Introduction: Why fit a K&N 57i Induction kit to your MGF? Well there are lots of good reasons that are suggested by K&N such as : possible 10% increase in fuel economy; improved throttle response and smoothness; more efficient filtering; increase of 8-15 bhp; smoother torque curve etc. But as interesting and useful as these improvements are, the really important ones are the noise the car makes when you rev it and the manic Cheshire cat grin that you can't get off your face.

This kit has a great advantage that the noise it produces is only there when you want it. Cruising at a steady speed and it is almost unnoticeable. But press that right pedal and particularly above 3k revs, the sound is beautiful. It is also relatively cheap, reasonably insurance friendly and easy to fit. One on the must have list of MGF accessories.

Step 1: Gain full access to the engine bay (see FAQ "Open Engine Compartment").

You should have a view similar to Photo 1. This is a VVC so the MPI may be slightly different.

Step 2: Undo the clip (Photo 2) holding the flexible ducting to the plenium chamber (throttle body), and pull the ducting free of the throttle body.
Note: You may wish to disconnect the flexible ducting from the airbox as well; this makes it easier to perform the next step but is not essential.

Step 3: Undo the clips holding the top half of the airbox in place and remove it from the engine compartment. The air-filter itself can now been seen in the lower section of the airbox and should also be extracted from the engine bay.

Step 4: The lower section of the air-box is normally attached to the car by....

1. Two black plastic screws hold the air-box to the mounting bracket, but often only one remains. Remove these.

2. One 9mm bolt located in the gap between the edge of the engine access and the side of the car. This is awkward to reach and the bolt is soft metal so rounds the corners easily. Having the right sized spanner is essential. Unless you have a ¼" socket set, it is unlikely that you will be able to use a socket due to the limited access. Undo this bolt and pull the box away from its retaining lug.

....Whatever method is used, removed the bolts and manouver the bulky lower half of the air-box through and out of the engine compartment.

Step 5: Facing the front of the car, peer down into the engine bay. On the left (below where you have just removed the air-box) is a black plastic box, this is the resonance chamber and attached to it is a rigid elbow shaped tube pointing upwards.

To enable the K&N cool air induction tubes to be fitted later, the elbow must be removed. It is quite a tight fit and can require some force to pull it free. Twisting and pulling towards the engine should do it, but be warned there is limited space down there and when it does suddenly come free there's a good chance you'll knock you hand/fingers!

Step 6: Carefully open the plastic wrapper around the filter cone so that the large end is accessible, but the rest of the cone can be kept in the plastic. As the cone is oiled, keeping it in the plastic will keep your hands cleaner and prevent any dirt getting on the cone before fitting.

Step 7: Assemble the filter cone by connecting the cone, a metal tube and a length of intake hose together as described in the 57i kit instructions. The intake hose is curved asymmetrically, and the curvature must be closest tot he cone filter itself.

Step 8: Affix the assembly to the plenium chamber and tighten the jubilee clips (Photo 3 and Figure 8.1). It is tight enough when it is no longer possible to pull the intake hose off the plenium chamber when attempting to move the attached cone back and forth. Do not overtighten as this may affect the throttle linkage. Once the filter is secure removed the remainder of the plastic wrapper.

Step 9: Fit the two cool air ducts into the engine bay....

1. Extend the cool air induction tubes to approximately 40cm (if not already the correct length).

2. Ensure you have cable ties large enough to go around both tubes, or connect some shorter ones together to make longer ties.

3. There is a little contention as to whether the tubes should be connected together at one end before being threaded down through the engine bay, or left separate and connected after. I went for the positioning first and connection later and thought this was easier, but either will work.

4. Thread the tubes down into the engine bay (free ends first if you have connected then together already) into the gap left by the airbox and rigid elbow. Continue to push them through until the free ends are under the car. It may look like there is not enough space for both tubes to go through, but they will fit.

5. If you are using the Tom Randell bracket, I suggest you fit the bottom of the tubes first, but it is not essential. TR provides excellent instructions of how to fit his bracket so I will not repeat them here.

6. Fix the top end of the induction tubes so that they are 4" (10cm) from the K&N filter. If you have not already done so, connect the two tubes together with a large cable tie. Loop a smaller cable tie through this and fix...

   1. VVC - to the filter box mounting (Photo 4).

   2. MPI - to a suitable point on the front fire wall. Note the MPI throttle body is in a slightly different position to the VVC illustrated in the supplied K&N instructions.

Step 10: Attach the induction pipes to the underside of the car. There are many methods of doing this with the two most popular being simple cable ties or the Tom Randell bracket. Both are effective, but the bracket makes the job a little neater, and may help protect the tubes from gentle knocks with speed humps. Whatever method is used to attach the induction tubes, a similar process is required to fit them. You do not need ramps for this process, but you may get a bit dirty from lying on the ground, so best do this when it's dry....

1. If you are using a TR bracket, follow his instructions on how to fit it to the cross member.

2. Underneath the car, next to the near side rear wheel, draw the cool air induction pipes so that the plastic moulded end caps of each underlie the rear sub-frame cross-member. To do this pull and if necessary extend both of the induction tubes and draw them forward.

3. Bind the two tubes together with a long cable tie.

4. If using a TR bracket, fit the induction tubes into the bracket and secure. An alternative to the TR suggestion is to run a long cable tie around the two tubes and the top part of the bracket, which is parallel to the road. This works for me.

5. If not using TR's bracket, underneath the car loop a cable tie over the top of the cross member and down again so that it encircles the cross-member. Present the two induction pipes to the cross member. Link the cable tie encircling the cross-member through the one around the induction pipes and tighten.

6. Trim any excess material, i.e. ends of cable ties.

7. Check everything is secure and you have retrieved all tools from the engine bay.

Step 11: Replace the engine cover as per FAQ "Open Engine Compartment"

Step 12: Start the car, rev the engine and just try and get the Cheshire cat grin off your face. Enjoy!

8th June 2002, David Mills

Notes:

• Most insurance companies regard the K&N as a performance modification, it does afterall increase the engine's performance by approximately 8bhp for MPI and 15bhp for VVC (MGF). Check with your insurance company before you buy/fit a K&N (or similar), each insurance company seems to have it's own policy regarding such modifications. Some will allow fitment, normally with an increase to your premium and/or other conditions, whereas other insurers will point blank refuse and threaten to cancel your policy.

• It's also worth bearing in mind you will be limiting yourself to those insurers who will allow modifications when you next come to phone around for insurance quotes. From experience I'd say only 30-40% of insurance companies will be willing to quote you for insurance when they find out you have a K&N fitted. :(

• Not informing your insurer that you've fitted a performance air-filter is tempting, but be warned: Failing to inform your insurer of modifications can result in your policy being void should you need to claim and they learn of your dishonesty. YOU HAVE BEEN WARNED!

• If your car is still covered by warranty then fitting any non-standard parts can be a bit of a grey area. In theory unless the air-filter has been proven to play a part in any failure leading to a warranty claim then there should be no problem. However, we all know how some companies will try an wriggle out of something if it's going to cost them money. Check with the company providing the warranty if fitting a performance air-filter will invalidate or effect your cover. If they agree make sure you GET IT IN WRITTING! :)

8th June 2002, Paul Lathwell