Will it going from a 3.5'' to a 4'' exhaust make a lot of difference in power?

[Brazil]

I currently have a 3.5'' exhaust from down pipe back ''no cats''; What I would like to know is if I change to a 4'' exhaust on my soon to be single turbo Supra will I gain a significant increase of power?

[tooquicktostop]

Don't think it will make much difference on its own, would only become a factor if you are going very big single

[mellonman]

i done a thread somewhere with a link and it has a large affect your be surpised i think it was a back to back test on a 3 - 3 1/2 but still

http://mkivsupra.net/vbb/showthread.php?278633-3-quot-vs-3-5-quot-exhaust-confirmed-results&highlight=exhaust

Edited November 17, 2012 by mellonman
linky (see edit history)

[hodge]

Not at all. You'll only see a restriction if your going for BIG power. 3.5in is ample.

[Brazil]

Interesting read that...! what a massive difference going up 1/2'' made..!

[Brazil]

Is it possible to modify my back box to flow 4''?

[Brazil]

Not at all. You'll only see a restriction if your going for BIG power. 3.5in is ample.

 

Based on the test found here http://www.modified.com/tech/modp-1102-exhaust-test-tech/ they got 40whp difference going from 3'' to 3 1/2''.

[Hartmann]

yes but the test car also moves alot more air tru the engine than a std or bpu supra .. and more air in the engine the the more the recistiance factor in the exhaust comes to play

[hodge]

Based on the test found here http://www.modified.com/tech/modp-1102-exhaust-test-tech/ they got 40whp difference going from 3'' to 3 1/2''.

 

Yeah but your talking 3.5in to 4in. I made 778whp which is around well a bit more at the steering wheel, at 1.5 bar with a 3" catback, 4" downpipe and midpipe.

[Guest Nicholas]

5" ftw!

 

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5" FTW!

[JamieP]

Bigger the better for sure, I tried a 3" exhaust on my supra once, never again, on a 700bhp car id say it lost 100 bhp over the 4".

 

3.5" is a decent size though, on a 600bhp supra it would be fine i think.

[Hartmann]

5" ftw!

 

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5" FTW!

 

show off ;D