SoC impact on drivetrain performance?

SoC impact on drivetrain performance?

We all know the performance of the car is impacted by the state of charge, and I've seen many graphs and videos about how it changes when on a dyno, but wanted to see the impact on driving performance at the track So, I hooked up the OBDII dongle and Scan my Tesla app to my LR RWD and headed out to the track.

A few things that were interesting to me about the data:

~ The brake overheat warning goes off when the estimated brake temps hit 600 C (1,100 F.) I have Mountain Pass Performance upgraded rotors and pads and had no problem with brake fade, but the chime goes off based on the estimates the system makes assuming you have stock components.

~ With a nearly full charge (above 90%), my RWD is producing 250 kw (335 hp) and 270 nm (200 lb-ft) of torque (at full throttle at 104 kph (64 mph) at the beginning of front straight. By the end of the straight it is producing 209 kw (280 hp) and 135 nm (99 lb-ft) at 177 kph (110 mph).

~ By a few laps in I was down to 60% SoC it was only producing 197 kw (265 hp) and 224 nm (165 lb-ft) at 62 mph at the start of the straight down to 151 kw (202 hp) and 113 nm (83 lb-ft) at 102 mph.

If you are tracking your Tesla then you already know this, but be sure to get your hot laps down early in the session for any chance at setting a PB.

EVRider | 05. mars 2020

Why the question mark in your title? You’re not asking a question, you’re answering one.

one.more.again | 05. mars 2020

I just like question marks?

lbowroom | 05. mars 2020

"the chime goes off based on the estimates the system makes assuming you have stock components"

What else could it do?

kallian | 05. mars 2020

Batteries have this problem hence some folks dont like this. With ICE the fuel flow is constant till the tank is on fumes. With batteries high amp drain gives voltage sag pretty quickly. The only way to prevent this is having a pack way bigger than you would need. Now of course you are increasing weight. But if only built for racing and not long range, then there can be more parallel pack configurations and less serial maintaining more consistent lower voltage.

M-A-B-MCMLXXX | 05. mars 2020

"I just like question marks?"


DiminishedSeventh | 05. mars 2020

I’m Ron Burgundy?

howard | 05. mars 2020

kallian, The Taycan seems to do much better with respect to energy output roll off under extreme extended performance usage than the Tesla. Perhaps better battery cooling on the Porsche?

cherylcal662 | 06. mars 2020

good to know about soc will keep it in mind

kallian | 06. mars 2020

@howard, this is true but they built the pack to game it, hence it shows why its rated only at 192 with a much larger pack. Cooling is not it, the V raise happens over time after you stop pulling current. But drops more rapidly as you pull again. Either way, the battery drain happens as you use it, then the "fuel" flow is still lowered with batteries.

Best way is to have much much higher capacity capable of let us say (current P100D) 1500A for several minutes with a peak of 2500A. But then you will love the peak 2500A performance and hate the 1500A nominal one.
No matter what you will feel the sag as V drops. You can always hide the 2500A performance by limiting the vehicle so the user will never know.

one.more.again | 07. mars 2020

Killian - thanks for the info. I've often wondered how the Formula E cars keep running at speed while they are down to 1%. Based on your response, I assume their packs are all in parallel?