So, my little 749 has been on the dyno today. I knew the mapping was likely to be significantly out because the motor was rebuilt with the kit cams, rather than the 'hot' inlet and road exhaust cams that came with the bike. The mixture was up and down throughout the rev range and needed up to 28% more fuel at points. If I'd run the bike like this, I would have been running so lean that the motor may have melted a piston or two. Pointless spending big bucks to have the motor rebuilt only to have something as simple as fuelling destroying all that hard work. So, after Johns hard work, the little guy now has 147bhp at the wheel and 76 or 78 torques. Should be interesting on the track - hopefully, the 749 thing will be evident :biggrin:
Wow thats impressive J. how much would the equivalent 999 put out and at what cost to the wallet. If you dont mind telling of course.
a tripple 9 is from high 130's to maybe 150. This is a World Supersports bike - the motor stands me at maybe 6k with the new parts we've bought for it.But there aren't many Factory 749's left.
Come on Jerry, get it booked. I've got a badly busted finger that I hope will be alright to ride with.
@Peter, a bit of headwork and bigger valves should see it closer to 150. A good return on a track bike. Maybe not really needed for thfe road
Jerry I'm staggered that that kind of power is achievable by modification to the standard engine. I think that a standard 749s engine would output something in the region of 110 at the crank, so say -15% for transmission losses =93.5 at the wheel, so your 147 is more than 50% up on a standard 749s ( don't know what the 749rs figures are). Would be interested to know one day what exactly one has to do to get that, as you mention it don't come cheap! I wonder how much more stressed the engine is, and how it will fare with that extra loading? Where is the limit on these engines, how much more can be done to squeeze anymore out of it? Don't forget you are mortal when you get the thing on the track. 5
Yes, remember that the R motor is shorter stroke than the other motors and has ti rods and valves. This will help it rev higher with reduced stress. If money was no object, you could maybe increase lift and duration and with a higher rev limit... But with that comes reduced life. This motor now has a rev limit close to the peak so I'm not revving the tits off it. It should last a looong time now! Next step is to get the forks revalved and then it's on the track! I'm hoping to get Nannelli - the WSS rider - on the bike for some parade laps this year or early next. Very exciting!
Jerry I very rarely use it on the road ,and to be honest it's more than powerful enough for my hillclimb comps ,my next big spend will be carbon wheels ,far more beneficial for me that way. Regards Pete.
holy toledo! my mapped and 'cleaned' 999R does 148 RWBHP! so your's is really on the edge! congrats! and enjoy! grtz Koen
Koen, you're probably closer to Biggelaar than Ivan. Get yourself down there and I'd bet that Toine can find another 10 bhp
numbers numbers numbers.............as a comparison they mean diddly squat, even id they were compared one after tother as the dyno room would be at a different temp.....then theres the poetic licence of which dyno you use of course!
