Power of DC 2009 Autocross

Though the eMR2 couldn’t be there, this Saturday’s Power of DC autocross event hosted a variety of factory and conversion EVs from all over the east coast.  Three Teslas, including a Sport model, tore around the course with the Sport model setting fastest time of the day by rounding the course in under 18 seconds. Though the Teslas set the pace, it was a Mini-E that set the record for the most runs as it rounded the track nearly  all afternoon.

Among the conversions, surprisingly it was a VW Rabbit pickup that cut the cleanest path around the cones despite it’s nearly 3/4 ton of batteries.  A sunburst yellow Destiny 2000 (based on a Pontiac Fiero chassis) gave it a run for the money but the Rabbit’s driver was an obviously experienced hand who could make the most of his car’s abilities.

Other interesting vehicles that ran the course included the WVU Formula Lightning racecar, a Porsche 944 conversion and a daily driver VW Jetta.  Below the pictures are the times for all the day’s runners, courtesy of Chip Gribben.

AUTOCROSS
Saturday, August 29
place/et/driver/vehicle/runs

Production EVs
1) 17.761 – Dave Bolling – 2009 red Tesla Sport (31 runs)
2) 17.979 – Don Auker – 2008 blue Tesla (44 runs)
3) 18.718 – Tom Jamison – 2009 prismatic blue Tesla (19 runs)
4) 19.316 – Ken Barbour – 2009 Mini-E (64 runs)
5) 23.289 – Bryan Murtha – RAV-4 EV (5 runs)

Conversion EVs
1) 21.214 – Dave Cover – Porsche 944 (6 runs)
2) 21.948 – Alan Arrinson – VW Rabbit truck (13 runs)
3) 22.648 – Doug Stansfield – White Hyundai Tiburon (5 runs)
4) 23.441 – Bob Rice – VW Jetta (11 runs)
5) 24.842 – West Virginia University – Formula Lightning (9 runs)
6) 26.643 – Joe Lado – Destiny 2000 Fiero (24 runs)

Posted in EVs, Miscellanea | Tagged , , , , | Leave a comment

A Week of Gas-Free Commuting

Finally, this past week I was able to enjoy commuting in the eMR2 v2.0, equipped with a new single speed transmission, motor coupler and batteries, every day.

There’s still some mechanical work to do, such as address the howling rear wheel bearing and sticky CV joint, but all the EV conversion components are performing as designed.

Pictures and video coming soon, as well as a report from Power of DC happening tomorrow in Hagerstown.

Posted in EVs, Miscellanea | Tagged , , | Leave a comment

New Coupler Design

A couple years ago when the eMR2 was still in the design stage, there were two competing coupler designs:  a simple dual spline coupler (described in a previous post here) and a more complex design that incorporated the spring cushion hub from a stock MR2 clutch.

Incorporating the cushioned hub would insulate the splines for shock loads and provide a little misalignment tolerance.  After the experience with the straight coupler these durability advantages, along with a provision to securely clamp the coupler to the shaft to prevent any axial movement, made the additional cost of the design justifiable.

The clutch hub was harvested from an ACT performance street clutch disc and cost about $90.

ACT Street Performance Clutch Disc

ACT Street Performance Clutch Disc

The rivets fastening the friction disk to the hub were carefully drilled out.  The rivets also serve as spacers for the hub plates and can be seen at the bottom of this picture:

Dismantled Clutch Hub

Dismantled Clutch Hub

Substitute spacers with the proper ID to fit the 1/4″-28 screws that replaced the rivets were easily sourced from McMaster-Carr.  They can be seen between the screw and old spacer.

The yoke was machined by Robert at Artistic Machining and then sent to Form Tools to have the spline EDM’ed.  A shaft collar was also incorporated into the design to nail the whole thing down.DSC00951DSC00950

All the parts were put together with red Loktite and installed just prior to bolting together the motor and transmission.

DSC00956

Posted in EVs | Tagged , , | Leave a comment