i'm not saying gm is lying. the under-rating issue is simply the dyno slide, but 18% may apply to one vehicle and not another. it's different for auto, stick, wheel and tire combo, rear differential, etc. when your talking these power numbers, percentage is important. 3% difference is around 10hp as an example which some people pay alot to pick up 10 hp, so yeah a few percent is a big deal...

 

That would make perfect sense, BUT explain to me how my 305hp motor is pitting down 315 at the wheels?

 

315rwhp stock from a 305hp version?

 

I can't say anything for your claim about 315rwHP but I can say... What marketing value is there in underrating your engines? I don't know what the spread on HP output for LS1 engines is. I would imagine the published HP ratings are for the bottom of the spectrum though.

Brian

 

Bottom line is.. he average HP at the wheels of a 380hp rated car is no different then any other ls1 with a lid and catback..

 

It seems a little hard to believe that with a simple Lid and Catback you can see 380hp at the crank on an otherwise stock LS1.. If its true, its cool, but just seems odd.. I guess if the cars really make like 350 at the crank than it does seem right..

 

that may be the bottom line, but a lid and a catback doesn't get you 5hp away from the 01' Z06. the bottom line is people are paying extra for the round about number because the sticker on the hood says so. anyone that was at the berger even can see the wonderfull numbers the gmmg cars put down.

 

Let's see ... I laid down 330 RWHP (SAE Corrected) at Hypertech two weeks ago with only a lid and a cutout.

Assuming a 15% drivetrain loss in the 6-speed tranny, that works out to 388 HP at the flywheel. So, I'd say it's not too hard to get 380.

If you want to take the 13% drivetrain loss, then it works out to 379 HP at the flywheel. I still ain't complaining.

 

I'd bank on less DTL than that, people with 12 bolts and modest 383s have seen only 13% DTL as compared to an engine dyno, but there is no foolin, the LS1s make the power.

 

wow, very cool!! I can't wait to get my LS1!! Everybody's around here trying to get me to keep my iroc cuz its so clean, but my hearts set on a LS1, and u just made it worse! I want it more now LOL.

 

Factory HP numbers are at the flywheel with *NO* accessories but what is required to run the engine. And although it could be considered false advertising for a manufacturer such as gmmg or slp to make the claims that they do, it'd be REAL hard to prove as the factory claims are notably low.

 

wrong.. the ls1 is not rated at the flywheel

most people dont know that...

its not at the wheels either..

its rated at the tranny tailshaft.. ofcourse thats unoffical and you wont see gm say that

 

That was back in the 60s.

 

Last i checked, thats the way they are required to do it even still.

 

nope