+ Reply to Thread
Page 1 of 8 1 2 3 ... LastLast
Results 1 to 10 of 80

Thread: Suzuki GSXR600 & MoTeC M400 problem

  1. #1
    Hi all,

    I'm getting lots of troubles trying to fit our brand new MoTeC to our FSAE car, which is running a Suzuki GSXR600 k4-k5 engine.

    We're getting a Ref/Sync Error. It says Not SYNCed and the engine won't start. The camshaft and crankshaft sensors are correctly plugged to the ECU and they bring us this:



    As far as I know from the MoTeC Webinars, crankshaft and camshaft sensor outputs are clashing, and this could be a problem. They suggest to change the sensor position.

    On the other hand I didn't find anything related to change the sensor position on the internet, so I guess It's not necessary.

    Any ideas?

    Regards,
    Oscar

  2. #2
    Senior Member
    Join Date
    Feb 2004
    Location
    Costa Mesa, CA
    Posts
    773
    What mode are you using (7, hopefully)? What's your CRIP set to? They're both set up as and wired to be mag sensors, right?

    As you can see, your sync tooth is right in the middle of your missing tooth on the ref wheel. IIRC, they recommend *at least* 30 crank degrees of separation so that the ECU has time to pick things up properly at higher RPM. The problem is when they overlap it's not sure which half to give the sync tooth to. In the missing tooth modes, the sync trigger is there to indicate which one of the two crank rotations you happen to be on. It's also the point from which your CRIP starts counting. On the GSXR's, it's common to relocate the trigger pin up on the cam to the opposite side for just this reason. Drill a new hole (still press fit) on the other side and push it in. Voila! It doesn't need to be exact, but it's nice if you do it so that it's repeatable somehow from cam to cam (spare engines and such). That way you don't have to change the CRIP every time you swap engines. You can also just write the crip on the engine, but it's just easier if you're consistent.

    -Kirk

  3. #3
    Thank you for your fast reply.

    This is our Ref/Sync sensors setup:



    Regards,
    Oscar

  4. #4
    Senior Member
    Join Date
    Feb 2004
    Location
    Costa Mesa, CA
    Posts
    773
    Although I agree those look right, try flipping your edge polarities. That's a similar CRIP to what I have in an old file, except the edge polarities were flipped. Our wiring may have been flipped though. Keep in mind the CRIP is the number of crank degrees between the sync tooth and TDC(compression) on #1. You'll need to confirm this visually on the engine. That shouldn't effect sync status though, just timing.

    If you hit F1 while on the mode setup, and go to Mode 7, you'll see they recommend you have the tooth ratio set to 50. You've got it set at 90. That would mean it's expecting to find the missing teeth much later than the reality would suggest. You can learn more about the tooth ratio by hitting F1 on that setup parameter too.

    -Kirk

  5. #5
    Knee-jerk reaction is that your cam sensor is wired backwards. Should get +ve voltage when the tooth is approaching. I would check the trigger setting too (rising/falling), and make sure it is consistent with your signal. I have seen both these problems in the past on an F4i.

    Just found this page which has a good run-down on what I'm describing. Wish I had seen that two years ago...
    Owen Thomas
    University of Calgary FSAE, Schulich Racing

  6. #6
    Great, we'll be working on this in a few days.

    Will post results here. Thank you VERY much. If you're visiting Spain for some reason, let me know it ;-)

  7. #7
    Senior Member
    Join Date
    Feb 2004
    Location
    Costa Mesa, CA
    Posts
    773
    Owen, you can choose to trigger off either the rising or falling edge on the Motec ECU's. It shouldn't matter how it's wired in this case, as you can adjust your settings accordingly. The cam is definitely 'rising' based on the scope capture.

    It's not like I do this every day, so I have to sort of relearn the details every time I do it again. I think I'd want to trigger off the falling edge on that ref though. The missing teeth mean it doesn't provide a clear, sharp crossing for a rising trigger. I'd rather trigger off the back edge of the first tooth after the gap so it gets a clear crossing.

    -Kirk

  8. #8
    Originally posted by Owen Thomas:
    Knee-jerk reaction is that your cam sensor is wired backwards. Should get +ve voltage when the tooth is approaching. I would check the trigger setting too (rising/falling), and make sure it is consistent with your signal. I have seen both these problems in the past on an F4i.

    Just found this page which has a good run-down on what I'm describing. Wish I had seen that two years ago...
    Well, but that can be fixed selecting Rise of Fall consequently... right? Isn't that option for this?

    EDIT: Kirk was faster than me

  9. #9
    Senior Member
    Join Date
    Feb 2004
    Location
    Costa Mesa, CA
    Posts
    773
    In summary, I'd start by leaving the sync trigger as it is, swap the ref trigger to falling, and set the tooth ratio to 50.

    Hopefully it should work given the spacing between the sync crossing and the falling edge of the ref after the missing teeth.

    -Kirk

  10. #10
    I'm going to test that right now. BRB.

+ Reply to Thread
Page 1 of 8 1 2 3 ... LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts