open downpipe?

[abrxy3]

going to the track again this friday, i was planning on running an open downpipe. im pretty close to stock, just an intake and a boost controller, will running an open downpipe hurt or help me? i know that turbo cars dont need backpressure but ive also heard that if the turbo isnt large enough torque will still be lost.

 

[DSMNightmare]

I would think it would help somewhat. You might lose some low end torque but what you will gain in midrange and top end should make up for it. You have to remember that Cat is on of the biggest hp killers on your car next to the T25. No I had a little bigger setup than you when I started using a test pipe at the track but let me put it this way. When all I had was 3" cat back I ran 15.9. By adding a 2.5" dp and 2.5" test pipe I dropped my time to 14.9. With just what you have now 14.9 should be easy as long as you hook up. Opening up the exhaust you should be able to do better.

Two words of advice if yo don't do the track much.

1. Dont worry about the tree. Too many people get hung up on the tree and dont realize that your time does not start until you leave the starting line. So you can red light or green light it does not matter.

2. If you do watch the tree leave on the last yellow. Unless you are hella quick you should prolly leave when the last yellow just lights up.

Good luck,

Mike

 

[abrxy3]

yeah ive only been to the track once, and with only a gutted cat and a MBC set at 15 i ran a 14.9 as my best. ok, so what youre saying is...RT is not calculated into the 1/4 time, but it is a factor in who wins?

 

[wastefuldreamer]

Run a test pipe instead of a gutted cat. It makes a difference.

 

[spoolup]

also on the open down pipe, get one of those little chap knoff ehaust tips that bend down a little to prevent burning everything under your car. You will have to go to a exhaust shop and have them cut a flange (or find one elsewhere) and weld that turndown to the flange. Cheapo trick for more noise and power. PS this gets loud. ask taloned_one he idd it for a while. his firewall shook getting on the throttle.