Heath Lewis' 0-40mph (0-64kph) challenge

@Heathlewis threw down this challenge.

originally he did 0-50mph (80kph)… but was gracious enough to drop it to 40mph (64kph) for us regular folk. (i kinda feel like he did it for me… :smiley: thanks heath! )

I wanted to be the next person to thrown down. but i didn’t get around to it for a while.

i tried today, but I screwed up recording telemetry on my attempts. :frowning:
we inspired RedBeard (Brandon Torgeson) to go. and he put down a competitive time.

image

I actually think both of them can probably do even better.

Anyone else down to try? :slight_smile:

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I’ll definitely have a crack when I gear a higher ratio on my Race Board. Actually, now I think about it, I will probably try on current gearing too so I can compare how much of a difference it makes. Also be good to know how my Vesc based setup with outrunners compare to the Stooge approach.

Edit: Actually I have to do this on my current gear ratio otherwise I won’t hit 64km/h haha.

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What do you think is the best way to validate claims? Stopwatch and measured path? Radar gun? Metr? Phone gps (relive app), go pro gps?

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bit of trust, and video?

check out @davidbonde’s thread somewhere on this site about measuring for t-race. gopro and other standalone gps devices have 10 samples/s the phones aren’t good enough with only 1/s

@Heathlewis shows both the dead reckoning from his vesc telemetry, and gps data from the camera.
The dead reckoning is likely very accurate, if calibrated. (ie tire sizes aren’t always what they claim. ). camera gps is also fairly accurate i think but could get thrown off near buildings where gps signals get reflected. neither of these guys were near that kind of stuff.

Brandon (and myself) don’t have vescs on our race boards. so… it’s only gps available to us.

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No vesc, likely excuse (lololol :wink: :+1:)

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I guess that’s not 100% true, we have rpm data logged in the Mamba XLX telemetry if we pull it off before it gets wiped. but you have to connect a computer to get it. can compute speed from that like vesc does. but only post facto, and manually. :smiley:

ahhhh shit

i just changed gear rarios and can only jit 35 now sad days, and now my board is kaput

i’ll do a for fun 0-35 tops, but that’s going to be around 3 weeks out minimum until i can

maybe if i get an average acceleration over 3 launches i can get a slip and see how long it’d take me to hit 40

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If anyone ever wanted to make it official then a dragy GPS would be the way to go…

too bad i don’t have moni

My 0-35 entry with a Dragy gps. 5.10 sec


The phone gps lags quite a bit compared to the dragy.


This was at 100A per motor with a peak at 6200watts

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wow that thing is 100hz. go pro is 10-18hz.

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Check out some of the YouTube videos comparing it to actual dragstrip results. It’s pretty much dead on

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which one?

i see one that’s 10Hz butbit’s $160


Their website pic claims 10hz GPS but also measurements within 1/100ths of a second which would mean 100hz if they were being completely honest I think, so IDK. They have been measured to be extremely accurate though, with a measured 0.15% margin of error in the quarter mile compared to official timing equipment so either way, it’s really good.

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but is 10hz. “really good” ? or is the thing 100hz? or… did we do math wrong. :confused:

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will my wallet be ok with me pulling another $160 for a drag race on top of the $200 or so i’m about to spend to repair 3 100Ds on top of the $300 or so i’m about to spend on drone parts

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I cant say for sure what spec is but it is for sure accurate, in the car community there is no one who will argue with a dragy result. Quick Tech: Dragy GPS-Based Performance Meter - DSPORT Magazine

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This is the telemetry from 1 of 2 motors.

zooming in, and poking around, it’s a pain, and i wasn’t diligent enough to be accurate enough. but I think i ranged from 3.8s to 4.9s in my attempts.

so… both @Heathlewis and Torgeson beat me. that said my power setting was set to 80%. so… I can presumably do a bit better.

fun peak wattage number there for only one side.

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ok ok, i’ll fund some money to pull out my butt and i’ll get a dragy

hopefully i can use it soon

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The RaceChrono app would be perfect for this. Needs a fast (10hz or higher) external gps. You can feed gopro gps data to the app. Phone gps are only 1hz normally.

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