Intro

We should NOT select drivers based off of height.

Instead, we should select drivers based on torso length, leg length, and lbf output onto pedal.

Important Terminology and Schematics

Torso Length (TL) = Length from torso to top of head

Leg Length (LL) = Length from torso to bottom of shoe (since driver will be wearing shoes in car)

Open

This is the 37th percentile driver model. It represents our maximum TL and will allow us to get a range for our LL.

Press brake = driver foot on pedal at neutral pos, and provide force to push it down and keep pushing to brake.

Slam brake = driver foot SLAMS down on pedal to brake and stays there in an effort to stop fast.

Max TL and LL

[TL] Based on the 37th driver percentile

• max TL = 64.92 - 36.89 = 28.03”

• min TL = 27.44”

  • Fringe cases exist, but usually a driver under the min TL has too short legs. Do not be afraid to measure a driver under this min TL, as they may have really long legs

[LL] Based on the 37th driver percentile

• max LL = 36.89 + 2 = 38.89”

• min LL = 36.89 - 1 = 35.89”

So what’s important?

TL is important to not fail on regulations. If our driver TL goes above 28.03, our driver will be LESS than 30mm away from roll cage padding, and so we will get a 2 lap per day penalty for every 10mm we infringe upon this reg.

LL is important so our driver can actually press the pedal with enough force to actuate the braking system to make the car lock up.

So, as long as driver LL is within range, TL < max TL, and force output exceeds 140lbf, our driver should be good.

Height is not as important as TL and LL. We can have someone who’s 4’11 with huge legs.

• Measuring it still doesn’t hurt though, it can help us find a trend between acceptable drivers, their TL, LL, brake tests, and height to see what kind of height range tends to do best.

Important Exceptions

Kenta and I’ve set a +2/-1 on the max/min LL. We think this is a good range to get adequate input, but it’s a bit arbitrary. Of course the pedal box will be fixed due to the nature of the jig and the car, so to this end if we measure multiple drivers falling in this range we can get a good idea of how inaccurate our assumption is and so make find a good range for the LL can be further established based on what results we get at 10/18 workday.

Driver leg strength is another big factor in amount of force output onto pedal. So, if a driver falls short of min LL, you should still measure them since they may be jacked.

TLDR: The only HARD Limit is max TL, as that’ll kill our lap count.

How to measure?

I would create an excel sheet with two tables, like the samples below:

Feel free to code (2) such that the cell turns green for acceptable drivers that exceed the lbf to lock up req and are under TL max. Nice to have as a visual but not necessary

(1)

(2)