Hp on a Dyno

[William L.]

If a new Z06 is 505 HP at the flywheel. What would the HP be at the rear wheels?
I guess what I am asking is what % do you loose from flywheel to an actual
Dyno pull?
Thanks Bill

[Edward J.]

Re: Hp on a Dyno

Bill, Ive Been To Carlise, Pa. The Last Few Years Ive Seen A Few On The Dyno There About 385 Hp Stock At The Rear Wheels

[Bill M.]

Re: Hp on a Dyno

I guess what I am asking is what % do you loose from flywheel to an actual Dyno pull?
Thanks Bill

General rule: 15 - 20%

[Steven B.]

Re: Hp on a Dyno

Bill, my last two engines, a 283 and a 350, lost about 20% from the engine dyno to the chassis dyno with same state of tune.

Steve

[Duke W.]

Re: Hp on a Dyno

For front engine/rear drive vehicles like Corvettes the generally accepted manual transmission driveline/tire efficiency factor in direct drive is 0.85. That would be fourth gear in either a modern or vintage Corvette. Using a gear that transmits power through the countershaft will lower results another 3-4 percent.

For automatics without lockup converters 0.80 is usually used.

Also understand that RWHP can be "observed" or "corrected" to several air densities, and the above factors to estimate SAE net at the flywheel are only valid if "SAE correction" is used for the raw RWHP data.

Duke

[Steven B.]

Re: Hp on a Dyno

For front engine/rear drive vehicles like Corvettes the generally accepted manual transmission driveline/tire efficiency factor in direct drive is 0.85. That would be fourth gear in either a modern or vintage Corvette. Using a gear that transmits power through the countershaft will lower results another 3-4 percent.

For automatics without lockup converters 0.80 is usually used.

Also understand that RWHP can be "observed" or "corrected" to several air densities, and the above factors to estimate SAE net at the flywheel are only valid if "SAE correction" is used for the raw RWHP data.

Duke

Duke, right on with the 0.80 for auto.! The 350 is a TH400 and it lost 20% without the AC or Smog Pump belts. The 283 manual lost 17%.

Steve

[Steve B.]

Re: Hp on a Dyno

If a new Z06 is 505 HP at the flywheel. What would the HP be at the rear wheels?
I guess what I am asking is what % do you loose from flywheel to an actual
Dyno pull?
Thanks Bill

Bill, a new ZO6 puts out mid 400 rwhp on most dynojet dynos

[William L.]

Re: Hp on a Dyno

Bill, a new ZO6 puts out mid 400 rwhp on most dynojet dynos

Thanks Guy's for all the input. The reason why I asked is, I have a friends 2007 Z06 here and after headers,cross over pipe, Corsa exhaust, new airbox , K&N filter, and a computer tune. It pulled about 485 HP @6500RPM on the Dyno yesterday. I guess with a few addon's you can make a little more HP.
Thanks again
Bill

[Duke W.]

Re: Hp on a Dyno

What kind of horsepower was that? Observed? Corrected? How so? Get it?

Duke

[Dick W.]

Re: Hp on a Dyno

The two that I know about pulled about 440 +/- RWH corrected. They were tuned and would pull about 470 +/- after tuning. Without major mods, I think that this is the limit of the engine with stock cam and headers