Microsquirt on Motorcycle

[Crazyswede]

So I have a 2008 KTM 690 enduro bike that is fuel injected and I have ridden and raced for the last 4 years and about 8000 miles. The stock fuel injection system works but leaves a lot to be desired as it was designed around meeting emmission controls and takes a lot of work to get to propper running. Similar to the T5 Suite there is a program called "Tune ECU" that allows you to tap into the EFI programming on the stock computer with nothing other than a connection cable, a laptop, and the free software. I have a reworked race map on the bike now and it is much better than stock...but much worse than the aftermarket plug/play computer some people are running (which costs $700). The biggest problem with the bike is that the wiring harness is horrible and the throttle body is a computer controlled unit which needs its own map in order for the bike to run.

I would like to make my own harness for the EFI and configure the microsquirt for the bike. I hope to have 3 harnesses when done...one for charging system, one for EFI, and one for lights and controls...all color coded with proper water proof connectors and proper wiring...vs the 22 gauge wires running to non sealed connectors (brilliant for a dirt bike).

The EFI is relatively straight forward but I am am curious about the ignition pickup. I am assuming my bike has a shutter wheel for the existing timing and this will hopefully work with the microsquirt. I have to dig into the bike ignition system as it sits now but would appreciate any input on the ignition setup.

[DrewP]

Does it have a crank and a cam sensor, or a crank trigger only?

The injected '06 Suzuki LT-R450 I worked on only had a crank sensor, but ran full sequential injection and spark sort of like how Trionic does it. When started it would run wasted fuel and spark. The generator flywheel had a toothed pattern machined into it, and the ECU would watch for the rapid acceleration of the crank right after the power stroke and set that reference as 0* TDC for the rest of the run cycle and switch to sequential firing.

It's been a while, and I can't remember if Microsquirt will do a cam and a crank trigger, or a crank trigger only?

Have you looked at Performance Electronics ECU's? They are a big FSAE sponsor and have a cool new ECU out that's pretty inexpensive, and they're usually very willing to share baseline files for different bikes to at least get you running.

EDIT: They start out more expensive than I remembered, but their support is great, the new PE3 starts at about $1k.

[Crazyswede]

I am pretty sure this bike only has a crank sensor. It is a single cylinder single plug, single injector 650cc.

[DrewP]

Right, but if all it had was a crank sensor and minimal logic, it wouldn't know if the piston was at 0*TDC at top of compression stroke, or 360*TDC at top of exhaust stroke, so it would fire spark and injector at every TDC like the C900 does, which is very inefficient for best power since it's spraying fuel when the intake valve is closed every other revolution.

That's a problem for FSAE cars, it's pretty common for people to machine the cam covers to add a cam pickup sensor so it can run in sequential mode. I've heard of people adding trigger wheels to the ends of cam gears, or reading directly off one of the cam lobes with a hall sensor to reference which TDC the engine is at.

If all it has is a crank sensor then you can also just run it wasted, it'll go through fuel faster, but I imagine you've already got a huge tank on there for distance racing anyway.

But things to find out, since that'll have an effect on what control scheme you decide to use.

What's your plan for the electronic throttle body? Does MicroSquirt support electronic throttles?

[Crazyswede]

my plan is to ditch the electronic throttle body. Right now we have the throttle map maxed out such that it is 1:1 with the hand throttle. my husaberg tb is direct with a cable and works fine. I will have to dig into the existing ktm ignition setup.

[DrewP]

My experience was with Megasquirt, but it was very capable at handling different ignition types and trigger wheel setups, I think Micro is the same way. Some reading and some experimenting and you'll be there.