Hey guys, new to this forum but just looking for a bit of info on a project I want to pursue. It involves taking a kit car or ultra lightweight sports car such as a Lotus Elise (Yes I know this sounds exactly like the first gen Roadster), and installing P100D internals. In the article, it is mentioned that the builders used two Chevy Volt batteries as opposed to Tesla batteries for a higher discharge rate and the fact they were lighter. Was the article referring to base Tesla batteries or performance batteries such as the P100D? Anyway, the real question I'm asking here is what would be the best combination of internals to use in an electric drag oriented car?(Tesla Drivetrain and Tesla Batteries, Tesla Drivetrain and Volt Batteries, etc.) This is the article I'm referring to Btw- https://electrek.co/2017/09/18/tesla-powered-electric-kit-car-9-second-quarter-mile/-
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dhrivnak
Active Member
The challenge is likely the battery as there is no way to fit a Model S battery under an Elise. How fast do you want or need to go? A stock Roadster with a 3.0 battery will run 13 or faster in the 1/4.
More of a hypothetical for the fastest quarter mile I can achieve. Let's just say I somehow could fit a P100D battery under the elise- would that be better than the two volt batteries used in the article?
I think this will be more complicated than you are expecting. I am NOT an electrical engineer but I am a gearhead and have some very basic understanding of how this works.
I believe with projects like this batteries are often dismantled. There are modules of batteries run in series to get voltage up and then those are run in parallel to get overall capacity and amperage up. How much voltage, amperage your motor needs, actual use/capacity it needs and how much heat will be generated will all play into how you redesign your battery.
A P100D battery is designed for high voltage and amperage for performance and high capacity for range, for drag use you have no use for the range. I suspect by using the Volt battery they were able to get high voltage and amperage without the weight penalty of a LOT of range.
I know I didn't give you any real information but hopefully I gave you some ideas to help you ask the right questions.
A P100D battery isn't going to be a good dragrace platform due to the weight from excessive capacity.
I believe with projects like this batteries are often dismantled. There are modules of batteries run in series to get voltage up and then those are run in parallel to get overall capacity and amperage up. How much voltage, amperage your motor needs, actual use/capacity it needs and how much heat will be generated will all play into how you redesign your battery.
A P100D battery is designed for high voltage and amperage for performance and high capacity for range, for drag use you have no use for the range. I suspect by using the Volt battery they were able to get high voltage and amperage without the weight penalty of a LOT of range.
I know I didn't give you any real information but hopefully I gave you some ideas to help you ask the right questions.
A P100D battery isn't going to be a good dragrace platform due to the weight from excessive capacity.
Sorry, I should've been more clear. This car would theoretically run like a Dodge Demon. Bring it to the track when I want, but also get me from Point A to Point B. Also, the complexity of this project is understood, as I definitely couldn't take this on alone. Range isn't the main objective here, but still is a factor. I just see the potential of the P100D on a sportier and lighter chassis.
I would buy a salvage MS P100D and contact the guy that has figured out how to "tune" the MS. Going to need someone that can do that anyway.
If you are going to have a high power high capacity battery I don't think you will loose that much weight vs. a MS by the time you have adapted everything. Yes they are heavy BUT the battery is the weight difference vs. a more traditional car
If you are going to have a high power high capacity battery I don't think you will loose that much weight vs. a MS by the time you have adapted everything. Yes they are heavy BUT the battery is the weight difference vs. a more traditional car
Brando
Active Member
It is all Aluminium. Carbon Fiber to save some weight? search
model S GT racing
lighter chassis? how can you do that and not lessen crash safety?
I guess you could make suspension out of carbon fiber.
Disc brakes switch to carbon like Formula 1.
Battery pack? won't think so
Gut the interior (see above GT racing)
Have fun, which is surely part of the point of considering this project.
.jg.
Member
Perhaps you could start with a salvage P100D (e.g. body damage) and try to fit all the important parts onto a space frame chassis. This would replace the body shell with a space frame chassis, dispensing with glass, interior, passenger heating/cooling, entertainment system, doors, etc. Like an electric version of the Ariel Atom.
Brando
Active Member
The Tesla Model S battery pack has "1/4" balistic aluminum bottom" according to Consumer Reports when they covered the added titanium protection added to the Model S to prevent battery puncture fires (the front of the pack was the weak point, not the bottom).
Replace the top (body) with carbon fiber and roll cage would seem a good approach, right?
i.e. Keep the chassis/battery pack so called skateboard
PS- I think the fastest Model S P100DL is already as fast as the Demon (using the same type tires) ?
.jg.
Member
Yes - I guess you would start with the battery pack and build a space frame chassis around it, with mounts for motors, suspension and steering components - all positioned where they would be in the original car. The space frame would also surround the passenger space, with an integral roll cage. You could then use carbon fibre or perhaps cheaper lightweight materials to house anything you need to protect from the weather - like the electronics controlling the motors, lights, etc. I guess one of the big challenges would be in engineering the space frame chassis to be light but to have sufficient strength and rigidity, in order to handle the weight of the components and stresses from all that power/torque.
There might also be some other constraints if you plan to use the vehicle on the roads e.g. I don't know the rules in the USA but in the UK, the wheels could not be completely uncovered.
BTW Would you have any problems insuring such a vehicle for road use?
Can't remember the guys named but there was somebody trying do something similar only on a van (http://cafeelectric.com/stretchla/2017/05/22/the-end-of-the-strechla-and-a-new-beginning/), pretty cool and ambitious project imo, maybe some of his info would crossover. Last I heard the project was just too much for one guy and he had given on up it understandably, also Tesla was not particularly helpful I guess in terms of support. If you're into drag stuff this is probably moot, but my 2 cents is do it for a truck/suv/van. That way fitting stuff might be less of a problem, plus there are a lot of electric drag type stuff, but not too man electric trucks/van.
