[mandrbarrett]

Does anyone know by how much the fuelling is likely to change if HC pistons are fitted?

I have not been able to find much on the internet regarding PC maps for HC pistons. Also from the engines perspective, it may be getting more energy from of the (more compressed) intake charge but I cant see how HC pistons can draw more air, and therefore do they require a fuelling change at all?

(1000DS with K&N + airbox mods, PCIII and Staintune header pipes)

Any input would be gratefully received.

Cheers,

Mark.

 

[brad black]

theoretically less fuel from the increased efficiency, most likely no change. unless it pings and you need to drown it.

 

[Guest]

My shop (the reputable Desmotosport) said no fueling changes were needed after installing the HC 944 kit.

I didn't believe them and had a PC-III dyno tune done anyway.

And they were basically right, the map didn't change much at all.

 

[mandrbarrett]

Thanks for the responses,

Mark.

 

[Guest]

Mind you, these answers presuppose you had your bike tuned after you did the airbox mod & the pipes. Those mods will require a fueling change.

(I'm 99% certain that's the case, but I figured I'd make sure)

 

[mandrbarrett]

PCIII with appropraite map from their website.

Thanks for your concerns,

Mark.

 

[moperfserv]

Actually high compression pistons do increase the amount of air your engine takes in.
As the compression ratio increases, so does the expansion ratio of the power cycle and the volume change ratio of the inlet cycle.
The amount of increase in air will be small compared to the power from increased cylinder pressure and expansion ratio, but it also means that timing adjustments are appropriate.
That also supposes that the timing was correct for the stock CR. In that case, the timing will need to be retarded a couple degrees at the top.

Doug

 

[Guest]

Which isn't possible with a PC-III (at least on my bike, an m900, there's no ability for the PC to change timing) :'(

 

[mtn_mnztr]

According to what I've read to do HC pistons really right you need to change ignition timing, fuel delivery, and maybe cam timing. To change ignition timing and fuel delivery you'd need to remap the ECU (which in your case would require a new FIM ECU, I think). Then you'd have to get adjustable cam pulleys (I don't think your 1000 came with them). Then you'd need to take your bike to a FIM tuner and have them come up with the best ECU map and cam timing to make it all happen. Or in the case of BCM Ducati of New Hampshire they say you can just ship them the ECU along with a list of all the mods and they can draw on their past experience to come up with a map.

I guess that if you really wanted to tweak it at that point you could get a PC3 and custom map to further refine fuel delivery.

I'd give the guys at BCM, or Chris at Cycleworks (a board sponsor) a call and talk through all this before going down this road. It's the cost and complexity that's kept me from getting a 966 HC kit so far.

 

[Speeddog]

Since the stock Monsters seem to be pretty happy with 87 octane, a reasonable approach for a high-comp kit would be to step up to 89 and see how it runs.

Not the optimum solution, but a healthy step in the right direction.

Perhaps Doug or Brad have some experience in this area?