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MG MGF Technical - New throttle bodies - now from SU!

Hi all,

a while back I was chatting with the chaps (Burlen Fuel systems in Salisbury) who took over the commercial rights to Skinner's Union (SU) trade marks and designs when I was researching a throttle body article. It transpired that the plastic throttle body originally used in the MGF was manufactured by SU - but the company was taken over by US based Dana industries and the factory eventually closed in 2001 (the time when the MGF started to recieve the alloy Del'Orto throttle body).

At the time of these discussions, they told me that they we working on producing new throttle bodies to the original SU design. Well today I recieved this email from Mark:

Dear Rob,

You may remember some time ago we discussed our venture into manufacturing the alloy throttle bodies for the K Series engine.

Well, I am pleased to say that they are finally ready. (About time!)

Both sizes are available - standard 48mm to replace plastic items and 52mm to up performance.

48mm - 105.00 plus VAT but special introductory price 90.00 plus VAT.

52mm - 110.00 plus VAT but special introductory price 95.00 plus VAT.

Hope this is of interest. If you want any further information, just let me know.

Kind Regards

Mark Burnett
Sales and Marketing Manager

The intro prices are pretty good - I've already got a Del'Orto, but for anyone else considering an alloy TB, then then the SU might be worth checking out.
Rob Bell

Don't know enough about compatibility..
Which one (if any) fits a VVC Rob.. ?

-- I feel Christmas coming..
Neil H

One for santa's list, I imagine they are not to difficult the fit!

Do you have a contact e-mail or address for them.

Simon B

Either Neil - they'll be exactly the same as the ones already on the car :o) As you say Simon - they'll be a doddle to fit...

The 48mm v 52mm throttle body debate is always good to bring up - but if you are spending to change your throttle body, go for the larger one: it gives you a much cleaner, sharper throttle response, and can result in a couple of bhp and lb.ft gain in torque :o) Plus, it is a good mod that'll work well with other engine mods that you might have planned for the future.
Jeepers - I sound like a sales person! I'm not!!! No connections with the company at all. But it's got a superb reputation in the classic car community - so I've no reason to doubt that the TBs they'll be selling won't be at least as good as the ones that we're used to :o)

The company's web site addy is
Tel: 01722 412500

Rob Bell

So.. I have a standard VVC TB.
.. If I fit a.. 52mm TB, I need no other parts.., it just fits?

And if I do, it'll be a sharper reaction, and perhaps better performance to boot?
Neil H

>>So.. I have a standard VVC TB.
>>.. If I fit a.. 52mm TB, I need no other parts.., it just fits?
>>And if I do, it'll be a sharper reaction, and perhaps better performance to boot?

Yes - just don't expect too much from the change. As Rob says, it perhaps comes into its own more in association with other mods.
Dave Livingstone

Yup - exactly as you say Dave: performance gains are very modest, but the 'feel' with the new TB is worth it - IMO. New throttle body is a direct swap for the existing item - no other parts required Neil.
Rob Bell

Just checked with Mark: the TBs are ready to go from now, and I have some pix of the finished items. Look a little different from the alloy TBs we're all used to: true to form, as Mark said that they're based on the plastic TB design, they look like the plastic TB, but in alloy! LOL

They look good - and come complete with the throttle position sensor :o)
Rob Bell

How much of a DIY fit is the TB? Or am I better getting it fitted while other work is being done?
Andrew McD JAZ5788

It's actually really easy to do Andrew - the only thing I'll say is to pass on a tip I got from Tim: buy some ratchet ring spanners. The reason is that the retaining bolt located under the rear deck panel is a real pain to get to, and a ratchet makes a difficult to access job easy.

In essence, what you need to do is:
1. remove the airfilter pipe from the throttle body (either a spring clip if still the original Rover item, or a jubilee clip)
2. undo the four retaining bolts holding the TB to the inlet plenum
3. remove the two rubber hoses
4. Remove the TB, and untuck the throttle cable from the throttle cam on the TB
5. Remove the loom plug from the throttle position sensor

Reassemble with new throttle body:

1. Attach the throttle cable and wind it round the throttle cam.
2. Reattach the throttle position sensor loom plug
3. Reattach the hoses
4. bolt the throttle body onto the inlet plenum
5. reconnect the airfilter.
6. Set ignition to 'on' but don't crank the engine. Depress throttle 5 times in quick succession. Switch off ignition.
7. Now start engine and marvel at the improved throttle responsiveness. :o)

Also see Steve Taylor's instructions on how to install the TB onto a FWD car - it's a bit easier for these guys! LOL
Rob Bell

Thanks Rob, How long do you think the offer from your source will be available? As I will at this stage wait until the new year. but that does not seam to hard. Would I be as well to fit the KN filter at the same time? Is this as simple?

Andrew McD JAZ5788


How long will the intro price last?

Been a bit of a heavy month!!


Rob, I have just been reading your instructions on fitting on your site. It does not seam too bad. Where can I get Tom Randell's K&N brackets? And would I need to raise the stern of the car fit the brackets?

Andrew McD JAZ5788


I wonder what the size if on the 1.4?

could do a reshuffle
big 52mm throttle body onto F
F 48mm onto Lab Rat

Yes Rob named it!!

I actually don't know how long the offer will last - I'll drop Mark an email and find out.

Andrew, the K&N installation is pretty easy - as you've seen from the site. Regarding Tom's K&N bracket - best contact Tom - email is tom dot randell at btopenworld dot com (hope Tom doesn't mind me posting his email address!)

Neil - both the sizes will fit the Lab Rat... apparently the 82bhp 1.4 has a deleberately restrictive throttlebody that actually doesn't open all the way. Therefore just fitting a 'standard' ought to have a big effect - and bring you close to the ZR 105 spec :o)
Rob Bell

Hi Rob, I have been on ot Tom and will get on in the new year. Thanks for your help. Happy Christmas, Andrew.
Andrew McD JAZ5788

You're welcome Andrew :o) Merry Christmas to you too

Regarding the duration of the offer - it's a "whilst stocks last" type offer, but Mark tells me at current sales levels, that means that they'll be available until about March time (no guarantees of course!)

If you want one, might be worth ordering sooner rather than later methinks.
Rob Bell


I cant tell what throttlebody is on the LabRat.

It's such an easy swap when I do the F I will put the original 48 on the LabRat...Unless somebody could pass me their ex-F unwanted 48mm Throttle body!!

...let's experiment!!! that's what it is for!


Hey Guys if any of you are considering Gas Flowing the engine a bigger throttlebody has got to be a MUST hasnt it?


Yup - have a 52mm already and waiting for greater things from the head... :o)

Your plastic 48mm TB on your F should bolt stright onto your Lab Rat's inlet plenum... :o)
Rob Bell

Do you know if the 52mm Throttle body will fit happily into a 216? I'm guessing it will, but wondered if anyone could confirm, before I spend even More on the wretched thing.



Oh - Merry Christmas and a Happy New Year to everyone. I hope you're all well. Although I don't post much now I do still look in often...
Kieren Gibson

Kieren, if it is an MPi equipped K-series (and the 216 is I believe), then the alloy throttle body will indeed just bolt straight on :o)
Rob Bell

Thanks for that Rob - just need to sort out the warped Manifold first...and Happy New Year....


Kieren Gibson

This thread was discussed between 12/12/2003 and 28/12/2003

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