I contacted Mattias about setting up VEMS on my BMW 535 (E28) on which I have 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.
- Proper tdc_delay has not been set due to misunderstanding settings
- tdc_delay should be 60 degrees before TDC
- Crank advance must be set to 0 to align the TDC marks on the engine/crank
- Will report back on the correct tdc_delay within a day
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 verymuch?
- If you board resets while you are in another view in megatune, and change it, MegaTune can ruin config: See GenBoard/UnderDevelopment/FirmWare/Settings. So make sure to exit all views (main view with gauges is safe) when you are cranking and are low on power.. //Emil
- Upload the config settings that I sent you initially, that will remove any doubts about variables that MegaTune may have altered to strange values. The secondary trigger setting is probably not the only setting that changed. //Mattias
We are working on a workaround to stop MegaTune trashing config - even if the board resets.