A Chevy Coupe Electrified by Tesla - Saved or Sacrilege?
They say electric cars will kill hot rodding, but could they simply be in new guises?
Paul Mangelsdorf is testing that theory with his ’40 Chevy coupe. Rather than keeping internal combustion, Paul chose a Tesla Large Drive Unit to power the classic metal. There are all kinds of parts we don’t understand from there, so we will let Paul explain just what’s underneath the Shocking Chevy.
“The Tesla LDU is controlled by an open inverter/ EVBMW open-source control board,” he said. “The motor is powered by two second generation Chevrolet Volt batteries. The car has CHAdeMO fast charging, as well as an on-board charger from a Tesla Model 3 (called the PCS). There are parts from another dozen or so cars, including Prius water pumps, a Trailblazer throttle, Sonic handbrake and more. It’s truly a hot rod with a different fuel type.”
The coupe has a G-body Monte Carlo front frame, but keeps the original rear frame with the addition of 2005 Pontiac GTO independent rear suspension. Just like his internal combustion brethren, Paul had to seek parts in junkyards and modified what he found to work.
“I got into EV conversions in college, when I led a team to finish an effectively abandoned Chevy S-10 conversion project. While that truck was quite slow, it got me hooked on EV conversions and drag racing.
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“When I decided to build my own car, I was looking for something cool, and preferably pre-1955. I had been on the lookout for a 1940 Chevy coupe, as it was my grandfather’s first car and was always ‘the one that got away.’ I found the shell and frame of the car between Fayetteville and Rockingham. It was in rough shape, but had most of the body panels, and the G-body front frame had already been swapped over. I later learned that the guy I had purchased it from bought it from the widow of the last guy to work on it , and it was one of 18 cars he was working on when he passed.”
Paul worked within his time and money constraints, making concessions where needed.
“I went back and forth on the specific drive train for almost a year, before settling on the Tesla LDU. The Chevrolet Volt batteries were selected because they are affordable and power dense, though they are not energy dense. This means that they can deliver just as much or more power than a Tesla pack, but have much less range.
Like many other competitors, Paul arrived at Hot Rod Drag Week with a couple of issues to fix. His inverter tune had an issue where going full throttle for more than about a second would trip an error and shut the car off, but the more worrying issue was that the onboard charger was only pulling 2kW of juice, even though it should be capable of 11kW.
“On Monday, my first pass hit the error, but my second pass rolled slowly to get a clean 13-second run,” Paul said. “Heading out on the route, things were mostly going well, but after Fayetteville there was no fast charging along the route until past Rockingham. After sitting for way too long at slow chargers (which use the PCS to deliver power), I left Southern Pines around 1.30am and had the bolts back out of one CV joint around 2am. After bolting back in the seven non-broken bolts, I limped into Rockingham, where I got three hours of sleep with the car slow charged using the RV plugs.”
After finding a fast charger on Tuesday morning (and making a visit to the hardware store for more CV bolts), Paul pretty much repeated day one. Error first, then a 13.
This time there were more fast chargers along the first part of the route, keeping the volts flowing, but the main cooling pump failed. A quick visit to Autozone had that fixed, just in time for the charging desert Paul was about to reach.
“There were several slow charging stations, but with the PCS only adding about four miles of range per hour of charging instead of the 14 it should have, I quickly began to run into issues. On Wednesday morning, I ran out of charge about one mile from my next stop in Elizabethton and I had to use a generator.”
The coupe eventually made it to Bristol at 2pm, taking a 20-second slip for the day with no power to spare for a run. It took another five hours for Paul to reach the next fast charger, at which point he could finally start turning miles at a decent rate.
The next day at Carolina Dragway proved a happy one thanks to a personal best 12.652 run at 113mph. “Indescribable joy,” Paul related. But as we all know with drag-and-drive, the next challenge is always just around the corner. “About one mile from the track, the water pump cooling the PCS (which also provides 12V power) began smoking. Apparently, running nearly continuously for a week will kill a Prius water pump! Without a spare, I opted to unplug the pump, as the DC-DC function doesn’t generate much heat, and this worked fine to get me to Darlington.”
Paul was hoping to make a hero pass on Friday, but a brief test rip at the back of the pits saw the motor ripped from two of its three mounts. He did however make a very slow pass to complete the week.
“To the best of my knowledge this was the first EV conversion to complete Hot Rod Drag Week,” he said. “I had hoped to be the first EV at all, but that title was taken in 2019. I wanted to prove that it could be done, and that I myself could do it.”
Written by Luke Nieuwhof. This article originally appeared in Sick The Magazine’s Fall 2023 issue.
