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Retarding timing to reduce power

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This is a motorcycle related question. I have been tuning a Ducati 996 (1000cc) race bike with Maxx ECU and getting great dyno graphs. Problem is there is too much power when feathering the throttle at full lean angles, typical big V twin. What we are trying to do is reduce power in this area, high revs low throttle, to give a better feel by retarding the ignition (gone from 45 to 30deg) and getting good results, but how far can the ignition be retarded under low load safely? Is there a point where it becomes a problem, as we would still like to take out more.

This is EFI, non fly by wire and no cat in exhaust.

No problem doing this.

One thing I would be bearing in mind while doing it is that the longer you keep ignition timing significantly retarded the hotter exhaust valves get which in its turn can be causing knock if fuel in use doesn't have high enough octane rating.

As Shota said, late timing is going to be putting a lot more heat into the exhaust valve and system. In extreme circumstances this can lead to valve failure, dropped valve seat insert, or heat damage to items close to the exhaust.

I don't know the linkage details, but it may be possible to adapt a more progressive mechanism into the linkage if the rider has trouble developing the feel required.

Thanks for the responses. Could fit EGT's and monitor as we move in small increments down as the Maxx is logging, we are down at 5% throttle were it's an issue. EGT sensors probably a bit slow to respond to get accurate info.

Open tipped sensors will be more than fast enough to get an accurate correlation. I'd also investigate a K type CHT mounting location if you're already going through the trouble and then overlay the two. That should at least tell you how much heat you're keeping in the head VS cooling system when EGTs are high due to an over-retarded ignition strategy.

I agree with Shota's comment on exhaust temps. If you'll only be in that area momentarily during a corner you'll likely be ok with a good bit of timing retard, but I wouldn't suggest someone cruising around 15 degrees below optimal timing.

I like Gord's thought on a progressive throttle mechanism which I've seen work well for this. Depending on resources, drive by wire may be an option as well.

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