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Need Advice on Stock 17.5T asphalt

Need Advice on Stock 17.5T asphalt

Old 09-26-2010, 03:45 AM
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Default Need Advice on Stock 17.5T asphalt

I'm new to Electric RC , I'm looking for some advice to extract more performance from my ESC/motor/gearing..

I'm competing in 17T Stock on asphalt and I'm running the following gear:

17T Ballistic Novak Stock Spec- (Stock Timing - 30 deg) - I have not touched it
(no motor fan)
Novak Product Info

Novak Pro ESC (Expo Curve 2, all other settings are default)
Novak Product Info


Car is Top Photon- 2.0 IDR -
Running 64Pitch 100 Spur and 50T Pinion (FDR 4.0)

At my last meeting, during the second run the ESC detected the motor temp as high and shutdown about 4min into the race; For my next run I changed to a 45T pinion which lowered the temp, gave excellent acceleration out of the corners; but was seriously down in top-end speed. FDR 4.44 (even with the previous 100/50 the 'faster guys' had more raw speed)....

So... the Ballistic Manual recommends for Touring car an FDR of 4.0, and the Havoc Pro ESC Manual recommends 3.75

I just want to get the most out the gear that I have.
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Old 09-26-2010, 06:47 AM
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Hey anthony,

It was great to meet you last night and race against you( even if i was driving a 540)

As for your gearing question i would possibily look at changing to 48p spur and pinion as you saw last night 1 little bit of crap from the track can cause you lots of dramas. Just a suggestion.

Maybe you could try a 47 tooth in it as that may give you a good compramise(sp) in speed and it might be enough to keep the heat down enought to get through the race.

Cheers
Adrian
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Old 09-26-2010, 08:00 PM
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Firstly I would add a good high speed motor fan and heat sink as that should drop your temps by at least a good 10c. The suggestion to go to 48 pitch gears is a good one for outdoors. But dropping 5 teeth to a 4.44 ratio from a 4.0 is a large jump to drop temps as usually you would drop 1 pinion tooth at a time if you have all the required pinions. You could keep the current ratio you have and then add a little bit of motor timing to your can and see how that goes as that will take away a bit of your bottom end grunt and add some top speed. It is a balancing act with speed and heat though.

IMO You should add the fan and then try one tooth at a time and see how that goes. If your stuck for pinions add a touch of motor timing and see how that temps out.
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Old 09-26-2010, 09:40 PM
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Originally Posted by Benzaah View Post
Firstly I would add a good high speed motor fan and heat sink as that should drop your temps by at least a good 10c. The suggestion to go to 48 pitch gears is a good one for outdoors. But dropping 5 teeth to a 4.44 ratio from a 4.0 is a large jump to drop temps as usually you would drop 1 pinion tooth at a time if you have all the required pinions. You could keep the current ratio you have and then add a little bit of motor timing to your can and see how that goes as that will take away a bit of your bottom end grunt and add some top speed. It is a balancing act with speed and heat though.

IMO You should add the fan and then try one tooth at a time and see how that goes. If your stuck for pinions add a touch of motor timing and see how that temps out.
Shopping List:
http://www.shopatron.com/products/pr...ber=5416/135.0
Temp Gun

How many degrees of timing? add 5 degrees, then have a 3min run - temp, run for another 3 and check temp?

Ant.
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Old 09-27-2010, 01:18 AM
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Originally Posted by anthony_ling View Post
Shopping List:
http://www.shopatron.com/products/pr...ber=5416/135.0
Temp Gun

How many degrees of timing? add 5 degrees, then have a 3min run - temp, run for another 3 and check temp?

Ant.
Ant, That motor cooler wont fit your ballistic. The ballistic has some what of a motor heat sink built into the can. just get one of these And blow it straight at the motor from the rear of the car forwards.

http://www.amainhobbies.com/product_...PM-Cooling-Fan


You dont need a fancy temp gun either. these are fine.

http://www.amainhobbies.com/product_...Gun-Tempguncom

I always try and move the sensor board about 2 mm at a time when adjusting timing. You will notice the extra zing but It is a fine line sometimes.

3 mins and temp around 65 as this will rise to mid to high 70's at 5 minutes. Under 80 for club days under 95 for big events.
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Old 09-27-2010, 03:34 AM
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Sounds like your motor might have a toasted magnet, or rotor. Check and make sure the motor is cogging a full 6 ticks in a single rotation.
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Old 09-27-2010, 06:45 PM
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Originally Posted by Foxxrocket View Post
Sounds like your motor might have a toasted magnet, or rotor. Check and make sure the motor is cogging a full 6 ticks in a single rotation.
Ok cool, do I just remove the motor and slowly turn by hand? or can you feel the notching while installed?
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Old 09-28-2010, 07:12 PM
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Originally Posted by Foxxrocket View Post
Sounds like your motor might have a toasted magnet, or rotor. Check and make sure the motor is cogging a full 6 ticks in a single rotation.
Thanks for that tip, Interestingly, when I had checked (with the motor installed) I couldn't feel the cogging due to the spur/pinion mesh being too tight... Once I'd set the mesh correctly I could definentely feel the 6 ticks.. and the drive train was nice and free. I wonder how much of an affect that would have on the motor temp... i'm sure there would be some additional and unescessary friction caused. Anyway I've got a novak heatsink and temp gun plus a range of pinions to play with...

looking fwd to a test day.

Ant.
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Old 09-28-2010, 08:53 PM
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Having the mesh too tight is a major culpret of heat and loss of speed. I'd say as long as you haven't seriously cooked the motor, it will be good as gold. You may have taken a few hours off the motor's life, but i'd say if it doesn't grunt and groan now, you'll be fine
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Old 01-05-2011, 01:58 AM
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Originally Posted by JR007 View Post
Having the mesh too tight is a major culpret of heat and loss of speed. I'd say as long as you haven't seriously cooked the motor, it will be good as gold. You may have taken a few hours off the motor's life, but i'd say if it doesn't grunt and groan now, you'll be fine
Finally had a chance to test this out.. I've added a little timing and a motor fan and temps are under 60 deg Celsius after a hard run of 8min.

The car accelerates really nice, but lacks top end..

If I go to a smaller pinon, say by 1-2 teeth what should I expect in terms of temps with the current timing?
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Old 01-05-2011, 03:38 AM
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Motor timming runs hand in hand with gear ratios and ESC timming. It's about finding that sweet spot, where all three work for you.
Run a good base line final drive ratio and then advance or retard the motor one tick. And if you're running 160F with in 5 minutes, you're right where you want to be. It will also be noticeable if your lap times go up or down
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