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 - K&N 57i cone air filters

I've been trawling the arhcives and read many reports re how wonderful these are in both putting a grin on the driver's face as a result of the 'improved' induction noise and also for the improvement in performance, particularly on the MGF.1.8i.
I have also noted that Fabrice fitted one of these filters using an old 820efi airbox which ensured that only cold air was drawn into the manifold. Can anyone advise which avenue to go down. ie. Just replace the standard air box with the K&N and the two pipes provided with the filter or adopt the slightly more troublesome (fitting wise) Rover 820 airbox method as advocated by Fabrice???
Geoff Smart

I still have a few brackets for the K&N cold air pipes if anyones interested.

Once sold out there will be no more manufactured.

Email for more info.

Tom Randell

I still fancy trying to get hold of an 820 airbox - has anyone got one they don't want? They must be pretty thin on the ground now, dating from around 1989/90. Must have joined all the other Rovers in the great knacker's yard in the sky.
M Cunningham 1

Hi Mike! The reason for posting this thread arose as a result of me today aquiring an 820efi air box from a local scrapyard for a fiver. The first yard that I visited! This indicates that they are still about although if this thread indicates that K&N filters operate more efficiently in these air boxes, they might become less available than previously.
Kind regards,
geoff s.
Geoff Smart

The enclosure by itself does not make an air filter more efficient.

For that you need to run a large diameter tube from the enclosure to a supply of cold air and the most convenient source for this is the left hand side vent.

From personal experience I'd say don't bother with the K&N because servicing it is too fiddly. Get one of the proprietry units such as Piper Cross which are easier to take apart for cleaning.

Hi Geoff - hope that means you are mobile again, and the wheels are behaving! I can see I'll have to get out and about to find one. Maybe I'll manage another winter project if the insurance will wear another addition to my mods list.
M Cunningham 1

> I'd say don't bother with the K&N because servicing it is too fiddly


Has anyone here actually got 50k miles on their K&N?

I can't see the K&N actually needing to be serviced more than once for the majority of people, and even then it's going to be every 4 or 5 years, so hardly a major problem!
Will Munns

Hi Will

Serviced mine last week - took two minutes to remove, five minutes to clean, one minute to re-oil and two minutes to replace!

OK so it actually took longer as I waited half an hour for it to dry after washing it before re-oiling.

BTW I do take it off every now and then to blow off any excess dust.
Ted Newman

I'm pleased that everyone who uses a K&N keeps it well washed and that as Ted says it is easy. What I want to know is whether or not wearing a protective 820efi air box over my K&N is preferable to 'unprotected' ecstasy without the air box???
Surely someone must have tried both methods and as a result can comment which is best!
Geoff Smart

the 820i gives you more power, the unprotected gives you more noise.

Noise feels faster ;-)
Will Munns

Noise feels faster ;-), says Will. And it does make a wonderful noise. For me its perfect because you don't notice it below about 3000 rpm, so I can potter around with my beloved and she thinks what a fine car the F is. But when I'm alone I can give it some welly and once the revs climb it growls away fantastically and encourages you to stick the foot down harder. Oh, and Tom's brackets are the mut's nuts. Excellent design.

Mike Howlett

Just found this on the 'B' forum, makes interesting reading.

I personally would go for the cold air box solution, I had a K&N cone on mine for about 3000 miles, changed it for an ITG Maxogen kit, better, but MUCH more expensive!!!
Jay Smith


Just fit the K & N with or without the 820 box and you
will notice the difference right away. Hardly any
difference in top end speed, but mid-range acceleration
is improved and smiles galore over that sound.

Bill Pearson
W.A. Pearson

Hi Have a KN filter -about to put in place a heat shield. Good friend has one works well - we cannot get the rover airboxes over here.

100ml pipe in from side vent using air scoop. Great results

Question - has been asked before - has anyone tried the KN "apollo" this a boxed KN filter?
David Richards

Just to make things clear, an enclosure by itself will not improve performance: One factor is the air filter but arguably the biggest is feeding in cold air, such as via the side vent.


I have a K&N cone filter which I have tried with and without the 820 airbox. Much prefer it without, feels faster, sounds fantastic, etc.

The 2 K&N supplied pipes do supply cold air as long as you are moving over ~5mph, providing you use a bracket under the car such as Tom's (I bodged my own using meccano type exhaust hangers). And yes, I did stick a thermometer probe on my K&N last summer to prove it to myself!
P Davey

The 820 airbox works amazingly well - but it isn't necessarily about top end performance or noise - it's about low- to mid-range torque which was instantly better when I first performed this modification. In fact, it lopped 2secs a lap off my time at the Weathersfield sprint (IIRC). :o)

Besides, for a fiver, it's worth the punt :o)
Rob Bell

Thank you all for the input! I feel that Rob has with his experience summed up what I was wondering. I think that I will try to be 'more swift but silent'
Mike - the wheels not only look but feel good. Best wishes in connection with your next mod.
Geoff Smart

This thread was discussed between 19/03/2007 and 23/03/2007

MG MGF Technical index

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