MicroSquirt.com read only forum (Jan.15,2018)

So we have a CBR600RR running Microsquirt for an FSAE car. It has a gt12 turbo and is running E85 fuel. We have a GM type 3 bar map sensor and an innovate wide band and used it to help with the autotune feature.We had a horrible time getting it to run right with the factory COP setup so we stuck LS1 coils on it and it is much better. It will start and run ok but the two main probs we have are as follows;

It doesn't want to idle below 2000rpm. We do have some custom bigger cams in it so I expected it to be a little finicky but it basically shuts off if you get it below 2k. We are just running the throttle blade - no idle air motor. I tried varying the injector pwm from 45 to 90 with very little difference in quality.

The main problem is it won't rev above 5700rpm. I've tried a number of things and it just acts like a rev limiter there. Attached is the latest msq and a datalog where you can see me slowly revving it up and see it just freak out at 5700.

Any ideas?

If you look at the trigger +/- column you will see it count down a little bit when starting, which is not unusual, but after it starts it is stable and reliable. When it reaches near 5700 rpm it starts to count down very fast. This means it is missing tooth pulses. This is unusual as on this engine it usually sees extra pulses at high speed because the signal gets stronger the faster the wheel turns, unless you have a Hall sensor instead of the more common VR sensor. What you don't want to do is change configuration parameters. This engine will rev easily to well over 10000 rpm, but you need to fix the missing tooth problem. Problems with tooth detection is probably the most common problem that people have. There are many posts dealing with these problems and with the CBR engine in particular. I would do a search on these to see what people have tried in the way of adding/ reducing resistors, diodes, etc.

I haven't been able to find much else out there about these engines losing signal as we've seen. Do you think it would be beneficial to do something like run the vr through a 4 pin HEI and then to the mS?

Also, I was thinking about it and the way our car is set up, it has a trigger offset of 13 degrees I think which is actualy off and should be at around 1-3 but as I start moving it any closer to that that timing at the light gets way off. If I move the offset the other direction it is linear with ignition timing though. It seems like anything closer than an offset of 11-12 degrees and the actual timing advances something like 20-30 degrees. I have tried using a -355 offset and the thing doesnt even want to try to start.