[toddshotrods]

Thanks for the info on killacycle, Todd. It means that for a bit over 200lbs you should be able to squeeze out 800hp, or else have 400hp for less than 140lbs. Interesting .

BTW, except for the fact that neither the motor nor controller has been designed, we are still talking todays technology. No superconductor or exotic material needed.

Dawid

You can't even consider those cells, unless you have sponsorship, or happen to be incredibly wealthy. The fact that they're mad efor F1 cars, and have such high power density, means the price would be beyond astronomical. I know some guys who build seven figure (that's not a typo) hot rods and race cars, and that may even be out of their budget.

It does hint at what might be coming our way someday. The cells, like A123 M1s and Kokams, that we think are so hot today were unheard fo not so long ago...

 

[major]

http://www.plettenberg-motoren.com/UK/Motoren/aussen/Predator37/motor.htm

This motor delivers 15kw in a 1.9kg (4pnd) package.

I wonder how you connect the three 2/0 cables to it

 

[2cycle]

So killacycle has more hp than Zombie?

 

[DavidDymaxion]

When the Zombie had a Kostov it was lead acid. With its Kokam pack it is now higher -- Wayland estimates 900+ hp! http://www.plasmaboyracing.com/blog/?p=170 . So Zombie wins in hp, but I think Killacycle still has better power/weight.

So killacycle has more hp than Zombie?

 

[2cycle]

When the Zombie had a Kostov it was lead acid. With its Kokam pack it is now higher -- Wayland estimates 900+ hp! http://www.plasmaboyracing.com/blog/?p=170 . So Zombie wins in hp, but I think Killacycle still has better power/weight.

The way I read it he stated the pack is capable of 900+ hp. His motor surely doesn't put out that kind of power because if it did he'd be a lot faster than he is. 900 hp range is what a few of my friends have in their cars and they run waaaaayy faster than WZ. 900 hp in that light of a car is 1.2's 60' and mid 5's in the 1/8 @ 120's mph without even trying. My friends car runs 4.9's in the 1/8 with 950 hp.
Anyway the WZ article also says he predicts using half that pack power will net him 10 second times, so I would say he's got around 500 hp like killacycle does.

 

[major]

If you use this type motor @ 150kw, it will be approx. 40lbs. Add 75lbs for a pack similar to Killacycle, and another 40lbs for the controller, the whole propulsion system will be approx 160lbs for 200hp cont, 400hp peak.

Hi Dawid,

I'm not sure if you are serious here or not. First you jump to a conclusion about doubling stated power to get peak of 400hp. And do you really think the little motor can be scaled up by a factor of ten? I guess you could just use ten of the little guys. But how much of that 15 kW apiece will be required for cooling air over and thru the motor? Be interesting to try. They were about 1000 euros apiece. And then again for a controller. About ripe for a go kart, wouldn't you say?

I have to wonder a bit about these hobby/model motors and equipment. They have made great strides recently with the availability of LiPo batteries. But I just recieved a Tower Hobbies catalog today and was looking at ESCs (electronic speed controllers). They have a TL2522 listed at $149, 1.36 oz, 1620 amperes rated. For brushed motors.

Regards,

major

 

[DavidDymaxion]

Apologies if that was confusing -- I didn't mean to imply pack hp was what he was getting to the ground.

I agree his times are not consistent with 900 hp, but he only tuned the Zillas for 1/2 the pack's potential. His times are in the ball park for 450 pack hp. This is a fresh pack and he'll be working up in hp. He'll need some more safety equipment to go into the 9's, which he hopes to do. So, so far his motors have passed hp of around 450 hp... but hold the phone for a moment...

He did once accidentally wire something up backwards that disabled the Zillas' current limit! He estimates he might have been dumping 3000+ Amps, per how far down the very stiff batteries sagged! He said the car felt very fast. They could not get it to hook up. That might have been as much as 800 hp input to the motors! (That's my estimate, not John's, by figuring 3000 Amps and batteries sagged to the 1/2 way point.) His motors survived, but Otmar warned he likely greatly shortened his Zilla's life. I would guess the high Amp excursion was very brief, and don't forget he is running twin 9 inchers now. Ah heck, John tells the story much better, check it out it is a great read:

http://www.plasmaboyracing.com/blog/?p=239

The way I read it he stated the pack is capable of 900+ hp. His motor surely doesn't put out that kind of power because if it did he'd be a lot faster than he is. 900 hp range is what a few of my friends have in their cars and they run waaaaayy faster than WZ. 900 hp in that light of a car is 1.2's 60' and mid 5's in the 1/8 @ 120's mph without even trying. My friends car runs 4.9's in the 1/8 with 950 hp.
Anyway the WZ article also says he predicts using half that pack power will net him 10 second times, so I would say he's got around 500 hp like killacycle does.

 

[Bowser330]

interesting....in the blog Wayland mentions running the motors in series mode exclusively, no more electronic series parallel shifting...hmmmm

this means that the motors are getting 1/2 the voltage and the full amperage form the controller...

so with a 400V pack, they would be getting 200V & 2000A from a ZillaEHV2K....

I always thought you wanted the high voltage to push the peak amps out to higher rpm...it seems as though wayland is only putting less then 200V into each of the motors...

Is it because the re-gearing is allowing him to get to 125mph trap speeds at a lower rpm and therefore still in the peak torque range of the <200V motors?

 

[toddshotrods]

With all this in mind, and getting back to the main subject for this thread, I think the next big step for EV drag racing is going to be purpose-built motors. Right now battery packs are the limiting factor. Even though they are available now, you have to be sponsored, wealthy, or single (read, free to "waste" as much money as you please - like me), to afford to experience it. When that changes and more people have access to serious power, the motors are going to become the weak link. Also, as battery technology advances, the sponsored, wealthy, and single, are going to push existing motors way beyond their physical limits.

Right now the solutions are a bunch of subtle improvements and some not-so-subtle band-aids. If you go back and look at ICE drag racing you will actually see a lot of similarities, including the use of dual (and triple and quad) motors to get more power; and borrowed and modded factory parts. Eventually, purpose-built racing parts, and even full engines, replaced all that and now we have 8000hp T/F and F/C.

If Jim doesn't have any real secrets inside those motors, someone eventually will. If he does, they will eventually be discovered by others and competition will drive advancement. When I started racing motorcycles Vance & Hines had secrets inside the cylinder heads that allowed them to totally dominant the rest of the field. Now, there are others who can compete head-to-head with Byron Hines' porting work, and there is a healthy, competitive, sport.

I really have no idea what I'm talking about but my instincts tell me that custom winding is the key to massive power in the future. Every one is afraid to even consider it right now, because the motors haven't reached their physical limits yet. Time-consuming yes, but time is money and racing ain't cheap...

 

[DavidDymaxion]

The Advanced DC motors can only take around 160 or 170 Volts. His leacid packs would sag so much he needed to go parallel. The new lithium pack is so stiff he decided to stay in series.

interesting....in the blog Wayland mentions running the motors in series mode exclusively, no more electronic series parallel shifting...hmmmm

this means that the motors are getting 1/2 the voltage and the full amperage form the controller...

so with a 400V pack, they would be getting 200V & 2000A from a ZillaEHV2K....

I always thought you wanted the high voltage to push the peak amps out to higher rpm...it seems as though wayland is only putting less then 200V into each of the motors...

Is it because the re-gearing is allowing him to get to 125mph trap speeds at a lower rpm and therefore still in the peak torque range of the <200V motors?

 

[Tesseract]

The Advanced DC motors can only take around 160 or 170 Volts. His leacid packs would sag so much he needed to go parallel. The new lithium pack is so stiff he decided to stay in series.

Yup. Mind you, it's not a bad thing to stay in series... As long as you haven't run out of voltage (hit 100% duty cycle) that is.

Actually, I just know there is an optimal (physics-based) method for determining when you want to hit 100% duty cycle in the controller for a straight-shot drag race. Applying a little math here ought to do the trick... unfortunately, I've been out of school way too long to remember how...

 

[DavidDymaxion]

Also you'd need to take into account it takes time for the Zilla to shift from series to parallel.

I think the optimal controller would have three main transistor switches, and gradually and continuously shift the motors from series to parallel instead of doing it in one big step.

Yup. Mind you, it's not a bad thing to stay in series... As long as you haven't run out of voltage (hit 100% duty cycle) that is.

Actually, I just know there is an optimal (physics-based) method for determining when you want to hit 100% duty cycle in the controller for a straight-shot drag race. Applying a little math here ought to do the trick... unfortunately, I've been out of school way too long to remember how...

 

[GerhardRP]

Actually, I just know there is an optimal (physics-based) method for determining when you want to hit 100% duty cycle in the controller for a straight-shot drag race. Applying a little math here ought to do the trick... unfortunately, I've been out of school way too long to remember how...

I wouldn't mind giving it a shot... If I can get my hands on the Zilla dumps that went with the White Zombie's record runs. I am a physicist not planning to drag race myself. As I said before, I am sure the best gearing is that which allows a flat out motor/controller at launch to make just enough rear wheel torque that the tires barely slip.
Gerhard

 

[2cycle]

You don't have to figure it out if your controller can sample rpm quick enough to plot it against time and not let the rpm increase faster than a predetermined rate which takes a few passes to set a base line. We can do this with ICE using the ignition to limit power off the line to control wheel/track spin. The rules against traction control are for active systems such as this and NHRA doesn't allow it so be careful. I believe using this acceleration limiter approach is the best way to do it but is the most looked at by NHRA as well.
I would think this would be very easy to do with an electric motor seeing it's so easy to do with ICE.

 

[E4mula]

There would be a lot of variables to set up a physics based algorithm for launch control; track prep/temperature, tire temperature, etc.. that could change on each run. Better to let the processor in the controller handle the dynamics.
You could set up a ramped acceleration rate like 2cycle suggested which would be great for consistency in bracket racing, but not if you're trying to set new time records or to run at the traction limit.
Setting up a drag racing launch control routine wouldn't be too difficult. Class rules at the track may disallow it though.