Jump to content
Greenday694

BMW m50 single Vanos trigger 2 offset

Recommended Posts

I'm trying to find out what is the correct offset for my engine. The base tune I received with my link G4 Plus was set at 297.5 ATDC on Trigger 2 VVT. The problem I had with this was it showed up as Inlet left hand position advanced 6 to 7 degrees. I was instructed to turn on cam angle test  and go into runtime values and copy the offset to the trigger to VVT. Now my offset is 285. And because I keep having so many problems at lower engine loads I'm questioning whether this is the correct offset or is my intake cam actually Advanced a little too far.

   I don't have any problem with pulling the valve cover and rechecking the cam timing. It takes a little longer with my engine , because I have to use a dial indicator on the top of number one piston to find top dead center. Because my aftermarket single Mass flywheel does not have the Notch for the Locking pin.

  Thanks for any help.

Share this post


Link to post
Share on other sites

Have you gone trough the crank trigger calibration where you mark TDC and lock the timing to 0 degrees and adjust the offset? 

Once this is done you can move on but do not alter this figure again.

You can turn vvt off for low engine load tests and illuminate a VvT issue.

if all is well carry on and set the VvT up.

Share this post


Link to post
Share on other sites

Back again. I did set up my base timing, it was off 6 degrees. Then went back and reset my VVT. Definitely better. But still can't find anybody with a dyno that will do my car with this ECU.

   So I'm still struggling to get the timing Maps set up. On a hard pull, I'm still getting a lot of knock events. Even though I pulled a lot of timing. At 29 PSIA , 11.9 AFR and 4000 RPMs I am running  about 10.2 degrees before top dead center. That is really killing my power. But yet I'm still picking up knock events even though I can't hear anything. I keep thinking that it's picking up some other engine noise, valve train, injectors, supercharger or something else? The base tune I have is set  to 7K  narrowband. Is this the right frequency for my engine? It's a cast-iron block M50 with the M54 B30 crank rods and pistons.

   I have taken a chance once, and bumped the timing up a few degrees. It really came to life. But I also got a ton of knock events. But still couldn't hear anything. Any help would be greatly appreciated.

Share this post


Link to post
Share on other sites

To be absolutely sure of the knock frequency, you will need to use Frequency analysis program like Wavepad.

Guessing is a bit hazardous with Turbo engines.

My feeling is that your present setting is not right.

Share this post


Link to post
Share on other sites

You cannot rely on the knock control system to detect knock correctly unless every part of it has been set correctly.  Usually this would be set up using audio based knock detection equipment after the ignition table is properly tuned.  I would say 7KHz will work reasonable for a 80mm bore.  More likely it is your knock target that is no good.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

×
×
  • Create New...