E30 Zone

I have recently bought a 1986 323i, and want to retain the M20 engine. Obviously, chips are out as this is a non-motronic car, but what would my first step for tuning be? Am thinking of stainless manifold and exhaust but would be curious to know what others think. Not interested in an engine conversion. Obviously, the scope for tuning here is limited so really want to go for 'biggest bag for the buck' mods. Any pointers greatly appreciated.

Easiest way to boost power with an M20 is a capacity increase!

If you can find a servicable eta engine,swap your head onto it and try that.

Eta engine is the 2.7 M20 fitted to the E28 525e,BTW.

BTB make the best of the exhaust manifolds,but you will need to dig deep to buy..

When I had L-Jet 320i 's, a couple of tricks I did were to remove the centrifugal rev limiter from the rotor arm, as it cuts in rather brutally at 6,000 rpm, totally killing the ignition - almost like driving a diesel! The ECU in any case, has a built in rev limiter, which cuts in more progressively at around 6,250 rpm, so there's no harm in doing this.

This makes quite a surprising difference when you're really gunning it, as you don't just 'hit a wall', it gives you a little more opportunity to use the power band.

Another trick is to advance the distributor as much as possible until it just begins to pink going up a hill in a high gear, then back it off a touch until it just doesn't pink. Then your ignition timing will be optimised for the engine.

Don't forget, alot of these will have been set up for fuel used 25+ years ago, and the octane rating of today's fuel may well be different, so it pays to adjust the timing to compensate.

Make sure your cambelt is in good condition before going in for any tuning though!

you can convert the car to motronic if required not easy but it can be done there was a thread on here then you can have a M20 2.5 2.7 , 2.8 if required. but the conversion to motronic 1.1 or 1.3 can be done with a few days spare and reasonable mechanical/ electrical knowledge