MoTeC Global Forum

I think that there is only ref sensor available (4+1).
Anyone with some experience?

The Motronic on the e30 m3 uses the starter ring gear teeth as the engine speed and a peg on the flywheel for the ref signal. AFAIK there is no such option on the M4.

You will need to fit a trigger wheel to the crankshaft damper for the ref. You can use the sync sensor from a E34 M5 with a little work.

Will you be building a new loom? If not you are restricted to batch fire injection.

Some links for you

http://www.massivebrakes.com/accessories/trigger-wheel-and-bracket/
http://www.massivebrakes.com/accessories/s14-tps-spacer/
http://www.massivebrakes.com/accessories/s14-block-off-plate/
http://store.nexternal.com/vacmotors/vac---s14-crank-trigger-kit-w-sensor-p1609c167.aspx?Thread=True



Steve

Steve thanks!

It is an historic class Gr.A rally car. I have to check first if it is allowed to change anything on original trigger system. Regulations are very restricted...

Yes. It will be a new loom. Sync sensor will be a problem. I hope that I don't have to pull camshafts out from the engine (again)

But first I have to learn old M4 trigger modes again.

There is BMW mode 171-173 in the M4 but I am not sure if this applies to the standard setup.

You could also try ref/sync mode 11 -14 with a high tooth count (135) + sync and set the injectors for group fire. This mode works on 944 Porsche I think which has a similar flywheel setup

Mazi,

I am in the process of fitting an E34 M5 S38 cam sensor to my S14 engine, it is pretty simple. If you look here you will see what I mean.

http://bmwfans.info/parts/catalog/E34/Sedan/Europe/M5_3.8-S38/1995/browse/engine/timing_and_valve_train_timing_chain/


http://bmwfans.info/parts/catalog/E34/Sedan/Europe/M5_3.8-S38/1995/browse/engine/bottom_housing_mounting_parts/

You need to fit it to the inlet side, not the exhaust, as the exhaust has three studs, not two. You also need to have a little material removed from part 10 in the second link, but that is an easy job for any machine shop.

The sensor is mag.

SprinterTRD,

The motronic uses the starter ring gear teeth for the engine speed pulse and a peg on the flywheel for TDC Ref. That is two sensors just to establish engine speed and ref. There is only two speed sensors on the M4, so sync will not be possible with the original ref set up.


Steve

Steve, You are confused with the MoTeC terminology,

The ringgear is the REF input in the ECU which measures engine speed and crank angle.

The SYNC input on the ECU is the single pin. This input is used to tell the ECU which cycle (inlet/exhaust) number one cylinder is on. To get sequential injection the Sync pulse only happens once per 720 deg.

This is 2 sensors to 2 ecu inputs (Ref & Sync) the Digital (speed) inputs are not used.

In some special REF/Sync modes digital 1 is used as the sync input. It is all explained in the online help when you highlight the Ref/Sync parameter in setup and then press the F1 key.

In the case where the flywheel is used for both signals the injector setup is set to a group fire mode which means all the injectors will fire in 360 deg.