUR.

>>13928210

Being charged per pull is retarded. It should be in a time increment.

A dyno is a tuning tool. Every dyno reads differently, even among the same brand. Someone making 400whp on their local dyno might only make 320 on the one near me.

So the numbers are largely meaningless, and used only to fluff egos.

doing pulls on the street using logging tools is where its at, so much cheaper too

>>13928210
>>Cheapest Dynapro dyno is 75/pull for tuning.
That fucking sucks. You need at least 5 pulls to get a decent tune. What a ripoff. That's what happens when there aren't very many shops with dynos though, market monopoly, charge whatever the fuck you want to charge.

>never dyno'd it but it makes around 300hp

>>13929421
I haven't dyno'd my current project car yet but I know that it makes around 280whp based on the weight and 1/4mi ET/MPH. You can estimate power output *fairly* accurately if you know the weight and performance numbers of the car because you can use the performance of cars with similar performance numbers and weight as a basis for estimation.

>>13929565
and injector duty cycle if you're tuning the thing

>>13928109
52psi in my dsm, never been to the track or a dyno. no need. car is fun as fuck.

>>13929577
Only if coupled with the other mentioned numbers. Duty cycle alone means jack shit, because you could be using 300hp worth of fuel and making 210hp because you made a shitty tune.

>>13929583
that would show up in your afr

>>13929577
>lets ignore base fuel pressure and ignition timing

>>13928458
goddamn 4chan ate my post

There are several factors into the BHP output, no dyno should be that far out if the dynos are all correctly calibrated.

If you have two different brand, different action dyno's in the same building with the same parameters they will read the same.

you could have the same model dyno, same calibration date 25,000km away and it will read a different value.

engine temp, air temp, fuel temp, air density, humidity all affect horsepower. (and im sure i missed a few things)

This is why high end drag strips have their own weather things (whats it called in english? weather sensors?) that can record air temps, humidity, air pressure even wind direction as top teams will be making minor adjustments to try and work with the weather for the best possible result.

>>13929586
To some extent, but you can gain a lot of power without changing the AFRs much at all if your ignition timing is optimal.

>>13929589
>engine temp, air temp, fuel temp, air density, humidity all affect horsepower.
minimal. every 10 degree change in intake temp is 1% power change. ive seen it time and time again on cars from 300hp to 1000

>>13929595
>every 10 degree change in intake temp is 1% power change.
Gross oversimplification and wrong overall. Look up density altitude. It is not a linear relationship like you think it is.

>>13929602
ive seen it with my own eyes.

>>13929607
Reading is fundamental. Re-read what I said. You're finding patterns that don't exist and *grossly oversimplifying* something that is far more complex than you think it is.
>10 degree change in intake temp is 1% power change
Is patently false and dependent on FAR more factors than you say it is.

No tuner shop worth its weight in piss doesn't have a full suite of weather condition sensors with which to apply correction factors and print current conditions on the dyno chart. If your tuner/dyno operator doesn't know what correction factors and density altitude are, RUN.

>>13929594
sorry for trying to keep my original post brief instead of some tldr bullshit

>>13929614
http://www.csgnetwork.com/relhumhpcalc.html
enjoy.

>>13929660
>>13929660
https://wahiduddin.net/calc/cf.htm
Educate yourself.

>>13929667
oh god get out of here with that. thats just some shit you found googling around

>>13929676
Correct. I googled it to help you out and show you an explanation of why you're talking shit. with your
>durr hurr 1% power for 10 degrees
crap

>>13929667
>wahiduddin
sounds like some a-rab terrorist thing, you're obviously an enemy of freedom so i'm reporting you

>it has 900hp
>never dyoed it tho

Because my butt dyno tells me it's fast

I saw a guy run a Z28 catfish on the dyno.
His fat ass fucking girlfriend said there was something done to it.
Initial thought between me and my friends was that it would run 260 or 280.
We heard it the first pull, and I quickly held back and said it ran 340.
My buddy said it ran under 330 for sure.

We bet a dollar on it. It ran 325.
The guy looked pretty disappointed, and even more disappointed when we told him we had bet on it.

But I mean, to me that's still a respectable amount of power. Just, with the bolt-ons he had. It wasn't enough.

>>13928109
Because dyno's can't reliably or accurately measure beyond around 3000 to 4000hp. Anything below that can and should be dyno tested, anything above that isn't tuned for direct power output, but for performance itself. Funny car/Top fuel etc. engines like that aren't tuned to get a good dyno number - you just look at all the telemetry you've got, and tune your engine accordingly.

>>13928210
>Cheapest Dynapro dyno is 75/pull for tuning.
At that point you'd almost consider getting a dyno yourself.

>>13930896

>Tfw end goal in life is to have a Jay Leno tier garage with two of my own dynos

>>13928109
IT costs money.
A scale is free to use just walking in a store and taking one off the shelf.

>>13930896
>dyno's can't reliably or accurately measure
>beyond around 3000 to 4000hp

And why is that a problem again?

>>13931119
It's not a problem. I was just stating that there are no excuses whatsoever to not dyno a modified car/engine if it doesn't produce 3000+hp.

same reason i've never measured my dick
whats better that saying it makes 403.7 hp?
saying,
>ive got no idea

but seriously, some people build cars for fun, and the way it makes them feel. I put an intake on my truck, and will probably get an exaust purely for the sound.
>muh rumble

>>13931169
what if you dont care about the power, just the noise, and the feeling?

also
>mfw local car club did a free dyno day
>took dead stock 6.0 gas 2500HD
>turbo subaru's all around
>truck is a bitch to dyno, cant really get a full run
>still make most power of the day
>still slowest car there

that v8 life