Looking for a CHEAP S4 Turbo downpipe. Have my eye on Corksport, but rx-7store.net has a Racing Beat one for $90



Also since I'll now be running a Turbo, can I run it without a muffler? Okay don't laugh.... I know Rotaries are LOUD... and I know a Turbo will quiet it quite a bit, but would it be streetable (I ran my Supra with just a dump tube and loved it).



Project Zuki is getting a Turbo transplant... Looking for a cool hood scoop if anyone has any ideas? (Thought about a WRX STi type)



Thanks guys!

 

the problem with changing the exhaust on a turbo is not a question of being "streatable". you need to worry about over boosting. turbos work off of exhaust back pressure. the faster ur exhaust is flowing, (ie. downpipe, or no muffliers) the faster ur turbo will spool, creating more boost. if your engine runs lean, you will blow your engine. take great precaution when modifying the exhaust of your rex, if its turbo.

 

i love my RB 3" dp its awesome. you are gonna have to make it custom anyway



if you put a mid muffler and a rear muffler it should be acceptable as far as loudness

 

Once, while I was putting my exhaust together, I ran the car with just the downpipe, hi-flow cat, and a 45 degree turndown. I drove it a few miles just for the hell of it. Let me tell you, it was loud. Not too bad at idle and cruise, but when I got on it, she roared. If I had passed a lawman, he would have bagged me for sure, and I live down here in the Land of Loud Cars. At the very least, you'll have to run one muffler, and that's if you can stand a little cabin noise.

 

i'm not shur about the more boost thing.. I agree with the fast spool thing. I not shur about the high boos is why ? If the wastgate is in good chape is not suppos to get more than 5.5 psi, no ?? could you elaborate more on this ?



thanx



chicoutimi

 

its a boost spike the boost will come on faster than the wastegate can react to it.. this can cause your engine to lean out..I saw this when my subie was turbo and I ran a cat...when I removed it I would spike at 7psi instead of only going up to 5psi...and that was under hard accel.

 

Yes. Less restriction in the exhaust will enable the turbo to push higher boost pressures. The stock wastegate, particularly on S4 TII's, can be overwhelmed by the extra flow. It's called boost creep, and it can kill your engine! You should definitely do your homework before you begin modding, especially with a turbo car.

 

i'll sell you my old S4 down pipe.



it's only 2 1/2" ID, but i'll give it to you for cheap, say $35 shipped?