Will the mugen exhaust be sufficient if I'm running the greddy turbo kit with the factory boost setting? Should I also change the downpipe to 3", because I heard that the diameter is very small on the Gredd kit.
I'm just running on 6psi. So I should change it to 3"? I'm thinking of getting the HKS titanium muffler, then do a custom piping. What about the downpipe?
I think 2.5" piping w/ a Apexi N1 is good for 6psi. The Mugen exhaust has the double loop which is good for NA but hinders the removal of exhaust gases for FI.
Are you never going to turn up boost? If not, then 2.5" downpipe and either a 2.36" or 2.5" exhaust should be fine. If you think you are going to boost higher later though, you may as well get the 3" exhaust now. Is the AC in the way if you get a 3" downpipe? I know I can't do 3" without losing my AC.
Originally posted by mugenbb6 Will 3" cause me to lose some power on 6psi?
yeah, in your case you would have too little back pressure. B/c due to the large piping, your exhaust gases won't flow out as fast for 6psi. 3" is too much for the JRSC.
Why not? I had it on my lude with a JRSC and it was fast... dyno'ed 227 hp @ wheels..
The manual for JRSC says to use a catback system with there setup... Maybe its bad for turbos but JRSC seems to run fine..
Keg
That's becuz a turbo runs off of exhaust flow...so the theory is that a freer flowing exhaust will help spool the turbo faster and less heat will be pushed back up into the motor. With a JRSC, especially at 6 psi, the blower is not exhaust dependent and the back pressure with only 6 pounds is not likely to affect your power as much. The mugen exhaust scavenges well, looking at the loop design. Scavenging is a bigger factor for FI to an extent, but diameter eventually takes precendence depending upon how much you are boosting, etc. The exhaust flow from a JRSC is a more progressive increase in flow, whereas in a turbo setup the exhaust will come in large bursts while in boost, where the scavenging benefits are marginal and diameter is more advantageous.
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