On Sunday, Chip Yates’ electric superbike unofficially became the fastest electric motorcycle in the world, reaching 190.6mph in a timed mile. Here, Chip gives HFL readers an exclusive look at the performance data recorded during that run. Check out the lateral Gs and gyro yaw data recorded as the bike went into a 190mph wobble; that’s probably the best visualization of a tightened sphincter we’ve ever seen.
We record over 150 channels of data from the MoTeC and the UQM, which talk to each other over a high speed CAN network - I have chosen 7 channels of interest to display here in the MoTeC i2 Pro analysis software that we use.
My cursor is the vertical black bar that I can sweep across the data to show specific values at any point in time - in this shot I have left the cursor at the point just after I lifted off the throttle. The first column of numbers just following the channel names are read from my cursor position. Note my throttle position at the cursor of 34.3% which occurred just after I passed the speed trap and began slowing.
More to the right you see three symbols and values for each channel. The first is a blue carrot which is the lowest value seen in the data. The second is the red carrot and is the highest value seen in the data. The third is the orange carrot and is the average value for the channel seen in the data. My lowest and average values are a little skewed because I had to sit on the runway so long before the run, but the max is the real max.
Throttle position - runs from 0-100% (ours needs to be calibrated as it shows a max of 106.2% - oops). The throttle position command from my twist grip goes to the MoTeC in a table that determines what torque command will be sent to the UQM. The UQM sends a feedback channel to the MoTeC called Signed Torque Feedback ("Signed" or "Sgn" means it can be a positive or negative value - negative torque is KERS). The thing to note here with my throttle position is that I'm almost never at 100% due to my efforts to stabilize the high speed buffeting - when we solve that you can see we can be alot faster.
G Force Lat - I showed this so you can see the effects of the high speed wobble - we look at this in conjunction with the channel below called Gyro Yaw Velocity. This channel comes from an on-board accelerometer on the MoTeC ACL (Advanced Central Logger) we use as our "ECU".
Sgn Speed Feedback - this is the UQM motor RPM at the shaft. The redline is above 8,000 RPM - for this run I had the bike geared so that 8,000 RPM would be around 229 MPH. I geared it this high because we expected to exceed 200 MPH and I allowed some headroom for wheelspin. Because we have excessive torque on hand that we literally chop off and don't use, there is no penalty for me overgearing the bike slightly like this. We used tire warmers and didn't seem to encounter any wheelspin - I'm sure having a ton of battery weight over the rear wheel helped traction a bit also!
Signed Torque Feedback - this is the UQM reporting back to me what torque it is providing. I have a channel called Requested Signed Torque that is what I'm sending to the UQM. We overlay my requested signed torque with the Signed Torque Feedback to see if the UQM is giving me what I want. Note that the max torque I used for the run was 358.2 NM out of the UQMs incredible 550 NM available to me. The torque of 358.2 NM converts to 264.2 ft/lbs that I used to get down the runway. The max torque I have available to me of 550 NM converts to a mind-boggling 400 ft/lbs of torque. The 365 ft/lbs we commonly quote has been outdated by some of our motor upgrades. You heard it here first! Note also the lowest recorded value of -96.5 NM. This is KERS from our automated software engine braking and also from my KERS position lever that I used while slowing down to grab back some much needed energy to cram in our batteries as I slowed down. You can see the value dip below zero and hold steady for awhile - this is the engine braking, then you can see where I squeezed the KERS lever a little bit and it dips even lower as I prepare to turn off the runway onto the taxiway.
Gyro Yaw Velocity - this and other signals for pitch, yaw and roll come from our aircraft AHRS (Attitude Heading and Reference System) made by MicroStrain - it has 3 gyros and 3 accelerometers and a magnetometer that we use for wheelie control, traction control and lean angle torque control. Note the stomach churning yaw rate amplitude and frequency - this is what I had to ride around and I only had two chances to break the record because we couldn't recharge at the track!
Ground Speed - this channel comes from our high speed GPS. The thing to note here is our measured top speed of 191.1 and how close that is to the Mojave Mile trap speed recorded for us of 190.6
The signed current feedback is the amps. Note the max of 522.1 amps!!