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MG MGF Technical - Low pressure turbos ?

I copied this from a MEGAless board. Thought it might interest some of you. Especially the £/BHP-gain ratio seems attractive. Ok, kinda Max power but hey, I´d settle for a big Turboed Supra ;-)

<<
article in Max Power recently about a Van AAken low pressure turbo system. Apparently it only boosts to .32 Bar, not alot I know but will be good to boost the poor amounts of torque provided by the 4 pot K engines !

I appreciate that the K's prefer supercharging but this kit is only £1100 fitted, and all you need is a fuel boost valve to up the fuelling appropriately. This also comes with the standard dump valve noises that are so cool !!

http://www.vanaaken.com/

It boosts BHp by about 20 Bhp and torque by about 15Lbft.

Any thoughts from the engine masters out there ??

;-( they dont do them for MG's! i called and asked! if you all want to call them and ask heres there number!
01344 777553

The Van Aaken kit mentioned in this thread is universal, it will fit the K in the Zeds. Just needs intercooler adapting slightly, no real drama.

With the turbo, I would definately advise getting an uprated ECU along with the conversion. It will do the fueling job properly and save mucking about with various addons to do a half hearted job. At the end of the day, running a lean mixture will blow the engine and it's not worth it - pay a little extra for a programable ECU.

I also believe that a turbo running at low pressure would have vertually no lag at all. I know that in my turbo, with a Garret T25 set to 11psi, it'll spool up from under 2k. Okay, it wont be giving huge acceleration at that point but just means you can much more easily drive round town at lower revs quite happily pootling up little hills and stuff without a worry
>>

Cheers,
David.
David

Interesting. But I'd still be worried about the ability of the pistons and piston rods to take the additional (albeit mild) increase of compression ratio and BMEP (the K-series is already pretty close to its BMEP limit in standard tune).

FWIW:

Brake Mean Effective Pressure:

Definition:

Brake mean effective pressure, or BMEP, is the measure of efficiency that express engine output relative to engine displacement. Simply put, BMEP is the average effective pressure of the cylinders as they progress through intake, compression, ignition and exhaust strokes.

The work accomplished during one engine cycle divided by the engine swept volume. It is essentially the engine torque normalized by the engine displacement. The word "brake" denotes the actual torque/power available at the engine flywheel as measured on a dynamometer. Thus, BMEP is a measure of the useful power output of the engine.

BMEP ? torque / capacity. A high BMEP is indicative of higher performance. A low BMEP tends to be indicative of higher reliability.

The highest BMEP [BMEPMAX] will occur at the point of maximum torque, which also happens to be where the peak volumetric efficiency occurs.

2-cycles require only one half of 4-cycle BMEP to produce the same power at the same rpm.

Two cycle:... BMEP = ( HP * 6500 ) / ( L * RPM )

Four cycle:... BMEP = ( HP * 13000 ) / ( L * RPM )
 
BMEP = Brake Mean Effective Pressure
 
L = Engine capacity (volume) [liters]
 
Q = Torque [foot pounds]



Power = work (Q * rpm) / time

hp =( Q * rpm) / 5252

BMEP = (hp * 6500) / (L * rpm)

BMEP = (Q * 6500) / (L * 5252)

Stock motorcycle engines will have a BMEP of 80 - 90 psi. Road racers can get up to 125 -130 psi.
Rob Bell

Rob are you sure that you are a doc?
not a physics lecturer or something??

Reminds me of my cardiology lecturer who did both engineering and medicine and is torturing all my class mates including me...

with his physics!
Nooooooooooooooooooooooooooooooooooo

LOL
Hanah Kim

Much better than a turbo - I spoke too one of the guys from turbotechnics at the motorshow - he said they were working on a mod so you could use thier supercharger kit with airconditioning :D
I'll start saving then. !
Kingsley

The Turbotechnics supercharger converion includes shortening of the con rods to lower the compression ratio. According to them the MEMS is quite capable of handling the conversion without problems. The price of the conversion is very high though and I still have not found anyone on the BBS who has had the conversion done.

I'm not sure about turbo's for the F as they must generate more heat than a supercharger causing an already hot engine compartment to become even hotter, even with an intercooler. Just my uneducated opinion.
T.E.D.

Tony,
Click on the lotus->technical to find out more info, guys there have done _everything_

Will
Will Munns

ROFL Hanah!

One of the other career paths that I'd have liked to have persued was automotive engineering... Mind you, that can be quite dry - far better to have an interest in the principles IMO and enjoy figuring things out ;o)

For the F/TF I agree, packaging a supercharger is far easier than a turbo. Very simple reason for this: space around the exhaust manifold. The exhaust manifold is already very close to the front (fuel tank) bulkhead. Therefore to fit a turbo - which needs to be located as close as possible to the cylinderhead - is going to require some very crafty packaging. The idea of having a superheated turbo that close to the fuel tank in the event of a massive rear-end shunt does not appeal however.

I have heard that MGR engineers did succeed in installing a turbocharger into an F. But this time, the turbo was mounted remotely, closer to the inlet manifold on some very elaborate pipework.

It wasn't a huge success. Hence the Supersports concept was launched with a Supercharger.

Regarding the TurboTechnics conversion, as Tony rightly says, this does involve some internal engine modifications - including new pistons and shorter con rods to reduce the compression ratio. The standard MEMS is retained (in all their conversions up to 260 bhp, and probably beyond) so that normal servicing at Rover dealerships can continue. There is, however, an additional ECU that controls two additional fuel injectors to modify the fueling, and this ECU also modifies the ignition map to suit the modified engine. All in all, a very neat and tidy solution.

If you think that TurboTechnics are expensive, check out the prices that BBR GTi charge for the turbocharged engines (although I have not heard of any MGF being so modified, so details on how the turbo is mounted are scant)... see http://www.bbrgti.demon.co.uk/ But the engineering changes are significantly greater.

Do you get what you pay for? Yes, probably!
Rob Bell

Rob,

Thanks for the BMEP explanation. Now let me convert to SI units *ROFLOL*. Interesting though. I am not a mechanical engineer myself, but tend to be very interested in learning a.o. about mechanics. Though I had my basics, as probably all of us.

FWIW: another supercharger converter on the market. At least to me:

http://www.force-one.co.uk/mgf.htm

DaviD.
David

Oops, starting to doubt their reliability, now I did some digging and found out they also fabricate this:
http://www.force-one.co.uk/disbike.htm *ROFLM*O*
How bad can it get!
David

David - stabilisers for a bike??? LOL I thought you got rid of those when you got to the age of 4 or 5!!!

Thanks for the supercharger link. Very interesting. Seems that they have not yet completed their conversion yet, but it seems to be similar in some of its details to the TurboTechnics conversion - and cost is about parity too.

I'll see what else I can find out.
Rob Bell

David, waiting for a reply. Judging from the fact that the Force-One Rover 200 is wearing a Mynheer 'Mimbari' body kit, and the supercharger is an Eaton unit from from the cam pulley - which is very similar to the kit that Mynheer appear to sell, I'd say that the two companies are partners.

Personally, I don't feel too comfortable with that cam drivebelt idea... but we'll see.

[No power quotes on the Force-one site, but Mynheer are quoting 180-185 bhp]
Rob Bell

This thread was discussed between 04/11/2002 and 08/11/2002

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