What size exhaust for 2.8TD Rocky?

[tehekho]

OK, so this is a double post - but I'm thinking that I may not be getting enough exposure in the daihatsu sub-forum...

I cut out part of the exhaust in the rocky the other night to ease re-fitting of gearbox. I had intended on a new exhaust anyway. Now I'm after the ideal size to run. It's a bog stock 2.8 Factory Turbo. I've wound up the fuel a little and it hoots along nicely. I'm assuming the factory system is either 1.75" or 2"

Would going 3" just be a waste of time?

Would the most sensible option be to rip off the downpipe from the turbo, go with whatever is closest to that size? The exhaust is going to just be crush bent, so perhaps a little bigger?

I'm not overly fussed about noise as with the turbo muffling everything, its quiet enough as is with about 1 foot of pipe and a bend...

[lay80n]

I had a 2.5 from the turbo back. Anything less is not a great improvement from factory.


Layto....

[tas80]

Yep, I also had 2.5" from the back of the turbo

[tehekho]

OK - I went and saw my mate in the exhaust shop last night and he suggested a 3"

But that will be with a custom dump pipe also as to not make a restriction somewhere...

So I'll be getting the flange soon and starting to bend metal it seems!

[DIRTY ROCK STAR]

3inch for sure.

[bazzle]

Only the 1st couple of metres matters, as the gas cools along the pipe it shrinks. A smaller pipe at the rear will keep velocity up and help scavenging.

Bazzle