Taking my LR to the drag strip

[xpitxbullx]

This is my plan:

1) remove unnecessary weight.
2) leave tires at 43 psi
3) slip start off
4) creep off
5) SoC above 90%
6) line up and enable brake auto hold
7) mash accelerator.

Any tips to improve my time? I’m supercharging it right before I go.

Thank you.

 

[SubSolar]

AC/heater off?

 

[StellarRat]

Change to wider, sticky tires. Take out all the seats. Completely empty everything that isn't nailed down out of the car. Charge to 100%. Go on a diet.

 

[Daniel in SD]

Change to wider, sticky tires. Take out all the seats. Completely empty everything that isn't nailed down out of the car. Charge to 100%. Go on a diet.

Stickier tires probably won't help. Smaller outside diameter tires would improve 60ft times but would slow you down toward the end of the 1/4 mile. I wonder what the optimal tire diameter is...

 

[StellarRat]

Stickier tires probably won't help. Smaller outside diameter tires would improve 60ft times but would slow you down toward the end of the 1/4 mile. I wonder what the optimal tire diameter is...

Good question. There's probably a formula for that. Don't ask me to find it.

 

[Daniel in SD]

Good question. There's probably a formula for that. Don't ask me to find it.

Force = Mass * Acceleration
Power = Force * Velocity
Model 3 drive ratio = 9:1
And this plot is all you need . Maybe I'll make a MATLAB script...

I wouldn't be surprised if it's pretty close to optimal for 1/4 mile times. 0-60 times would be way better though with smaller diameter tires. I want to see a Youtuber remove the brakes from a P3D, put 15" drag radials and set the 0-60 record.

 

[xpitxbullx]

Wasn’t as good as I thought it would be. Probably need to tweak my launch.

 

[SubSolar]

Stickier tires probably won't help. Smaller outside diameter tires would improve 60ft times but would slow you down toward the end of the 1/4 mile. I wonder what the optimal tire diameter is...

True, I believe even with the Performance model, stickier or wider tires haven't been proven to help in launching. I think the AWD system does it's job well.

 

[Drizzle]

Wider tires are only needed if the hp being driven to the tires makes them spin, right?

 

[xpitxbullx]

Wider tires are only needed if the hp being driven to the tires makes them spin, right?

Wider tires have better traction and more power can be supplied to them before they spin. The car definitely holds back on the launch with 18” Aeros.

 

[Drizzle]

So my question is how wide is really needed. The wheels could be as wide as the earth but you'd need the HP to back it up.

 

[xpitxbullx]

I’m just not sure how much of the torque is actually applied on launch. It might be programmed to hold back no matter what.

 

[MountainPass]

I wouldn't be surprised if it's pretty close to optimal for 1/4 mile times. 0-60 times would be way better though with smaller diameter tires. I want to see a Youtuber remove the brakes from a P3D, put 15" drag radials and set the 0-60 record.

How much does a parachute weigh?

 

[AlanSubie4Life]

I’m just not sure how much of the torque is actually applied on launch. It might be programmed to hold back no matter what.

This has been discussed. The P3D does not produce enough torque to break the MXM4s free (assuming dry, clean, non-freezing pavement in a straight line). The peak acceleration on a 0-60 run is substantially less than the maximum deceleration with MXM4s on a 60-0 stop. So, plenty of margin here (at the time of this writing)! If the 0-60 distance approaches 125-135 feet, then there will be an issue with MXM4s (the "traction limited threshold" is a little longer than the 125 ft 60-0 MXM4 braking distance because on a 0-60 run there will probably be tapering of torque prior to 60mph due to HP (presumably limited by battery) constraints...so the max acceleration on a 135ft 0-60 MXM4 run may exceed the maximum deceleration on a 125ft 60-0 MXM4 stop...which would mean the tires could break free).

Similarly, once the 0-60 distance approaches 105 ft, then you might have a problem with the PS4S tires. (Could happen a little earlier for the same reasons as above; it's approximate.)

POLL: What will my 60-0 stopping distance be with Pilot Sport 4S 265/40R18s be?

You can also compare 0-60 of MXM4 vs. PS4S tires; they are virtually identical, which implies no difference in torque application due to sensing of wheel slip, or holding back due to some loss of traction.

 

[AlanSubie4Life]

So my question is how wide is really needed. The wheels could be as wide as the earth but you'd need the HP to back it up.

Yes, but actually you need torque, not HP. You don't necessarily need a lot of HP to break the wheels free. Just need the potential vehicle acceleration ( a = F/m) to exceed the tires ability to grip (somewhere around 1.15g for the PS4S (265 width) - it might be a little less for 235 vs 265 but haven't seen the data).

If you want more kick, you need more initial torque, and to maintain the same acceleration (up until the pack limited power), you'd need to maintain that same torque (the torque curve vs. speed would be flat - see MPP data for an example) to as high a speed as the battery allows (that would be peak HP - which may also have a short flat section vs. speed, since torque will then have to start dropping off due to the power limit).

 

[Daniel in SD]

How much does a parachute weigh?

Keep the front brakes! Replace front tires. The youtube video will be "Amazing! RWD Model 3 beats P in 0-60 showdown!"

 

[MountainPass]

Keep the front brakes! Replace front tires. The youtube video will be "Amazing! RWD Model 3 beats P in 0-60 showdown!"
View attachment 357621

RWD Model 3 - FASTER THAN PERFORMANCE?

 

[Drizzle]

So the question remains, how much more torque can we get out of the battery if tesla is limiting it currently?

 

[mswlogo]

Why not charge to 100%

 

[MountainPass]

Why not charge to 100%

There are diminishing returns and increased battery degradation. By all means, if that pass means a lot to you, charge it to 100%.