1.2 Exhuast/Manifold

[joesturdy]

Don't really know much about exhausts on Novas so am after some help.

I've got 1.2 Merit and am going to buy a competition exhaust. The first thing I've noticed is that they all seem to be for 1.3/1.4/1.6 engines, just wondering what the differences are and whether I'll need to be a new manifold & downpipe for mine? Will all small block manifolds fit on my engine and if so do I need a 4-2-1 or a 4-1?

Maybe looking at something like this:

http://www.ashleyexhausts.co.uk/vauxhallopel-nova-sr-2-twin-box-exhaust-system-3-single-stainless-steel-tail-pipe-avxs1_p1411239.htm

Any help will be appreciated!

[mowgli]

all the bigger ones fit straight onto a 1.2.
you can get a good improvement over std just by fitting a 1.3 4-2-1 manifold & downpipe, and match the exhaust, & clean up the 2-1 bit. ask c612*** he is the master on this sort of thing.

[joesturdy]

Cheers for that, will have an investigate! Found this but it says it's to be used with a 4 branch, is that just recommendation or will it not fit anything else do your reckon?

http://www.eurorallye.co.uk/product_info.php?cPath=8_9&products_id=192

[mowgli]

the thing is this.... the same bore factory exhaust fits the 1.2 (55hp) & 1.6 (100hp).. unless you are going stratospheric on the tuning, you really don't need a costly exhaust, just replace the crap 4-1 manifold with the 4-2-1 std 1300 one. a decent straight thru back box will release a few extra hp, but even if you do a 4 branch, it won't gain useable hp for road/rally usage.

[joesturdy]

Sounds good to me, I'm not too bothered about performance if I'm honest, just want a replacement for my rusted up standard exhuast with a cat, thought while I'm at it I might as well upgrade a bit!

One last question, should I get specifically a 1300 one or will 1400 be similar, if not the same?

Cheers for the help

[paul james]

Based on previous discussions and my own experience, the standard 1.3 4-2-1 manifold is better than the 4-1 manifolds you can buy new. You can get aftermarket 4-2-1 manifolds though, but they are quite hard to find. I would get a 4-2-1 manifold, 1.3 or aftermarket, and get a secondhand system to mate it to, stainless Magnex systems are up for sale a lot.

[joesturdy]

I'll keep an eye out for one! Thanks

[paul james]

rusted up standard exhuast with a cat

I didn't see this when I replied. Keep in mind that if you ditch the cat and don't put another back on, you may well not pass the MOT. Not just on the fact that its visually not there to test, but your emissions could be too high without one. Back in the day I replaced the cat on my 1.2i with a straight through 1.2 carb exhaust section and it shouldn't have passed its MOT due to emissions.

[joesturdy]

I was under the impression that because it was pre 1993 it didn't need one?

[paul james]

I believe its from 1992 when cars required a cat actually, and even if the tester ignores the fact the cat is not there, you still have the emissions test to get through.

[joesturdy]

It's 91 so hopefully that shouldn't be problem, emissons-wise I think I'll risk it and keep my old exhuast with cat to slap back on if it needs re-testing

[moffat]

if its a 91 nova then it wont have a cat anyway... ive got a 92 nova with no cat :)

[mowgli]

is it carb or spi?

[joesturdy]

Forget that, it's a 92, not sure what I was thinking earlier! It's spi

[moffat]

must be a late 92 on a k plate to be a spi, so will have a cat