Flex on us with your boards

21

SO…

As there is no other measured results here im going to set the bar and lay down some times. As this is for science my build is dual 6880 190kV motors - 5:1 gear drive - 8" slicks - 12s4p 30Q - Unity.

Firstly there are a few caveats :

  • I did not charge my board before heading out. you can see in the logs im getting some serious battery sag and im sure a fresh pack could bump these times a little.
  • due to my low gearing and not having a full battery i was not able to reach 30mph so these times are to 25mph

First run was in my daily ride mode:

  • motor current 60A
  • battery curent 120A
  • wattage limit 5kW

so I hit the power at 12:46:31 and reached 25mph at just before 12:46:38. This means 0-25 in just under 6 seconds. you can see that in the first 4 seconds im being limited by the motor current limit then as the motor current raises i think the 5kW limit becomes the main limiting factor and battery current levels off and motor current begins to drop.

Not bad but i think i can do better so i switch to my track race mode.

  • motor current 80A
  • battery current 160A
  • wattage limit NONE

I give it the beans at 12:52:03. For the first 2 seconds i can feel the crazy power, sitting on the 200A motor limit. looks like my battery can also feel the power sagging from 46.5V down to 39V at which point i believe the low battery “cuttoff start” must have taken over and started reducing power. battery voltage and battery current instantly level off and becoming limiting factor as motor amps drops away. this is maintained for a few seconds before I reached 25mph at just before 12:52:08.

This makes the 0-25mph time around 4.8 seconds, not bad for a 280lbs gorilla.

As you can see both of these runs were limited by my battery. A full charge would go a long way to improving these times and i also think i could squeeze a little more motor power out of the unity if i needed to. on a full battery i should also be able to reach 30mph but it can get scary on by current bushing setup.

3 Likes
22

Me on streetwheels vs Raptor 2 when its snowing :joy:

9 Likes
23

wow :astonished: thats an impressive setup you ditched him :rofl:

3 Likes
24

what motors you running?

25

4wd 6374 220kv on geardrives
Test version of this board

IMG_20191002_171514
IMG_20191002_171514.jpg2736×3648 3.25 MB

6 Likes
26

Here is the old Gem SoCal Performance Day. Has a 50meter 5.5 seconds acceleration test.

Found it, BigBoytoys quad build 50m run. 5.5seconds. You can hear the front wheels chatter, breaking traction off the line. No doubt Derek would be on top today.

9 Likes
27

Last time I tried to 0-30mph I crashed terribly

image
image.jpg579×751 187 KB

4 Likes
28

I’ve never been able to full throttle go from 0 to max on my board with 40A per motor – the start acceleration requires you to be low to the ground and hold on to the front, but then when you get speed you have to take a different stance to control the thing, and it’s just too sketchy for me to try :smiley:

3 Likes
29

Same here, im not going to even try. Fastest to 100 metres probably be a better idea too, more reliable and easier to time.

2 Likes
30

Went out again today to do a full battery run.

Seems like my board can really sag a 12s4p 30q pack.

hit the power 1 tick past 12:38:29. Again sat at around 200A motor current limit, This time for around 3 seconds so slightly longer than before. At this point the 100A battery current is causing the sag to hit the low battery voltage protection. Battery current starts to be limited and the motor current drops off. end up hitting 25mph 1 tick after 12:38:33.

SO . . . without taking my motor current to unsafe levels or replacing my battery i think this is the best im going to get.

0-25mph in 4 Seconds flat.

5 Likes
31

image

3 Likes
32

Same. Tried to get some data for this thread and noticed horrible sag. Turns out group 1 of my 12s7p decided it didn’t want to put out voltage and has been at 0v for who knows how long.

And I still couldn’t handle the acceleration at full send.

5 Likes