2.5" or 3" Downpipe for T28?

[johnfsmith]

I'm about to buy a hi-flow cat and down pipe for my car. I'm planning on getting one of the T28 turbos in the near future and I'm not sure if I should get 2.5 or 3 inch down pipe and cat. Any suggestions? My mods are listed below and I'm not going to be racing.... just a street cruiser...

Injen Intake
Thermal Research 3" Exhaust System
Greddy Type S BOV
Greddy U/L IC pipes
TurboXs Boost Controller

 

[L2RTSiAWD]

3 inch is the best.

 

[99GST]

Get a 2.5" DP mating up to a 2.5" cat.
Having 2.5" will allow for the gases to exit a bit quicker than the 3". If you were to go with a bigger turbo than I would say get a 3".

Again, that is just my opinion.

 

[doug]

I say go with 2.5". And if there's any way you can get away with running a test pipe instead of a cat, that'd be best.

 

[SPEEDY]

Originally posted by doug
I say go with 2.5". And if there's any way you can get away with running a test pipe instead of a cat, that'd be best.

That is the exact set up that I run with my Big28, and it works awesome! On a side note... I have read and heard that this very set up is good enough for 11 sec time slips.

 

[doug]

Originally posted by SPEEDY
I have read and heard that this very set up is good enough for 11 sec time slips.

I have read and heard the exact same thing.

 

[GKing25]

ge the 3''. It's worth it

 

[250lemans]

how about a 2.75 i think the rs.r 70mm judging by my caliper is 2.77 that's what i got it looks good not in the car yet 147 shipped at turbo import