best exhaust for c20let

[tony k]

whats the best size exhaust for a c20let nova as might make my own one just want to know the best size

[kevster]

3.5" bore

[Adam]

3" is fine for about 300+ hp.

For a std Let, 2.5

[R1CH]

3.5" bore
What ?

I'm running a 3" downpipe with a 2.5" system on mine (2 silencers), running jut shy of 300bhp without any probs.
TBH if i was gonna do it again then i'd go for 3", with just the 1 silencer (back box), not as loud as you'd expect it to be !!

Rich

[tony k]

cheers peeps i was thinking a 3" one but just wanted too make sure would my back box be ok as its 2" i think might be 2 an half

[Philsutton]

Im running a 2.5 inch bore system on mine an still pulled 127mph on the standing 1/4.

But 2.5 inch for standard and 3 for anything more, but if you fit an external wastegate then you can run a smaller exhaust.

[tony k]

i was going to buy one off gazz but its only 2 inch im running internal wastegate

[R1CH]

Not big enough really, you want at least 2.5", you'll be best changing your back box so its the same as what ever system you get.

[tony k]

cheers fella just waiting for a rear gearbox mount then order the pipe so i can get making one up the fella round the corner has a pipe bender

[R1CH]

Unless he has a Mandrel bender then i wouldn't bother, just as easy to buy some pre-formed bends and some straight pipe, you can also create bends by cutting angled sections ... like a lobster back.
3" system is very tight on a Nova, especially where it goes around the gear lever.
Have fun !

[kevster]

sorry guys only saying 3.5 as most turbos we have come in to work rich makes there system 3.5 bore s/s
i am now think hes not doing it right lol
saying that i think tommy is running 3.5 with just a backbox kicking out over 300bhp

[tony k]

im going to be runing between 300 and 350 so a 3" one would be ok with that brake

[Dar]

I also think that if your running an exhaust system 2.5" or over on a Nova. It is well worth putting an internal gear shift in to give you more room underneath. Its very tight in that area even with a 2 1/4" system.

[Jack]

I'd have thought a 3.5" system would give problems with boost creep, unless there's a decent wastegate or restriction just after the turbo.


It is well worth putting an internal gear shift in to give you more room underneath
I was half thinking about putting a cav gear lever on my saloon at some point. is it essentially just a case of mounting the cav lever in the car, cutting a hole in the bulkhead and lifting the nova linkage through to the cav item, or is there more to it than that?

[Dar]

In a nutshell yes. There is a bit more cutting and welding involved, but thats about it. I will look to see if I have the right piccys to make up a decent guide.