Can somebody explain to me why a 3" exhaust would make a difference when your turbo outlet is only 2.5"

Think of your exaust as a straw. If you have a 2.5cm straw and you blow through it your mought opening is still gonna be the same as if you had your mouth on a 3cm straw. But with the 3cm straw your going to still be able to blow more out at a time.

u can run a 2.5 exhaust,it will spool up faster but a 3 inch is better,less back pressure and breathes alot easeir.u get more air flow..im not real good with expalining it.but usaly every one uses a 3inch exhaust..

If the turbo can't expel the gasses fast enough out of the turbo, then it chokes off. The larger the exhaust the better flow and the less the turbo has to PUSH the gasses out, they will just flow.

Brent

u can run a 2.5 exhaust,it will spool up faster but a 3 inch is better,less back pressure and breathes alot easeir.u get more air flow..im not real good with expalining it.but usaly every one uses a 3inch exhaust..

Why 2.5" will make the turbo spool up faster?
I tought 3" will make the turbo to spool up gradually, instead of like an on/off switch at around 2900rpm....

the less back pressure on a turbo motor the better. figure your turbo is basically the last point for back pressure so run the biggest exhaust u can.

with that being said run a 3 inch inlet and at least 3 inch outlet on your muffler.

stratton.

where does this 2900rpm come from? Every turbo size spools at different rates, and depends on mods. Larger exhaust to get the most power from your turbo. Small exhaust chokes it off and limits the turbo. I think the difference in spool (if at all) is negligable on this.

Brent

where does this 2900rpm come from? Every turbo size spools at different rates, and depends on mods. Larger exhaust to get the most power from your turbo. Small exhaust chokes it off and limits the turbo. I think the difference in spool (if at all) is negligable on this.

Brent

I said that as an example of my personal experience with the T25...

Imagine a large room packed full of people. The building is on fire and everyone is trying to leave.

There are two doors. Both have an opening 2.5 feet wide. One door leads into a hallway that is 3 feet wide. The other leads into a hallway that is 6 feet wide.

Which door would you rather use?

the hot air coming out of the turbo cools off and gets bigger and slower its a molecular thing. thats why it can come out of a 2.5 and make more power going into a 3in

it is said that you can go too big, but its not something you have to worry about. basically the air in the back of an exhaust that is too big will cool off expand and slow the hot air down making more back pressure

the hot air coming out of the turbo cools off and gets bigger and slower its a molecular thing. thats why it can come out of a 2.5 and make more power going into a 3in

it is said that you can go too big, but its not something you have to worry about. basically the air in the back of an exhaust that is too big will cool off expand and slow the hot air down making more back pressure

What about a cutout right after the downpipe?

there is no backpressure that way as far as i know

its what i have for my car