I am assuming you are using the M42 motor (not the M40 or M43).
1. If so, there are couple of mods that could improve your HP. there are usual ones like doing a CAI (it has to be CAI not just a mushroom filter that sucks hot air from the engine bay).
2. Straight thru exhaust/mufflers to improve flow.
3. Using better spark plugs or CDI devices. Simple mod is to solder a capacitor to the + and - of the wire to the ignition coil. But have to experiment with getting the right values. bosch IR fusion are good stuffs. Also use magnecor wires will improve things a little.
4. Chipping will give you the biggest possible boost but its not exactly cheap. Using a piggy back is another solution.
5. Adjusting your cams. Yes, this is not very well documented but M42s come with adjustable cam sprockets. You can advance your intake cam a little to boost power (eg. 5 degrees)
6. 4-1 exhaust extractor from ebay. Cheap and boost high end but at the expense of low end.
7. minor things like 5 point grounding etc may also help a little.
8. Fan delete mod. Remove the clutch fan and use an electric fan instead.
9. Remove your AC compressor (if you don't mind the heat). Using an electric pump for power steering or remove PS pump completely.
10. Replace ancillary pullies with those lightweight underdrive ones. Eg. Ruff engineering pullies.
11. remove water pump and use electric water pump instead. Require customising though.
12. Lightweight clutch or M20 clutch. The stock dual mass clutch kills performance.
All these will gain you quite a fair bit of performance. Of course its not going to be tremendous but do expect at least 20-30HP gain easily. |