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MG MGF Technical - 52mm Throttle body


will the standard air box and connections on the 1.8 MPi fit on to the 52 mm throttle body or do I have to wait until I decide on a new cold air system?

Thanks for your input


David, it will all fit without problem: the external diameter of the 52mm TB is the same as the 48mm.

Change instructions here:

Good luck
Rob Bell

Thanks Rob, appreciate the prompt reply and the directions it will go on tomorrow. I am kicking around the idea of a green stuff twister cold air system - has its own heat shield. will have to source intake and a joiner from the filter to the throttle body. The green stuff appears to have a greater air delivery capacity than the kN. Any thoughts?

Kind regards

even though I won 3 drag races on the trot in the little red rooster, A 52mm throttle body would be a nice additon.

Where is the best place to get them from?



There are 4 on sale on eBay right now.

I have been quoted Ģ95.00 + VAT by the manufacturer (part number ABF 623) - Burlen Fuel Systems Ltd.

Good luck!

Sam Murray

Burlen now own the rights to the original SU throttle body and do both the 48mm original and 52mm in alloy - they're very nice.

The alloy throttle bodies used on MGs are Del'orto. I can't imagine that there would be any difference between them - so go for whichever is cheapest. Burlen Fuel systems will sell direct, but you can also contact the MGF Centre, Brown and Gammons, Mike Satur et al. for the Del'Orto 52mm TBs. If second hand, can be had for less money :o)

Might be best to remove the TPS from your existing TB and fit it to your new one to avoid compliance issues...

David, the Green filter is almost identical to a K&N in construction. I gather that the company that makes Green filters used to actually have a licence from K&N - so the similarities are probably not surprising.

So long as you get a good cold air feed to your filter, I don't believe that there will be any difference between a Green or K&N (or indeed ITG, Ramair etc). The heat shield is a very good idea - but fully enclosed is better still.
Rob Bell

With the 52 mm - sure it wonīt be "Burn Lean Fuel System" ? Donīt forget to add the FSE ! ;O) /Carl.

You honestly don't need an FSE with a 52mm TB Carl. On the RR, the engine never ever runs lean, what ever the throttle position or the throttle transient.
Rob Bell

On my VVC with fully enclosed intake system and a big outside intake duct there was a problem on long straights/high speed /full throttle when doing trackdays.
A slight "lift-off" on the throttle gave better acceleration! Uprated fuelpressure cured this. So it probably had to do with the engine getting too much air and a little too lean running for max power.
Probably wonīt be indicated on a RR session where the fans blow for the front radiator only and the air to the intake is rather static ?

That's a possibly explanation Carl. I've not tried the same dynamic test as you. Perhaps time to invest in an additional lambda and a stoichiometry display?
Rob Bell

It makes sense to invest in a fpr.

It only makes sense to fit an uprated fuel pressure regulator *IF* you have the facilities to ensure that you are feeding an appropriate quantity of fuel - which means monitoring the lambda...
Rob Bell

Carl, injectors not flowing enough fuel should have shown up in a rolling road session IIRC it was Dave that fitted a uprated fuel pressure valve because it showed up on his car (but non other at the same day).
Will Munns

Will, my VVC is so old so the "full flow" injectors are there and they supply more than enough .There was another thread about diff. in injectors over build-time some time ago.
In my cat-tube is a separate lambda-sonde inserted, (on show on Dieters site / cat-tubes) and a DIY readouton my panel. The original standard lambdasonde goes out of action on full throttle and is useless as an indicator even for a separate instrument/readout. It seems that MEMS inserts a predetermined voltage every time there is full throttle. This fooled me for some time as I thought it was a true reading from the sonde !!
A quick squeeze in a vice for the standard fuel-reg. will increase the pressure slightly,but IMO it is nice (but at a price!) to be able to do small adjustments to suit alterations made to the induction,street or track use etc. etc.But this of course can only be set correctly with the above mentioned extra lamdasonde.

This thread was discussed between 08/05/2006 and 09/05/2006

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