1995 Impact L.S.R. (Land Speed Record) Prototype
Nicknamed "Sunnyside Up"


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GM Impact set an electric vehicle Land Speed Record
of 183mph in Fort Stockton, TX c1994

The LSR prototype modifications included:

1)  The addition of six (6) additional 12V batteries to the regular pack to
raise the voltage from 312vdc nominal to 384vdc totaling 20 kWh
traction pack.  Additionally, using an assumed 14.8V as a fully
charged level for each 12V battery then, means that the end-of-charge
pack voltage was in the neighborhood of 484V.

2)  Added aerodynamic modifications, including a) taping seams and 
headlights; b) adding an aerodynamic tail-cone; c) removing mirrors; d)
adding bonneville wheel discs, and; e) xxx; the GM engineers were
able to achieve a drag coefficient of 0.137 on the LSR car.
The production EV1 yielded a 0.195 CD.

 3)  The standard Impact/EV1 motor/transaxle had a low-geared 11/1
gear reduction ratio.  This design helped the Impact’s
induction motor to rev' quickly as it magnified torque through the
numerically high gear ratio allowing the Impact a 0-60mph
time of 7.7 seconds.  In the late 1990s that was considered extremely
quick on the low end, but limited the top speed to 80 mph,
where the induction motor spins at 13,500 RPM.  Alternatively, the
race-prepped Impact’s transaxle had a much taller 3/49 ratio
allowing for higher top-end speed.  

4)  Engineers made modification to the inverter to handle the
higher voltages and put-up more current, eliminated the  electronic
governor (that capped the system at 80 mph/13,500
RPM).  A little known fact is that the Impact/EV1 motor is capable
of spinning up to 24,000 RPM.

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 Part of the equation: 
Areo' + RR + Voltage + Inverter Amperes = Speed

The LSR run.  The impact did a rolling start and took over
five (5) miles to hit its top speed.



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--->  Additional pictures below  <---


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