RGA-1200
March 25th, 2008, 08:44 AM
Now that my laptop is back from it's brush with death, I can get back to what I was doing yesterday, which is fiddling with the accel settings.
Background is - Laverda 3 cylinder 1150cc air cooled 2V engine, approx 8500rpm max, SM4, GSXR throttle bodies etc, GM LS1 coils, first attempt with EFI and this type of engine never before injected so no base settings. Did 3hrs on the dyno at the local dealer to dial in most of the fuel map, using his Autronic analyser. Put out 10hp more than a brand new BMW R1150 on the same dyno, happy with that from a 1971 engine design!! :)
Plenty of revisions from on-road riding and logging later I now have it running pretty smoothly, the only glitch to feel is when doing what I would call a low rpm launch, where you feed out the clutch at say 2krpm but with plenty of throttle. The bike pulls pretty well but gets to about 5-6k and dies.
Due to the lack of electrical capacity and the desire to carry around the minimum of stuff, I remove my Innovate LM-1 for normal use. Yesterday I put it back on to have a look at what was happening during the low rpm launch situation. As I suspected it leans out badly around the time the cough happens at 5-6krpm. See log1.jpg
I was interested to see what I do with the throttle in this situation, I had no idea I fed it in like that while doing a launch like this. So rpm is increasing, and throttle is increasing.
Also, from some higher speed tuning from a few months ago, Log2.jpg shows a log of a normal acceleration where I snap open the throttle after decelerating. You can see the initial leanout, then recovery. The bike pulls fine during this, there is no discernable hesitation. In general terms it's going great on high throttle use, it will pull hard from 1000rpm in top gear which is truly amazing for this type of motor. Only during the launch do I notice any misbehaviour.
The third thing is that when just blipping the throttle from idle there is a audible hesitation before the motor revs up, but I don't have a log of that. To me these all point toward insufficient "acceleration pump" fuel.
I do not fully understand the accel settings, can someone explain them more clearly, or have a look at my cal file and suggest some adjustments perhaps? In fact a general look-over by someone more experienced than I would be appreciated, as this was all done from scratch with very little input other than fuel map by my dealer.
In general it likes to run rich, I tried to run 14-15:1 AFR during low throttle use and it just did not like it. Seems to like to be in the 13's when taking it easy, and 12's under power.
Sorry for the long post, hope I explained it all.
Thanks in advacne
Steve
Background is - Laverda 3 cylinder 1150cc air cooled 2V engine, approx 8500rpm max, SM4, GSXR throttle bodies etc, GM LS1 coils, first attempt with EFI and this type of engine never before injected so no base settings. Did 3hrs on the dyno at the local dealer to dial in most of the fuel map, using his Autronic analyser. Put out 10hp more than a brand new BMW R1150 on the same dyno, happy with that from a 1971 engine design!! :)
Plenty of revisions from on-road riding and logging later I now have it running pretty smoothly, the only glitch to feel is when doing what I would call a low rpm launch, where you feed out the clutch at say 2krpm but with plenty of throttle. The bike pulls pretty well but gets to about 5-6k and dies.
Due to the lack of electrical capacity and the desire to carry around the minimum of stuff, I remove my Innovate LM-1 for normal use. Yesterday I put it back on to have a look at what was happening during the low rpm launch situation. As I suspected it leans out badly around the time the cough happens at 5-6krpm. See log1.jpg
I was interested to see what I do with the throttle in this situation, I had no idea I fed it in like that while doing a launch like this. So rpm is increasing, and throttle is increasing.
Also, from some higher speed tuning from a few months ago, Log2.jpg shows a log of a normal acceleration where I snap open the throttle after decelerating. You can see the initial leanout, then recovery. The bike pulls fine during this, there is no discernable hesitation. In general terms it's going great on high throttle use, it will pull hard from 1000rpm in top gear which is truly amazing for this type of motor. Only during the launch do I notice any misbehaviour.
The third thing is that when just blipping the throttle from idle there is a audible hesitation before the motor revs up, but I don't have a log of that. To me these all point toward insufficient "acceleration pump" fuel.
I do not fully understand the accel settings, can someone explain them more clearly, or have a look at my cal file and suggest some adjustments perhaps? In fact a general look-over by someone more experienced than I would be appreciated, as this was all done from scratch with very little input other than fuel map by my dealer.
In general it likes to run rich, I tried to run 14-15:1 AFR during low throttle use and it just did not like it. Seems to like to be in the 13's when taking it easy, and 12's under power.
Sorry for the long post, hope I explained it all.
Thanks in advacne
Steve