M3 ECU

[tomk]

I've been offered an e36 M3 engine but it doesn't have its ECU. Is it going to be hard to source a replacement, is it tricky to map? Any idea of rough cost, second hand or new?

Thanks
Tom

[jmc330i]

Which M3 - 3.0ltr or 3.2 Evo?

If its the 3.2 (or very last of the 3.0ltrs) it will have the EWS security system and it will be pretty expensive to buy the matching ECU and EWS stuff.
I wouldnt of thought the 3.0ltr ECUs (non-EWS) will be that expensive, but I dont know how hard it would be to find one. If it is a 3.0ltr, you need to check youre also getting the Vanos ECU, as its a separate unit to the main engine ECU - the 3.2 Evo has an all in one ECU.

If the engine was cheap enough, I would probably buy it and run it on MS, Emerald etc and lock the cams - ok you would lose the Vanos, but AFAIK it can mapped to run with pretty healthy power figures that way.

[tomk]

The engines from an L plate car making it a 93/94.

Am l right in thinking that M3 E36s, 93 and after have vanos? what year was the final 3.0ltrs?

Thanks for the advice James.

[Ant]

Standalone it dude.

VEMS can handle the VANOS if you wanted to use it ?

S/Hand ECU will be the easy option, provided its non-EWS as stated by James.....

[Gunni]

I vote for a standalone, and then post the maps when done ;)

Locking the cams is not going to slow or weaken the bottom end that much,

on my 3.0 the vanos didn´t activate , making 10 more nm´s at 3k,
that was it...

what the non actived vanos did tough was steal about 50hp from the top end !

[tomk]

This is what Rob at Vems suggested, what do you think? Good website aswell.

VEMS Motronic55, plugs into the stock ECU harness (although you will need to
check that the harness is a 55 pin connector - some have more pins than
that). These come in at £598.30

Altenatively a VEMS of the right spec Primary VR, secondary HALL, MAP
250kPa, ignition driver 6+2 £345.22
Means you can make your own loom up by buying the plugs and wires for £49.39

Or (what I'd go for personally) a pre-made harness with all the connectors,
fuses and so on for a straight 6 which comes in at £133.20.

Then the wideband sensor comes in at £53.83, which is an essential peice of
kit as it makes fuel mapping so easy.

[jmc330i]

The engines from an L plate car making it a 93/94.

Am l right in thinking that M3 E36s, 93 and after have vanos? what year was the final 3.0ltrs?

All the E36 M3s have Vanos, the 3.0ltr has single and the 3.2 double.

As for the EWS, being from a 93/94 M3 it shouldnt have EWS. The 3.0ltr M3 ran from '93 to about mid '95 and its the last few '95 models that have EWS - AFAIK all E36s from Jan '95 have EWS fitted.

It sounds like finding a secondhand ECU will be the easiest and cheapest option (dont forget to check about the Vanos ECU), but if I had the money to do it, I would go standalone - I would like to hear more about the VEMS

[Jhonno]

I have an ecu that was sourced for my 3.0 non ews m3 lump as the engine came without to begin with.. Reciept was for £293..

[HairyScreech]

posibly somthing only ant can answer but wont ms be able to use a switchable output and a look up table to set the vanos?

[Gunni]

This is what Rob at Vems suggested, what do you think? Good website aswell.

VEMS Motronic55, plugs into the stock ECU harness (although you will need to
check that the harness is a 55 pin connector - some have more pins than
that). These come in at £598.30

Altenatively a VEMS of the right spec Primary VR, secondary HALL, MAP
250kPa, ignition driver 6+2 £345.22
Means you can make your own loom up by buying the plugs and wires for £49.39

Or (what I'd go for personally) a pre-made harness with all the connectors,
fuses and so on for a straight 6 which comes in at £133.20.

Then the wideband sensor comes in at £53.83, which is an essential peice of
kit as it makes fuel mapping so easy.

That Ecu will NOT work with the S50.. not even close.

posibly somthing only ant can answer but wont ms be able to use a switchable output and a look up table to set the vanos?

The S50 vanos is not switchable as it´s variable of about 40° cam timing on the intake cam , and that requires full on maps in the engine management system.

Honda Vtec is switchable as is the Toyota VVTi system I belive

[Jhonno]

Gunni.. Ive spoken to 2 people now who are looking at running an s50 off standalone (one is Omex) the other has apparently already been done by Ant using VEMS, by using a modded ICV and another outputs and copied tables or something..

[Jhonno]

the vanos runs off a pump to increase/decrease oil pressure in the unit to drive the vanos 'gear'.. Surely that is switchable/mappable as its a simple on off or similar

[Gunni]

I feel that if you don´t have dedicated vanos map your just guessing at the degrees of timing you have

The vanos gear is driven via 100bar oil pressure, the pressure is released onto either side of the cam gear house
via electronic pmw valves, when the ecu sees the gear at the right cam angle the both close and the cam is locked in place, this happens really fast and continuesly

You have to control two PWM outputs at the same time trough a logic control,
i.e the ecu sees the cam at 25deg, it checks if it should be at that point during the current load and rpm operation,
if not then wich valve should open????

[tomk]

Thanks guys, looks like l'll be looking for a replacement ecu then. Anyone?
Going to have a look at the engine tomorrow night

[1an]

Ant said already that he can map it on vems, why not spend the extra and have a standalone management and make the most of the engine?

[dannyboy759]

German ebay is your best bet for parts like that, they dont seam to charge over the top prices like breakers etc do over here

[tim_s]

Thanks guys, looks like l'll be looking for a replacement ecu then. Anyone?
Going to have a look at the engine tomorrow night

funnily enough I have an e36 m3 3l S50 ECU (0261203075) and matching VANOS control box for sale! pm me