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MG MGF Technical - R820 Airbox replica works!

Hi all.

It's been a long time since I last posted here. However, from time to time I check this space.

I was tired to damage the K&N 57i hoses on every speed bump so I just went and bought a R820 airbox, following Rob's advice. 10 quid.
Trouble was that I could source only one and my friend Joao wanted another one for his MPI. We installed it on his car and I made a replica of the box in carbon fiber.

Impressions on installing:

- This airbox lid doesn't close with quick fittings but with 6 bolts. It's more time consuming;
- The lid was a bigger interior insert allowing for K&N support on the steel part. So the 57i cone isn't just hanging from the base, is also supported on the left hand side, i.e. opposite to the throttle body;
- I had to fabricate a different alluminium bracket compared to Rob's. VVC engine;
- The main problem with this box is that the wire supported hose that links the box to the throttle body (the smaller one) is attached to the box itself with a jubilee clip and not to the K&N collar. This means that the K&N base may let some dirt in to the engine. I know the cone fits snuggly to the airbox, but it's a possibility. What do you think? Is it mad to leave it like this?

Driving impressions:

Uau!!! The lower the revs the better the engine is now compared to 57i cone without the airbox. As the engine builds up speed the torque increase compared to the previous set up gets less noticeable. I just drove her for 30km so far and I just pushed it as far as 5200 rpm in 4th. And it continued to be better than previously. Do you think that there's a point when the free 57i cone performes better than with the airbox?? Say 6500rpm onwards?


Valter >´99 VVC & '73 BGT<

That's great news Valter! :o) I've been looking everywhere, but it seems that the R820 airbox mod has proven rather popular!!!

The carbon airbox sounds great - I would think that there is a market for this if you were to consider making more... Any pix available?

Regarding performance, I would say that so long as the capacity of the box is large enough, and the instake is capable of supplying enough air (the Rover airbox was designed for the T16 2.0 litre engine using a 56mm throttle, so it ought to be perfectly adequate with an 80mm intake), then an enclosed K&N ought to work just as well as an exposed cone :o)

BTW the K&N on the metal collar? I've lived with this and have looked at the throttle body after many miles and years of driving, and its clean (which was more than could have been said for the filter, which was noteably caked in dirt... not quite as bad as the exposed cone with the under body pipes, but not far off)
Rob Bell


I simply don't have the time to fabricate more boxes. In fact I outsourced this job for free. I just assisted them and explained what I wanted. I used a special resin (blue colour) that is good till 130ēC which is way more than what's achieved on the F engine bay.

I'll send pictures asap.

My biggest question now is, since my inlet pipe is connected to the airbox and not to the filter as you did, there may be dirt air escaping between the filter base and the box, right? This will be directed to the engine, even if the cone is adjusting snuggly to the airbox.

Valter >´99 VVC & '73 BGT<

If you have a good seal Valter, this shouldn't be a problem. One potential solution to the problem is to get some 80mm outer diameter tubing (it can be metal or plastic) - cut it to a suitable length and slide the filter on this, and the other end into your duct to the throttle body.
Rob Bell

This thread was discussed between 12/07/2006 and 14/07/2006

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