how does GM take away our HP in the newer models(GT)?

[manicdan]

we all know that the 03 has 180, and then in 04 it droped down some, and then more i 05, to 170 which is what i have, and then i belive it goes down to 165ish and stays there.so im wondering what exactly did the do to remove that HP, i know lift engagement was changed from 6200 to 6800, but did they change how lean the engines burn or ignition maps.but this is an odd way that im wondering if has anything to do with it, when i changed my air intake, there was a tube that the air first enters to that goes into the airbox. and along this 2ft tube that wrapes around the battery theres one part of it that gets alot smaller, its about 1 inch in diamater vs the rest thats about an inch and a half. could they have simply made that small change to limit how much airflow we have in the top-end of our RPMs?

[drunkenmaxx]

first, a smog pump thingy was added, then, the method of rating HP was changed, thus lowering the number.

[manicdan]

so if i were to race an 03 would there be any difference?

[SeattleJeremy]

Yes, the 03 is slightly faster. But in reality if you raced someone with an 03 the better driver would win.

[millster]

Definitely as Jeremy notes, you'd be hard pressed to find any appreciable difference in performance between the model years. The '03 did truly have more HP than the later years but not so much more that it would change the overall performance. Given two totally equal drivers in totally equal conditions, an '03 could maybe pull a nose over an '04 or '05.

[ragingfish]

my understanding is they've also retuned the 2ZZ again this year to adjust to help improve emissions.

[kevera]

The only benefit is the lift engagement.That would be the advantage in an '03.So '03 would be slightly faster.

[Petrucci914]

I thought that the only thing that changed is the way in which they measure horsepower. Other than that I thought everything remained the same.

[manicdan]

well not to sound mean but yeah any kid could tell u the diff in 10hp is nothing compared to driver skill.what im asking is if there really is any difference, given that lift kicks in earlier thats 20is hp extra for those 500 rpms, but other than that is the engine tuned or limited in any other way that can be undone

[kevera]

Also as Drunken said,the smog pump that came in '04 and detuning to meet emissions,killed that hp number a little.And the benefit of earlier lift engagement.