mk1 golf 16 exhaust manifold..

For good power, you're looking for 4-2-1 ideally, and long, smooth merges of the pipes instead of a stubbly little pyramid. Having said that, I've just gone an ordered an Ashley manifold and full system!

It would be hard to tell the specific power gains on a Mk1 because you can't do a comparison test with the original manifold (because it doesn't fit). Also you have to bear in mind, you've also removed the cat (probably) and I'll be running a different cam and other mods which should gain me a bit more power.

The 4-2-1 set up is by far the best manifold type as it produces the best pressure waves back through the exhaust to the valves and in laymans terms it creates a vacum around the exhaust valve of the next cylinder about to start its inlet stroke and during the valve over lap period assists the expelling of the last of the exhaust from the combustion chamber.

But none of this happens properly unless the manifold is fully tunned to your engine. The lenght and diameter of the primary and secondary branches are decided by your choice of camshaft, capacity, and where in the rev range you want the manifold to be most efficent.

The last manifold I made was for a 4.2 v8 and had 36 inch long primarys and these were shorter than needed as finding space for 24 foot of inch and 5/8 pipe is hard work.

For completeness , if you want a 'standard' manifold, there is the option of the Scirocco 16V manifold should be mentioned, they dont normally come up as they're 'relatively' rare in the UK.

Having said that….you can buy aftermarket Rocco 16V Manifolds in the states…

http://www.eurosportacc.com/mk1headers.htm

Damn good price as well, with the current exchange rate its around ?180 (plus obviously very expensive postage…)

i like the look of that manifold, searched it up after seeing it on that white mk1 jetta that i also loved. yeah the prices for postage are stupid, i went to order it recently then found out that the hard way.
but other than that…
Finally a 4 branch thread that has actually been useful!!
ive spent so so so many hours over the last week looking on the net for info about manifolds and this is the best thread around.
It looks like i will be going for the storm one asap.
i hear and have seen lots of pics of he ashely being cheap and not fitting any car, other than one.
Will let you know if/when i get it and how well it fits on mine also.
thanks again everyone.

oh also, does this manifold fit the 9a engine? or is it for the kr? or are they the same?

9A and KR are the same the supersprint will fit the ABF as well and the ashley will fit it if a suitable spacer is put betweent the head and the manifold or the pipes can be lenghted a bit if you have the wear with all to do such a thing.

regards
rich