Welcome to our resource for MG Car Information.



MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGF Technical - Cone filter

Inspecting my secondhand MGF (MY2000 42,00KMS) before buying I noticed it had a cone air filter fitted directly on to the throttle body by jubilee clip. Since buying the car and reading this site I believe that there should be an extension tube between the cone and the throttle body fed by air cooling pipes of which there are none. My question is does this really matter? There does not appear to be any overheating problems so should I leave well alone or are there potential problems?
R Yeeles

>> My question is does this really matter? <<

The answer to that is yes, absolutely: it matters.

I've done a number of RR investigations, and if you mount the cone filter directly to the throttle body, you'll instantly loose 5 bhp compared to the same cone filter on a 5" spacer. In fact, you've probably got less power now than if the standard air intake set up had been retained!

Then there is the question of the cooling ducts. Here the problem is hot air ingestion: the hotter the intake air, the less dense it is, and therefore the less power you get out of the engine. Your cone filter is sitting in an engine bay whose temperatures, even on a cool 20C day rises readily to over 60C: you're loosing power hand over foot...

The best solution is to remount that filter on a spacer tube, and better still, enclose it inside an airbox.

I've done this using an old Rover 820 airbox ( - but any airbox of suitable dimensions should do the trick.

Good luck!
Rob Bell

IIRC the pipercross cone filter was directly mounted onto the TB. The length of the tube depends on the type of car you're running (MPi/VVC).

Spot on on both counts Erik. :o)
Rob Bell


Depends what you want, mate (excuse cod Aussie slang). If you're desperate for a few extra bhp, then take the above advice. If you aren't, and live in a dusty environment, refit the standard air-box and inlet pipe setup. The cone filter and inlets pipes is particularly prone to throwing all kinds of debris on to the filter.

Whether it's better to use the standard Rover panel filter or a K&N is debatable. The Rover filter has a far greater surface area then the K&N, and there's hardly any published data on the efficency of the K&N. (Before anyone jumps in, there's none on the Rover filter either.) Just weigh up the pros and cons and decide what you want to do.

Regards, Kes.

Thanks fellas (we dont use cobbas any more), I think I will revert to the original set up and start looking for a local who has converted to a cone and has the orignals bits still lyong around.

R Yeeles

This thread was discussed between 10/12/2004 and 12/12/2004

MG MGF Technical index

This thread is from the archive. The Live MG MGF Technical BBS is active now.