My project is to turbocharge a BMW E30 325i M20 engine.
Engine specs:
- cyl count=6
- main trigger= 60-2 on crank http://www.vems.hu/wiki/index.php?page=MembersPage%2FGergelyLezsak%2FTrigger
- stock internals
- T3/T4 turbo 50 A/R Compressor, 0.63 A/R Turbine .57 Trim 3" inlet stage 3 wheel
- Oil cooling on pistons http://www.e30tech.com/forum/viewtopic.php?t=5223
- Intercooler will be as big as possible
- Lime green 440 cc bosch high imp petrol injectors
I guess we have a lot in common: http://www.vems.hu/wiki/index.php?page=MembersPage%2FGergelyLezsak
read: original MegaSquirt documentation besides VEMS manual, since MegaSquirt is basically the same.
[GenBoard Version User's Manual]
http://www.vems.hu/wiki/index.php?page=GenBoard
Q: Which parts do I need to get full control of injection and spark?
Assembled v3.3 controller
- ignition driver 8
- Knock and EGT knock and 2 EGT
- LCD and PS2 yes
- MAP connection offboard(electronic)
- primary_trigger VR
- secondary_trigger HALL
I want to use a bosch map/temp sensor I'll get the number later on. Pro's con's mapsensor
- mounting
- line though firewall
- speed
IAT sensor: GenBoard/Manual/IntakeAirTemperature
- faster then stock bosch
Spark control
With your stock 60-2 wheel you can control a wasted spark coilpack directly with VEMS without any additional triggers. You can borrow a coilpack for a 6 cylinder car from an EDIS6 equipped car, like a Ford V6 (You don't need the EDIS module itself, just the coilpack!).
Laptop connection: Basically you use the serial port on the computer, and the corresponding port on the Genboard is either through the smaller EC18 connector or from a pin header inside on the board, which is usually routed to an end-plate in the form of a regular DB9 (standard serial RS323) connector.
LPG section
I wil be running LPG with a Vaporised Sequential Injection System. http://www.prins-lpg.com/en/products/vsi/index.html
Stage one plans:
- Use Prins vapouriser, injectors and use VEMS to control the amount of fuel.
- LPG doesn't have a steady fuel pressure in the fuel rail. So I will have to add a variable map where injector times are dependant off. I don't know if I just can add a variable or I can reconfigure a built in variable like Vbatt.
Future problems:
- The biggest injectors support only 50 hp per cilinder. This can be raised by raising the pressure. Problem with raising the pressure is the injectors only open till about 3.5 bar. By a fuel cut-off pressure will raise very fast and will exceed 3.5 bar very fast. Solution will be something like a pressure release valve.
- Second problem with raising the pressure is the vapouriser will not be able to vapourise everything so liquid LPG will be injected. This way I will not be able to control the amount of fuel injected precisely.
- Develop a second base map and a possibility to switch between maps while driving.
Second stage:
- Add an other base map to Vems. I want to be able to run on petrol too.
- This option isn't available jet
- Running both high and low impedance injectors.
- Or possibly you can bring there commmon household Propane-Butane cans to refill. It's very common here (in Hungary) to run LPG cars on household PB cans, since it's much cheaper. The only difference is the smell (to help police :)
- This will be to tricky CNG and LPG is to different for me right now. I may experiment with this later on.
- Q: It's true I can boost it a bit up and inject the LPG with more pressure. This way I should be able to run higher hp levels.
- I even thought of eliminating the reductor at all. This way you may can utilize the icing effect of the pressure drop as a charge cooler :)
- Q: Can you tell me more about such a nitrous valve?
Low impedance injectors
VEMS GenBoard/VerThree (v3.x, like v3.3) has 8 output channels that are capable to drive low impendence injectors.
I'd love to run the LPG injectors directly and not with a supplementary controller, cause I have total control over VEMS while I only have indirect control of the proprietary controller.
Problem is my 440cc fuel injectors are high impendance and the LPG injectors are low.
I guess I could only run the LPG injectors at first and later on develop a system to run both fuels with VEMS.
- Q: there is a difference in the signal to a high impedance injector and the signal to a low impedance injector. How is this configured in VEMS. (Peak and hold for low impedance.)