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Losi XXX-SCT + viper 17.5 gearing help.

Losi XXX-SCT + viper 17.5 gearing help.

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Old 07-13-2012, 10:52 AM
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Default Losi XXX-SCT + viper 17.5 gearing help.

hey guys, i just picked up a viper vtx10R + 17.5 motor combo for my losi xxx-sct. i need some recommendations for gearing help. i plan on running boosted 17.5 at golden state in a few weeks. i have the 86 and 88 tooth spurs along with pinions ranging from 16t to 24t. i am running the gear diff trans btw
i have been running my truck at 23/86 and it goes for about 5-6 min and it hits the motor temp alarm (set at 170) but my IR temp gun says 140 when it goes off, the sensor must be internal
my timing is as follows
acc boost:
start rpm 3500
finish rpm 12500
max adv. 27 deg
top speed timing:
slew rate 10deg/1000 rpm
top speed timing 18 deg.

thanks in advance.

Last edited by AndrewTom; 07-13-2012 at 10:58 AM. Reason: forgot to add some settings :)
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Old 07-13-2012, 11:07 AM
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also, i am running 2s 5000mAh 35c packs.
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Old 07-13-2012, 11:44 AM
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Perhaps I'm looking at this wrong but if I'm understand the slew rate correctly, you're maxing out 27 degrees of timing in 2700rpm. If I got that right and you're looking for a linear boost, you'd want 3 degrees of boost/1000rpm. That may help bring your temps down quite a bit and subsequently allow you to run more total boost.

Edit: Looked at it again and had a few things wrong. You're adding 3 degrees/1000rpm for acc boost and 18 degrees of top speed timing in 1800rpm. Again, if I'm looking at everything correctly.
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Old 07-13-2012, 12:37 PM
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I have the same car/motor/esc. I'm running an 18t pinion and 88t spur. I make sure my boost doesn't come on till half throttle while holding the wheels off the ground. I'll be taking it to the track this evening. I'll let you know how my temps are.
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Old 07-13-2012, 12:45 PM
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I was geared 25/88 with my SCT. Had a Viper 17.5 too. I didnt like the truck much and ended up selling it. But 25/88 with viper 17.5 was too steep. It would get to about 180 after 6 min main. That was on boost and a medium sized indoor clay track.
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Old 07-13-2012, 06:36 PM
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Default i think this is resolved :)

okay so here is what the issue was.
i have been email viper about my issues with heat, and Eric said to set the esc and motor temp alarms at 220 deg. F.
Mine were set at 160 deg. F
also, the temp reading is Internal, so i basically messed up .
but really, there should something that says the sensor is internal, and where its recommended to set at. oh well, better safe then sorry
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Old 07-13-2012, 11:27 PM
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