[gward70]

I'm new to the forum and I know nothing about electric cars / motors but I want to build a ROCK BOUNCER

The motors would need to be able to turn some 44 inch tires and take massive amount of pressure

This is a old buggy but one of my favorite compilations

https://www.youtube.com/watch?v=GzXVLbs41Ew

Can anyone tell me if they think this can be done ?

I need a lot of wheel speed and torque

 

[nucleus]

I haven't seen it done yet, but I think your best performance dollar ratio solution is to buy a wrecked tesla and use the rear drive unit in place of the transfer case.

The left output becomes the front driveshaft output and vice versa.

Jack Bauer on these forums has a solution to drive the Tesla unit, and EVTV is developing as well, and they are not the only ones.

The Tesla is a single speed 9.73 ratio, you will need to upgrade the stock open differential, RVTV has a nice solution.

You can play around with ratios here.

Have fun!

 

[dcb]

power to weight and weight distribution are going to be your biggest challenges. Plus gearing, and the fact they use a torque converter which further boosts low end torque.

http://www.pirate4x4.com/forum/general-4x4-discussion/1083955-mini-rock-bouncer.html

"Most of the rock bouncer buggys are 500-750 HP and 3500-4500 lbs. And you can tell a hell of a lot of difference in the rigs with well built single mixer propane motors (500 HP max) and the built efi motors or dual mixer setups."

Even though you say "not Distance" I'm sure it still takes quite a bit of energy to do a run, repeated every run.

Now if you wanted a 1 motor per wheel rock crawler, the per wheel torque control would be very useful, and the weight not as much of a penalty, but trying to blast up the hill is gonna be a challenge, and a challenge to your wallet

 

[Jeremyfc1]

Once you get to one motor per wheel then it's a how do you design the suspension to take full advantage of that. Maybe portal hubs with cvs to motors mounted inboard. On some crazy ifs irs buggy.

The ac90 that I'm building arround is 125hp 400ftlbs which in a flat tq curve will basically gernade the parts I'm using. tq from 0-6000rpm should be plenty to do what most bouncers do.

It's battery protection and driver protection that will be the biggest challenges.

 

[Jeremyfc1]

If I had an actual budget. It would be Remys. I.e. Two into an atlas 3-4 spd tcase. As far as drive train. If I were able to just finance it and scavenge parts it would be tesla drive unit in a mid mounted buggy like they do with the Honda motors

 

[solidr53]

I haven't seen it done yet, but I think your best performance dollar ratio solution is to buy a wrecked tesla and use the rear drive unit in place of the transfer case.

The left output becomes the front driveshaft output and vice versa.

Jack Bauer on these forums has a solution to drive the Tesla unit, and EVTV is developing as well, and they are not the only ones.

The Tesla is a single speed 9.73 ratio, you will need to upgrade the stock open differential, RVTV has a nice solution.

You can play around with ratios here.

Have fun!

The gear ratios aren't matching properly. Most axle ratios are in the 2.5-6.0 range, so it would have top speed of about 60mph.

Unless you could somehow build an axle with 1:1 ratio, that would be doable and very optimal for bouncers.

Does anyone have more ideas of getting tesla's large motor into normal axle ratios in 90deg mid-engine configuration?

 

[galderdi]

I am not quite sure why we are steering down the Tesla path for this project. Sure they are great for a lot of things. But the gearing issues and the need to hack into the system would turn me off.
I would be thinking of whatever design works in a traditional Rock bouncer but replace the ICE motor with one or maybe two big/simple brushed DC motors. Run them through the normal gearbox and transfer case to give great flexibility in gearing. The torque is the main objective in those vehicles. Range will just be dependant on the size of your batteries.