Engine management

[ed325i]

Would it be poss to fit the complete engine management from the m50 engine to a m20 so the air mass meter and coils could be used.

[Turbo-Brown]

Only if you could adjust the fueling and ignition.

The ignition would be miles out for the M20 and the fueling probably wouldn't be right either.

[ed325i]

If I was to use a m52 2.8 system on a m20 2.8 would it be miles out ?

[Turbo-Brown]

The ignition would be even if the fuel wasn't, and a 4v head has much more capacity to breathe than a 2v one.

Don't forget you'd need to rig up a cam position sensor too so that you could run the sequential ignition.

[ed325i]

Don't forget you'd need to rig up a cam position sensor too so that you could run the sequential ignition.

I didnt know that thanks

[Turbo-Brown]

Probably wouldn't be hard to do, but the trigger would need to match the format of the M5x engine which might just be a 'plip' or it might be something more complex.

[Gunni]

Turbo Brown, remember that..
The motronic only measures air mass, so it would infact inject the correct amount as measured by the MAF,

The timing on the other hand would be way off, probably beeing more retarded then a M20 with equal compression,
raising the compression on the M20 would push it closer to the specs of required ignition advance as the M5X

and yes the cam sensor would be needed,
If the crank sensor would be adjustable it could be moved to "fix" the timing ,

standalone would be alot easier

[Turbo-Brown]

Does the Motronic just use the TPS for accel enrichment or something? (I'm basing my assumption that there is a TPS on my S50 having one).

[ed325i]

If the ecu was for a m52 2.8 and the m20 was a 2.8 would the timing be out ? As its the same crank.

[Ant]

Timing will still be miles out ED, 4 vlave heads generally require far less advance on the ing.

[Gunni]

But as I said if you can move the Crank signal to comp then you should be within the ballpark of usable advance

[Ant]

I see where you're going here Gunni.

you propose moving the trigger angle away from stock to compensate, 2 teeth would be 12 degrees, but thats accross the board so (example) 10 degrees advance @ idle would be 10-12 = retard 2 degrees, IMHO the ECU would still need the igntiion tables remapped to suit the 2 valve configuration.

the cam phaze signal would need tweaking by 50% of that to tie up both ends.

Could well work, but I dont fancy R+D ing it

[Gunni]

what you would do is move it to advance the curve all together,
as in general 4v heads have less advance across the board,
so by moving the sensor further forward, maybe just a single tooth, you´ll have 6degrees more advance everywhere,
beeing 16 at idle, or so,
and so on,
a tooth and a half would make idle stick at about 19degrees. and advance all the maps 9degreess wich is acceptable vs. the 4v head.