What size should I go with??? (Exhaust)

[rs4rush]

So it comes the time that my car is almost complete! All that left is to finish my exhaust. So here is my mod list. I want the most potential out of my exhaust while still keeping it legal. What do you guys think? What do some of you run with a similar set up? Also what diameter of the piping do you use? What high flow cats have worked out best for you? Much appreciated ~Cory


Induction:
Precision GT4088 turbo
Heat Coated Turbonetics racegate(vented too the atm)
Full 2.5" custom hardpipes
Turbonetics godzilla BOV
NPR intercooler
10" K&n intake

Fuel:
Walbro 255lph
Aeromotive fpr
Siemens 720cc fuel injectors
Autometer cf fuel pressure gauge
New fuel filter

Exhaust:
RPS headers
Boost logic turbo blanket
Custom down pipe

Engine:
Greddy metal head gasket
ARP head studs
act clutch
Stock block
Stock valvetrain

Electronics:
HKS vpc 550 chip
apexi safc 2(black)
Aem wideband
HKS turbo times
Autometer water temp gauge and boost gauge
Greddy Profect B 2 Boost contr.
Brakes:
suprasport brake package :}

 

[MK3Brent]

I'm using the same turbo, and I run an open 3" downpipe.

Should be fine.

I'll go 4" once I go GT42R.

 

[BorHor]

3" should do

 

[SupraOfDoom]

BIC 3.5". Randy makes awesome stuff.

Or ETS's 4". Turbo's love to breathe.

 

[theKnifeArtist]

well, you can't go too big, so just make sure you don't go too small
i vote 3.5"

 

[foreverpsycotic]

3" is just fine for that turbo.

 

[sneakypete]

what diameter is your downpipe? if im not mistaken, there isnt much point in running an exhaust wider than your downpipe.
also i noticed that your running 720cc injectors and your vpc has the 550 chip. i dont know much about the vpc but isnt the 550chip for 550cc injectors?
-pete

 

[rs4rush]

Ya my down pipe is 3inch I think... I will double check.

 

[MK3Brent]

what diameter is your downpipe? if im not mistaken, there isnt much point in running an exhaust wider than your downpipe.
also i noticed that your running 720cc injectors and your vpc has the 550 chip. i dont know much about the vpc but isnt the 550chip for 550cc injectors?
-pete

The vpc will work with the 550 chip while running 720 injectors.
People like Genna and others from 7mpower.com have done this.

All that's going on is a difference scale for the converted karmen vortex frequency from the map sensor. If you also have an AFC, you just have to take out more correction.

 

[sneakypete]

oic... wasnt very sure about that. didnt know if corrections could be made