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so what BHP can I expect
austin man - 13/7/09 at 09:54 PM

1.8 litre silver top zetec, 2 litre cams pair twin 40's, K+N filters, standard cast manifold ??

200mph - 13/7/09 at 09:58 PM

135-145, with more once you ditch the manifold

Steve G - 13/7/09 at 10:04 PM

Standard cast exhaust manifold?? As above, 135-140bhp with your strangling exhaust system. 160bhp when you upgrade to a "proper" exhaust

will121 - 13/7/09 at 10:11 PM

take it they are 130bhp cams? im going for 140-145bhp are you going to get it on a RR to prove us right or wrong?

austin man - 13/7/09 at 10:12 PM

so you think the manifold is that restrictive ?Whats the GBS manifold like any good, as the car has been built on a budget dont want a £500 manifold on a £3k car

200mph - 13/7/09 at 10:15 PM

anything tubular and reasonably unrestrictive will be better - have you seen the inside of cast exhaust manifolds?

Would certainly be the limiting factor in your engine at the moment.

alfasudsprint - 14/7/09 at 08:15 AM

surely a good porting job on the manifold will help.

cliftyhanger - 14/7/09 at 09:13 AM

I doubt porting a cast manifold will help much, the basic design is errrr basic.
The earlier escort cast manifolds look a little bettre than the late mondy ones, and the focus tubular ones (often about £20 on fleabay) look OK too. I just bought an ST170 manifold (probably as good as ANY aftermarket one, better than most in terms of performance) for £50. May be tricky to use in many cars, not ideal for most locost stuff but wilkl fit my next spitfire with a little cut and shut
For ease the focus one may be good??
Don't be fooled by manifolds that are just chucked together, it take a lot of cleverness and experience to design one, something I suspect many go-faster manufacturors lack. At least OEM stuff will have some proper research/development, albeit with cost reduction added. hence my choice of the ST170, it was developed properly without the mass-produced cost restraints.
All IMHO of course

MikeRJ - 14/7/09 at 09:36 AM

quote:
Originally posted by austin man
Whats the GBS manifold like any good


Pretty dreadful to be honest, the one I have for my crossflow is laughably bad:

Stud holes hugely oversize. Around 5mm I'd guess.
Primary pipes significantly larger than the (undersized) hole in the flange, therefore very large step where they join.
The center two pipes on the xflow are very close together, on the GBS manifold they didn't even manage to weld the middle of the pipes to the flange so there is a large gap joining the pipes together.
Weld quality is just about acceptable on the outside, though a few "hedgehogs" on the inside.

I'm going to chop the flange off, shorten the (very long!) primaries slightly and weld a properly made flange on since the exhaust doesn't fit my Striker very well as it stands anyway.

Jenko - 14/7/09 at 10:49 AM

I would go for 125 with the cast manifold....

Not only are they very rough, but also, the primaries will be too short for good power...

NS Dev - 14/7/09 at 12:35 PM

cliftyhanger's idea of using an st170 manifold is probably a good one if you are pinching the pennies.

You won't get a manifold of any quality level at all for less than £300 new, and £500 for a good one. ( we certainly wouldn't entertain making one for less than £400 )