Exhaust size...
 

Im looking to get a turbo back exhaust system and was wondering whats the Pros and Cons of going with a 3.5" or 4" exhaust system over a 3" exhaust system. Because I like the sound of the 4" over 3".

rebuilt 7mgte with forged internals, p&P head, Brian Crower Stage 2 cams. soon to be either 61-t turbo or 71mm turbo. other than that stock

now make that your sig. =)

:werd: k now made

Blasphemy!!!! Just kidding. You spelled "Supra" wrong in your sig.

I would just stick with the 3" piping.. Any bigger and you will have problems sourcing mufflers without having to reduce it into it.. Im running 3" on my MKII N/A and it is loud as hell.. Plus i dont see any benifit in exhaust flow after a 3" unless your running a huge race only car or a cummins,lol..

Agreed. I think 3" is fine....anything bigger is overkill unless you're running some serious HP numbers.

this was the exhaust I was thinking of going with...

http://www.extremeturbosystems.com/T...duct_info.html

well with the new turbo Ima be getting I was gonna be running around 20psi

christ. you should be trying to run 500 hp or better with 20psi..
f it. if you got the cash go bigger. if you can find 4" the whole way out.

"note" I did not look at his current specs. I am not saying running 20psi is warranted for his current build. just stating my opinion.

I found a 4" dp for like $350 and 4" cat-back for like $900 and for 3" dp was like $260 and 3" cat-back was like $700 so its not much more an it sound better IMO.

my goal is around 500hp-550hp for this summer

im sure there might be some minor things that take their tole by using a huge exhaust.. gass milliage or what have you. I THINK the only downfall would be back pressure. but that's for n/a's so nothing for turbo's to worry about.

well I been reading up on another Supra forum site 2day and they were saying will lose low-end TQ but will gain top-end HP and can run more boost due to the better flow and Turbos work better with less back pressure, back pressure is only needed for n/a cars

yea i know.

The only downside I could think off would be clearance; if you have lowered the car, 4" exhaust might bottom out easily. Just a thought.

yeah that sure is true mine is lowered and my 3in cat has a few scrapes on it already

the cars sits on stock springs and 17" rims with 245/45/R17 front and 255/45/R17 rear

im running a 4.5 megan on my supra and it idles very low yes it does get loud when i get on it but its deep and sounds amazing.

U just running that size muffler? Because Im looking to run a 4" from the turbo back

yeah it has a very deep tone to it, i took out the cat and just ran a straight pipe, muffler was only 90$ i dont buy full set ups because i dont want to pay that much for some chrome pipe.