63 replies to this topic

[Kelpiecross]

Very clever Woozy - that certainly is a simple way to work it out.

[imaginesix]

It might be limited by thermal management with repeated full power drag runs, rather than battery power limited.

[chunder27]

I think Garlits made a decent electric dragster in the early 10's. No idea what runs he was doing though.

[Wuzak]

Very clever Woozy - that certainly is a simple way to work it out.

 

Possibly an overestimate since at low speeds and at launch teh Tesla will not be making peak power, but will be making peak torque.

 

https://electrek.fil...png?w=897&h=498

[Kelpiecross]

Possibly an overestimate since at low speeds and at launch teh Tesla will not be making peak power, but will be making peak torque.
 
https://electrek.fil...png?w=897&h=498

Close enough I would think. My original thought was just to work out the energy needed to accelerate the car in question - just the basic theoretical amount needed. I actually expected this figure to be so high on its own (without all the various resisting forces) to show that the number of runs would be very limited - and was not going to get any better with all the forces added in. My guess was actually out by at least a factor of about 10.
I still think EVs are not really practical though.

[thegforcemaybewithyou]

Has anyone more info on how the launch mode for the Tesla works? Is it self adapting to the current road grip available or does it try to reach a fixed tyre slip ratio?

[Greg Locock]

Not answering the question, but why would it need different logic to the launch mode of a directly fossil fueled car?

[Lee Nicolle]

I think Garlits made a decent electric dragster in the early 10's. No idea what runs he was doing though.

The electric Dragster did just under 200mph in 2014 .

I believe that sanctioning problems [and Dons age] has put paid to any more development. 

You Tube  Don Garlits electric dragster for a lot of info.

[Wuzak]

The electric Dragster did just under 200mph in 2014 .

I believe that sanctioning problems [and Dons age] has put paid to any more development. 

You Tube  Don Garlits electric dragster for a lot of info.

 

This video shows 7.258s @ 184mph.

 

 

The video says the car has 1.5MW (2000hp). How does that time and speed compare with regular dragsters of similar power?

[Kelpiecross]

Possibly an overestimate since at low speeds and at launch teh Tesla will not be making peak power, but will be making peak torque.
 
https://electrek.fil...png?w=897&h=498

I would have thought that a power curve like this would imply that a gearbox would be helpful in initial acceleration. Maybe not for a Tesla as it is probably already on its grip limit anyway - but possibly useful in a much lower powered EV? Do any EVs have gearboxes?

[Wuzak]

I would have thought that a power curve like this would imply that a gearbox would be helpful in initial acceleration. Maybe not for a Tesla as it is probably already on its grip limit anyway - but possibly useful in a much lower powered EV? Do any EVs have gearboxes?

 

Some have gearboxes.

 

I think most electric motors have n initial period of constant torque, followed by a period of constant power. With cars like the Tesla Model S the motors run beyond this rpm range, and power falls off.

 

Thus, gears would be required for access to higher speeds while maintaining the initial quick launch.

 

Garlits' dragster I think uses a 2 speed 'box.

[chunder27]

To be honest a lot of decent spec drag cars could do 7 second runs.

 

In terms of rails, that is way too slow to match anything other than pump fuel.

 

It's slower than Pro Stock and Pro Mod.

 

But when you think it's new tech, it is fairly decent speed.  2000hp is not a lot in drag racing terms. A lot of the import classes and the like run double that.

 

Even those Civics I was talking about earlier can have over 1000hp

[Magoo]

This video shows 7.258s @ 184mph.

 

 

The video says the car has 1.5MW (2000hp). How does that time and speed compare with regular dragsters of similar power?

 

Not too shabby for an 80 year old guy. 

[Canuck]

Hmmm...Larry Larson ran a 5.95 / 244 in his S10 in late 2014. That's quicker than Lutz I think.