Plaid Horsepower and Torque

[jd1008]

I just took delivery of my Plaid Model S. I've only put 150 miles on it and have yet to floor it but it seems very quick.
I've seen several video's of Model S plaid cars racing super bikes, Lambo's, Ferrari's and Hellcats etc. There is a recent video of the Model S easily beating a heavily modified McLaren 720S with 1,000 HP. The Tesla beats the 720S from a standing start as well as a rolling race and even beats the 720S after giving it a one car lead in a rolling race where the Tesla had three large men in the car. The Tesla weighs about 4,800 lbs and the McLaren about 3,100 lbs.
How can the Tesla win all these races with essentially the same horsepower as the 720S when it has a 2,000 lb disadvantage? Is Tesla understating the horsepower and torque of the Plaid car?

 

[DerbyDave]

You have 100% torque from start. Non-electric cars' torque is not instant and takes time and distance to build.

 

[AMPd]

You have 100% torque from start. Non-electric cars torque is not instant.

Case closed

 

[EVFamilyGrins]

The Plaid's advantage is the new carbon fiber sleeves on the electric motor rotors. This allows the Plaid to have a near linear torque curve and have that full torque instantly available anytime. Tesla says peak horsepower happens at 80 mph and holds steady all the way to 200 mph (once Tesla does OTA to unlock current limit of 163 mph). Where the Raven Model S would beat ICE cars off the line and then get caught as it's torque curve couldn't match the ICE cars at higher speeds, the Plaid's constant torque at high speeds allows continual acceleration at same rate through the 1/4 mile. The Plaid is not only faster 0-60, but also 60-120 than the ICE supercars.

 

[Mash]

1. Plaid has almost linear power curve and certainly torque is going down quite rapidly to have that.

2. The reason why EVs are faster is that power curve is flatter, while ICE specs are only about peak point and with a gear shift power disruption actual average power is significantly lower than peak. Also, EVs are way faster and more precise at torque and traction control, so they can accelerate much closer to optimal torque for traction. Average power and torque control wins.

 

[ICUDoc]

The Plaid's advantage is the new carbon fiber sleeves on the electric motor rotors. This allows the Plaid to have a near linear torque curve and have that full torque instantly available anytime. Tesla says peak horsepower happens at 80 mph and holds steady all the way to 200 mph (once Tesla does OTA to unlock current limit of 163 mph). Where the Raven Model S would beat ICE cars off the line and then get caught as it's torque curve couldn't match the ICE cars at higher speeds, the Plaid's constant torque at high speeds allows continual acceleration at same rate through the 1/4 mile. The Plaid is not only faster 0-60, but also 60-120 than the ICE supercars.

New LR owners report spectacular rolling-start numbers up to high speeds.
They don't have carbon wrapped motors.
Is there some other change that has helped with maintaining torque at higher speeds?

 

[URBAN LEGEND]

Each motor has 400 hp. It’s rated at 1020 hp. Where are the other 180? It’s putting out more than advertised for sure.

 

[EVFamilyGrins]

Each motor has 400 hp. It’s rated at 1020 hp. Where are the other 180? It’s putting out more than advertised for sure.

No one has been able to dyno a Plaid to confirm the hp. However, just because the motors are rated at 400hp each, does not mean the car is delivering enough current to get full hp out of motors. Tesla has to balance performance vs range and battery health. A 1/4 mile pass uses 3% and I wonder how much battery the Nurburgring record lap used?

Currently, I think the hp is pretty close to what Tesla says. However, betting that Tesla has a plan to unlock some of those 180hp in reserve when Porsche or someone figures out how to match the Plaid performance.

 

[URBAN LEGEND]

I’m mostly with you. But the times and power don’t add up. The few cars I’ve seen beat Plaid all had 1500 hp. Either way it doesn’t matter. Plaid is super fast.

 

[EVFamilyGrins]

Tesla is not under reporting HP. The Plaid was originally designed to use the new 4680 cells. The current 18650 packs just can't utilize the full specs of the motors. Once they get the 4680 cells going, maybe we'll get an updated Plaid+ with the full 1,200HP or the long awaited Roadster 2.0.

 

[lbowroom]

Carbon fiber sleeve only stops them from grenading at high rpm allowing the 200mph top speed

 

[TIppy]

In this article they say the acceleration is 1g at 68.1 mph. Power is mass x acceleration x velocity. If you use 5000 lbs as the mass, this works out to 678058 watts to accelerate the car at 1g. There's an additional 15820 watts of drag for a total of 693879 watts which is 931 hp at the wheels. So if they're talking hp at the motor shaft, that's about 9 percent loss to the wheels assuming 1020 hp. I suppose it might not have reached peak power by 68 mph, but it looks pretty close on the curve they published.

The numbers in the article for 100 mph work out to 932 hp, but the equation I have for drag is less accurate above about 80 mph.

Testing the Tesla Model S Plaid: Milestones, Records, and Other Geeky Factoids

 

[URBAN LEGEND]

Tesla is not under reporting HP. The Plaid was originally designed to use the new 4680 cells. The current 18650 packs just can't utilize the full specs of the motors. Once they get the 4680 cells going, maybe we'll get an updated Plaid+ with the full 1,200HP or the long awaited Roadster 2.0.

I’ll support this effort by Tesla.

 

[TIppy]

the Plaid's constant torque at high speeds allows continual acceleration at same rate through the 1/4 mile

The power is almost constant above 80 mph. But because hp is torque x rpm, the torque is decreasing as the speed (and therefore the motor's rpm) increases.

If you look at the article I linked above, you'll see that the acceleration has dropped to 0.36 gs at the quarter mile mark while travelling at 152.6 mph.

 

[ICUDoc]

Carbon fiber sleeve only stops them from grenading at high rpm allowing the 200mph top speed

Whilst I remember Elon saying that, also I seem to remember something about the carbon wrap (because it isn't very conductive) results in a lower back-EMF, thus increasing efficiency / efficacy of the drive electronics at higher motor speeds?

 

[Jerret]

They're going to need to build in a structurally-certified roll cage into the vehicle, you can't even run the full 1/4 at max acceleration at most dragstrips because they're just too fast. They've done an incredible job.

 

[dfwatt]

You have 100% torque from start. Non-electric cars' torque is not instant and takes time and distance to build.

There are several other issues though, one of the biggest of them being the parasitic losses (anywhere from 10 to 12 % in rear-wheel drive to almost 20% in some all-wheel drive setups) from the 90-degree torque translation in a conventional drivetrain versus the just a few percent parasitic losses in a direct drive gear reduction transmission like the Tesla has where there is no torque translation. A tip-off about this is that electric vehicles get very close to or in some cases right on their rated horsepower in terms of wheel horsepower but conventional ICE Vehicles simply can't. Plus as other people have mentioned the full torque of the electric motor is available at low RPM. Additionally, your peak horsepower is not the same as total ability to accelerate mass, it's the area under the horsepower curve. Plus there's no shifting which means no lost time such that energy transfer is continuous– another advantage. Plus the Plaid motor has an amazingly flat horsepower curve such that it's putting out close to or at its rated horsepower for an enormous range of speeds - all that makes it virtually untouchable. So it's a host of factors explaining why electric vehicles appear to accelerate faster than their power-to-weight ratios would suggest.