Ok guys what are yalls thoughts on exhaust.... First off let me say that IT IS going to be straight pipe no matter what size i go... What are the pros/cons of 3" compared to 4"? Yeah ive read my research but this is a big decision to make so it deserves a thread... I was planning on doing 3" all the way back but ive had some people tell me to do 4"...... Why would 4" be a bad idea besides the fact that it will most likely rub in certain places..My goal hp wise will be around 350 to 500hp...Your thoughts/experiences???

3" vs 4" straight pipe which is best????

 

Why not have an electric cut out. That way you can have a 2.5" exhaust with a resonator, muffler and simply with a flick of a switch the exhaust will flow better.

If you don't want that 3" exhaust will be plenty. I was making 345whp at the wheels with a 2.5" exhaust on my supercharged setup.

Regardless if your going with a straight pipe setup its going to be hella loud, you will get annoyed quick unless its a track/drag car only.

 

3Inch cause 4 won't fit over the axle

 

Yeah i dont mind the loud sound of a turbo maxima spooling and heck i ve been running it with open downpipe so i doubt it would be louder than that... I had 2.5" on there but man i dont think its letting my turbo breathe much..... Thats why i want to do 3" all the way. I think it would sound good and let my turbo breathe i do plan on getting a cut out for when i want to run open downpipe

 

I think you'll be fine with 3". It really depends on your power goals though. You say between 350 and 500hp but thats a big difference. Which is it?

For N/A cars, bigger isn't always better, but for turbo cars, it is (downstream from the turbo, at least). 350-450hp, 3" will do fine. 450+, 4" would be better, but you can get away with using a 3". The idea is to reduce the amount of backpressure downstream of the turbo so the compressor wheel doesn't have to work as hard to make boost....and that's generally the goal; faster spool!

Hope that made sense

 

i can't imagine fitting a 4" pipe in the max without some serious rubbing. Not even sure if it'll even fit with all the turns in the back over the beam. 3" gets tight and tricky to clear.

as far as HP, "smoothmax" seemed to cover it pretty good.

4" straight pipe will be extremely load and annoying IMO.

 

Well said sir....Well said.. I appreciate the input...Does anyone know of a Turbo Maxima running straight pipe (besides mine soon to be)...lol

 

I had a 3 inch exhaust from the y-pipe back. No cat only a straight through resonator.

 

Why limit yourself with 4" why not go 5" ?

 

Stick with 3" there are people making lots of power on 3". As long as all turns are mandrel.

 

I made 374whp on 7psi with a 2.5" exhaust (open wastegate)

 

Im hoping to atleast make the samee

 

Details on your setup?

 

3" is all you need. you only need 4" if you're getting really serious, doesn't sound like you need that much exhaust flow. bigger is always better when you're talking about turbo, but I don't think you will see any appreciable gains at your planned power level, you would mostly just be adding packaging complexity and cost.