i'm planing on being boosted soon on a 5.8psi turbo would i be better with 2.5" exhaust or 3" exhaust? i mite go larger psi later...somewhere around 7-10psi

 

2.5 is fine for both psi lvls, 3'' would work too.

you might see slight high end gains on the 3'' at 5.8psi, moreso on the 7-10. but nothing very noticeable as you arent really maxing out the 2.5'' exhaust untill 10+ psi.

 

I run the ptuning 3inch turbo back and even at 6.5 psi there was a huge difference between 2.5 and 3 inch

 

agreed

 

how huge? i was always told 2.5'' wasnt near maxed out untill 350+whp

 

Bout 500 rrpm faster spool. And a noticable difference in pull.

 

3" FTMFW!

 

ahh good deal

 

i have 2.5", but im a ricer.

 

i mean im NA****

 

me too i feel greater pull on the 3" over the 2.5", just waiting on my 3" dp and spipe and i will hit the dyno

 

ok so the kit i'm buying comes with a 2.5" downpipe...can i go with a 2.5" s-pipe and then 3" the rest of the way?

 

i got a 3'' dp to 2.5 inch back exhaust... waiting on retune

 

so if your downsteping on the pipes then if they get bigger as they go it shouldn't hurt anything right?

 

Read here:

https://www.scionlife.com/forums/viewtopic.php?t=246080

 

I have a 3" piping from the turbo back ^^

<3 it

 

thanks for all the help...i'm not sure the exact specs of the turbo i'm getting but i think i'm going to go with the 2.5"downpipe thats on it then 2.5" s-pipe and 3" the rest of the way

 

It's nice to see that you are doing research and asking questions. We have a good write up on this topic here:

https://www.scionlife.com/forums/viewtopic.php?t=212939

This FAQ is written about our 3" exhaust systems, but applies to turbo exhaust sizing in general.

 

i had actually read that earlier today...i always try to do my research...get the most outta your money that way