Witchkraft Racing: The Search for Speed

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Monday Morning Grind

My dad and I got back from the dyno last night, after James had finished freshening up the motor. We didn't end up with any more horsepower (actually a touch less), but given the bike has new gaskets and rings, breaking the motor in on the track may help free up a bit more there. James also tried some different cam timing, which may or may not turn out to work better than what we were initially using. After a good race weekend on the motor, we're going to bring it back to the dyno and see how everything looks. If we're still down on power, we'll likely go back to the original cam timing James was using.

One thing we also tried was the new VP U4.2 race fuel. We did a couple quick runs using it, without changing our current fuel map and the U4.2 worked well. We were 1-3 tenths better in overall torque and HP, which isn't much; but the air/fuel ratio was right where it needed to be, indicating a map specifically for U4.2 wouldn't be drastically different than the U4 map we currently have. Also worth mentioning was that the U4.1 fuel (that we tried at the beginning of the season) required a completely different map from our standard fuel map. We were told (from VP direct) that U4.1 would be replacing standard U4. However the number of complaints about it led to it being replaced by U4.2, which we confirmed is closer to standard U4 than the troublesome U4.1.

The toughest thing with dynoing a bike is keeping an apples to apples comparison. The couple tenths increase we saw with U4.2 could be misleading. The bike was a touch cooler (after sitting while we switched fuels) and maybe that contributed to the slight increase. Overall, the dyno room was warmer than it was last time we were there (12 degrees to be exact). Now while the dyno uses corrected numbers to account for this, nothing seems to be more reassuring than a true apples to apples comparison with all variables consistent; which in the world of motorcycles, can be difficult to ensure.

James does feel that we're about maxed out in terms of the power we're going to get with the R6. There's only so much you can do and while we're limited in having the previous generation of R6, our hands are tied in a way. The new Yamaha platform just has some advantages over ours; plain and simple. We're really just going to have to make up its shortfall in other areas around the track – the corners specifically.

Monday, July 30th, 2007 | POSTED AT: 6:21 AM
FILED UNDER: General