I was planning on upgrading my exhaust as my next mod, what do you guys think of this setup. For my downpipe ill get the 3" one from Racing Beat...they don't list it on their web site but im almost positive they make one (does anyone have that part #), im gonna cut the flange off the end of it and slip fit a 3" dynomax high flow cat, followed by a flowmaster y pipe (3" inlet/dual 2.5 outlet) and custom welded cork sport mufflers. Since im not sure how much boost the car is gonna run after this setup i was planning on doing the walbro upgrade as well as rewiring my fuel pump. I was also thinking of pulling the turbo and porting the wastegate while i had the exhaust off, how difficult is this? how much boost can I expect with/without the ported wastegate. is this setup even safe to run?

 

umm. i bought the RB DP 3" it was $125 i also bought some 3" flanges and gaskets from RB. i went to muffler shop and had them make me a custom 3" midpipe to go from rb dp to stock catback. you will probably hit atleast 10psi with full exhaust. personally i would go with a single full 3" exhaust. i love the exhaust. right now i have stock catback so its super quiet everyone thinks my car is stock ! just call racing beat directly to order the parts

 

Sounds very very similar to what I will be doing. Thunderfabrications sells a combo 3" DP/MP for like $175. I am going with that, changed my mind from the corksport dp & mp. I have the fcd in the mail and the fuel pump. I already got the intake. Hmm...sounds like we are going to be doing the same things here Why don't you try it first and let me know if your engine goes jk man, keep me informed on how things go though.

 

I totally vote for porting that wastegate! It is a bit of a bummer to pull the turbo to port it; I did mine because the shop broke 2 of the 3 studs taking the stock downpipe off and pulled the turbo to have it helicoiled anyway. I used SS nuts and lots of high temp anti-seize when I reassembled it. When I went to remove it 6 months later I just had to "crack" the nuts loose w/ a wrech and was able to remove the nuts w/ my fingers!! from above the car w/ everything but the heat shield in place. Hint, use SS nuts and anti-seize when reassembling!

 

What exactly did you notice after porting the wastegate? How much boost were you running before/after? Quicker or slower to max boost? Thanks.

 

I got the RB downpipe and presilencer with a Corksport single catback exhaust. Expect to be hitting around 10-12 lbs of boost. UPGRADE the fuel system (pump and injectors) otherwise, you'll be running lean, especially if you have intake too. 720cc injectors are good because they're drop in. Mine are on their way.

- Kevin

 

I don't expect to be running lean without the injectors though. I am going to keep the stock catback on for a while and will have the s-afc to tune a little rich on the high end. If I do start to run a little lean then, on goes the stock intake box I do figure I'll be fine with fcd, dp/mp, intake, walbro fuel pump, and s-afc though. I am planning on waiting and getting my 720cc injectors and then a catback. And then....

 

You should have that single N1 anyday now too I think you'll be very happy with it.

Dont use a standard cat for a piston car our exhaust is much hotter than that of a conventional engine. It will melt the cat adn plug it up then you'll be replacing the cat again. I have a 2.5 high flow bonez on my (totaled) 87 I think they make a 3" version too. I got mine through rotary performance www.rx7.com. check out their sight for more info.