When I bought my G, the guy who had it did some kind of custom set up. What he did was weld an extra pipe right before the muffler in the rear with a removable cap so when the cap is off, the exhaust exits here and actually sounds pretty good. I put the cap back on this morning because I was tired of listening to it. Since then the car feels a little quicker. I figured it would be quicker without it, but was I losing too much backpressure with this set up? I'm thinking it might be all in my head but let me know what you guys think.

 

Not back pressure. Loss of exhaust gas velocities.

 

who had the remote controlled one up toward the Y pipe

 

http://www.quicktimeperformance.com/QTEC/index.php

They have the remote ones here... seems to work better on older muscle cars though.

 

anyone got a more detailed answer?

 

I'm with you. I'd always been told not having the proper back-pressure could hurt performance. From my experiece, I found out the hard way. After I'd dialed in my car with most of the basic bolt-ons and tuned, I thought I might make a little more power by opening up the exhaust some more. So I swapped out the coupe mid-pipe and stock sedan muffler for a Fuji y-pipe-back exhaust. Back to the dyno for retuning and hopefully more power... I lost horsepower across the entire powerband with a peak loss of 8 hp!

So even though, in my case, it seemed like the free flowing exhaust SHOULD have benefitted me, I actually lost power. I've since put on a freer flowing intake in the hopes that it will balance out the exhaust's flow, but I haven't had a chance to get it tuned since adding it. If it doesn't, then I'm going back to coupe middy and stock muffler.

 

I've also wondered about this... I had the kinetix high flow cats and at first it felt slow because the loss in back pressure was creating the low end torque i think... But when i went to the track i was 4mph faster... 13.8 @ 104 w/ hf cats, intake, & plenum compaired to 14.0 @ 100 w/ intake... I didn't like the cats on cuz the G felt slower at lower RPM's... CAn anyone fine some solid info on this topic because most companies claim that there exhaust system creates HP, but with my personal experience this idea is kinda shady...