[Wicked Carts]

by chance do you know what the battery pack weighs????

[jr dragster]

I would guess with the alum box 27 to 30 pounds

[Wicked Carts]

Originally Posted by jr dragster

I would guess with the alum box 27 to 30 pounds

crazy lite

[tropes]

Originally Posted by jr dragster

were running the A123s 20 ah pouch cells with an alltrax 7245 72 volts 450 amps and a mars 1003.I will post some vids later.

What RPM is the Mars 1003 turning? Our K91 seems to hit the wall at 3900. That's why I wanted to advance the brushes.
Tropes

[major]

Originally Posted by tropes

What RPM is the Mars 1003 turning? Our K91 seems to hit the wall at 3900. That's why I wanted to advance the brushes.
Tropes

Performance curves are a bit tough to read, but http://evdrives.com/images/Motors/ME...o_ME1003-1.pdf states the Mars turns 3000 RPM at 72V. Both motors look to have similar torque in the 400 to 450A range. Mars being a PM motor has a flatter curve, but I don't see that as a factor. And I am surprised the mars can tolerate the high current.

I did find the K91 curve http://rapidlibrary.com/source.php?f...e36ac057062570 Looks like at 72V the 3900 RPM point is down to 100A. That is way way below peak power.

I still say it's the gearing

major

[tropes]

Originally Posted by major

I did find the K91 curve http://rapidlibrary.com/source.php?f...e36ac057062570 Looks like at 72V the 3900 RPM point is down to 100A. That is way way below peak power.

I still say it's the gearing

major

It could well be the gearing. Our 60 ft. times 1.7's are much quicker than the other juniors in our class but our 53 mph is much slower. we will make some modifications before July 14.
tropes

[major]

Originally Posted by tropes

It could well be the gearing. Our 60 ft. times 1.7's are much quicker than the other juniors in our class but our 53 mph is much slower. we will make some modifications before July 14.
tropes

Yeah, I think you need a giant step in the ratio. And do you know if you're pulling the full current limit (450A) at the start? That would be motor current, not battery current.

[tropes]

Originally Posted by major

Yeah, I think you need a giant step in the ratio. And do you know if you're pulling the full current limit (450A) at the start? That would be motor current, not battery current.

No, I don't know if the motor is drawing full current but i am having trouble hooking up even with the 10 inch Hoosiers. the motor definitely has torque.

[major]

Originally Posted by tropes

No, I don't know if the motor is drawing full current but i am having trouble hooking up even with the 10 inch Hoosiers. the motor definitely has torque.

What about cutting your ratio in half

[tropes]

Originally Posted by major

What about cutting your ratio in half

Sounds pretty drastic. That would be 2:1.