hmmm inlet manifold question........?

[paulwakinshaw]

Hi Chaps

I have been buying bit's & Pieces for my S1 for a while now and I have nearly come to the end of the road in terms of "bolt-on Bits" for my engine. Nest step is cams/ecu etc... All I have left to do is change the exhaust manifold for a free-flowing one.

One thing that I know nothing about however is the inlet manifold. I see from the PTP website that even their most basic kit (PTP 140) gives you a new VVC style inlet manifold. What I want to know is this, will it fit under the aluminimn engine cover i.e early S1? Is it easy to remove the old one/fit new one? will i need and special tools etc... etc...

Have any of you guys fitted one too? I know that the new one will be a little less restrictive so will give the possability of a little more power, but I'm not expecting any earth shattering power gains

Any help is most appreciated.

Wako

[djroadboy]

The VVC plenum won't fit under the early aluminium engine cover without modifications. There are ways and means of making it fit. I wouldn't think it will make any difference on its own but if you are going the cams/ecu route without the expense of throttle bodies then its a good buy.

Fitting it normally involves grinding some material off the top of the plenum and also modifying the engine cover. However, I have seen a Caterham with a VVC lump in it. I believe the plenum is a two-piece affair and he skimmed the flat joining surfaces to reduce the height of the plenum when fitted. This is the neat way to do it but it does reduce the capacity slightly.

HTH

Dan

p.s. If you find a second hand plenum try and find one for me while you're on!

>> Edited by djroadboy on Thursday 14th October 16:26

>> Edited by djroadboy on Thursday 14th October 16:26

[reAnimate]

Unless the plenum is matched to the ports in the cylinder head, you will lose torque and power.
Spend your time cleaning up the insides of the plastic inlet man you have now you'll get much better gains.

[steff]

I've a lotus 135 upgrade on my S1 which uses the VVC plenium and its got an aluminium bootlid with no clearance problems.

[bogie]

as per reanimate - its been proven that ona std engine then more gains are to be had by cleaning up the ports/deflashing etc on the plastic manifold rather than fit the VVC one - you tend to lose torque with the VVC one......and then for a non std engine (ported big valve head, cams etc) its better to ditch the manifold and go with throttle bodies instead.....

[paulwakinshaw]

Thanks for all the help chaps.

It looks like i'm gonna stick with the plastic one then, I will get some advice from DVA when the time comes for the mods and see what his thoughs are too.

Has anyone actually de-flashed their own manifold then? I guess its just a case of removing small pieces of plastic inside to give it a smooth finish.... any takers for my question?

Cheers

Wako

[bogie]

DVA will tell you the same as above...and yes its *fairly* easy - you need to be careful though you dont take too much material away...you really need to de-flash the plastick manfifold and port match it to the head...also do the same with the exhaust manifold - theres about 1/2" of metal weld clag in there !

I cheated - watched DVA do mine whilst he was fitting a new head

[paulwakinshaw]

Hi Bogie

Thanks for the info. I assume that you had work done by Dave Andrews prior to your TT upgrade, is that correct?

If so what did you have done by Dave?

I am looking at geting in the first instance some piper BP270 cams, verniers and an Emerald ECU, then that leaves the option of headwork until next summer and the ECU should be able to handle further future upgrades. Any info on the my choice of cams? - I have decided on the BP270 because I want to be able to drive my car like normal, I don't want it sounding like a bag of hammers at 1500rpm !! the other option is BP285 but retaining the Hydraulic lifters but i'm unsure if this is really to wild a move!

Cheers

Wako

[bogie]

yeah - I was running the DVA155 kit for a while - ported big valve head, 633 cams...Dave tidied up the other stuff at the same time.


I had probs with it running lean and a lumpy idle - it was actually making 163bhp on a standard ECU...no wonder it wasnt to healthy


In hindsight (and now having more knowledge) I would have gone for 270 cams + verniers, Emerald...and get it mapped properly. You can use the Emerald from then on.

The 285's are great and you could get up to 200bhp with them if you had ported head/DTHTBS etc...but youd really want forged pistons etc....and it starts getting expensive/unreliable.

Better off with 270s, few bolt ons, Emerald...even on a std head you should see 145-50bhp ish...160-65ish if you get the head re-worked later.