any point tuning the m20b20?

[JazzyE30]

any point tuning the m20b20? i have used the search and most say no point chucking money at it but i have a good low miles motor with full s/h but its so slow up until now my daily runner has been my mk2 golf gti fitted with a 2ltr bottem end cam etc i want the e30 to have the same sort of kick as the golf but it just dont feel very punchy if you know what i mean? i got the e30 for the mrs but fell in love with it as soon as i drove it home so the golfs going can use the money from it to put into the e30 but am i wasteing my time with this motor?

[Gunni]

Get another engine or put a turbo on the B20.

[320Touring]

The m20b20, despite the beating it gets on here, is a good engine..

Its Oversquare, so rev's well!

Easiest mods to get some additional Oomph are

1. Service it! get the tappets set correctly, and spark plugs gapped properly. Change the cambelt waterpump and tensioner.

2. Fit a 2.5 m20 Inlet Manifold AND throttle body- Once you change the Chip in the ECU, it should free up some torque and BHP

3. Depending on the year of your car, you may be able to upgrade to the later Motronic 1.3 engine wiring and ECU, so you can get the fuelling air and spark mapped correctly to take advantage of the 325i TB and manifold

4. Getting more radical, a 323i camshaft (266 degree duration) would liven the engine at higher RPM.


The best advice is also the cheapest..

get to know your car, learn it's limits (preferably NOT on the public road ) and learn to carry the momentum- if you dont slow down, you dont need to put the speed back on

[JazzyE30]

The m20b20, despite the beating it gets on here, is a good engine..

Its Oversquare, so rev's well!

Easiest mods to get some additional Oomph are

1. Service it! get the tappets set correctly, and spark plugs gapped properly. Change the cambelt waterpump and tensioner.

2. Fit a 2.5 m20 Inlet Manifold AND throttle body- Once you change the Chip in the ECU, it should free up some torque and BHP

3. Depending on the year of your car, you may be able to upgrade to the later Motronic 1.3 engine wiring and ECU, so you can get the fuelling air and spark mapped correctly to take advantage of the 325i TB and manifold

4. Getting more radical, a 323i camshaft (266 degree duration) would liven the engine at higher RPM.


The best advice is also the cheapest..

get to know your car, learn it's limits (preferably NOT on the public road ) and learn to carry the momentum- if you dont slow down, you dont need to put the speed back on

thank you some good info there
first thing i done was set the cam rockers to 0.25
will start looking for a 2.5 inlet
car is a 84 so think its the old ecu set up not sure if anyone does a chip for it

[Speedtouch]

An '84 car will have the analogue L-Jetronic, so no chip available.

However, a tweak you can do is to remove the rev limiter from the rotor arm (spring-loaded centrifugal 'switch' that grounds out the HT at high rpm.) Fear not - there's a rev limiter set into the ECU anyway, at around 6,250 rpm.

This mod gives a much nicer 'soft' rev cut-out rather than the brutal 6,000 rpm cut out of the standard set-up.

Also, advance the distributor as much as possible by undoing the base clamp and rotating it clockwise in small increments until it just pinks on hills then back off a touch.

Worked on my '84 and '87 L-Jet 320i's. In fact, the '84 was quite quick, doing 0-60 in around 8 sec onto a top whack of 125 mph

[Jim320i]

Also, advance the distributor as much as possible.

What do you mean by this fella? Also trying to improve my 320 chromie but without modding it withextra parts etc and theres no chips for it.

Also, my dizzy and rotor arm are the one that sits under the inlet manifold... Can the mentioned above work on mine?


Sorry to hijack the thread!

[Speedtouch]

As above, slack off the dizzy base clamp and turn it clockwise as described.

Yes, I meant the type that sits in the block under the inlet manifold.

You'll need to remove the rotor arm and look underneath it to see the spring-loaded switch - just remove it.

[Jim320i]

Thanks pal! I'll give this a shot tomorrow.

Turning dizzy cap section, wont it take the timing out on the dizzy? Or am I talking nonsense?

[320Touring]

The m20b20, despite the beating it gets on here, is a good engine..

Its Oversquare, so rev's well!

Easiest mods to get some additional Oomph are

1. Service it! get the tappets set correctly, and spark plugs gapped properly. Change the cambelt waterpump and tensioner.

2. Fit a 2.5 m20 Inlet Manifold AND throttle body- Once you change the Chip in the ECU, it should free up some torque and BHP

3. Depending on the year of your car, you may be able to upgrade to the later Motronic 1.3 engine wiring and ECU, so you can get the fuelling air and spark mapped correctly to take advantage of the 325i TB and manifold

4. Getting more radical, a 323i camshaft (266 degree duration) would liven the engine at higher RPM.


The best advice is also the cheapest..

get to know your car, learn it's limits (preferably NOT on the public road ) and learn to carry the momentum- if you dont slow down, you dont need to put the speed back on

thank you some good info there
first thing i done was set the cam rockers to 0.25
will start looking for a 2.5 inlet
car is a 84 so think its the old ecu set up not sure if anyone does a chip for it

The loom swap is actually fairly easy- you just need the full loom fron the engine bay, the later ECU and the crank pully wheel- any post 1988 6cylinder setup would work (320 and 325)

[Jhonno]

The short answer is no.. Throwing money away after little gain.

[JazzyE30]

hmmm iv got a Porsche 944 2.5 Engine sitting here doing nothing lol i told her in doors i wouldnt play with this one ......the e30 is yours dear i wont touch it.......

[Speedtouch]

Thanks pal! I'll give this a shot tomorrow.

Turning dizzy cap section, wont it take the timing out on the dizzy? Or am I talking nonsense?

If you're worried about it, just mark the original location using Tippex or similar, then it can be reverted back to original if need be. Most are probably in need of adjustment anyway!

[Jim320i]

Well I only just done the cambelt & waterpump service the other day on here and took me a while and with a little help from Daimlerman, I reaslise the dizzy also had to be timed up...

[Speedtouch]

Indeed. A car I currently run has a Fiat twin cam, which should be set to 10 degrees of advance at 850 rpm. It was on TDC (no advance at all!) and ran quite poorly. When set to the correct setting, what a difference it made!

[Jim320i]

So, i'm just turning it clock wise until it wont go no more? Ignoring the marking etc? Assuming it will go well past the markings at this point...

[Speedtouch]

No, with the engine warmed up, turn it just a little at a time, maintaining a good idle, tighten the base clamp and take it for a run up a hill in high gear and listen for any pinking (pre-detonation).

You want to get it as advanced as possible but without any pinking.