Launch tips and tricks for fastest timeslips

[bhzmark]

Consolidating some info scattered about in other threads, this thread reports and discusses tips and tricks to fine tune launches at drag strip for the fastest times.

Definitely helpful:
- Max power battery heat
- charge as close to 100% as possible -- power decreases consistently with decreasing SOC Max Power vs State of Charge and Temp
- very shallow stage (give more running room before tripping the start clock)
- drive around the water and find stickiest part of the track
- spooling Launch Mode for a little bit before letting the brake go. Basically hold the launch until the suspension settles fully,

Probably helpful (good theory but no or little data to support)
- fewer heavy options (no pano, UHFS, power hatch, SAS, dual charger, 3rd row, etc.)
- lighter wheels and tires (19 instead of 21, forged instead of cast)
- take out the Chademo adopter and all other junk in the trunk/frunk
- stickier tires

Who knows? (no real confirmed datapoints to back up some of these speculations)
- Slip Start mode on (if tire and track conditions allow? can you spin too much in some cases?)
- Creep Mode off
- use (don't use?) Hill Hold during wind up stomp if not using Launch Mode
- adjust SAS (make it lower?)
- turn off all other elec load in car esp Ac/heater (even DRLs etc.? )
- lower (raise?) tire pressure
- fold side mirrors

Confirmed Doesn't Matter
- Pearl White is not faster than basic white

Would like further validation/replication on the latter categories to move to definitely helpful or doesnt matter.

 

[NSX1992]

As I have reported before Charging above 94% actually increases your e/t.

Slip mode automatically disengages at 40 mph and it allows some momentum before the timing light is broken.

 

[bhzmark]

As I have reported before Charging above 94% actually increases your e/t.

Anyone else replicate this. Which doesn't seem to make any sense since plotting SOC/kW shows higher SOC --> higher kW up to 100% SOC.

 

[John Chow]

I can confirm that adding a NOS sticker has no effect on ET.

 

[bhzmark]

In other threads people are reporting high power output (as reported in kW by powertools) from:
- higher SOCs up to 100% and
- by turning the AC off.

"I also did some further testing at various SOC with AC on for example at
99% I got 509KW,
97% I got 508KW
96% I got 503KW
then I turned the AC off @ 92% I got 507KW
from: Newer P90DL makes 662 hp at the battery!!!


So we have additional data points suggesting:
94-100% SOC AND AC and other auxiliary power off.

Also, someone also reports the way to have both high SOC and Max Battery ready is:
"charging to within an hour of reaching 100%, turning on Max Battery, charging the rest of the way, and then getting to the drag strip at as close to 94-100% SOC as you could while on Max Battery."

 

[Chris TX]

You can remove quite a bit of weight by taking out the frunk plastics and big tub. It might even make tech inspection easier so they can see the 12V battery tiedown.
You should also keep the steering in Sport mode as it uses less power for the rack.
Remove the floor mats.
Drain the wiper fluid (could easily be 10lbs shaved)

 

[St Charles]

Sticky tires and tire pressure will absolutely help, especially if the track has little or no prep. The fastest Model S times all have a 60' in the 1.5x range. This can be accomplished with AWD and all season tires as long as the track prep is good but you can guarantee it with a set of Mickey Thompsons or M/T Racemasters. Once you establish grip, you slowly increase tire pressure until you achieve a good balance of 60' time and MPH at the end of the track.

 

[bhzmark]

As I have reported before Charging above 94% actually increases your e/t.

Slip mode automatically disengages at 40 mph and it allows some momentum before the timing light is broken.

After some experience I think what you observed is that the car gets more power as the battery gets hotter, even hotter above the minimum temp for ready on max batt. So that first run or two at close to 100% is a cooler battery which then further warms up, even above "Ready" and then becomes faster.

Best way to take advantage of this would be to run on a really hot day.

 

[Old Wyseguy]

Like I've said on other threads . . . move your seat forward! It will help maintain WOT at launch as the G-forced tend to push your weight away from it. Yes, practical experience here!

 

[Dithermaster]

I have a 2013 P85+ with none of the options you listed above, but I ran it last month at a local 300 ft. drag event, and it did pretty well. Now I'd like to do better next month. The track is slippery; I tried one run with traction control off and it smoked the rear tires for 300 ft. Awesome show, but lost that race. Some of the options I've been pondering:
* Floor it all the way quick and let traction control handle it, or go part way on the pedal and try to modulate right below traction control threshold (who's better, me or the computer -- I'm guessing computer)
* I have air suspension and was on Low. I'm considering using Standard or maybe even High to get more weight transfer onto the rear axle. Reasonable theory? Is there any chance that launching in High or Very High could be bad for the car?
* Air pressure. I'm running 45 psi all around in staggered 21s. Should I change it?
It's just a "Thursday Night Street Drags" at the local oval track, but I'd like to do the best I can. I especially want to beat the diesel trucks that belch out black smoke. They have a ton a torque and 4WD, which is a big advantage on this slippery track.
Thanks!
P.S. The ironic thing is the trophy I won has a big piston on it...