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Old 01-13-2012, 07:34 AM   #991
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ok Sakura Masters,

I got a weird one.

Using this car for VTA Racing with 2S and 25.5 Novak Ballistic Motor.
Geared 4.84 with a 92Spur and a 38 Pinion
19T Center Pulleys
Front Diff 30,000wt
Rear Diff 500
Other than that stock everything else. But on our track I'm getting the motor up to it's Temperature limit. Now my Other VTA car a Associated TC4 FT (shaft drive) Geared taller at 4.6 comes in no problems after 10 min at 130F

No Timing advance on either car and the same track with the same traction. Anyone got any Idea's? Also the Track is very Very tight lots of 180 degree corners and about 40x60'

The current gearing is the smallest I can go in pinion as the motor is tight against the motor mount. With the Pinion off the car rolls free
I was going to suggest that perhaps something was binding with your chassis, but if the chassis rolls free with the pinion removed then that's not the problem.

Is your gear mesh too tight perhaps? Maybe the bearings in the BL motor need service or replacement. Maybe you have something set on the ESC that's creating resistance. Have you tried resetting the ESC?
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Old 01-13-2012, 08:14 AM   #992
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Originally Posted by jdeadman View Post
ok Sakura Masters,

I got a weird one.

Using this car for VTA Racing with 2S and 25.5 Novak Ballistic Motor.

Geared 4.84 with a 92Spur and a 38 Pinion

19T Center Pulleys

Front Diff 30,000wt
Rear Diff 500

Other than that stock everything else

But on our track I'm getting the motor up to it's Temperature limit.

Now my Other VTA car a Associated TC4 FT (shaft drive) Geared taller at 4.6 comes in no problems after 10 min at 130F


No Timing advance on either car and the same track with the same traction.

Anyone got any Idea's?

Also the Track is very Very tight lots of 180 degree corners and about 40x60'



The current gearing is the smallest I can go in pinion as the motor is tight against the motor mount



With the Pinion off the car rolls free
How is your belt tension? The belts should be pretty loose for vta. Looser than a tc. Which motor are you running and how old is it? My ballistic ran hot when it was new but now its a lot cooler. Also check the motor shaft end play. Mine was too tight and I had to remove a shim. Your motor may he internally bound.

The car should roll free with the pinion on. If you add the pinion and it binds you may have a tight motor.

You may just be undergeared. Try bumping up to a 4.0 and check your temps.
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Old 01-13-2012, 09:02 AM   #993
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Originally Posted by jdeadman View Post
ok Sakura Masters,

I got a weird one.

Using this car for VTA Racing with 2S and 25.5 Novak Ballistic Motor.

Geared 4.84 with a 92Spur and a 38 Pinion

19T Center Pulleys

Front Diff 30,000wt
Rear Diff 500

Other than that stock everything else

But on our track I'm getting the motor up to it's Temperature limit.

Now my Other VTA car a Associated TC4 FT (shaft drive) Geared taller at 4.6 comes in no problems after 10 min at 130F


No Timing advance on either car and the same track with the same traction.

Anyone got any Idea's?

Also the Track is very Very tight lots of 180 degree corners and about 40x60'



The current gearing is the smallest I can go in pinion as the motor is tight against the motor mount



With the Pinion off the car rolls free
It does not sound right at all. I am running a 93 spur, 50 pinion and while I have fans, I come off at 120 after an 8 min main. It is possible that you are undergeared, and if you are pegged at max RPM the entire time that will cause a motor to run hot. Also, as someone else said, ESC settings might play a factor. Especially things like drag break.

Do you have a fan(s) on it? Have you removed the center colored ring from the motor (that alone dropped the temp on my ballistic almost 10 degrees)? Is there any airflow getting to the motor (between the wiring and nearby electronics)? What kind of ambient temps are you having? How long are you running to get it that hot? What is your temp at 1 min and 5 min? Usually if you cannot touch your motor after 1 min on the track, something is wrong.
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Old 01-13-2012, 09:34 AM   #994
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Belts: All Loose as possible just about to skip loose

Mesh: Nice and Free Not too tight

Motor: Now that's one area I didn't check as the car feels drag with the motor on

I Will pull it apart. I was also going to swap motors between the cars to test that as well

Gearing: Like I said we have a very tight track and a small straight and the car is not at full RPM for the whole track just the last half of the straight

Sounds like the Motor is my Problem and I will try and remove the Blue Ring on the Motor to see if that helps.

The Only other thing I can think of is the chassis is not open under the motor so I wonder if that is causing more heat to build up
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Old 01-13-2012, 10:21 AM   #995
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Did you ever free-rev the motor? I accidentally got a 13.5 motor, 1s battery, to about half-throttle which i think ended up ruining it. It never ran right after that. The rotor seemed bound up, but i could never figure out what was wrong.
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Old 01-13-2012, 12:10 PM   #996
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How is the car handling? If it is alot better than your TC4 you might be on the throttle more, or using more brakes... Ride height OK not dragging on the ground? Same ESC in both cars? Is your temp higher than 160F? if not then its fine.
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Old 01-13-2012, 12:47 PM   #997
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Car is good but diferent than the TC4 I can get faster lap times with the TC4 but the Sakura just feels nicer.


Temps have been in the high 180's once I am just not trying to find out why.


No Chassis Rub and spec ESC's so not much different settings wise.

I run no drag brake and only use brakes on one corner
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Old 01-13-2012, 12:48 PM   #998
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Did you ever free-rev the motor? I accidentally got a 13.5 motor, 1s battery, to about half-throttle which i think ended up ruining it. It never ran right after that. The rotor seemed bound up, but i could never figure out what was wrong.
No I never do that
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Old 01-13-2012, 01:18 PM   #999
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I'm betting on the motor being shimmed too tight or the FDR is too high. Everything else seems ok.

Never saw the answer. Which motor is it and how much run time is on it?
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Old 01-13-2012, 06:13 PM   #1000
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Novak Ballistic 25.5 Geared 4.84 I started out at 4 then went to 4.3 then 4.6 now 4.8 It;'s better the higher the FDR but still too hot for my liking
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Old 01-13-2012, 06:26 PM   #1001
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Novak Ballistic 25.5 Geared 4.84 I started out at 4 then went to 4.3 then 4.6 now 4.8 It;'s better the higher the FDR but still too hot for my liking
Wow. Something has got to be causing this. My ballistic was running 160 at a 4.0 and no timing when it was new but my belts were too tight as well. Ambient air was around 85f. Now I have a twin cooling fan on the motor and am running a 3.8 in 70f ambient and it comes off at 120 or less after 8 minutes. Have you tried adding a fan just to see? Maybe trying to run some laps without the body on? Maybe its just not getting any air flow.
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Old 01-13-2012, 06:48 PM   #1002
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Novak Ballistic 25.5 Geared 4.84 I started out at 4 then went to 4.3 then 4.6 now 4.8 It;'s better the higher the FDR but still too hot for my liking
I should clarify. Use a motor checker which can limit amps through the motor to prevent burnt motor. If all you got is your ESC to power it, then at least use a amp limiter. Run it about a minute. If it gets hot, you probably got a shorted turn somewhere. Also you should do the standard motor tests with your voltmeter.

Last edited by ariemus; 01-13-2012 at 07:24 PM.
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Old 01-13-2012, 07:47 PM   #1003
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So I pulled the motor apart. The motor did not feel bound up but I tore it down anyways

Cleaned it and re-assembled it and left the 2 shims in the front of the rotor as it still had about .25mm play.

Left the ring off and put it in my cordless drill and measured the AC voltage from a constant rotation of the Rotor

A-B = .82V
B-C = .82V
A-C = .82V

So that checks out

Meh Don;t know going to put it back in and See how it does.
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Old 01-14-2012, 11:57 AM   #1004
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I have a dumb c-hub question. Is the left hub referring to the left side of the car as you look at (battery side) it or is it referring to it as the US drivers side/servo side?
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Old 01-14-2012, 11:20 PM   #1005
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I have a dumb c-hub question. Is the left hub referring to the left side of the car as you look at (battery side) it or is it referring to it as the US drivers side/servo side?
Left and right are always viewed from the drivers perspective. left = drivers side right = passenger side assuming the car is left hand drive. Or electronics = left side and battery = right side on the sakura.
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