MembersPage/MarteleurTim (2005-08-09 22:55:38)

I want to turbocharge my BMW 518i E28 M10 engine by using VEMS


Trigger secion

... describe the available trigger signals (links are OK too)

Current plan for Ignition

I keep the distributor, lock plate in the distributor and rotate so that the inductive pickup triggers 50-60° before TDC, remove vacuum hose.

Q: Will this signal be controlled by an ignition IGBT and fire the coil by another ignition IGBT?

A: The input from the distributor trigger is sent to trigger input #1 in the EC36 connector. The ECU then timing advance and fires the coil using one IGBT, also in the EC36 connector.

Changed plan:

I keep distributor only for distribution. I use Hall sensor on crank as a trigger input for the VEMS.


ITEMS TO BUY:

I recommend buying a pre-assembled Genboard to avoid this part of the project, but in case you feel confident with electronics and like the idea of saving some money - then go ahead. I would advice you to fully populate the board with as many fuel injector FETs and ignition IGBTs as you can afford - they can be used for a lot of other things and the minium I'd recommend is 6xFET + 5xIGBT. That allows you to run a direct-fire (distributorless) setup in the future.


Q: What about TPS? Should I look for a TPS with WOT switch and potentiometer?

A: You have to use a true potentiometer type TPS for full use and control, a WOT switch is useless and has no function with VEMS Genboard. In the tuning software you configure and calibrate the maximum and minimum TPS values (idle and WOT). You can also set the idle threshold value (1-2%).

Only in some cases do you really need to know the exact position of the throttle plate. You can use a resistor grid with the stock "on/off" TPS, to make three distinct positions/resistance values (idle, in between, WOT). It has worked really well on this car: MembersPage/MattiasSandgren/BmwSevenTwentyEight

The basic idea is to connect the TPS In (EC36-1) to a pullup resistor towards +5V (EC36-28) and a pulldown resistor towards GND. The pullup resistor is shorted by the WOT switch (raising TPS In to +5V) and the pulldown grounds the signal. To protect from a short (should never happen), connect a resistor between GND and the pullup resistor and Idle-switch so that there is a minium resistance to be met between +5V and GND at all times. Use 1K resistors, or similar size. I'll make a pretty drawing if/when I have time.


Q: How will I control coldstart issues?

A: First by tuning the coldstart fuel enrichment. To avoid having too much air enter the engine when it has warmed up, get an idle air solenoid from a Motronic car and do like this: MembersPage/GergelyLezsak/IdleControl