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
- IAT sensor: GenBoard/Manual/IntakeAirTemperature
I guess we have a lot in common: [MembersPage/GergelyLezsak]
A great guy who's car I deff like to see when it's finished: [MembersPage/MattiasSandgren]
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Electric fan
Will need to apply a relay, since there is no output for 30A. Several injector FETs can be driven in parallel, but this is not recommended (very easy to burn traces with misconfiguration). Check GenBoard/Manual/DigitalOut/Table and determine a free output you want to use to control the relay.
EGT
My GenBoard (serialNr=355 and 356) has two EGT cables connected to the board, at nearby locations.
You can connect two EGT sensors. MegaTune will log both mcp3208channel4 and mcp3208channel3 (raw values). However, only mcp3208channel4 is displayed on LCD page0 (mlp00).
Raw values mean that the
- real_celsius_value = egt1_offs + (raw_value * egt1_cal / 256) where typical values:
- egt1_offs=00
- egt1_cal=49 (that is decimal 73)
Peak and Hold
Q: How is the signal to the injectors configured. I checked the board for it's flyback and it's there. The drivers and the LowZ type but how is the signal to the injectors configured? I need a Peak and Hold steering.
A: Do you need instructions for MegaTune or configuration file tweaking? It's very easy, you can set the PWM % and how long the peak should last (typically 1.0 ms).
Resistors
http://vems.hu/www.vems.co.uk/VEMS/
Q: What resistors should I use in the diagram? Between V+Batt and the components.
A: You mean fuses? These are commonly used :
| Current consumer | Fuse rate | 'Description/Comment |
| VEMS Genboard | 3A | It actually draws a couple of hundre mA, but this is the smallest automotive fuse commonly found in gas stations |
| Lambda | 5A | |
| Injectors | 10A | This could be the main fuse, and a separate 3A fuse for each injector for safety if you get a short in an injector you could fry the driver with only one main fuse |
| Ignition coil | 10A | Possibly even higher, depending on the coil primary resistance |
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