Crank HP vs RWHP

[VaderCamaro2010]

So my stock LS3 SS camaro was putting down about 345 rwhp (thats about what they average) with 426 hp at the crank. With a few bolt on mods it made 410 rwhp on the dyno....a gain of 65 hp. So does that mean its making 490 hp at the crank? I know crank hp doesn't really matter but just curious.

[derklug]

Using simple math, it should be 506 at the crank, but that assumes that the loss through the powertrain remains at the same percentage.

[JUISSD]

Originally Posted by derklug

Using simple math, it should be 506 at the crank, but that assumes that the loss through the powertrain remains at the same percentage.

Yep. Your loss was 19%. However there are a lot of variables to consider. Did you use the same dyno? Were the weather conditions the same? Dynos are primarily tuning tools and the numbers can vary.

[Sax1031]

Dynos are a tuning tool and nothing else.

[Entaille]

Originally Posted by Sax1031

Dynos are a tuning tool and nothing else.

word. people get way too fixated on numbers.

[mikeSS]

ya i always tell my friends and people what the crank HP is ... only people that know cars will understand RWHP... its goos to have a idea what crank HP is

[GQ4Life]

I tell everyone engine HP.. if they car guy I will say wHP too..
Standard is 15% drive train loss on manual ..
So take 410wHP divided by .85 is 482HP at engine
Stock 430HP times .85 equals 365wHP what a lot of LS3's dyno
Ur dyno prob reads low no biggy its just a tool to give estimate to compare & tune

[clg_98ta]

Originally Posted by Sax1031

Dynos are a tuning tool and nothing else.

True dat. Your 65 hp gain at the wheels with 'simple bolt-ons' is a very good gain if you are talking just intake/exhaust mods.

Perhaps the first dyno was low for some reason - with 15% losses, a stock LS3 should put down 362 hp at the wheels. Are these corrected numbers?

[Crowley]

Most shops will say there is a 15% loss for the Manual/LS3 camaro .. that being said, 415 at the wheels would put you around 488 at the crank ... (415 / .85 )

That being said, is that 415 at the wheels on a dyno jet .. and as stated above, was your stock and then modded numbers on the same dyno and in similar conditions?

thanks,
Crowley

[armysig]

Originally Posted by JUISSD

Yep. However there are a lot of variables to consider. Did you use the same dyno? Were the weather conditions the same? Dynos are primarily tuning tools and the numbers can vary.

I have found out the hard way on this. I did some addons to my car, I do have a baseline prior to those, but I went to a different dyno, and the numbers off the second one were so inflated that it was just stupid.

Basicly I baselined at 370rwhp, and 365 max torque. Second dyno with new addons, 441rwhp and 460 max torque. Sure the numbers look great, but it's not a true representation of what i really have.

I should have been around the 395 to 405rwhp and just a shade over that for torque.

Baseline mods
Cold Air Inductions intake
Borla S-Type cat back

Addons
Dynatech Headers
Dynatech High flow cats
Custom Tune

So my next course of action is to take it back to my orginal dyno I used and see what the true gains are.

[DGthe3]

Your first run seemed a little low. I think the LS3 Camaro's are usually roughly 20 hp more than that

[GQ4Life]

Most LS3's seem to be 365 to 375

[oldfriend]

Originally Posted by derklug

Using simple math, it should be 506 at the crank, but that assumes that the loss through the powertrain remains at the same percentage.

YEAH IT CAN BE SIMPLE MATH, BUT YOU CANT GO BY % , LETS SAY SOMEONE DROP IN A 1000 HP ENGINE AND ALL OVER SUDENT YOU LOOSE 19% OF THAT IT WILL KNOW LOOSE 190HP TO THE DRIVE/POWERTRAIN , SORRY BUT THIS DOES NOT MAKE SENSE AT ALL!!!!:bo w:

[DGthe3]

Originally Posted by oldfriend

YEAH IT CAN BE SIMPLE MATH, BUT YOU CANT GO BY % , LETS SAY SOMEONE DROP IN A 1000 HP ENGINE AND ALL OVER SUDENT YOU LOOSE 19% OF THAT IT WILL KNOW LOOSE 190HP TO THE DRIVE/POWERTRAIN , SORRY BUT THIS DOES NOT MAKE SENSE AT ALL!!!!:bo w:

Please turn caps lock off before writing a post.

Drive train losses are more complex than a simple percentage but the loss at the interface of a pair of gears is based on percentage of input power, not an absolute value.