bick888

Does anyone know if a st170 inlet manifold fit 2.0L zetec? and if it does, is there much gain from doing so?
nice 1

focusrsred

Yes the manifold will fit straight on. You need to get the ST catalytic convertor though if you want to run a cat as it runs underneath then up the back of the engine, instead of down the front like the zetec. Most folks just stick a de cat pipe in and worry about MOT emissions later.

As for power gains I'm afraid I couldnt really give you a solid answer. All I know is that the design is much more condusive to flowing gas, being tubular and y branch, but the length of the primary pipes and secondary pipes are almost certainly arranged to benefit the harmonics set up on the VVT 'Duratec' ST engine. Also without figures for flow rates from both heads it would be near impossible to suggest how the effect on gas velocity, from the increase in pipe diameter, would effect performance of the zetec.

In my opinion, as these are both of 2.0 litre displacement I would suggest there are definite gains to be had from fitting the ST manifold purely on the basis of the free flowing design. A friend of mine fitted one to his 2.0 ESP and he reports that the car does seem more responsive.

Hope this helps.

GTechR

Yup what he Said!!

bick888

Thats brilliant matey

RichieST

iTrader: (2)

hang on mate, didn't you say inlet manifold??

GTechR

Oh yeah... Well spotted!!

In that case, no, no point the ST Inlet manifold is designed specifically to work with the ST VVT system, it has a vairiable inlet tract which alters the volume of the air in comparison to where the valve timing is.

Some people use the flange part to mount Bike throttle boddies on the Zetec head.

Your best bet is to keep an eye on ebay for either a focus central or if your really lucky a Jackson racing ( much better quality) 76mm throttle body, which will mount on the standard inlet!!

STFUN

No, no, no. The DSIM works independantly of the VVT. It normally changes over from the long runner setting to the short runner setting at @5500rpm. Although not designed for the 2.0 Zetec (which the ST170 lump is anyway with some improvements)it can be made to fit. Overall gains however will probably not be that great as the 2.0 cylinder head is not optimised to make best use of it.

pdfbt40

The ST170 INLET manifold has the same port centres and stud/bolt spacing as the standard and RS manifold. However, the runner is much deeper by being higher at the top. The head needs porting to match, particularly for good injector performance. I'm can't remember if there is a problem with alternator clearance. The mounting is lower on the ST170, mainly because of RHS engine mount and clearance needed by the auxilary belt.

As said, the reason for the ST170 manifold is the dual length inlet runner. The change over (also reported as 6000 rpm) is the cross over point of the ST170 engine's torque curves with each different tract length. So as such, the manifold does not necessarily give more power, but widen the useful torque and power band.

Without using the long tract length (its spring default is short) you might move the torque curve higher in the rev range, so a bit more power, but less flexiblity in driving. Also, with the standard management, the rev limiter might inhibit this.

Martin

coxyboi

As said above maybe able to use the electrics to activate the Imrc if it was wanted, would allow the st's throttle body 65 or larger 67