Exhaust sizes

[dub be good to me]

i've found that 2" exhaust on a petrol mk1 seems to be about hte biggest to go without losing some midrange on a stock cam. i think a well tuned and high revving engine could benefit from something bigger, but it all depends what your doing... for a roadie, i'd stay to about 2".

Been doing a bit of searching and have come up with a few more q's...

Mandrel Bent (method of bending without reducing diameter)?
Is it worth going mandrel bent on a 2" system (+extractors) for a road mk1 (1.8 NA)?
As it is only NA*, is the improved flow considerable? Does this improved flow result in a loss of back pressure and subsequent torque (remembering it is only a 2" system)?
*Mandrel seems to be recommended for forced induction, head/cam work etc.

Stainless?
From what I've read stainless seems to be a waste of $.. if mild steel is going to take 20yrs to rust out, its probably not worth it right?

Resonator?
As a noise reducer it works by bouncing sound waves back upon each other, does it reduce flow that much?

P.S- Because I'm getting the 268 cam, I'm going with a 2" mandrel bent, mild steel system with resonator (+extractors)... happy to be corrected if this is a bad idea though

[Golf Loon]

Spyda. Mk1 and Mk2 extractors are totally different. They willl not interchange.

Find out which they are before continuing.

[Spyda]

Been doing a bit of searching and have come up with a few more q's...

Mandrel Bent (method of bending without reducing diameter)?
Is it worth going mandrel bent on a 2" system (+extractors) for a road mk1 (1.8 NA)?
As it is only NA*, is the improved flow considerable? Does this improved flow result in a loss of back pressure and subsequent torque (remembering it is only a 2" system)?
*Mandrel seems to be recommended for forced induction, head/cam work etc.

Stainless?
From what I've read stainless seems to be a waste of $.. if mild steel is going to take 20yrs to rust out, its probably not worth it right?

Resonator?
As a noise reducer it works by bouncing sound waves back upon each other, does it reduce flow that much?

P.S- Because I'm getting the 268 cam, I'm going with a 2" mandrel bent, mild steel system with resonator (+extractors)... happy to be corrected if this is a bad idea though

I don't think the extra cost of mandrel bent is worth it when compared to the gains.

Spyda. Mk1 and Mk2 extractors are totally different. They willl not interchange.

Find out which they are before continuing.

Is that to do with clearing the p/s stuff or because the head is different?

And what about fitting it the 1.9 SD motor?

[dub be good to me]

I think Loon is referring to a clearance issue.

I'm running a Mk2 engine with my Mk1 manifold (only until the extractors go on) and it fits up np...

[Jarred]

..

P.S- Because I'm getting the 268 cam, I'm going with a 2" mandrel bent, mild steel system with resonator (+extractors)... happy to be corrected if this is a bad idea though

It sounds good to me Simon. Same thing that I had on my 1.6L. Slightly oversize for a 1.6, but should be a good combo for a 1.8.

the main part where a golf exhaust is 'squashed' is when it goes over the rear beam.

If I was building something a with a little bit more poke, i'd consider getting the rear section mandrel bent, but it would have to be worth the extra money. realistically, on our cars at least, something like that would only be worth an extra ~2kws imo. (if you're lucky)

[velly_16v_cab]

i run 1 3/4 pipe on my sportline back in the uk.
it coped with the 170 bhp i used to run,

my mate who tunes 16v's swears by 2" pipes (but he is pushing out almost 200 bhp)

[dub be good to me]

It sounds good to me Simon. Same thing that I had on my 1.6L. Slightly oversize for a 1.6, but should be a good combo for a 1.8.

the main part where a golf exhaust is 'squashed' is when it goes over the rear beam.

If I was building something a with a little bit more poke, i'd consider getting the rear section mandrel bent, but it would have to be worth the extra money. realistically, on our cars at least, something like that would only be worth an extra ~2kws imo. (if you're lucky)

It does sound good, I had it done today
Was a little bit extra, but decided i'd outlay a little extra and be happy enough if I went with further performance upgrades (cam or head or forced induction etc..)
-I got a mild steel 2" mandrel bent system with flexible joint > resonator > muffler
-I also had mk1 extractors fitted which required a little bit of modding (touch of grinding as flange was to big) to fit up under the mk2 inlet manifold - Sypda, this is prob what Loon was talking abt
+ added dtm - aka rain catcher - exhaust tip (twins FTW!)

Not including the tip and extractor muck abt, the exhaust setup cost $480 from Ringwood Performance Exhaust.. if you're coming for a night cruise you can check it out

P.S - I have a 1 7/8 inch (non-mandrel) bent exhaust tube (one tube with the two bends required for a mk1 golf) if anyone wants it?