crimlwC6

I'm building a track only 99 FRC. My question is does removing the mufflers and running straight pipes reduce power, add power or make virtually no difference? The car will be getting headers, x pipe and a tune before returning to the track. The forum seems conflicted on the issue based on the searches I did. If there is no performance gain then I'd leave the mufflers in and take the 40 lb weight penalty in hopes that I could run at a local track with noise restrictions. I've considered straight pipes and then when the budget recovers picking up some supertrapps. Thanks in advance,

spazegun2213

first, YMMV depending on exhaust, engine, etc. My ls6, gained well over 30whp untuned. I went from a stockish exhaust (hollowed cats) to American racing headers (their racing 1-7/8s) into 3" dumps. I was shocked, and told the tuner to take timing out of the top end (st-2 car). What mufflers do you have now?

crimlwC6

Eventually is stock (LS1) except for the custom air intake that was built to accommodate laying the radiator forward. I'll be installing kooks 1 7/8s headers w/ kooks x pipe and then getting a tune done.

VGLNTE1

I made 10more rwtq with just my cut outs open vs modded ti mufflers. This was on my 416 with 3/4 long tubes, no cats

crimlwC6

Thanks for the responses. I'm guessing that it will be good for 5-7 hp on the top end for my car and 30 or so pounds off the **** end of the car. Any thoughts on the impact on torque in the lower rpm range?

VGLNTE1

Increased on mine, but i have more cubes

sperkins

My '99 stock LS1 with headers etc. dyno'd 346 with ZO6 Ti mufflers and 352 with straight pipes, but I don't think it was really that much since they were done at 2 different shops and the accuracy of the higher reading dyno is in question. I'd run the mufflers if I could hear the engine during a race.