Open exhaust?

[01RaptorTA]

Well i've had my y-pipe off for a couple weeks now. I just cruise around town, dont get on it ever. Just for sound basically. I got to talkin with my buddy and his C4 vette with straight pipes and he swears up and down that its 10x better. My arguement was that when i had my Cobra, i had open exhaust as well for a couple weeks to test it out and i was .3 slower in a 1/4 mile. So is having completely open exhaust good or bad? Also, is blocking the EGR path with a plate harmful? He also swears that it helps, but i would think it would hurt the engine...

[Mr. Luos]

I removed EGR a long time ago. It doesn't effect anything at WOT though anyways.
If you cap it, you will need to turn off the codes with tuning software.

Open exhaust won't do much good (if not lose power) on a mostly stock LS1.
I know ever with my motor I loose a good amount of power with my cutouts open under 4200 RPM's. Then it comes alive.

[01RaptorTA]

Hmmm...So why would you need to remove it/cap it if it doesn't do much good?

How bout an open exhaust all the way back, not just dumping after the headers? I guess that would be the only variable between my cobra and his vette. I had it dumped after my longtubes, he had straight pipes all the way back to the tips, no cats or muffs.

[Mr. Luos]

Straight pipes wouldn't hurt anything as you still get some backpressure.


With my car, I am never under 4200 RPM's at the track. I open have it open for that.

[9t8z28]

Do you have LT headers or stock manifolds?

[01RaptorTA]

Stock manifolds with those pain-in-the-ass cats

[9t8z28]

Well, no wonder why it is slower and I'm sure, sounds like shit. It is also bad for the engine! Now, LT headers are a different story.

[01RaptorTA]

Actually it sounds baaaadass lol. Thats why i left the y-pipe off. At idle it sounds cammed, and at WOT it sounds like a fuckin stock car. But like i said, it doesnt ever see over 4k RPM, i just put around town with it right now.