Thinking of fitting new exhaust

[Beddo88]

Hi all,

So I'm starting to have enough of a blowing exhaust, (silencers gone) and the downpipes blowing too.

Its possible to repair, but for the price im considering getting a new system, manifold back. Which manifolds are better? 4 into 1, or 4 into 2 into 1?

And obviously the rest of the system needs to match up to the manifold bore size. Do I go for 2" or 2 1/2"? And will all manifolds / downpipes end at the same point so I can attach the rest of the exhaust?

Theres a selection on ebay around £160 (manifolds) and a full exhaust kit for about £200. (jetex 2" bore). Would the two combine? For example:

http://www.ebay.co.uk/itm/VW-SCIROCCO-M ... 608wt_1139 (manifold)

http://www.ebay.co.uk/itm/110581114342? ... 1034wt_901 (exhaust system)

Cheers,
Dan

[jon89gt]

depends on what your after 4-1 gives you better top end and 4-2-1 gives you better low and mid range.

think 2.5" is a waste if your not running over 150bhp, so i go for 2"

jon

[The Autoad]

If you must buy a 4-branch then get one with a flexy joint, otherwise cracking is an issue as it ages. Get some opinions on which of the ebay four branches fit easily, as some can be hit and miss.

Personally I would go for a mk1/mk2 >84 six stud manifold and downpipe, then a Jetex 2". A nice system with no issues.

[Beddo88]

Sounds like a plan, the "2 is the cheaper system by some margin too. Surprised by the prices for a complete manifold back system too. Now to find somewhere to store the little fella so I can strip it down....

[Roxylife]

depends on what your after 4-1 gives you better top end and 4-2-1 gives you better low and mid range.

think 2.5" is a waste if your not running over 150bhp, so i go for 2"

jon

2.5 inch is enough for well over 200bhp..

2 inch will be MORE than enough for a std scirocco is mild states of tune....

2.25 inch for a relativley spicy 2.0l is enough..

With regards to manifold design, that advice is not strickly true. Pulses, flow, volume, priamry and secondary length, collector design are all factors of manifold design. There is no rules to what generally works, its so difficult without back to back RR tests and calibrations to determine such a conclusion.

The standard 6 bolt cast manifold wont 'cost' you any power in standard form, but will be a much better fit and more reliable than a 4 branch for daily use... A ported standard 6 bolt manifold with a decent 2 - 2.25inch system with a couple of boxes is what I would go for in this instance.