Introduction:
Why buy an expensive induction kit when you can make your own induction shortener (adapter that comes with induction kits) and then just get a cone or cylinder filter of your favourite brand (K&N, Pipercross or any other). While you're at the job, you can also clean the throttle body (also described in this article), to get a smoother idle.
The job:
1. Remove the pipe leading from the grill to the airbox and the pipe from airflow meter and throttle body.
2. Cut this pipe just before the first ridge after the smooth part. This should be the correct size for the throttle body.
3. Make another cut after the second ridge up from this (about 7.5cm). This will be a tight, very tight fit on to the outlet of the airflow meter (check it fits before you do any more).
this picture roughly shows where you cut
4. Roughly central on this piece of pipe, cut two hole's for the supplementary air device and breather hose spigots in similar positions to that of the standard hose (90deg. apart). The best way to do this is with a piece of tube of the right diameter and a lump of wood inside. Hammer the tube through the hose in the required places. If you have a spare SAD spigot use this to cut the holes.
5. Carefully remove clips from around spigots on the original hose and take the spigots and fit to new hose.
6. Remove the remainder of the intake system, airbox and AFM. Including the AFM support bracket.
7. Fit new cone or cylinder air filter to AFM inlet (130mm long, 100mm diameter with 70mm neck). You can see from the pictures that my filter is sat nearer the AFM, this is because I have used a Green top hat adaptor on mine to do away with the original longer black one & gain more room between the filter & washer bottle / washer motor. I got mine from Demon Tweeks - Product code: GREBR01V TOP HAT ADAPTOR, (£12.99 + vat & delivery). Your choice but a worthwhile addition I think.
everything assembled and ready for fitting
8. Clean inside the throttle body with some carb cleaner while you have access, move the butterfly to get greater access.
9. Fit new hose to airflow meter and place in line with throttle body and attach breather and SAD hoses to spigot's.
10. Tighten jubilee clips to hold everything together.
11. Make a bracket to support the AFM to the slam panel either from removed AFM bracket or any other metal plate available. Attach to one of AFM bolt holes with bolt removed from original bracket. Use any M6 nut and bolt to hold bracket on slam panel, drill a hole in required place. Be careful when drilling you are above your radiator!!
12. Fit it all into the engine bay and clamp it onto the throttle body. Carefully turn the airflow meter to a suitable position to allow the plug to reach with some slack. Tighten everything up.
your new shortened induction kit installed!
13. Start the car and check it ticks over as it did before you started. Nothing should be different because you shouldn't have adjusted anything.
14. Book you car in for a rolling road session ASAP to correctly adjust your fuelling. Preferably take it to a Bosch injection specialist and have the whole system checked properly if you had any cold running problems before.
15. If your tickover is a bit bouncy, like many, remove the brass adjusting screw from the throttle body and clean it with Brasso or some metal polish until it gleams and spray some carb cleaner through the hole it fit's in to. Count the amount of turn's out take's to unscrew it form the throttle body and retighten it by the same amount This may not cure it completely but when you take it for the rolling road session they should be able to fix it. I have been told spraying carb-cleaner around the bypass next to the flap on the airflow meter can also fix this. You can also clean through the bleed air screw housing on the throttle body with the carb cleaner, remove the idle speed screw and with the engine running at a high tickover (use the quadrant on the throttle body). With the straw in the hole, cover the hole with your thumb or finger an spray a bit at a time. Keeping an ear listening for the car starting to struggle and be ready to give extra throttle if needed. Keep the hole covered or the car will stall. After this stop the engine and refit the idle speed screw and set your tickover as it was before and you're done.