# EV noob looking to build drag car



## Lason (Dec 9, 2008)

Hey guys, just had a couple questions. I spend part of the day yesterday searching this forum for ideas on a electric drag car and learned quite a bit. Im still unsure on if it is something I will do but I really would like to try sometime. 

My main question is, is there any controllers out there that would be able to handle the power now that Zilla's arent available any longer? 

Also it appears DC is the way to go for a dedicated drag car but being that I am so used to ICE's I cant tell what motors are capable of power wise. Of course my first instinct is to throw a couple of the biggest motors I can find together and see what it does but that looks PRICEY! 

Also the battery situation has me a bit worried. I raced electric r/c cars for years so I have a general idea of how electric motors work along with the controllers and all that but I dont understand all the electrical lingo and what a motor will need to run. I know from the model cars that we added more cells and got faster times but it seems they dumped off quicker and the run times went down. So in my situation Im trying to figure out what kind of setup would provide a high rate of discharge into the motor without hurting the cells and how many cells I need. I looked at the LiFePO4 (sp?) cells but it seems a pack would run $10k or more, is that correct? 

Sorry for all the noob questions guys, Im just starting out in all this. My dad recently got into all this and build a EV fiero to drive around my hometown and got the idea in my head of a EV drag car. I currently have a Datsun 240Z that I built from the ground up that is tubbed out, roll cage and has a turbo V8 so Im mechanically inclined and able to fabricate pretty well. I thought about converting my Datsun but I dont know how feasible it would be so maybe the best solution would be to build a car/truck from scratch with EV in mind.


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## martymcfly (Sep 10, 2008)

There is a show on Speed channel called Pass Time. One night last season, a guy ran a Electric s-10. I think it ran a mid 10 quarter mile. I don't know what he had in it, but it was pretty cool.


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## Lason (Dec 9, 2008)

Yeah I have seen that one. Its a cool truck for sure. I posted about it earlier this year on a local drag racing board Im a local on. Most of the guys couldnt believe it but thought it was very cool. Thats kind of the reason I am looking at EV. Anyone can run brutally quick times with a ICE but EV is something everyone thinks cant be that quick. I like being different and trying new things so this seems right up my alley. 

Heres the link to the truck
http://teva2.com/berubes10.html

**EDIT**

While searching for some recent info on this truck AKA "smoke screen" it has run a quickest of 11.083 in the 1/4. Im looking to run single digits and seeing that he is the #1 on the NEDRA list I dont know if its possible with current technology. 

http://www.nedra.com/records-mc.html

**EDIT**

Also found the same truck for sale! $58k!!!

http://www.austinev.org/evtradinpos...ory&fromfrommethod=showhtmllist&fromfromid=18


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## TX_Dj (Jul 25, 2008)

Lason,

FWIW, Dennis Berube' (who owns that S10) is also the owner of Current Eliminator, which was the first electric drag rail, who held the world record fastest EV dragster times for years and years until Killacycle finally surpassed him.

Remember this, though... Bigger is not always better.

It does look like Dennis used a 13" motor in that truck, direct drive to the differential. It likely puts out gobs of torque for a single motor DC truck, but likely is stunted on HP because of the rotational inertia of the larger diameter motor. That's not to say it's not impressive. 

A lot of the more successful guys have been doing a "siamese" motor configuration, with two custom built 8" or 9" motors mounted end to end, direct driving the differential.

In this configuration, and with the correct Zilla + Hairball, one can program the controller to activate a series/parallel contactor bank to rewire the two motors on the fly. This ends up acting kinda like a powerglide transmission, without incurring the efficiency loss of the gearbox. You get mega torque for the launch, then "shift" for mega HP for the follow-thru.

But yeah, without getting your hands on a Zilla, your efforts will be stunted unless you can find someone to build you a custom controller that can give you the amps you need, and handle the volts....

FWIW, most of the bigtime draggers these days are using LiFePO4 or similar light-weight, extra-dense storage tech, with extreme discharge profiles (10C or better), and they're high-voltage packs at that.

I.E. I want to say CrazyHorse uses 300+ V, as do most of them... and to get a controller that handles that kinda voltage and 1000-2000 amps, you gotta have a Zilla. 

Now- for your tidbit about the RC cars. Volts generate RPM. RPM generates speed. Amps generate torque. So, volts * amps = watts. HP and Watts are analogous. There are ~750 watts per HP. Adding more cells in series raises your voltage, making it possible to go faster. It also reduces the amps pulled to provide the same wattage, so unless the motor/controller are modified to pull more amps at the higher voltage, runtime will actually be *longer* with more cells.

If a cell in the pack provides, let's say, 20 Watt-hours of capacity, and has a voltage of 5v, a 5-cell series pack will provide 100 Watt-hours capacity and a voltage of 25v. Adding 2 more cells will increase capacity to 140 Watt-hours and raise the voltage to 35v.


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## Lason (Dec 9, 2008)

Great info! Thanks a lot! I think I decided to build another ICE for my car and concentrate on that for now. Maybe when/if the zilla's ever start being produced again or another alternative comes out then Ill pull the trigger on this build. I may still build a EV go cart or 4 wheeler though just for giggles.


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