4s 8000 lipo what brand?

i would just use the 2000 kv and turn your epa on your radio down for 6s, this is like changing the pinion, it just controls the motor rpm back to what it was running on 4s, so really its like gearing down 3 teeth

[lincpimp]

Originally Posted by superek4

should start with my 6s 5000 on 1600kv or 2000kv on 35mph?

I would run the 1600kv motor on 6s geared for 35. I think it will give you the best result.

Originally Posted by big greg

i would just use the 2000 kv and turn your epa on your radio down for 6s, this is like changing the pinion, it just controls the motor rpm back to what it was running on 4s, so really its like gearing down 3 teeth

You need to write a guide on how to lower your efficiency dude. Dropping the epa will only heat the esc up more, and is a poor substitute for a properly setup system.

I am guessing (since I do not race) that you benefit from having a faster truck for qualifying in order to get a better placement for the main? I am also guessing the qual is shorter than the main? Yet another quaint but pointless method to determine the starting grid, IMO. Race officials should not allow gearing or setup changes for the qual to the main, IMO. Get racing back to skill, not equipment... Probably why I do not race...

Originally Posted by lincpimp

I would run the 1600kv motor on 6s geared for 35. I think it will give you the best result.



You need to write a guide on how to lower your efficiency dude. Dropping the epa will only heat the esc up more, and is a poor substitute for a properly setup system.

I am guessing (since I do not race) that you benefit from having a faster truck for qualifying in order to get a better placement for the main? I am also guessing the qual is shorter than the main? Yet another quaint but pointless method to determine the starting grid, IMO. Race officials should not allow gearing or setup changes for the qual to the main, IMO. Get racing back to skill, not equipment... Probably why I do not race...

i have never noticed the mmm getting any warmer dropping the epa, ive heard that about old speedos but dont agree with it on the mambas, ive heard multiple others say the same thing but never noticed this among me and a dozen or so others around here doing it

[lincpimp]

Originally Posted by big greg

i have never noticed the mmm getting any warmer dropping the epa, ive heard that about old speedos but dont agree with it on the mambas, ive heard multiple others say the same thing but never noticed this among me and a dozen or so others around here doing it

Ok, at anything less than full throttle the esc has to switch the fets to chop the voltage down. That is what warms up escs, and that chopping has a by product of heat. No way to get around that. And making heat means that you are losing runtime...

[littlegiant]

Originally Posted by big greg

i have never noticed the mmm getting any warmer dropping the epa, ive heard that about old speedos but dont agree with it on the mambas, ive heard multiple others say the same thing but never noticed this among me and a dozen or so others around here doing it

Dropping EPA is a method of limiting the power of the motor but there is this concern that it may lower efficiency in the motor or esc. To my understanding, the motor will not be affected much as long as it is running within its optimum rpm range - where there is no significant predominately iron or copper loss.

As for the esc, switching loss of the mosfets is the main cause of concern when lowering the EPA. According to my findings, other than switching to rotate the magnetic field within a brushless motor, the esc varies the input power to the motor by doing pwm switching when powering each phase of the motor coils. Usually pwm is done at a constant frequency - only the duty cycle is varied. But at 100% duty cycle, the mosfets are turned on all the time. Anyway, a well designed esc will operate its mosfet at an efficient pwm frequencies while maintaining good performance. And to top it off, with advancement in mosfet technology, good quality mosfets can switch at high frequency with minimum switching loss as long as the switching current is of an acceptable range. Switching loss goes up as switching frequency goes up/switching current goes up. Switching loss due to gate capacitence is neligible at constant on or off state but becomes significant when switching at high frequency. This explains why mosfets heat up more when running at a lower than 100% duty cycle. At 100% duty cycle, the mosfets are still switching to rotate the magnetic field of the motor around the rotor but the switching frequency of the mosfets is reduced.

I doubt that there will a big difference in esc temp by lowering the EPA in todays well designed escs with quality mosfets. Many reported that running their brushless setups at half throttle seems to heat up the motor/esc more.
I am thinking that maybe there is lesser air flow (lower speed) or that the motor's efficiency is lowered due to it running at a lower than optimum RPM (copper loss). But then again, I highly doubt that the temperature increase will be a lot. Probably just 1 or 2C depending on the setup. I will test out different EPA values once I get my HW150A.

Slap me hard if I got it wrong. :D

[superek4]

I use heats as practise rather than push d car to it max becoz in main it's more endurance than quick dash.

The setup is heavier n safer driving, always stay away from crowds

Originally Posted by lincpimp

I would run the 1600kv motor on 6s geared for 35. I think it will give you the best result.



You need to write a guide on how to lower your efficiency dude. Dropping the epa will only heat the esc up more, and is a poor substitute for a properly setup system.

I am guessing (since I do not race) that you benefit from having a faster truck for qualifying in order to get a better placement for the main? I am also guessing the qual is shorter than the main? Yet another quaint but pointless method to determine the starting grid, IMO. Race officials should not allow gearing or setup changes for the qual to the main, IMO. Get racing back to skill, not equipment... Probably why I do not race...

[superek4]

Wats the safe cut off for racing? 3v per cell or 3.2

[littlegiant]

Originally Posted by superek4

Wats the safe cut off for racing? 3v per cell or 3.2

Low current application, 3V.

High current application 3.2 - 3.5V to be safe. For your case I think 3.2V will suffice.

I've been setting the LVC to 3V for all my lipos be it they are used in 1/36 or 1/10. So far no damage. My 1/10 e-savage (modded) is geared for 40 over mph.

[superek4]

Originally Posted by littlegiant

Low current application, 3V.

High current application 3.2 - 3.5V to be safe. For your case I think 3.2V will suffice.

I've been setting the LVC to 3V for all my lipos be it they are used in 1/36 or 1/10. So far no damage. My 1/10 e-savage (modded) is geared for 40 over mph.

thx man, so how's ur car going to any race?

that was a good write up, as for it dropping efficiency, your not wot barely at any tracks i run on, so i dont think it will do much difference

[littlegiant]

Originally Posted by superek4

thx man, so how's ur car going to any race?

Race?

LOL I am still a student. No $$$ to get spare battery packs. Only have a set of batteries.

[jzemaxx]

With 6S why not lower the throttle curve in the MMM settings. Leave EPA at 100% though. Not sure how it effects temps and efficiency but I figure its there for a reason.

Also- 6S 5000 = 111W, 4S 8000 = 118.4 watts. So the 4S with the right gearing would have a runtime in theory of 6.25% more then the 6S setup.

[superek4]

ok, i hv previous record of my last race i charged my batts n it ended at 3380, i estimated i hv ran for 20-21mins so izzit 3380/21mins? =161mah per min?

i had 12pinion at 50spur with 1600kv motor so what batts i need to do 30min?

izzit 161mah/per min x 30mins?= 4830mah i need to run a 30min race?

if i am going to run at 13pinion do i need more mah?

[superek4]

Originally Posted by littlegiant

Race?

LOL I am still a student. No $$$ to get spare battery packs. Only have a set of batteries.

uni student? can afford to play e savage? not bad i used to play Nikko when i was student

[nitrostarter]

I'm a working, broke student that plays with multiple r/c's....