This is a big debate among my car group - They swear up and down our car is not rated by WHP - I was under the impression when Chevy put our car out they rated it 205 WHP


Am I just totally smoking crack with this? or on the ball?

 

Gm uses crank power figures for its rated outputs . GM also has a tendancy to undertate the #'s on alot of its performance cars .

 

Actually the SAE standard calls for it to be measured with the flywheel in place and all accessories attached (a/c, exhaust, alternator, w/p, etc). If the engine did not have to spin that flywheel and was measured at the crank, power numbers would jump up. Just to clarify though, no manufacturer rates power at the rear wheels (or at the rear of a transmission for that matter), it is all at the flywheel.

 

so our cars were rated at the flywheel and not WHP?

 

Yes the fake # that you where given 205 they do not claim to be from the wheels. they follow the same route as the focus civic etc. Its not at the wheels.

Now that # in most cases is complete bull crap. Most people that Ive seen dyno's from are anywhere from 210-220 to the wheels. So as someone was mentioning the 205 # was pulled out of thin air. That was probably for insurance purposes etc. Dodge did the same with the SRT 4.

your car is about 210-220 at the wheels. but GM doesnt give those #'s out.

 

well several things come into to play when giving out the rated #s for said motor

advertised power is usually done at a certain rpm , also when most companies give out that number and rpm , they have tested alot of motors , and find a commom range and power level for the motors tested

say 205 @ 5600 (example only) , and that would be the number they give out

also the 2.0s/c can run on 87 octane gas , and im guessing that the reason for the low dyno #'s compaired to what everyone is getting has to due with the motor being run on 87 during the dyno testing , and the computer pulling out the timing to make it run on 87

even though gm says to use 91

it is the only sane reason i can come up with as to why the s/c motor dyno's at the wheels higher than the rated hp