Using MightyBoyEV - First Drive....

First 10km test drive - 7 AM start.....

Heading down to the weighbridge and then to the "trimmer" to have a new rear tonneau cover made

What are all these cars doing on the road?

Great acceleration with the 8" motor! - well to 50 kmh anyway - then fairly average performance to 70 kmh but easily better then the ICE was......

(Not sure what the maximum speed will be - but 80 - 85 seems easily achievable now)

Runs well.....

Some data to start with:

Total Weight

Total weight is now 750

With the spilt being 340 front and 410 rear (better then I planned for these old school SLA batteries)

Ride and Cornering

Ride is VERY hard with the short wheel base and high tyre pressure - but as you would expect....

Cornering is very much improved - most likely because of the upgraded quality shockers and suspension bits.

The weight distribution seems nicer then before - these small utes like a bit of weight in the back anyway.

Slight under steer - but not a problem at the speeds this car will be used at......

Other first impressions

Throttle curve could be improved (I am currently running default values and hope to program the motor controller this weekend)

Half speed reverse a bit too slow - but I think this will improve once I have setup the throttle curve to suit....

Controller heat sink is more then adequate - a bit of "over kill"  in my design....

Motor runs at a max of 40 degrees C (about 15 degrees above ambient) - based on a test run at 50 to 60 kmh - for a 5 km run....

Driving in 4th gear seems best from a drivers point of view but 3rd  appears to take slightly less from the pack- this needs some driving experience to determine the best option here.

Changing gears without a  clutch (one of my fears) does not present any issues-  but as it turns out, changing gears with this over rated motor isn't required anyway....

And lastly - Hard to go back to non-assisted braking system - may need to put in softer linings and pads at some stage.....

First stats on performance

For the first 21 km travelled here are some figures from the computer....

Power per Km = 108.7 w-h/km (or 178 w-h/mile)

AmpsMax =263 amps

VoltsMin = 60.3 volts (as occurred when 263 Amps pulled,,,)

MaxSpeed = 64.4 km/h (limited by speed limit in area)

AvgSpeed = 36 km/h

Watt Hours used from pack = 2274 watt-hrs

(test drive using 4th gear - and reverse only)

So first impressions are better then predicted - lets see what happens after a few battery cycles.....

I have also now reprogrammed the controller for a fairly linear throttle curve and removed the "dead" play in the PB-6 pot box - this seems really nice and smooth too drive and reverse is now 100%. 

Just for fun, and as a comparison, here is a quote from the Tesla Roadster people....

"Even with tires and gearing optimized for performance (rather that absolute efficiency), the Tesla Roadster only consumes about 110 watt-hours (0.40 mega-joules) of electricity from the battery to drive a kilometer, or 2.53 km/MJ."

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