1. Gearing
Some study of the data from Phillip Island showed we'd managed 241kmh down the front straight. That is seriously honking on a 2 valve bike. What was not obvious due to me lacking a lap top trackside was the RPM we where using, only 8000rpm. Thats 600 short of red line. If the bike got to readline it would be doing 280! Now given the aerodynamic shape of the db1, I am pretty sure it will not do that. So why geared so high? Well its cause we geared it that way in Feb last year when the ECU was not working over 7000rpm. We simply forgot to gear it back down.
So I have a 14T front to put on, which will give us a top wack of 260kmh, but should make the bike accelerate even harder. Lucky for us the gears are so wide ratio that we should not have problem with having to shift gears to much.
NOTE: After a think about it we've left the 15/39 on it, the bike is going hard enough to pull it. And we will review it after Eastern creek.
2. Rear Suspension
We have found ourselves running a 12kg per mm rear spring on the Beta EVO to stop the bike compressing the rear suspension under power and running wide. We now suspect this is due to the extra length of the monster swinging arm over the standard one. The monster one is 10% longer. We suspect that this playing havoc with the rising rate rear linkage. Basically we have to run a massively stiff spring to overcome the static sag we encounter with the extra leverage of the long swingarm.
At the faster tracks I have noticed that rear suspension tends to push through the front. The front being very soft and compliant. The rear is over powering the front causing a rocking sensation in really fast corners. Not a nice feeling and something we'd like to fix.
The changes are going to have to wait, till after Easter and round 1 of the nationals.
3. Fuel tank system
The design we created to get a low point for the fuel pump necessitated a surge tank mounted at the back of the bike. The surge tank contains the Ducati 999 fuel pump and has to be kept in fuel or it will get really hot. Hence the surge tank is below the main tank and is plumbed high and low to get the fuel to gravity feed into it. The major draw back of the design is the plumbing location, as it is routed directly above the rear header pipe. A fuel leak will cause a big fire!!
The re-mediated design is to use an external fuel pump, discard the surge tank, and enlarge the fuel tank at the front of the bike to take up the capacity we lose from the surge tank. That's a work in progress.
4. Engine performance
Lifting the power slightly and moving the max torque further up would be fantastic. As a result we added some bigger valves +1mm inlet and exhaust sourced from FastFrank in the USA. Mike gave the heads some attention porting them to let some of those lovely gases get in and out easier. The result of the work was an increase of 7HP above 6000RPM. Very nice, and more importantly the torque is nicely higher. Here is the pic, thanks to Roger at Weaponry for the dyno work.
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