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Old 10-31-2004, 05:10 PM   #8341
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KINGZJ: i belive you are correct, a smaller gear running a larger gear produces more torque,.

The larger the spur and smaller the pinion- the more acceleration, but slower top speed.

If you increase the pinion and decrease the spur you increase top end, but decrease acceleration.
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Old 10-31-2004, 06:11 PM   #8342
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A gear ratio is a gear ratio is a gear ratio.... All day long. Bigger spurs have only PROVEN to be bigger. You just can't get around the laws of physics. Now if you're saying you're only changing the spur to a larger one, and keeping the same pinion, sure it will accelerate faster. You've just changed the gear ratio. But if you're saying that if you had two identical cars, with identical ratios, but one had a bigger spur and pinion, then the one with bigger spur would accelerate faster, then you'd be wrong.

The fact is that when you change the size of the spur, other factors come into play: You move the motor to different location, so the weight distribution is different. This is even more of a factor in pan and oval cars (where this silly myth is really perpetuated). There is also more drag on small pinions, due to the more extreme angles of the teeth. This probably isn't a real factor with our cars until you start to get below 15 or so tooth pinions, but thats just a guess.
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Old 10-31-2004, 06:12 PM   #8343
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Quote:
Originally posted by xxxkat
Why do you want run such a large spur..???

I was told that if you run a large spur, but keep the same ratio, (i.e. 96/23 vs 100/24) you gain exceleration.

I did not belive this, so I tried an experiment where I ran one race the a 96/23 and the next race with a 100/24. I felt as though the acceleration was a smidge better and my lap times increased by about two tenths. I also dropped the moto temp by about ten degrees. This allowed me to go a little taller on the pinion and dropped my lap times about another tenth.

I thought it was interesting that the motor temp dropped about 10 degrees.
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Old 10-31-2004, 07:41 PM   #8344
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Default Hara clip on heat sink

Saw his heat sink at Nats last summer and wonder whether it is for sale anywhere.
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Old 10-31-2004, 07:58 PM   #8345
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Default Re: Hara clip on heat sink

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Originally posted by coolrcdad
Saw his heat sink at Nats last summer and wonder whether it is for sale anywhere.
you can get the clip on heatsinks from ebay...available in a variety of different colors.
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Old 10-31-2004, 08:29 PM   #8346
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Under what listing? I tried some searches and didn't come up with anything.
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Old 10-31-2004, 09:01 PM   #8347
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integy sells a few different ones try www.integy.com
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Old 11-01-2004, 06:59 AM   #8348
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Bodido,

Useing the same ratio with a larger spur will help a bit in acceleration. I am not going to argue it because I dont know the physics behind it but a while ago it was proven not only on paper but I proved it to myself on the track. We are not talking huge gains but a couple of tenths is still worth it to me.
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Old 11-01-2004, 08:53 AM   #8349
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Default Gear ratios

Thats totally impossible, if anything the car would go slower due to the bigger spur being slightly heavier, but then this is marginal.
Did you just put a bigger spur on with out changing the pinion? if so you would change the gear ratio, so yes you would have better acceleration, but if you just change the size of the spur and keep the exact ratio, this isn't going to give you more acceleration at all.
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Old 11-01-2004, 08:54 AM   #8350
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Heck, we would all be using HUGE spurs
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Old 11-01-2004, 09:15 AM   #8351
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Quote:
Originally posted by tunerjetta29
integy sells a few different ones try www.integy.com
the sames ones sold on ebay...

do a search: (pro4, pro-4)
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Old 11-01-2004, 09:20 AM   #8352
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Thanks guys.
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Old 11-01-2004, 09:59 AM   #8353
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Default Re: Gear ratios

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Originally posted by X2
Thats totally impossible, if anything the car would go slower due to the bigger spur being slightly heavier, but then this is marginal.
Did you just put a bigger spur on with out changing the pinion? if so you would change the gear ratio, so yes you would have better acceleration, but if you just change the size of the spur and keep the exact ratio, this isn't going to give you more acceleration at all.
This is what I would of thought. But, I tried it. I put on a larger spur and pinion, keeping the same gear ratio. My lap times went down 1-2 tenths and the motor temp droped 10 degres.
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Old 11-01-2004, 10:15 AM   #8354
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There is a reason PRS gears now sells a 134t 64p spur.
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Old 11-01-2004, 10:44 AM   #8355
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The larger spur creates some kind of mechanical advantage. I know someone will read all this crap and set the record straight from a technical point of view. I use the largest spur I can fit in the car and I also end up using larger pinions.

When I used to run my ta04r in tcs races everyone wondered how I had so much extra off the corners with a car that is typically a slug. The answer is I was using a 128 tooth spur and a 37 tooth pinion while everyone else was running a much much smaller spur. They would come over and ask my overall ratio and would match it but still were lagging and motors were hot as hell.
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