LS1 Question.
Originally Posted by TXCAMSS
Well FWIW, I put down 436 rwhp on the dynojet with FLP LT headers. When I swapped to the Kooks 1 7/8 headers (both thru y-pipe and single cut-out) AND added a 12 bolt rearend with higher 3.73 gears, the car made 459 rwhp. That was with the same tune and only a day apart on the same dyno. I should have lost about 15-18 rwhp with the addition of the 12 bolt. That would have been a at least a 33 rwhp gain with Kooks by themselves. I was pleased to say the least.
There is definitely a performance difference between the various headers out there and the Kooks are superior IMHO.
I would have never guessed it, but I have seen similiar results from others since I installed mine.
My guess is that the headers are making the difference. There's one way to find out
Good luck to ya!
There is definitely a performance difference between the various headers out there and the Kooks are superior IMHO.
I would have never guessed it, but I have seen similiar results from others since I installed mine.
My guess is that the headers are making the difference. There's one way to find out

Good luck to ya!
Originally Posted by SouthFL.02.SS
LT's do make a difference (already noted), but healthy numbers to healthier numbers seem to be the trend (when switching to a superior LT over a regular LT). In this case, he has LT's with below than average numbers. Blaming the LT design is BS. Even MAC midlengths make good numbers. Something's wrong with fuel or timing or valve events.
I agree with this, Yes maybe there are differences in quality and design that will produce minimal gains but not 47hp, It makes sense in some of the posts here that are pointing towards a problem with the cam
Were you hearing audible ping on the low HP car or was the PCM registering KR from the knock sensors?
Is there a significant mileage difference between the two cars?
Last resort, the Z06 MAF. IF that causes a lean condition you won't be able to run the same amount of timing.
Is there a significant mileage difference between the two cars?
Last resort, the Z06 MAF. IF that causes a lean condition you won't be able to run the same amount of timing.
Originally Posted by technical
Were you hearing audible ping on the low HP car or was the PCM registering KR from the knock sensors?
Is there a significant mileage difference between the two cars?
Last resort, the Z06 MAF. IF that causes a lean condition you won't be able to run the same amount of timing.
Is there a significant mileage difference between the two cars?
Last resort, the Z06 MAF. IF that causes a lean condition you won't be able to run the same amount of timing.
Edit- KR on the tech 2.....They had to richen it up and pull some timing to make it go away.
Last edited by HRJ; Oct 13, 2005 at 09:26 AM.
Update - A compression test was performed on both cars this week. The results were identical. So that kind of eliminates the cam being a tooth off. I know I need to figure out why the car shows detonation so much earlier (lower timing, I mean) than the other one. We get that figured out, then we can get the timing back up and reclaim the lost power. The only reason I have such a hard time believing that its a problem with the SW headers is that I have the exact same ones on my 2005 GTO LS2 with the same cam and am putting down 417rwhp on the same Mustang dyno with just as much timing (a touch more if I remember correctly) as the stronger car has with the Kooks in this comparison.......


