For the Pirahna, you have a 2 motor design. Could you use the second motor as drag during the transition? Essentially, switch the second motor to reverse to provide drag (with just the right voltage, of course) and switch gears. Then put to normal and accelerate. The reason I say this is I think when the motor transitions to 2nd gear it is too close in speed to mesh if it hits wrong.
I want to ask what kind of clutch you got but I am afraid that might be a trade secret. :) Lyle --- BFRListmail <[EMAIL PROTECTED]> wrote: > Hi all, > > Well, Mike asked for a report on how the gear > changed worked on my bike, so > here goes. > > Went Wednesday to the Milan Dragway Test/Tune > session. I'd only been to one > other wednesday nite race, and it was pretty packed. > This nite was the > same, and the last one for the year. Even the 40 > degree nitetime temps > didn't scare anybody off. Guess those gassers make > big power in the cold, > but I was definately down on power. I can always > squeak 600 amps out of > each string of Hawkers, but this time I could only > pull about 500. > > Launches were OK. I geared 1st gear just a tad > taller than my last time to > the track where I was getting quite a bit of wheel > spin. The track was > definately cold, but was also sticky. 2nd run I > made I thought I pulled the > front end up, at least stroked the shocks out, but > maybe didn't lift the > wheel. One guy commented on how the bike launched > really good, but just > quit a few hundred feet out. I can't even feel the > clutch pull in. Not at > all. Looking at the data confirmed what that guy > said. You can see the > volts drop and amps spike when the clutch comes in. > But the amps take > forever to drop back off. The volt take forever to > come back up. I was > clearing the 1/4 mile at about 2000 RPM. I can run > about 2900 RPM in 1st > gear. > > Analysis? That larger split between 1st and 2nd > gear is bogging the motors > down. But mathmatically, I don't know why I went > with such a steep 2nd > gear. At 2900 RPM I'd be turning probably 90 MPH. > Not going to happen. > > So then I did some homework. I read that a shunt > motor (mostly the same as > a PM motor) doesn't respond well to changes in load. > I guess I've proven > that. A shunt motor won't make the torque to > reaccelerate the load. A > series motor is the answer for that, or at least a > compound motor. > > So I'm looking at a few options: > > A) Change the gearing so 1st gear is 1.375:1 and 2nd > gear is 1:1. This will > put a smaller load change on the motors, and should > hit just over 70 at 2900 > RPM. > > B) Lower the voltage way down on the clutch (voltage > yet to be determined) > so that the clutch actually slips and bring on the > added load slowly. Might > tear up the clutch though? > > C) Toss the transmission and see if I can get it > running as quick as I did > before the transmission. > > > Oh yea, Suncoast can ignore the preceeding as this > is all in an attempt to > dominate at the upcoming Battery Beach Burnout. > > > Later, > > Darin > BadFishRacing > > ----- Original Message ----- > From: "Mike" <[EMAIL PROTECTED]> > To: "ElectricMotorcycles" > <[email protected]> > Sent: Friday, September 22, 2006 10:44 AM > Subject: Re: [ElectricMotorcycles] Harley Drags > > > > >About the only thing I haven't tried is changing > the gearing between 1st > > >and 2nd gear. What are you guys with 2 speeds > running for gear ratios? > > >Or if you're running 2nd and 4th gear? I don't > think I've got enough > > >leap from 1st to 2nd, as I can't seem to SUCK > AMPS when I grap 2nd gear. > > >Any thoughts? > > > > Darrin, Did you find any answers since you posted > the above? I'm always > > curious. > > > > Mike > > > > -- > > > > The Electric Motorcycle Portal > > http://www.electricmotorcycles.net/ > > > > Electric Motorcycle Listserv > > http://www.electricmotorcycles.net/listserv > > > > > > > > -- > > No virus found in this incoming message. > > Checked by AVG Free Edition. > > Version: 7.1.405 / Virus Database: 268.12.8/455 - > Release Date: 9/22/2006 > > > > > > > ____________________________________________________________________________________ We have the perfect Group for you. Check out the handy changes to Yahoo! Groups (http://groups.yahoo.com)
