Hello to All,
Before getting into my post here, I want to publicly thank my friend Jim Husted for his heroic effort in rebuilding & improving the Siamese 8 these past weeks! Jim is ‘THE’ DC motor king! His artistry is amazing. I had the motor in the back of my work service truck yesterday in all its purple glory, and the ‘wows’ it got from all those who had the pleasure of seeing it, told it all. Thank you, Jim!
OK, here we go…..Advancing motor timing as you increase the volts to the motor under high amperage has been long known for its benefits, so it’s nothing new. If Corbin had listened to all of us seasoned EVers, the neutral timed ADC 8 inch motors would not have kept fireballing and taking out controllers….all they had to do, was advance the timing 10 degrees. They and ADC refused to listen, motors kept fireballing, and DC Power Systems faded away as the maker of fine air-cooled controllers pretty much over losing their shorts ‘doing the right thing’ as they covered all the controller failures in Corbin Sparrows. I helped more than on Sparrow owner advance the timing in their unique cars, and magically, all the problems went away as performance increased, too.
Loni wrote: > Are you manually adjusting the timing via a cable or the like? Seems like the sort of thing I’d get tired of fiddling with, like choke cables of yore.
Marko Mongillo’s fun little Baby Blue Datsun minitruck has an ADC 9 inch with a dash mounted pull-type cable that he uses to advance his motor timing. Jim Husted built the timing system in that motor, and it works wonderfully.
To do a motorized servo controlled timing advance on the Siamese 8 is a bit difficult. The first problem, is how tightly the rear motor’s shaft output end (with a com setup) fits into the little Datsun’s small driveline tunnel entrance. It’s so snug, there’s no room for an external lever-actuation system, with exception to perhaps the underside of the rear motor section’s com end. The front end of the Siamese 8, where another com section is, is the opposite, in that you can’t mount anything under it, as it rests atop a mount that bolts to the transverse frame rail, so any external lever-actuation system wound have to be mounted on top of it or maybe on one side or the other. Now, not having the exact place on both motor sections in which to mount these actuators presents the first big obstacle because they can’t easily be linked together with a linkage shaft of some sort. The second one, is that on the Siamese 8 motor, the timing rotation is opposite from one end to the other, so any mechanical twisting setup has to move in two directions at the same time, exactly the same way. You can see it’s not an easy thing to do with this unique hotrod electric motor. If anyone could come up with a mechanical system to accomplish this, it’s Father Time. Anyone who’s seen what mechanical marvels this guy can make with his hands, knows what I’m talking about!
On the other hand, we’ve had pretty good success with the Siamese 8 without any sort of adjustable advance system. Consistent low 12′s bordering on the 11s aint all that bad. However, even with the new stronger Genesis pack able to deliver lots of power, the pretty severe arcy-sparky event in March and the ‘wall’ of 12.1 blocking us from the 11s, all point to the need for more motor advance. I decided to have Jim to mods to give another 5 degrees of advance. This is a pretty big jump in timing that will definitely have a noticeable effect. It ‘should’ chase away the fireball monster while at the same time, give a considerable hp boost at the higher rpms we run at the far end of the track. It may take away some from the car’s outrageous launch…maybe not, but we’ll soon find out as we are heading back to PIR next Friday, June 29th, weather permitting. We had planned on going tomorrow but the weather forecast changed from what was predicted to be mid 70′s and sunshine, to colder and wet. Calls were made and travel arrangements changed for the Wall Street Journal guy as we now look to next weekend to try for the 11s again.
I’ve been pretty focused the past couple of years in the way I’ve run our racing strategy. I don’t make multiple changes, and instead, try to do one change at a time. We easily clicked off 12.1 second runs in March until we had the motor problem, and the battery current was never turned up higher than 1000 amps. It is tempting to crank up the battery pack current next Friday, but I’ll resist that and leave it set at 1000 amps. The only difference will be the 15 degree timing advance, and of course, the other performance mods to the motor that include a professionally balanced armature stack, beefier brush interconnect arced solid bus bars that replace the flex cables for better current carrying capacity (and heat dissipation away from the brushes), and other nice ‘Jim’ tricks applied….but the biggest change, is still the twist from 10 to 15 degrees in timing. In the event that the car does crack the 11s without turning up the battery amps, it will then be my call whether or not to turn it up to 1200 amps….we’ll just have to see how it pans out, I guess. I’ve got to keep in mind that the BIG EVent, the Wayland Invitational III, is less than a month away, and we need to keep the car running and in good shape for that.
The July races will be very exciting. Will Bill and his devoted team become the first EVers to run in the 7s in the 1/4 mile? Will White Zombie lightened from 2580 lbs. down to under 1900 lbs., fitted with taller 3:70 gears, wheelie bars, and an A123 lithium pack outputting 1400+ amps, run low 11s – high 10s? Tonight, after I return from yet another 320 mile round trip to Central Oregon and back (7 trips in less than 4 weeks now), Tim Brehm and I will meet up at my house at 6:00 pm or so to re-install the Siamese 8 in White Zombie. Then, after a quick spin around the neighborhood and a recharge to make sure all is well again, the car gets loaded up on the trailer behind Tim’s diesel Dodge. Tomorrow, Friday, I get to have a fun 85+ mpg run to Seattle in my Honda Insight with its hi pro sound system while Tim will leave later in the early evening to bring the car up. We’ve meet up with the SEVA gang early Saturday morning to be part of the 2007 ‘Gasless on Greenwood’ car show where 15,000 car fans will clog Greenwood Avenue to see a huge array of hotrods and of course, electric cars!
It’s going to be fun!
See Ya….John Wayland