4AGTE exhaust size

[jdm86gtz]

Car - Daihatsu Charmant

motor / part in question - 4AGTE exhaust

problem - What diameter

occurs/started when (if applicable)- not yet

personal situation (if applicable)- I like cake


What size piping for a 4AGZ with T25 from SR20? Going to run on AE101 ecu for now and was thinking of 3" down to where the cat
would be normally but would I keep it 3" all the way back or would there be an advantage in stepping down the pipe size to say 2 1/2" to the silencer box?
Also as a road car I don't want it to be silly loud.
Thanks.

[blinded]

I run a full 3" system in my car with a centre and rear exhaust. Turbo is a KKR330 which is about the same size as a t25 I believe. Also, mine is a daily and I would say the exhaust note is pretty quiet, I'd almost say legal actually!

[Matt]

3" if it'd fit... 2.5" won't choke it too bad, but defo try to get 3"

[FAST EDDIE]

2.5 will do fine unless your making 200kw

[AJPS]

+1 on 2.5

[Vaughn]

There was a thread about exhaust sizes that was for 20v though, but i would expect around the same size. supposed 3" is best

[mfxae86]

im running 3" to my "cat" and 2.5 from there back.... but not by choice. would much peffer 3" all the way.

[SHEPPO3930]

should make the dump and front pipe out of 3", then you can drop it to 2.5" from there to the back. this is fine on one ta22 4agte 20v i know of that makes over 200rwkw on 19psi.

[jdm86gtz]

I got a CX Racing T25/8 to V band adaptor to suit 3" piping which I am going to run down to the cat area.
I was going to do a step down decat pipe and use an AE86 cat back I have here, but then I was thinking I'd just get
a full system made up.
Sounds like 2.5" will work fine so thanks.