2.0 8V Turbo Exhaust

[aarontrophy 26]

Hi guys,

 

Is 3 inch system from manifold all the way to big?

 

Cheers

[welshpug 1,627]

depends on power level and turbo size, I would imagine 2.5" would be more suitable.

[mang 3]

I run a 2 3/4 looks good sounds good power level great :-) I know people the use 3" fine

[P2trick 0 1 Cars]

if used 2,5" perfect for this kind engine

[stef205 91 1 Cars]

its more about flow rather than diameter of piping, i use 2.5" with 3 highflow boxes.

[mang 3]

2.5 is no good if you want to run alot of power just get the 3" doesnt matter if its to big and then you know if you do want to run silly power you can :-)

[stef205 91 1 Cars]

Absolute rubbish this has been discussed loads of times on here. Matt on here was/is running almost 400bhp on a 2.5" system on his 180 charged engine.

[kuuner 56 2 Cars]

Yeah, but 400 bhp with a 2,5" is too small. Is the same as you breathe trough a reed. You get enough air in order not to die, but you will not breathe easy. Try to fit a 3" exhaust and you will notice that the turbo spools up quicker and probably produces the same bhp at lower psi.

 

For what I know is 2.5" adequate to max. 250~300 bhp. That's what they adviced me for my set-up. If you're on the max. you could consider to mount a 3" downpipe and go to 2,5" in the middle. The exhaust gases cool anyway.

[mang 3]

All I can say is good for matt thats not how I would run my car considering the mass of uneeded back pressure

[welshpug 1,627]

mass of uneeded back pressure

 

which is not there because he has specified the correct size for his application, not built a fart cannon, with good reason as its a track car and needs to be a sensible volume.

[Tom Fenton 1,526]

I think in actual fact he took off a 3" system to replace with a 2.5" system.

[kuuner 56 2 Cars]

for better noise reduction, but not better for the turbo spooling up.

 

http://www.tercelreference.com/tercel_info/turbo_exhaust_theory/turbo_exhaust_theory.html

[Henry Yorke 269 3 Cars]

Matts was supercharged though, not turbocharged, so the back pressure would have less impact on the turbo and the scavenge effect is needed more

[kuuner 56 2 Cars]

Ah okay, i missed that part.