M800 on E30 M3 (1989)

[razirafi]

Hello to all, I am currently working on completing a harness for the E30 M3 that will be used with the M800. I would like to ask for help about a few things.

1) The engine has a cylinder identification sensor (DME pins 25 and 26).
2) An engine speed sensor that reads the flywheel teeth (DME pins 8 and 27).
3) A TDC sensor according to the ETM (but is not connected to the DME).

Q: May I know which among these should be used for the REF and SYNC inputs? I have read that some are using some other type of trigger wheel and sensors. Can someone provide me info or a link to some info about this?

4) There is a BARO pressure sensor (DME pin 30).

Q: Can I use the Manifold Pressure input (A15) on the M800 for this? Is is advisable to make use of this sensor instead of a MAP sensor?

5) There is an integral sensor that combines Air Temp and Vane Airflow Meter

Q: If I connect these pins to the M800 directly will it work? In the ETM the sensor (supply) reference voltage (5V) flows through the Vane Airflow Meter resistance before it goes to the Air Temp sensor so I am inclined to think that the Air Temp sensor does not receive the full 5V reference.

6) Do I need to install another TPS on this setup? In the ETM, it looks like it is only a switch for closed throttle and WOT.

I have experience with wiring up and software setup of the I/Os of aftermarket ECUs like the AEM, ViPEC, and Motec (for the Mitsubishi EVO) but they were more or less straightforward as compared to this one for the E30 M3. I need help with this one so if anyone is willing to provide suggestions or a pinout chart of their setup, please do.

[Dragon]

I have tried the original crank triggers. It did not work well with M800.
I would suggest you install a trigger disc on the crank pulley instead.
You will need to add a sync sensor.
I think VAC Motorsports do a kit, although we did build our own.

Baro sensor cannot be used as a MAP sensor.
You can add one but it is not absolutely necessary although desirable, if engine is NA.

You can replace the airflow meter with a tube and mount an air temp sensor to it. This is always how I do it.

You will need to mount a proper TPS sensor.

[stevesingo]

Agree with the Dragon, the M800 can not use the original S14 crank sensors.

I have used a S38B38 (E34 M5) cam sensor on the inlet cam.

http://bmwfans.info/parts/catalog/E34/Sedan/Europe/M5_3.8-S38/1995/june/browse/engine/timing_and_valve_train_timing_chain/
Parts 9,10,20,21&22

http://bmwfans.info/parts/catalog/E34/Sedan/Europe/M5_3.8-S38/1995/june/browse/engine/bottom_housing_mounting_parts/
Parts 8,9,12,13&14

Alomost a direct fit, you just need to turn down the shoulder on part no 9 on the first link.



For the crank I made my own hub to take a trigger wheel (12t) available in the UK.



This was made with an interferance fit, heated up (with the pully in the freezer) and dropped on.

The pully was then fitted.


I have since elongated the pully holes to correct a sync rel position.

The sensor bracket was also made by myself



This used a BMW M42 crank sensor. Both sensors are inductive.

[stevesingo]

The stock baro is no good for use with the M800, you will need a 1bar map sensor to deal with baro.

The stock vane air meter is also no good for M800 (it is restrictive anyway). 95% of those changing from stock EMS on the E30 M3 move to A/n (TPS vs Engine Speed) for load calculation.

If you don't want sequential injection you can forego the cam sensor and use a 36-1 or the like on the crank only.

Have a search on http://www.s14.net for all things E30 M3.

[razirafi]

Oh wow, thanks for the info. I now have a better understanding on how to deal with this setup. With regards to the Baro, I did not plan on using it, I just needed to know if it can be connected to the MAP input and maybe tweak it in the parameters. Since most of the guys doing an ECU swap go for an Alpha-N setup, I will seriously look into and study this. With regards to the crank trigger wheel, am I correct in thinking that there needs to be an optimum tooth width (the actual physical width of one tooth, not the gap betwwen teeth) in relation to the effective sensing area of the crank sensor? Also, for a specific diameter trigger wheel with a set tooth width, will the tooth width need to be adjusted if the trigger wheel diameter is changed?

From the help that you guys provided, I am looking at this setup:
1) A real TPS
2) Air Temp Sensor that is a separate item from the stock AFM
3) Crank Trigger Wheel
4) Cam Trigger Wheel
5) MAP Sensor (I think I see some difficulty here as the S14 has ITB)

...did I miss something guys?

P.S. I am not sure if I used the correct term for the actual physical width of one tooth as "tooth width".

[stevesingo]

My trigger wheel is the Ford CV Joint Trigger wheel at 120mm dia with 12 equally spaced teeth. That is a circufrence of 377mm. 377/24= 15.7mm tooth spacing. It works fine with the BMW sensor.

http://trigger-wheels.com/store/contents/en-uk/d24.html

If you don't want sequential injection, you can use a 36-1 trigger with either the stock distributor or wasted spark. As you will probably have to make a new loom, you may as well go for sequential with individual coils as it is not much more work. I'm using Denso coils off a Honda VFR800 motorcycle with a 30mm extender fitted to make them long enough. No issues so far.

I am running MAP correction on my set up, but the map signal is pretty noisy at low engine speeds/wide throttle openings. I'm not convinced of the value of this at this time and my try it without, just correcting for baro.

Like a wrote, the S38b38 cam sensor is the easiest and chapest to use.

You will need a TPS. I use the BME E46 M3 sensor with a spacer from here...

http://www.massivebrakes.com/accessories.php?p=S14_TPSadapter

It is neat and tidy.

Air temp sensor mounted in the intake would work fine. There are a few intake options from the carbon DTM replica I have or the "Rongineer" box
http://www.rongineer.com/m3airboxkit.html

Which looks stock.

I am also driving my temp water gauge, oil temp gauge and oil light from the spare ouputs on the ECU. I have a cal file I can share and probably drawings for the crank trigger set up also. drop me a PM if you need them.

Steve

[AdamW]

With regards to the crank trigger wheel, am I correct in thinking that there needs to be an optimum tooth width (the actual physical width of one tooth, not the gap betwwen teeth) in relation to the effective sensing area of the crank sensor?

Yes, for a VR sensor the ideal tooth size is 1-2 times the size of the pole piece inside the sensor, generally about 5mm will be good for most crank sensors

5) MAP Sensor (I think I see some difficulty here as the S14 has ITB)

.
Use a 1Bar MAP sensor but don't connect it to measure manifold vacuum - either just leave it open to sense atmosphere or connect it to the airbox/engine bay to compensate for any aerodynamic effects.

[Dragon]

For ref sensor, we have tried a Honda Hall sensor (from K20A engine) and a MoTec slim magnetic.
Both works well for a 12 teeth wheel. We had a custom pulley made.
We used a GT101 Hall sensor for sync with special mounting adapter.

With multiple throttle bodies, one would use TPS as load axis with MAP providing the correction.
We did a few road cars with this config and it worked well.
All our cars were NA.

[razirafi]

Thank you so much for the insights, suggestions, and info on the parts to be used. I will go about this starting with the selection of the mechanical and electrical parts. Then installation and alignment of the parts, as well as completion of the ECU wiring harness. Once I will have this ready and start the tuning process, I will post my observations and questions if I will encounter problems along the process.

Thank you very much Dragon, stevesingo, and AdamW.