What twin turbo exhausts are you running? I'm look for up to 500 who and was thinking preferably true dual - berk h&c's as well. Ideally, not too loud...

Please chime in - thanks!

Josh

 

Currently using a stillen true dual catback exhaust. Not too noisy all things considered.
Ur sig says single turbo is that not true atm?

 

Good eye - I do have the turbonetics single with a modified Greddy EVO2 exhaust - but I'm in the process of getting a built motor and running the jwt 70bb kit so I'm needing advice....

 

Well when I had my JWT BB700 kit I used the stillen true dual. :-)

 

Great thread. I'm in the process of getting all my parts together for a JWT 530tt. I was planning on going with test pipes and single 3 inch after the y. Possibly adding a motor dyne HFC module to reduce rasp if needed. Does any one think a single 3 inch would create to much back pressure.

 

Did you modify your stillen muffler? I read about someone ran into an issue with it being too restrictive. The muffler was the culprit.

 

At the time I was using tomei expreme test pipes bolted onto the stillen true dual exhaust with no modifications that I know of. I'll take a closer look when i get home, good for over 600 whp with that kit and supporting mods. For what the op wants it seems like above average performance without the extra loud noise. I've heard the greddy and hks exhausts in person, yea it's a lot louder than mine at WOT. I'm no expert with the comparative hp gains, just my .02 on noise level.

 

Thanks for all in info guys. I'm having a hard time finding the size I need, well not even 100% sure I know what size I need. If I wanted to up the boost and hit 550 MAX hp... Is 2.5" too small? It seems all the ones I like sound wize are the 60mm Invidia Gemini or the 2.5" Fast Intentions... 2.5" APS... Heck even the Greddy EvoTT... But just not sure now.. guaranteed Ill be tuned in at 495 @ 12psi and then possibly a 14psi tune.

 

Cleared 600whp with tomei 60mm test pipes, stillen true dual exhaust plus supporting mods.
Anything over 19psi ish and you'll run into backpressure issues.
Have to call it ish cuz not every setup is exactly the same. I personally ran into issues around 19-21psi boost settings with a full 2.5" all the way back

 

I had heard some people making great numbers on a 2.5" system so its great to hear that it can happen once again. What size injectors were you using, and any idea where I can expect my 600cc's to max out at?

 

Using DW1000ccs. Rule of thumb is roughly 1cc per 1hp. It'll be slightly lower than 1:1, too many variables but it's a decent beginning. Add roughly 30% of flow if you use e85 though.
So without making too many assumptions the 600s with correct supporting mods should be good for high 400/ low 500s safely. Emphasis on safely because running near 100% duty cycle is dangerous.