Has anyone tested their car on the dragstrip or dyno before and after installing dual exhaust? I'm curious what the power gain really is.

I went from a single to a dual with H-pipe on another car, and seat of the pants felt like a 15-20 hp gain (just guessing). The factory system that was replaced had a crimped down y-pipe and stock muffler, so it was pretty restrictive.

So anyway, I just wanted to see if anyone had tested the performance gain of this mod on a thirdgen.

Thanks!

 

with a 1000stall converter and hooker 2460's and a single 2.5" dynomax catback (mandrel bent) the car went a best of 14.53@97mph. after the 1800stall converter and hedman longtubes/dual exhaust with h-pipe and summit racing chambered mufflers (the $39.99 ones) it has gone a best of 13.75@100.5

et dropped dramatically because of the looser converter in addition to the exhaust, i never did a real comparison. however, trap speed indicates power and i gained over 3mph.

 

well, here is my info if it helps.
i have hooker long tubes 2210, custom 3" y pipe to a 4" mufflex with a spintech dual out muffler. couldnt stand the interior noise of the muffler, so i replaced it with a 3" dynomax ultraflow, and put a set of bullets inline to tone it down even more. didnt change my track times a bit.
i run 7.50's 1/8 mile. (11.70's or so 1/4)

 

So you went from short to long tube headers in addition to the duals? Hmm, I guess with the multiple things that were changed at once, it's kind of hard to say exactly which mod did what. (longtubes vs short, one muffler vs the others and so on).

Regardless, that's an incredible drop in et for such relatively minor modifications!


Stage 20:

Did you follow the factory routing with that exhaust or do you have sidepipes?

 

yes, factory routing. stock location muffler. my bullet muffler serves as a tailpipe as well, which has a turndown welded to it.