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MG MGF Technical - Rolling Road Result -- MGF PTP

Hello,

Last Saturday we had a rolling road session together with some other MGFs and Rover's. I want you, the more technical guy, to have a look at the graph and maybe you could suggest what may be wrong...

http://dennis.core-lan.nl/mgf/albums/album79/DynoJet_ErikB_small.jpg

The car is an MGF 1.8MPi with PTP RT-Sport 165 kit, MS Vader, TTB, cat-bypass and SP/Milltek. Although the end result is not bad at all (the promised 165bhp is reached), the graph shows a 'problem' at low revs and at top revs (between 6500 - 7300rpm).

The technical guy at the rolling road said it is a powerfull engine, but it needs a better setup to perform like it is designed to be. And he's right.

If req'd I can post the AF-ratio graph as well.

Looking forward to your advice,
Erik

take a look at;

http://www.pumaracing.co.uk/power1.htm

this may help in your analysis of the results.
MG Mike

Hi Erik,
isnīt the AF-ratio the answer to your "problem" ?
Guess there is a need for a proper calibrated FSE-valve.... / Carl.
Carl

>>> isnīt the AF-ratio the answer to your "problem" ?
<<<
I'll post it as soon as I am home, so you guys could have a look at it.

>>> Guess there is a need for a proper calibrated FSE-valve.... <<<
Or the uprated/calibrated FPR (via Rob B), as I've got one laying around getting dusty.

If I have a look at the Elise Technical BBS, I see options as fitting veniers and having a remap of the EFI Euro 1 box. I guess the TTB is messing it up a bit.

Thanks
Erik

the graph of the AF-ratio:
http://dennis.core-lan.nl/mgf/albums/album79/DynojetAF_ErikB_small.jpg
Erik

Looking at the graph Erik it says 144BHP???
mike

That's at the wheels Mike. After adding 16% (like the guy of the RR said, and he culd be right after some results of standard MGFs) I get 167.
Erik

Yes, but Bruno (volcano VVC) gets about the same HP (please correct me). So MGRs power figures are wheelbased and not flywheel based. Right?
Bruno has Cat bypas, K&N and Phoenix, this all cant be responsible for 20HP
david

The A/F ratio does not look bad. If anything a tad high. Your Spec is similar to mine.

I wonder if you are starting to become throttled at high revs. Either lack of air at high reves (dirty air filter etc) or

is there a step between the exhaust ports on the head and the exhaust manifold. Or even a constriction in the exhaust manifold?

Erik is it the standard manfold?

When I get home (in about 10 days time) I will post my results and you will what I mean.

Steve
Steve Ratledge

>>> So MGRīs power figures are wheelbased and not flywheel based. Right? <<<
Absolutely not

>>> Bruno has Cat bypas, K&N and Phoenix, this all canīt be responsible for 20HP <<<
Throw in the TTB and a 4-2-1 and you get an advantage of 18, not taking into account being it bhp, HP (SAE), HP (DIN), ... which could be possible.

>>> wonder if you are starting to become throttled at high revs. Either lack of air at high reves (dirty air filter etc) or is there a step between the exhaust ports on the head and the exhaust manifold. Or even a constriction in the exhaust manifold?
Erik is it the standard manfold? <<<
What is 'become throttled at high revs" ?
It still is with the standard manifold.
Erik

Just echoing Steve comments really - neither graph looks too bad, and the A:F ratio certainly isn't going to cause significant problems.

I guess - as you say Erik - the restriction is at the top end where things are looking really very flat. Given that you are still running a standard manifold, I would suggest that this is where your problems lie: with a high-flowing engine like the one you have, the exhaust manifold quickly becomes restricting. Fitting a decent 4-2-1 manifold (such as the one made by Piper) is probably going to yield excellent gains almost everywhere I suspect - and perhaps more at the top end too...

But overall, it is a pretty good result. Just needs a little fettling now :o)
Rob Bell

Does Bruno have a 4-2-1 ?
So the 20HP+ is due to all of the above?
David

Bruno collected a 4-2-1 at MGF10 - if he's got that fitted already, he hasn't been hanging around! :o)
Rob Bell

The 4-2-1 is fitted to his VVC, but it didn't gave him te result he was expecting. Only 3HP more than the year before. Although he needs to check the fueling, as his AF-ratio line has raised over the complete rev-band.
Erik

That's fairly modest - but not entirely unexpected Erik. The 4-2-1 usually lifts the whole power/torque curve though - particularly noticable in the mid-range. If power is your primary objective (which I doubt that it is - you're probably more interested in the whole power/torque curve) then a 4-1 manifold is the best way forward.

I am not sure of the origins of Bruno's 4-2-1 manifold. It looked like a Janspeed to me - the Piper is better - and I would like to think that the Powerspeed on my car is better still - but I don't have the RR data yet to support this assumption! ;o)

Soon though!
Rob Bell

>>> That's fairly modest - but not entirely unexpected Erik. <<<
Why Rob ? Why is his engine running more lean than before the 4-2-1 ? Is it cause his engine is breathing better and that the fuel pressure can not follow ?
Erik

On the other hand I am thinking about a remap of the EFI Technologies Euro 1 box and the fitment of a set veniers. IIRC this is something that is done before in the Lotus scene, as the S160 is running with the same ECU.

I am not sure if a switch to an Emerald would be easy, as I don't get any specifications like timing, duration and lift from PTP (protecting their product/kit).
Erik

I was indead a little bit disapointed by the result of the dyno this year, only 3bhp more than in 2004 (now +/-165pk). The changes that were made since last year : 4-2-1 and a phoenix. I suspected to have a little 10bph more, but....
So these were the most expensive Bhp that I have ever bought for a car.
Is it possible that when I put a Fuel pressure regulator on my car, the expected BPH shall be achieved ? My fuel mixture is to low now, as Erik mentioned in a posting above ?
Bruno

I haven't seen Bruno's A:F ratio, so it is a little hard to comment with any confidence, but yes, when you improve breathing, be that via the inlet or through the exhaust, you are altering the parameters under which MEMS was originally mapped. In closed-loop (ie under constant throttle situations), the system is completely adaptive. Under open-loop conditions (full throttle), you are completely reliant upon the ignition and fuelling maps programmed in MEMS.

Therefore, to find that your engine tends to run lean when you've largely optimised the inlet and exhaust systems is not entirely surprising. Dave Livingstone found similar when DVA ported his cylinder head. He - and a few others who've had similar work performed - have had to fit FSE fuel pressure valves which has enabled optimisation of the fuelling.

It is possible Bruno, that you will need to do the same. The alternative is to replace MEMS2J with either the later mappable MEMS3 or an aftermarket ECU, such as the Emerald (which can control the VVC). BUT this is a very expensive solution.

Erik, regarding your car, as you already have the EFI ECU, I don't see the point of changing to an Emerald - what you have is perfectly capable of controlling your engine's ignition/fuelling needs. It probably does just need a little re-mapping, once you've completed all the optimisation work that is required. :o)
If you've not got vernier pulleys already fitted, then from what DVA advises me, you are very well advised to fit them, as the cam timings are unlikely to be optimised - and you'll be loosing power. They're not too expensive - but at 160 quid for the pair they're not cheap either :o( But arguably worth it in your case.

Rob Bell

Thanks Rob....

>>> They're not too expensive - but at 160 quid for the pair they're not cheap either :o( But arguably worth it in your case. <<<
I guess the problem ain't be the 160 quid, but finding someone who can set the perfect timing :o(
About remapping the EFI.... it's harder to find someone who can remap the EFI than to find a person who can remap an Emerald.
Erik

Erik, sadly you're quite right about the availability of experience in the EFI ECU. Do you have access to the software and interface?

Vernier's aren't all that hard to set up, once you've gained some experience. Tim Woolcott is now something of 'an expert' having set the timing on his car's verniers a couple of times now. You can certainly DIY. You will need a set of DPI (Dial Position Indicators) to show lift according to cam position. There is more explanation on DVA's website. I am also planning to write this up as a step by step guide - we're planning to sort out Steve Ratledge's car when we can all be in the same place at the same time! LOL
Rob Bell

Thanks Rob,

First thing to do then, shall be putting a FPR on my car. After a new visit to the Dynojet , I shall post my new power curve and A-F ratio.

Bruno
Bruno

Dave Walkerīs book has a very good explanation on cam setup (lift on overlap).
daVID

Tis an excellent read, I agree. Available from the Haynes publisher fairly cheaply too...
Rob Bell

Do you've got that book David ?
Erik

for a about 1 year now! Not that expense. Good reading.
david

What is the Title and/or ISBN of Dave Walker's book. I would be interested in reading it.
d mottram

Iīll post it when I get home. You can buy it through the emeralds website though.? although it has a BIG chapter on carburettor tuning and the fact that is is aming towards MTB systems, it is a good read.
david

Yes, it's listed on there: http://www.emeraldm3d.com/em_pricing.html (scroll towards the bottom)
Rob Bell

ISBN1 85960 835 3
bought for Ģ 17.99 I believe. Came with some rather nice emerals software to play around.
A/F ratio, ignition, idle, etc are parameters to be played around with on all engines, the ECU is merely the instrument. So it doesnīt really matter what instrument you play around with as long you understand the numbers;-)
David Peters

This thread was discussed between 24/10/2005 and 27/10/2005

MG MGF Technical index

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