I contacted Mattias about setting up VEMS on my BMW 535 (E28) on which I has a twin turbo setup. More information here (in Swedish): http://www.535twinturbo.com/
I previously ran with SMT6 but that was just crap.
Engine information
- Mostly stock M30B35, a 3.5 litre 6 cylinder even-fire inline (not odd-fire V6) engine with ~210 hp N/A with stock engine management
- 2 x Garret T3 from Saab NG900/OG93
- Custom exhaust manifolds
- 2 x EGT K-type thermocouples in the collectors
- 6 x 380 cc/min @ 3bar high impedance injectors
- Single coil and distributor (for initial setup, direct-fire setup might come later)
Trigger setup
The stock reference and speed sensor are not useable with VEMS as far as I know, these are mounted at the back of the engine. One measure engine speed through 360 teeth, the other syncs with the engine once every revolution. So it's kind of like a missing tooth setup - only it isn't.
The solution that will be used: Three M8 bolts will be fastened to the harmonic dampener at the front of the engine, 120 degrees apart with 8 mm protrusion. A Honeywell GT1 Hall sensor will be used to sense these.
What ign_tdcdelay (position of the pulses BTDC) will you use ? 55..65 crankdegrees ?
I get the zero mark line up with the mark on the engine on 45degrees
Assembled v3.3 controller wishes
- both primary and secondary trigger inputs should be of HALL type.
- MPX4250AP 255kPa MAP sensor mounted onboard, with frontplate mounted 6/4mm pneumatic connector.
- Serial RS232 is usually EC18pin14 and EC18pin15 (can be DSUB9 if you insist)
- LCD through frontplate
- PS2 through EC18
- 2 x AD597 chips (normally they have to be added to the order and mounting is free
- 2 x compensational cables through the frontplate, flying loom style
- 2 x K-type female chassis connectors (mounted by me)
050926 - Problems of the day
SOLVED - Switched Polarity
- EGT sensors dosent work, just show 16c when engine off, and when engine ON it jumps between 16c and 60c Is it just switched plus and minus or what?
- Switched polarity have different syndromes. Check ohmage (or voltage during operation) between the sensor wires and GND (should be near 0 Ohm and 0V)
SOLVED - fuse didnt have 100% contact whit the cabels
- Lambda act a little strange and unstable, yesterday it work perfektly but tobay it just "freezes" at like AFR17.95
- publish config, and preferrably the relevant LCD page too (the page that displays nersnt and Ri). Maybe capture the output of "perl bin/wbo2log.pl :COM2 mde02"
050928
- Now the engine fires up om the priming fuel, and then dying instantly after that. I´ve tryed the reg_fuel value frpm 1.0 to 10.0 and the "VE Table" 30% all over, but nothing can fire my engine up anymore, sparkplugs looks fine and are not completely fueled up.
- Have you checked secondary trigger settings? one of those settings has to be 02 when not used..
- Does it often hapens that configs chenges when voltage drops verrymuch? like yesterday by batterycharger whent crasy and overheated or something så megatune lock´d the voltage gauge to 6volt, can this damage the configs or something? I ask this beacuse the engine has works and run perfectly (except some EGT heat problems ond so on) but then something has happend, and if secondary trigger has changed i promise you i didnt touch it
- If you board resets while you are in another view in megatune, and change it, stuff can change. So make sure to exit all views (main view with gauges is safe) when you are cranking and are low on power.. //Emil
- And when does a "reset" happens? yes but this happens whan i tryed på upload the VE table to the box and then a box appears thats says "...cant upload beacuse to low voltage..." so i click NO och fix the problem with the batterycharger, try one more time and now i can uppload but some of the configs have changed, ive never crankd when now power so i dont se why it changes, is it a bug or cant i have now power 1time without fuck up the boxs config?
- There is a bug currently (going to be fixed in a newer version soon), if you restart the box (with or without meaning it) while you are in another view than config (i.e VE table), the VE data will be uploaded where the config should go.. which fucks stuff up.. so Dont restart your box while inside another view.
- And NOW u guys say that, dammit, then i have to start from the beginning again... =)