STOCK motor forum
#1757
Tech Addict
Imjonah
The way I udnerstand it, the MVP or orion has too much saturation time for the arm. That is why the brushes have to be narrowed to .140 or .145. This gives less time for the coils to be energizes and lets the motor run cooler.
12 scale has done this for a long time. Can't make run time? take a little off the trailing edge. It WILL help at the cost of torque, but adds RPM. Result, make the 8 minute race in 1/12.
I'll take a P2K2 or GM3 over em all!
12 scale has done this for a long time. Can't make run time? take a little off the trailing edge. It WILL help at the cost of torque, but adds RPM. Result, make the 8 minute race in 1/12.
I'll take a P2K2 or GM3 over em all!
#1758
Re: Imjonah
Originally posted by David Root
The way I udnerstand it, the MVP or orion has too much saturation time for the arm. That is why the brushes have to be narrowed to .140 or .145. This gives less time for the coils to be energizes and lets the motor run cooler.
12 scale has done this for a long time. Can't make run time? take a little off the trailing edge. It WILL help at the cost of torque, but adds RPM. Result, make the 8 minute race in 1/12.
I'll take a P2K2 or GM3 over em all!
The way I udnerstand it, the MVP or orion has too much saturation time for the arm. That is why the brushes have to be narrowed to .140 or .145. This gives less time for the coils to be energizes and lets the motor run cooler.
12 scale has done this for a long time. Can't make run time? take a little off the trailing edge. It WILL help at the cost of torque, but adds RPM. Result, make the 8 minute race in 1/12.
I'll take a P2K2 or GM3 over em all!
Sounds good to me. Thanks for that clarification.
#1760
12 scale has done this for a long time. Can't make run time? take a little off the trailing edge. It WILL help at the cost of torque, but adds RPM. Result, make the 8 minute race in 1/12.
isnt it the other way round taking of the trailing edge makes more torgue so u gear higher say from 6.3 to 6.1
isnt it the other way round taking of the trailing edge makes more torgue so u gear higher say from 6.3 to 6.1
#1761
sorry i jsut realized that what i said only happens when the brush is shortened on both sides not just the trailing edge.
#1762
Tech Champion
iTrader: (31)
hey, i'm running a Losi XXX-s with an 88t spur w/ 21t pinion on a Monster stock; with the type of track i'm running on, instead of top end straight- away speed, i need MORE infield acceleration. How do i accomplish this; go up in teeth or down in teeth? i know that gearing low gives me more accel. and low top end, but does gearing lower mean increasing the number of teeth or decreasing the tooth count ?
Help me out brothas'
-JayBee
Help me out brothas'
-JayBee
#1763
JayBee-Keep in mind you can under gear a motor just as bad as over gearing it. Both will cause heat and a lack of performance. When I ran the 48 pitch gears on my XXXS I always ran the orange 90 tooth spur. Just like now with the 64 pitch, the 128 is the biggest you can get. What I usualy do is find a good final drive ratio usually between 6.30 on longer tracks to 7.50 on tighter tracks. This still depends on the motor but should get you in the ballpark. Monster Jr. I have been running around a 6.5 on our med track and a 6.30 with my Core or Hellfire's on the same track. It seems I normally go down 1 to 2 teeth when I run the Monsters over my Core's. Hope I have helped.
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#1764
Your 88/21 combo is around a 7.66 final and to me seems too low. If you go up to a 23 tooth that will put you at a 7.00. Remember: Bigger # teeth on pinion gives higher or faster gear ratio. Less teeth gives lower ratio or more punch. Stock motors are funny in that they need to be geared close to their sweet spot to get performance on long or short tracks.
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#1765
Tech Elite
iTrader: (22)
I employed the standup on one side brush idea to my MHP. I don't have a dyno....but I defenetely felt a difference. The motor free spins a lot more and has a bit more (and noticable) top end. Laydown on posative with red red spring....standup on negative with green spring. The heat stayed down a bit more also. Its worth a try.....see for yourself.
#1766
Tech Champion
iTrader: (31)
Originally posted by POOKYT
Your 88/21 combo is around a 7.66 final and to me seems too low. If you go up to a 23 tooth that will put you at a 7.00. Remember: Bigger # teeth on pinion gives higher or faster gear ratio. Less teeth gives lower ratio or more punch. Stock motors are funny in that they need to be geared close to their sweet spot to get performance on long or short tracks.
Brant
Your 88/21 combo is around a 7.66 final and to me seems too low. If you go up to a 23 tooth that will put you at a 7.00. Remember: Bigger # teeth on pinion gives higher or faster gear ratio. Less teeth gives lower ratio or more punch. Stock motors are funny in that they need to be geared close to their sweet spot to get performance on long or short tracks.
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forgive me, i'm GREEN
- JayBee
#1767
I agree with what POOKYT says above; but, initially in Novice and the first several races of Sportsman Stock I ran in the 7.00-8.00 final drive range on my Monster stock motors on asphalt. The lower ratios proved somewhat easier to drive because the car slowed better (without actually braking).
As I have learned to carry more speed through the corners, I now find that I am getting closer to the gearing range that POOKYT recommends. Another 3-4 months and I may well be there.
Good luck with your racing.
As I have learned to carry more speed through the corners, I now find that I am getting closer to the gearing range that POOKYT recommends. Another 3-4 months and I may well be there.
Good luck with your racing.
#1768
Tech Master
Originally posted by JayBee
but does increasing the # of teeth or decreasing the # of teeth low gear the motor? and how do i figure final drive ratio?
forgive me, i'm GREEN
- JayBee
but does increasing the # of teeth or decreasing the # of teeth low gear the motor? and how do i figure final drive ratio?
forgive me, i'm GREEN
- JayBee
Ex:
Spur/Pinion= ??? x 2.35 = FDR
72/21= ~3.4 x 2.35 = 8.0.
Hope this helps.
#1769
JayBee's got a XXXS and the ratio is 1.83. Jay- take your spur gear size(88) and divide it by your pinion(21) that gives you a 4.19. Take that 4.19 and multiply it by the Losi's ratio of 1.83 and you will get the final drive ratio of 7.6685714 or about 7.67. The other gear I mentioned was using a 23 tooth pinion. Or 88 divided by 23 which equals 3.826. Then multiply it by the 1.83 and you get 7.0017. The main reason a lot of guys use 64 pitch gears is to give themselves more ratio's to get closer to whatever one they want. Also, once you get used to getting your final drive ratio, then you can ask a TC3 or a X-Ray driver what their final drive ratio is and you know how to gear your car. A 88/21 combo on your car is way different than the same gears on a X-Ray or a TC3. Confused still? Just find the fast guys at your track and ask them to help you find the right ratio and they should be glad to help you.
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#1770
Super Moderator
iTrader: (2)
The formula is correct, except that he already said he has a XXXS, not a Yokomo, so he'll have to use whatever the outdrive ratio of that car is. So for the sake of argument, let's say it's 2.5 to 1(just as an example, I don't really think that the Losi's outdrive ratio is actually that), then you'd take the spur, divide it by the pinion, & then multiply that by the outdrive ratio to get your FDR. Now, if you want to gain acceleration, you can go about it 2 ways, you can go to a bigger spur, or a smaller pinion. So if you start with an 88T spur & a 21T pinion(using the outdrive ratio that I gave as an example), the FDR would come out to 10.476 to 1, & if you just changed the spur from 88T to 90T, then your FDR would be 10.714 to 1(numerically higher, so better acceleration but less top speed), & if you kept the 88T spur & tried a 20T pinion, your FDR would be 11 to 1(even more acceleration & less top end than the 10.714 or 10.476 ratios). But to make sure you're doing it right, you do need to know exactly what your Losi's outdrive ratio is(it should be in the owner's manual somewhere)....