MotoUSA continued its shakedown of the Brammo electric superbike at Infineon Raceway after finishing the first test with some unanswered questions.
MotoUSA got its second taste of an electric superbike on the racetrack, having participated in another testing session aboard the Brammo Empulse RR. This time around we headed a bit further south of our first shakedown location, Thunderhill, for a trackday at the site of our upcoming real-world racing test – Infineon Raceway. With the first TTXGP race of 2011 right around the corner (May 15), we’ll keep Part II of the Brammo Empulse RR racing update short and to the point. But don’t worry, this coming weekend is for all the marbles against Brammo’s electric rivals, and that will surely breed a major story with full feature video!
If you read Part I of our Brammo racing feature, you know that following the initial shakedown some big questions still lingered. Teething issues with the electric motor unit brought our first test to a premature halt. The motor unit itself, produced by big-time hydraulic and aerospace corporation Parker, was originally designed to power devices like automated robots on a production line, not high-performance motorsports. The high loads and extreme temperatures from our initial shakedown at Thunderhill introduced plenty of challenges, and Parker came to Infineon prepared for real-world solutions.
After getting the motor out of the bike following the first outing, the boys at Brammo ran a series of tests to see what caused the shutdown. The culprit: Demagnetization. This happens when the motor overheated, reaching a blistering (by electric motor standards) 150 degrees Celsius. It caused the magnets in the motor to essentially delaminate from the rotors, stopping the electromagnetic forcefield which spins the engine.
Parker re-designed the Brammo motor in an attempt to eliminate a pestering issue of demagnetization.
In theory, the solution was simple (aren’t they all?). Well, kind of… Lower the operating temperature and stop demagnetization. But as we all know, some of the simplest ideas have the most complex solutions. This would now be the sixth iteration of the engine from Parker, with most of the previous problems stemming from the same temperature issue. Thankfully, Parker is a wonderful supporter of the race project and in no time had rebuilt the motor and returned it to Brammo (under a couple weeks shipped door-to-door).
Test data from our first run revealed that the motor was running nearly 90F under the delamination point.
With this updated motor, Parker was additionally optimistic, as for this revamp they had heavily redesigned its inner workings. With the entire fate of the race on the line… well, let’s just say the tension the morning of our final test at Infineon was a bit on the high side. (Parker even went as far as sending two of their motor techs to be on hand for the shake down – from a gigantic company like Parker, that’s some serious hands-on input!)
For this test, having acquainted myself with the bike at Thunderhill, there wasn’t any real need for a warm-up session. We could focus at the job at hand right away. Brammo had decided to run the first 10-lap session at 80% of full power, hoping to get the motor safely through an entire race distance and then pull the data from the MoTec system to monitor temperatures during the run. The techs could then determine if 100% power was even possible without demagnetizing.
After an out-lap to get the so-fresh-and-so-clean Dunlop slicks scrubbed in, it was time to get on the, err…. gas? (Figure of speech or not, guess you can’t really say that about a motorcycle powered solely by millions of tiny electric impulses.) Let’s just go with: twisted the throttle (yep, it still has one of those…).
After charging the motor to full capacity, which took approximately three hours, a full-power test was conducted.
Right from the get-go everything felt great. Test-to-test changes included speeding up the steering with a 25mm offset in the Attack triple clamps and removing the steering damper for the same reason. After T-Hill, I noted that the bike didn’t suffer from any instability issues, so for a tight and very technical track like Infineon I knew from past experience that the quicker a bike steers the better, so long as it doesn’t get too unstable. And the Empulse was spot on the mark; flicking from side to side quite a bit easier while still being rock-solid stable in all situations. It’s amazing how well the slightly hefty 470-odd pounds disappears on the RR. A low CG, the batteries as a stressed member of the frame, and without having the giant mass of rotational inertia from a petrol-powered engine between your legs (this is continually counterintuitive to steering), the Brammo is more flickable than even a lightened middleweight racebike.
Running at 80% power was noticeably less aggressive off the corners than full stick during the previous test, but everything went as planned for the initial outing, easily completing a non-stop 10-lap run without a hitch. An added bonus was that our lap times were right on par with what the leaders from last year’s Infineon race, a promising sign as we were in traffic at a trackday and still holding back on power.
After getting through Session 1 as planned, the boys had a look at the temperatures and news only got better. This meant for our second run we would do a full race simulation, 10 laps (both TTXGP races are 9-lap race plus an out-lap) at 100% throttle. Time to see if the boys from Parker had found the key combination. Due to battery charging times for the RR (roughly three hours needed for peak charge) we had to wait until the afternoon to put it to the test. Tense times in the Brammo pits filled the lunch hour as we waited for it to charge…
The Brammo performed well during the second test and experienced only a minor loss of power in the final laps.
With full juice and the Dunlop slicks skin-burning-hot, just how we like them, everything was ready to rock-n-roll. Out I went and instantly the throttle was pinned to the stop – no mercy. It was time to put this neutron-powered cycle to the test! Which is exactly what we did. And while not totally hitch free (more on that in a minute), the big news was that we completed the entire race distance while losing little-to-no power (there’s a very small trickle down starting around Lap 7-8, but nothing major)!
An added plus was that every lap was under the previous qualifying lap record (our best by nearly a full second) set by 2010 race-winner Shawn Higbee on the Zero machine. For this to be the case during a trackday with 40-plus other guys getting in the way (something they seemed to be extra good at that day!), things are now looking better and better for the rapidly approaching race weekend.
Fist-pumps were seen throughout the Brammo pits. The Empulse RR is the culmination of a year-and-a-half of hard work, with copious amounts of overtime put into the project by the Brammo team. That the Empulse RR came through with near-flying colors was worthy of celebration.
As for the aforementioned small issue: Under full power with wide-open throttle the bike would hiccup and hesitate (think of that feeling of a chain skipping on a sprocket) in several of the slower corners exits. This hampered drive a fair amount, delaying the acceleration for a good second or more, which would translate to a slower drive the entire way down the following straight. And in electric bike racing, with only limited power on hand, the key is to hold high corner speed and exit as perfectly as possible to complete any-and-all straights as fast as possible.
This is currently biggest area where electric bikes still fall behind their gas-powered competition, as having a single speed drivetrain limits the possibilities. This means they have to be tuned for a rather large compromise of acceleration and top speed, as going too far in one direction quickly results in either a very fast accelerating bike that tops out at 60mph or an extremely slow bike coming off the corners with a high top speed. (Brammo is currently working on a six-
One of the small issues the bike had was a hiccupping sensation when the throttle was cracked wide open during corner exits.
speed transmission setup as you read this, complete with a clutch and surely this will be the wave of the future.) And even through the crew did a great job to calculate the optimum setup, a major emphasis is still put on corner-exit drive and it’s still a big compromise. But the really strange thing was, thinking back, the bike didn’t do this when run at 80% power.
This meant a third session was in order, even though full charging in the 40-minute window between sessions wasn’t possible. We had to do the best we could to try and isolate the issue.
So for the first outing it was back at 80% power to see if the problem was new, a result of the recent change in parameters. After the initial three-lap shakedown we could be slightly thankful, as the RR was again perfect at this setting. Next run: 95% power. This was aimed to try and find the area where the issue was beginning to happen. Again good news: Nothing. The bike was electrifying (had to toss in one cheesy pun), though going for even quicker lap times wasn’t in the cards, as battery power was running very low and on my third lap it died, ending the day. (I predict the bike is capable of two or three seconds quicker a lap with the issue fixed and during the race weekend.)
But smiling faces were floating abound in the Brammo pits, as our pace at full power was well quicker than we had thought possible, especially considering it was during a crowded trackday. So heading into the race this weekend looks right on target. Though much of that depends on the amount of development the other teams have done. And with a year to do it, this is highly likely. And let’s not forget the new teams (rumor is Mission Motors will be lining up with Steve Rapp). Either way, everyone on the Brammo team is cautiously optimistic, myself included.
A third test was undertaken at 80% power followed by another test at 95% to isolate the problem, but in both tests the hiccupping sensation was gone.
The boys are now headed back to the Ashland, Oregon-Based shop to try isolate the 100% throttle issue on the dyno and hopefully resolve it with some of that wonderfully geeky magic they are so good at. But at the worst, we know we can run it at 95% without problem. This means, fingers crossed, that it all now rests on my shoulders. And that’s exactly the way I like it.
Pressure seems to breed performance and I have a rapidly growing need to spray some champagne (I was robbed of this last year from my second-place AMA XR1200 finish due to teams cheating), so standing on a professional racing podium, hopefully the top step, is still something to check off the ‘bucket list.’ In fact, it’s currently occupying pole position on said list, so rest assured that nothing will be left on the track and no shortage of effort will be spent to make it happen. So, as the old cliché goes, be sure to stay tuned: it’s going to be one for the record books – literally….
And if you are in the area, be sure to head out to Infineon this weekend to watch the second-annual TTXGP firsthand – we qualify Saturday evening and have a World Superbike-style format with two nine-lap races on Sunday (the first at 11 a.m. and the second at 4 p.m.). It runs in conjunction with the AMA boys in what will be their second round this year, so the racing action all weekend looks set to be a spectator’s delight. Also be sure to come by the Brammo pits and have a look at the bike. These boys have done an amazing job producing this carbon fiber work of art and it definitely deserves a closer look! Just keeps your eyes peeled for the green electric pit bikes sitting out front, that’s us…