Saturday, my friend and I took my Model S Signature Performance (MSP) and my Roadster out to High Plains Raceway (HPR) east of Denver, (see High Plains Raceway Track Details), for a day of fun. HPR has 8, 50-Amp RV outlets their so we were able to add charge whenever we were not driving. We had Michael Pettiford, Instructor Bio, as our instructor and as the driver to try for best track times to compare the MSP and Roadster (non-sport).
Quick Summary of lap time results:
Even though the Roadster looks like the sports car, the MSP definitely braked and handled the turns better. The MSP had a much more predictable balanced entry into the turns. The Roadster front would not get a grip and had a definite understeer tendency. Because of the better braking on the MSP, Mike could wait a significant distance longer before each turn before he had to apply brakes going into the turns.
From my previous work with Mike at HPR three years ago in the Roadster, we knew about that PEM cooling was the weakness of the Roadster on the track. This November day was much cooler, and the local service center had just swapped out my Roadster PEM due to cooling issues last summer. I am sure both helped. Three years ago, we could barely get one full, 2.55 mile lap in before the PEM hot warning came on and the power was reduced. This time, we could get two laps or more before the "dinner bell" rang and we had half power.
With its liquid-cooled PEM, batteries, and motor, I had high hopes for the MSP to hold power. Unfortunately, my hopes were dashed. In 1/2 to 2/3 of the 1.83 mile lap, the little dashed limit line came on the power display, usually reducing power from 320 kW to a little more than 160kW. This shows up in the MSP having a better maximum speed (at the end of the south straight away) before the power was limited, but having worse lap times because of the reduced power in the last 1/3 of the lap. The Roadster tells you the PEM hot is the limiting factor. The MSP just lets you know the power is limited. We don't know if it was the PEM, batteries, or the motor. We did do this at the end of the day with the MSP charge at 100 miles or so rated range. If the batteries are the limiting factor, a higher charge might help. Our second try, keeping everything cool as long as possible was heading to beat the Roadster time, but the car we were catching at the finish line did a goofy move and Mike aborted the lap. We were heading for a better than Roadster time, even with power limiting then. Because the track operators wanted to lock the gates soon after the track went cold, and we had 82 miles to drive home, we did not have enough battery energy left to make one last try. Every 3-4 lap session was equal to an hour of charging at 40 Amps. Even with the power limiting in the MSP, I think we could have beat the Roadster time by a second or two. Another day...
The 'vette times are with Mike's personal street car (he has other faster racing cars). It was 505 HP stock, but Mike guesses that he is currently getting about 550 HP with various mods. His "street" tires are very sticky, the kind that holds onto the sand and gravel in the parking lot. This time was on his first hard lap. He was definitely faster on the second lap when he developed a brake problem. As we came into turn 13, heading for the finish line, when Mike let up on the accelerator, we both hit the shoulder straps hard with uncontrolled, hard brake application. Mike steered to a safe spot on the outside of the course. With clutch in and parking brake off, we were not moving down a pretty good hill. The brakes were locked and smoke was coming out of both front wheels with that putride, hot-brake smell. After the track tow truck came out and some investigation, Mike discovered that a small piece of plastic had slipped down under the dash and was applying the brakes without any foot pressure. Apparently this had been getting worse as the lap went on and overheated his brakes. We went back to the pit area and that was the end of the day.
There were two modified Lotus Exiges and one highly modified (more horsepower) Lotus Elise on the track as well. All three were way more balanced in the turns and could slightly outperform the Roadster in high speed acceleration.
It was a very fun day. I learned that the MSP has more performance than I want to apply on the track and way more than I ever want to use on the road. Michael taught me some very good driving skills and is an excellent instructor. I strongly recommend him to anyone who wants to do some serious learning about how to drive your car hard and safely.
The big surprises were that the MSP power limits quicker than the Roadster under VERY hard driving, and that the MSP braking and handling exceed the Roadster.
Maybe we can get more Teslas out on the track another time. Its starting to get cold in Colorado, and I will probably put the snow tires on my MSP in the next month. We should start planning something for next spring. Maybe, we could even talk HPR into installing a HPWC. :wink:
Update: Here is a picture of me coming out of turn 13, entering turn 14 at HPR:
Quick Summary of lap time results:
- All times were for the 1.83 mile, North Course. This leaves the south straightaway at turn 4S, direct to turn 9a, see Track Map
- All results were with Michael driving, and me right seat timing from the start/finish line. Here are lap time, max speed, and average speed. The max speeds are from the uncalibrated speedometers in each car, the lap times are from my iPhone stopwatch, and the average speeds are calculated.
- 1:33.7, 113 MPH, 70.3 MPH - 2012 MSP Signature
- 1:31.8, 107 MPH, 71.8 MPH - 2008 Roadster
- 1:21.1, 125 MPH, 81.2 MPH - 2005 Corvette Z06, 550 HP
Even though the Roadster looks like the sports car, the MSP definitely braked and handled the turns better. The MSP had a much more predictable balanced entry into the turns. The Roadster front would not get a grip and had a definite understeer tendency. Because of the better braking on the MSP, Mike could wait a significant distance longer before each turn before he had to apply brakes going into the turns.
From my previous work with Mike at HPR three years ago in the Roadster, we knew about that PEM cooling was the weakness of the Roadster on the track. This November day was much cooler, and the local service center had just swapped out my Roadster PEM due to cooling issues last summer. I am sure both helped. Three years ago, we could barely get one full, 2.55 mile lap in before the PEM hot warning came on and the power was reduced. This time, we could get two laps or more before the "dinner bell" rang and we had half power.
With its liquid-cooled PEM, batteries, and motor, I had high hopes for the MSP to hold power. Unfortunately, my hopes were dashed. In 1/2 to 2/3 of the 1.83 mile lap, the little dashed limit line came on the power display, usually reducing power from 320 kW to a little more than 160kW. This shows up in the MSP having a better maximum speed (at the end of the south straight away) before the power was limited, but having worse lap times because of the reduced power in the last 1/3 of the lap. The Roadster tells you the PEM hot is the limiting factor. The MSP just lets you know the power is limited. We don't know if it was the PEM, batteries, or the motor. We did do this at the end of the day with the MSP charge at 100 miles or so rated range. If the batteries are the limiting factor, a higher charge might help. Our second try, keeping everything cool as long as possible was heading to beat the Roadster time, but the car we were catching at the finish line did a goofy move and Mike aborted the lap. We were heading for a better than Roadster time, even with power limiting then. Because the track operators wanted to lock the gates soon after the track went cold, and we had 82 miles to drive home, we did not have enough battery energy left to make one last try. Every 3-4 lap session was equal to an hour of charging at 40 Amps. Even with the power limiting in the MSP, I think we could have beat the Roadster time by a second or two. Another day...
The 'vette times are with Mike's personal street car (he has other faster racing cars). It was 505 HP stock, but Mike guesses that he is currently getting about 550 HP with various mods. His "street" tires are very sticky, the kind that holds onto the sand and gravel in the parking lot. This time was on his first hard lap. He was definitely faster on the second lap when he developed a brake problem. As we came into turn 13, heading for the finish line, when Mike let up on the accelerator, we both hit the shoulder straps hard with uncontrolled, hard brake application. Mike steered to a safe spot on the outside of the course. With clutch in and parking brake off, we were not moving down a pretty good hill. The brakes were locked and smoke was coming out of both front wheels with that putride, hot-brake smell. After the track tow truck came out and some investigation, Mike discovered that a small piece of plastic had slipped down under the dash and was applying the brakes without any foot pressure. Apparently this had been getting worse as the lap went on and overheated his brakes. We went back to the pit area and that was the end of the day.
There were two modified Lotus Exiges and one highly modified (more horsepower) Lotus Elise on the track as well. All three were way more balanced in the turns and could slightly outperform the Roadster in high speed acceleration.
It was a very fun day. I learned that the MSP has more performance than I want to apply on the track and way more than I ever want to use on the road. Michael taught me some very good driving skills and is an excellent instructor. I strongly recommend him to anyone who wants to do some serious learning about how to drive your car hard and safely.
The big surprises were that the MSP power limits quicker than the Roadster under VERY hard driving, and that the MSP braking and handling exceed the Roadster.
Maybe we can get more Teslas out on the track another time. Its starting to get cold in Colorado, and I will probably put the snow tires on my MSP in the next month. We should start planning something for next spring. Maybe, we could even talk HPR into installing a HPWC. :wink:
Update: Here is a picture of me coming out of turn 13, entering turn 14 at HPR:
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