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Hybrid Caterham race car conversion

1645 Views 0 Replies 1 Participant Last post by  Tom Forsyth
I've been racing Caterhams for a few years, and I got thinking about putting an electric motor on each front wheel to give better torque and 4WD coming out of the turns. The goal of the experiment isn't to save gas, get better 0-60 or to increase top speed - it's to go faster around the twisty parts of a track.

Because the batteries really only have to hold the juice from regen into the corner long enough to give it back to the motors coming out of corner, I'm hopeful the weight can be kept low. I have no idea what sort of size & weight that implies and would value any ballpark estimates people have. Is this an application for supercapacitors rather than batteries?

As for power/torque - the car currently has 200hp/160ftlb from the petrol engine, and that's a lot for the weight of the car. Adding even modest torque to the front wheels would be a fascinating performance improvement because of the extra grip. Any idea what sort of size & weight motor that would be?

I'd like to keep the front wheel, suspension and brakes relatively unmolested. Getting a drive-shaft to the front wheels will be an interesting engineering problem, but there is a surprising amount of space in the nose for a motor - the engine is mounted a long way back.

I'm not sure if it's best to have a single electric motor on the front feeding through some sort of limited-slip diff to the half-shafts, or have two smaller electric motors, one per wheel. The latter seems potentially simpler and raises the possibility of active torque vectoring. Would they still need a gearbox, or can electric motors do direct-drive right onto the axle?

My background is in racing petrol cars and I have no intuition about electrical power at all, so I thought I'd ask here for a high-level sanity-check on this concept - what are the most obvious show-stoppers? Has anybody done a similar hybrid/race car project I can check out?