Torque or Speed Motor???


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Wich is better in an electric drag kart?


My thoughts on this. I know everybody has one!!!!

If you have a cart running 6:1 gears, a high speed motor and stock wheels.

You have no torque.... to speak of In a 1/8 mile track.

If you get on it and take off down the street then yes at some point it will max out, but with a timed distance I don't think it has the distance to max out.

In a 1/8 mile you need 1/2 torque and 1/2 speed...yes

Torque at the light to get you moving and in a hurry.

Speed to carry the cart after about 1/2 way down the track.

Torque motor's respond very well to voltage increases as we all know, are they fast no! Can we get a middle motor that has good torque and top end I think we can. There are motor's out there.
This is where your tires come into play. The size of your tire is like changing the gear's.
The tires I ran in Albany made a good bit of differance in top end. We ran to runs in practice with the slicks and our speed was way down compared to the 59MPH we ran with the bigger wheel.


New Member
so what your saying is the way to go for tunability is a 2 speed motor?new to the carting world,
i am not a racer but just curious about this stuff.


What I'm saying is a stock Electric motor is around 2800 RPM motor.
A high speed motor is around 4600 RPM. Some place in the middle with RPM's and use a gear set and bigger tires. The torque motor will handle just about as much voltage as you can throw at it and turn those bigger tires and gears. But as with anything you have to have the funds to play with it and see where the sweet spot is. That don't sound nice does it!!!


New Member
sounds nice if you are wanting to win the race. but it would not be feasable to run , say two stage so to speak motor setup?


I know swimming pool motor have two speeds that you set it up on the one you want. It would be nice to have a motor that could be used for both at any given time.


New Member
Torque, did someone mention torque. I like torque now that I forced myself to study “Newtons” and all that stuff!

These kind of things must be taken into consideration when talking torque vs. speed:
*Total Kart Weight
*Weight distribution
*Frontal Drag – Karts max width and max height
*Drag Coefficient - for hard surfaces it ranges from 0.25 (very aerodynamic) to 1.20 (not very aerodynamic). Most high performance karts without windshield and top are typically around 0.35 to 0.45.
*Gearing and tire size too.
There are plenty of programs “hidden-away” in the deep vaults of the Internet that let you fill in the blanks and they calculate Torque/Speed. The more you play around with the inputs, the more valuable information you can gain. One thing is figuring-out the answer to the above discussion on finding the motor that has the right amount of torque and will provide maximum acceleration of varying distances. (like perhaps a eighth of a mile!) It’s a lot easier if you use average acceleration (speed) instead of actual acceleration. Average acceleration is ending speed divided by 2. EX: 0 to 60 mph in 1/8th of a mile takes exactly the same time as driving 1/8th of a mile at 30 mph. (Sorry, perhaps I was the only person on earth that didn’t think about that before!)

Two interesting facts (at least I think so) effecting torque/speed that I found in the vaults (described in much more depth than I state here)

*Total “wasted torque” caused by the rotational inertia of motor and other drive components. Ex. If inertia of the motor results in it to rotate (even by a small amount) it takes away torque that should be delivered to the wheels! The force required to hold that rotation is much greater than one would think. Despite a popular belief, any opposite rotation of the motor housing does not increase the initial speed like a spring, it just wastes torque!

*Amount of Tire ballooning – change in tire diameter resulting from the tire spinning at high velocity. At high speeds, the centrifugal force causes the tire to expand. This increase in diameter can drastically change the top speed. (determined by width and hardness of rubber)

I apologize to all those that already knew all this, just got on one of my soap boxes again! (been a long time, you must admit)


New Member
By the way DS, I've been noticing NICE cart and chassis! Really nice color choice! Color doesn't matter as long as it's black!