So I raced at this new track last night up in PA. I moved up here recently. I decided to run just an open pipe for the night and my times went up. Instead of running 14.3s to 14.2s I ran 14.4s and 14.5s. It sucked. Do you think the little back pressure that I had running thru a muffler helped?


3400 SWAP DONE. 187WHP 212TQ (14.2 @100MPH NA) 240WHP 310TQ (N2O)

With 1-2 tenths difference I would guess more that it's probably just affected by the current weather conditions more than anything. That and it's a different track. There's actually a lot of variables. It is still fairly consistant though.

yeah if you were say 15 second may be an issue but 1-2 tenths isn't an issue unless your a funny car or dragster when 1-2 tenths could put you from 1st to 5th


JBO since July 30, 2001

Nitrous Nate wrote:So I raced at this new track last night up in PA. I moved up here recently. I decided to run just an open pipe for the night and my times went up. Instead of running 14.3s to 14.2s I ran 14.4s and 14.5s. It sucked. Do you think the little back pressure that I had running thru a muffler helped?

How long was the open pipe? Did you just pull off the cat and back (if you have a cat), or did you put a pipe in place of the muffler and cat, or what?

If you just let it dump out shortly after the downpipe, I would say it affected you, and it's not backpressure. Common myth is that backpressure is good for anything. It's lack of pipe in the proper size to maintain velocity to help scavenge the cylinder. If you run, say, a 2" pipe from your header or manifold all the way to the back of the car, you are doing better than dumping it halfway.

This all depends on the RPM range and powerband, of course, but since your engine is mild, and not a high-revving beast, everything I just said is true.

I dont have a cat on the car. The pipe was dumping out just past the firewall. So maybe 3 feet long lol. Sounds like a beast tho. Im going to hook the muffler back up and race again next week and see what happens. The track temp and outside temp was like 70 degrees I thought that would have HELPED my times considering my best times were run with track temps well over 100 degrees.


3400 SWAP DONE. 187WHP 212TQ (14.2 @100MPH NA) 240WHP 310TQ (N2O)

I am betting that if you just ran a pipe from that to the back of the car, and it was the right size, you'd improve your power. If you wanna be able to run an open exhaust, make yourself a couple of test pipes to replace the cat and the muffler, and you should be good. Or maybe a couple of resonators.

I know exactly what that car sounds like with just a downpipe. When I first got mine running, that's all I had. Man was it mean sounding!

Yea its mean sounding but the droan in the car is unbarable lol. Seriously...


3400 SWAP DONE. 187WHP 212TQ (14.2 @100MPH NA) 240WHP 310TQ (N2O)