I was talking with some friends last night about plans for my car, and when the topic of exhaust came up, one of my friends suggested going with a single exhaust. Yeah it looks tacky (since there are two exhaust ports on the rear) but he mentioned that its cheaper, less weight (wow, 5 lbs, lol), and it gives ya a few more ponies since there's less back pressure since its a strait pipe and not a Y-pipe.



So here's my plan, I go with a single 2.5 or 2.75 inch exhast all the way back. Good or bad idea? I know it won't be signifigant HP gains, but when you're building a streetable NA, every last bit of HP counts. Please, banter or praise as much as you like.

yea its a good idea, if like you say that little hp gain is worth it.



but the dual exhaust has to be one of my favorite looks of the fc's. one of the few times i'd choose aesthetics over performance.

I hate pointing people to other forums but this guy (GTUsPA) is amazing! He is running 13's with his N/A.



http://www.teamfc3s.org/forum/showthread.p...&threadid=15029



This is a thread he started on the exact topic you are asking.

Streetable = not race car loud, but a single is usually louder than a dual, and even the real full exhaust setups that are duals are pretty loud, ie. louder than a build V8 machine by quite a bit. A single would be over 100db at about 10-20 feet away during normal driving, which is enough to make people put their hands over their ears and get the cops' attention.



Full exhaust hurts low end torque. One person on another rx7 forum tried ditching his RB presilencer on his header / catback setup (probably racing beat but I can't remember for sure) and noticed no decrease in acceleration (he timed it, before and after on the same stretch of road) and he even thought he may have gotten some power back by putting his main cat back in.



The moral is that single exhaust with big piping is great for turbo cars because it decreases backpressure behind the turbo, allowing it to create more boost. On NA cars, however, there are things like pressure wave tuning, inertial scavenging, and of course the sound issue. Na rotaries get very loud with an open exhaust, much louder than a piston engine would.



I am going to use a Racing Beat header but my stock main cat and cat back on my street ported S4 Na engine.

Thanks for the feedback guys!

Sorry for the hijack but that car is unbelievable.. 13.07 with an SP NA, wow!

thats the first i've ever seen that set up as well... (intake) could i pull that off with my T2? and with just a cone filter am i going to be worried about fuel cut of with out the FCD?

Isnt the car heavily weight reduced? something that will get attacked on rx7club as not being a street car?

he keeps saying its not s street car



mike

pull the engine, then port the hell out of it. if u have another car to drive in the mean time, porting is definately worth it.