Welcome to our resource for MG Car Information.
MG MGF Technical - FAO Mike re.Inlet Manifold
|Thanks for your comments Mike,just to let you know i do have mods on my engine.They are Piper Cams,Trophy TB,K&N,Vernier pulleys,icon chip.I would like just that bit more!!What would you suggest without porting?|
Many Thanks in advance,
Carl C13 AMB
|Sorry, I'm not Mike, but my suggestion would be to look at the exhaust side of the engine.|
The standard manifold is a very poor design, with internal welds that restrict exhaust gas outflow.
1. grind down the internal welds and add weld to the exterior of the pipe work
2. replace the exhaust manifold with a 4-2-1 (to maintain torque characteristics lost using a 4-1). These are available for about 400 quid all in from Exhausts By Design (EBD, web site: http://web.ukonline.co.uk/grahamf/index.htm)
The latter have proven results in the hands of the Elise boys, but has the problem with engine movement. You need a flexipipe inserted. If you are not too bothered about having the cat fitted, then this can be replaced with a flexible cat-replacement pipe. I think I've figured out an alternative arrangement that keeps the standard cat, but will require replacement of the exhaust back box (which is probably a good idea anyway, but worth only up to 5 bhp - talk to Mike about his excellent system).
The 'de-seamed' standard manifold of course avoids these pitfalls. It won't be as efficient as a proper 4-2-1, but cheaper. I gather that Andy G has had Mike perform this work to his car, and is very pleased with the result.
And then, ofcourse, we move onto the exhaust. As mentioned before, for about 300 quid, you'll get about a 5 bhp and 5 lb.ft gain from a Mike Satur exhaust - rolling road figures available from http://www.mgf.ultimatemg.com
Oh, and I'd also recommend you fit a heat shield or preferably an airbox for your K&N to ensure that it works at optimal efficiency. Some more info on this on the above mentioned web site.
BTW, if you are interested in porting, check out David Andrew's web site - extremely informative and educational - linked from the above site.
To check out Mike's performance offerings, look at his web site: http://www.mikesatur.co.uk
Hope this helps
|Carl, I would establish the power output you are achieving first by RR/Dyno testing, this will prove what power you have got at the moment and will help to decide which direction to move in. It also depends if you want more top end speed or mid range grunt. In any event even mild porting will achieve quite drastic improvements without even changing the valve sizes. Anybody who has driven our demo car recently could make comment (Andy G),this has stock exhaust ,cat ,manifold TB(plastic),stock cams, some mild porting with attention to detail around the valve throats and very accurate seat cutting, an (old) Pipercross filter with a cold air duct. It is quicker off the mark than the TF160!|
Chat later as I should be working;-)
|Just to confirm - Mike's demo car is quite ridiculously fast. Got back into my VVC and it felt positively sedate in comparison.|
|Mike, This porting, available for VVC heads as well? for how much..?|
|try this link http://www.elises.co.uk/components/s1/engine/simons.html|
|Yes - no problem on the VVC head either. Larger valves are also available, but I'm waiting for the high-lift VVC cams too before I take the plunge.|
|Hmmm, sounds very interesting!|
What sort of cost we looking at for a 'mild' porting of a VVC?
|From Mike's price list @ Jan 2002, E&OE!!|
VVC Stage 1
This involves reworking ports and throat and the standard valves (31.5mm inlet, 27.5mm exhaust) to gain substantial extra air flow through the head. All valves and seats are re-cut and new stem-seals and cam seals are fitted.
Supply (exchange): £450.00
all plus the dreaded VAT of course.
I really should be charging Mike for this sales job!!
|Thanks Andy, cheque in the post;-)Hanah,the VVC can be improved upon but the gains will mainly release top end power with relatively smaller gains in the low- mid range compared to a reworked 1.8i head, as I am sure you are aware, the VVC has better porting to start with. Larger valves, matching manifolds, etc etc will make the engine 'sweeter' and more responsive due to its better efficiency, actual BHP gains above a certain level(160-175BHP) without drastic alteration to the ancillaries is harder and costly to achieve. A lighter flywheel is also recommended btw.|
|Sounds all great.|
But I am in NZ?
But looks like websites have good information on this thing... but wouldn't trust someone who haven't tried this on F to do it on my car...
This thread was discussed between 01/05/2002 and 03/05/2002
MG MGF Technical index
This thread is from the archive. The Live MG MGF Technical BBS is active now.