cbr 600 f4i questions/issues

mitcht_84 · Post by **mitcht_84** » Thu Mar 06, 2008 2:33 am

I am running microsquirt on a cbr600 f4i for California State University Fresno FSAE car. It is running wasted spark with stock (COP) coils, a 12-1 crank wheel, 21.1lb/hr high impedence injectors, lc-1 wb o2, and E85. I am a bit confused on whether the input capture should be rising edge or falling edge. Currently i have it set to rising edge. Before using the microsquirt on this engine it had a performance electronics unit. The ignition coils were wired in series on the performance electronics unit with a 3ms dwell, and without much thought i wired them the same way on the microsquirt unit. Is this configuration going to cause problems? I only bring this up because of another posting:

"2) You *cannot* run two ignition coils off of one VB921, do not attempt to do this. What I did was to modify the MicroSquirt by removing the VB921s on the board and jumpering so that the processor output goes direct to the ampseal. I also hooked up 0.001uf caps from these outputs to ground for RF supression.

For a coil driver, there are many options. This engine used a Bosch 0227100211 4-coil driver (also crosses to HUCO 13 8055, Audi/VW 4D0905351). These are used on 1996-2001 Audi A4 and A8 1.8L Turbo. This driver works excellent. Just hook each injector output from the uS to two of the channels in this driver (total of 4 channels) in the proper wasted spark setup. I can draw a diagram if needed...

Set the dwell to 2ms for these coils."

I was also curious about my cranking rpm being above 350 rpm and how that affects the cranking pulsewidth. Starting the engine takes more effort than i would like it to, but runs fine after starting. There is another issue at around 8000rpm. The engine sounds like it is rev limiting itself. i have the rev limiter set to fuel cut, and 13500 to 14000 rpm. Wb o2 works good and i'm able to use autotune. The VR sensor wire is pretty much shielded (it is the coax cable that came with the wire harness) except for a short section and connector coming out of the engine. I would also like to know if you have any ideas on ignition timing for this engine.