Author Topic: BMW M50B25 Non-Vanos trigger  (Read 13373 times)

Offline KaliE36

  • Jr. Member
  • **
  • Posts: 18
  • BHP: 3
BMW M50B25 Non-Vanos trigger
« on: September 10, 2008, 07:09:34 pm »
Hello to all ,
did anyone here installed a V3.3 on a M50 non-vanos engine ?
I'm in fog about few things:
1. the primary trigger sensor should be a VR one. Usually, the 60-1 trigger wheel configuration use this kind of sensor. On the other hand, i was measured this sensor's resistance, and it is 525ohm.
2. the secondary trigger sensor have a resistance of 1320ohm ... any ideas about if this is a VR or a Hall sensor ?
3. what "TDC after the trigger" value do you use to use for this engine?

Engine details:   

BMW M50B25 Non-Vanos   

The engine was fully rebuilt with OEM parts (including new valvetrain)   
Cilinderhead ported and polished + 3 angle valve job   
CR = 9.3:1 (thicker HG - 2.05mm)   

Turbocharger   Garrett T3/T4, 60 trim, stage 3, external wastegate
Turbo manifold   Custom 6 runners stailess manifold
Wastegate   60mm HKS replica, free vent
Intercooler   Ebay, 50x20x90 mm
Blow-off   Forge
Intake tubes   60mm diameter
Exhaust pipes   70mm - main pipe + 60mm wastegate pipe, 76mm BORLA final exhaust dumper                        
Fuel pump    Bosch, 190lph                        
Fuel injectors   62lb, Siemens                        
Ignition coils   Beru, high voltage                        
Ignition plugs   Denso, K24                        

Target boost   1.2bar                        
Target power   380HP                        

Thank you for any input on this

Offline rob@vems.co.uk

  • Hero Member
  • *****
  • Posts: 3115
  • BHP: 49
    • VEMS Forum
Re: BMW M50B25 Non-Vanos trigger
« Reply #1 on: September 10, 2008, 10:51:56 pm »
Hi, theres lots of turbo'ed BMWs with VEMS on.
This is a good write-up:
http://www.vems.hu/wiki/index.php?page=MembersPage%2FFredrikHafslund
He's put his config and tables files up on the page.

And he's done a specific trigger page which answers a load of questions!
http://www.vems.hu/wiki/index.php?page=MembersPage%2FFredrikHafslund%2FInputTrigger
And tells us that the stock triggers are VR/VR

The chances are that you're reading two different resistances because the sensors are stimulated in very different ways - the 60-2 trigger (with the lowest resistance) is constantly stimulated and the voltage will climb quite high as the RPM increases.  Where as the stimulation of the secondary trigger is far less frequent and will not generate the voltage that the primary one does, so it will need a higher impedence sensor to generate a voltage on passing of the single tooth.

Offline KaliE36

  • Jr. Member
  • **
  • Posts: 18
  • BHP: 3
Re: BMW M50B25 Non-Vanos trigger
« Reply #2 on: September 11, 2008, 06:25:55 am »
Hi Rob,
thank you for your replay ...
yesterday I also measured the inputs on the Cam sensor, and there are 2 grounds (out of 3 wires) ... i suppose that one is the sensor main ground and second one - the shield ground
if I know well, a Hall sensor have to have a 5v input (that is not present on my sensor) - so, in conclusion, that sensor should be VR :)
now, considering this, the VEMS configuration that i have to order is: VR/ Auditrigger ? (actually, this confuse me a little bit, because the only options there were Hall or Auditrigger ... )
aaa ... btw, a interesting issue: after i re-connect both crank and cam sensors , the engine starts just after a very long (8-10sec) cranking  , even if usually starts after less than 1s ... i think that disconnecting the sensors generate a "reset" or something in the ECU ...
I will let you know how this installation progress ... the order list looks like:
1   Assembled VEMS V3.3 controller:   8 IGBT, 30v flyback, 1Knock and 1EGT, LCD Connection, MAP connection - Offboard
            Mounting-style: screws, Primary trigger - VR, Secondary Trigger - Auditrigger
2   V3 Harness:   6 Injectors, relays and fuses included
3   Pneumatic valve 3way   
4   VEMS MAP sensor   250kpa, 6/4mm, 5v supply, external
5   Bosch Knock sensor   
6   Bosch LSU4 wideband sensor   
7   Wideband connector:   with crimped wires
8   LCD 4x20:   red
« Last Edit: September 11, 2008, 06:27:31 am by KaliE36 »

Offline rob@vems.co.uk

  • Hero Member
  • *****
  • Posts: 3115
  • BHP: 49
    • VEMS Forum
Re: BMW M50B25 Non-Vanos trigger
« Reply #3 on: September 11, 2008, 08:36:40 am »
I'd not go for an external MAP sensor.  And the LCD is not a feature I'd bother with either.

Offline KaliE36

  • Jr. Member
  • **
  • Posts: 18
  • BHP: 3
Re: BMW M50B25 Non-Vanos trigger
« Reply #4 on: September 11, 2008, 10:42:25 am »
Thank you for recommendations ... I thought that a external sensor will provide more accurate readings, being closer by manifold ...
there were some issues with external MAP connections or else?
I'm pretty anxious to get this box ... but, is a little bit strange for me that everything have to be well planned before ordering