Need help for batt setup! Urgent! - RC-Monster Forums

superek4 · 03:55 AM

I used to race with 6s 3300 with neu 1515/3d but the motor broke.

I tried tekin 1550kv it's ran 80degree.

This 2 setup can run 12-13mins.

Today I tested 4274 hobbywing 2000kv motor with both 4s 4200mah@30c n 6s 3300mah@40c batts. Both cut off at 9mins 30sec.

My race is 10mins.

For 4s 4200mah I geared 17/46 about 38mph. Temp of batt 60 degree.

For 6s 3300mah I geared 13/46 about 40mph at 80% EPA. Temp of batt 55 degree.

Esc setting
Forward/brake/reverse
Punch 5
No drag brake
12% neutral
15 % timing
Brake 25%

At 11.25% timing there's clogging.

Both temp are about 70degree on motor.

Both set up are drawing about 330-380 mah per min. Very high

When I was using tekin 1550kv n neu 1350kv motor I was drawing about 220mah per min.

Much lower temp for the batt n motor too.

Problem is hobbywing only make 2000kv motor so what can I do?

My batt sponsorer is trying to help me make a lighter more Mah batt

The 4200mah@30c is from them.

I want to run fast n light n less heat on my batts

E-Revonut · 04.25.2010, 04:54 AM

On 6s try dropping another tooth or two on the pinion rather than adjusting speed with the epa. Dropping the gearing down will help to lower your current draw and you may get the extra time you need. 6s 3300mah is about 73 watt hours, battery I used last year was 5s 4500mah or about 83 watt hours and I could get about 17 minutes on the track. So you may need to put your truck on a diet and lose some weight or maybe be a little smoother with the throttle.

superek4 · 04.25.2010, 06:08 AM

13pinion is the smallest that I can fit in. The track I test is smaller than the race track. Now I m thinking which is better 4s setup or 6?

My CRT is on diet already from a 750gram batt to 400g.

E-Revonut · 04.25.2010, 07:53 AM

OK so you have a light battery. What about the rest of the truck? Carbon fiber towers? Light weight anything else? What tires and rims are you running? Lighter tires and rims will have a big impact on lowering your power consumption, as will balancing them.

superek4 · 04.25.2010, 08:21 AM

Quote:

Originally Posted by E-Revonut

OK so you have a light battery. What about the rest of the truck? Carbon fiber towers? Light weight anything else? What tires and rims are you running? Lighter tires and rims will have a big impact on lowering your power consumption, as will balancing them.

Wow! I m using hong nor truggy rims n aka tires. The other is proline caliber with vtr rims.

I am not sure are they light. Carbon fiber towers are expensive n breaks.

E-Revonut · 04.25.2010, 08:46 AM

The calibers on VTR rims is a lighter combo. How are you breaking carbon fiber shock towers? I have had mine for a year and the track I race at has some crazy jumps, never broke one and they have no sign of any damage. They might be expensive but if you want a light truck thats what you gotta do. Whats the point in a light battery if they rest of the truck isn't light?

superek4 · 04.25.2010, 08:52 AM

Quote:

Originally Posted by E-Revonut

The calibers on VTR rims is a lighter combo. How are you breaking carbon fiber shock towers? I have had mine for a year and the track I race at has some crazy jumps, never broke one and they have no sign of any damage. They might be expensive but if you want a light truck thats what you gotta do. Whats the point in a light battery if they rest of the truck isn't light?

Ok I will get those, are those carbon shock towers race worthy?

E-Revonut · 04.25.2010, 08:59 AM

My truggy is an Associated RC8T with the Factory Team Carbon Fiber towers, they are 100% race worthy IMO, they have been for the last year anyways. I don't know what's available for the CRT, how strong or expensive they are, but as long as you don't drive into something thats about 4 inches off the ground at full bore with no body on I don't see how anyone could be breaking them. Mine have been through hell and back and still look like new after I wiped them down.

superek4 · 04.25.2010, 10:16 AM

Only extreme racing make them us$24 per item.

slimthelineman · 04.25.2010, 10:58 AM

i can also vouch for the carbon towers, ran them for over a year on my FTRC8 and they never flinched in the 300 or so races they ran. more exposed on a buggy so a truggy should have no problem, and about 30g lighter each over the alum. try a plastic spur too if you dont have one already. only ones that ive seen last are the kyosho, again plastic was 8g steel was 32g. have all the alum. diff cups and stub axles but they are a little more expensive.

tedo · 04.25.2010, 10:59 AM

Also make sure your bearings are super smooth. Runtime decreased when there is cogging ANYWHERE on your truck. Make sure no rotating parts are rubbing anything. The diffs need to be perfectly shimmed also. Make that motor barely work, to get your truck moving.

Also try lowering your timing to 0.

Balanced revolvers are the bomb. Super light.

Yesterday I got 19 minutes on my 2000 (Tekin) on 5800 Flightmaxes. This was surprising (the track was perfect), Usually I can get easily 16 minutes with my 4s setup, and my truck only weighs 9lbs. I am running at 295Krpms.

Batteries and motor KVs are only half of a good long running set-up... the other half is to make sure your truck is set-up correctly, balanced, and smooth rolling. Lots of people forget about the second half.

slimthelineman · 04.25.2010, 11:01 AM

forgot, you are probably seeing higher temps on the new motor cause its higher kv than the previous two you ran, AND i would say much less efficient than the neu or the broken i mean tekin. this will also have a higher average current than the lover kv motors so that might be why its not running as long.

superek4 · 04.25.2010, 11:16 AM

yes it's higher kv, unless they make a lower kv motor for me if not I hv to use a tekin 1550kv. I find the truck works very well with 6s 3300.

slimthelineman · 04.25.2010, 12:10 PM

agreed i run a 1700 0n 6s 3200 and it works good. i was refering to the fact that a 1500kv motor will run longer and cooler than a 2000kv motor on the same pack voltage/capacity. the tekin is most likely a better motor. i would run that on 6s and just gear accordingly for your track/runtime

superek4 · 04.25.2010, 07:29 PM

Quote:

Originally Posted by slimthelineman

agreed i run a 1700 0n 6s 3200 and it works good. i was refering to the fact that a 1500kv motor will run longer and cooler than a 2000kv motor on the same pack voltage/capacity. the tekin is most likely a better motor. i would run that on 6s and just gear accordingly for your track/runtime

Yes true, I better use my tekin. Or hv hobbywing make a 1600kv motor.