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Old 09-28-2013, 09:46 PM   #1
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Default VTA gearing

I'm putting together my first VTA car and I'm wondering what a good basic spur and pinion is.
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Old 09-28-2013, 09:59 PM   #2
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Car would help. A good place to start (and some tracks mandate) is a 4.0 FDR. You can use a few gear calculators online to help get there.
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Old 09-28-2013, 10:28 PM   #3
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What he means by "car would help" is that some cars have a different internal gear ratio (IGR). For example, the TC3 had a 2.5:1 IGR and the TC5 has a 2.0:1 IGR. If you put the same pinion/spur in those two cars, you would have one car going 20% slower than the other.
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Old 09-28-2013, 10:50 PM   #4
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Wow I can't believe I left that out. It's an X-ray T2 007.
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Old 09-29-2013, 07:22 AM   #5
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From what I can see, that's a 1.7:1 IGR. Depending on what spur gears you have, and what pinion gears you have (and if the track enforces the 4.0FDR or the 4.3FDR) I would probably start with something like a 30t pinion and an 80t spur. That will give you a 4.53 FDR which would be legal in either case, probably fast enough to start getting your feet wet, then as you get to know the track better, you can bump the pinion up to either a 31t or a 34t depending on the track rules.
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Old 09-29-2013, 09:42 AM   #6
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Wow I can't believe I left that out. It's an X-ray T2 007.
Great car even better with the Exotek lipo chassie, I sure miss mine.
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Old 09-29-2013, 05:36 PM   #7
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you will want to be able to get anywhere from 3 to 4 FDR depending on track.

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(and if the track enforces the 4.0FDR or the 4.3FDR)
neither usvta or roar have a fdr rule, usvta did have a 4.2fdr rule back in the day's of 21.5t motors.
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Old 09-30-2013, 03:01 PM   #8
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you will want to be able to get anywhere from 3 to 4 FDR depending on track.


neither usvta or roar have a fdr rule, usvta did have a 4.2fdr rule back in the day's of 21.5t motors.
Dang! I was looking for it and couldn't find it and now I know why!

The last time I was talking to the guys about this for our local track, it was 21.5 with 4.2.... I don't want to have to buy ANOTHER new motor!
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Old 09-30-2013, 04:52 PM   #9
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Dang! I was looking for it and couldn't find it and now I know why!

The last time I was talking to the guys about this for our local track, it was 21.5 with 4.2.... I don't want to have to buy ANOTHER new motor!
in Canada you might still be runing 21.5's Check with your local track.
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Old 10-03-2013, 02:02 PM   #10
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Where can I find a good FDR calculator?
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Old 10-03-2013, 02:03 PM   #11
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Where can I find a good FDR calculator?
I use this one -> http://www.gearchart.com/index.cfm?f...n=chart.create
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Old 10-03-2013, 02:24 PM   #12
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Dang! I was looking for it and couldn't find it and now I know why!

The last time I was talking to the guys about this for our local track, it was 21.5 with 4.2.... I don't want to have to buy ANOTHER new motor!
Canadian VTA uses 21.5 motors so you are fine. Outdoors I ran an FDR of 3.31 running a Tamiya TB-03 with a Trackstar motor. Indoors I will likely move closer to 3.8 as the track is smaller.
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Old 10-03-2013, 02:40 PM   #13
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With a 21.5 motor in our CVTA class, I just ran a 3.88 FDR this past weekend at Lou's Speedway in London Ont. I believe it's a 90' straight. The Revtech came off at 135-140 degrees all weekend. In a few weeks our local track will be starting it's winter season up on a 60'x60' track which doesn't have the grip or flow that Lou's has and I'll likely be gearing to a 3.9 or 4.0 depending on the layout.

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Old 10-14-2013, 03:14 PM   #14
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The track we run is like a big oval that cuts back in on itself and runs through the middle. It's big and sweeping on the outside, tight and technical on the inside so I'm thinking somewhere between 3.80 and 4.00. Thoughts?
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Old 10-14-2013, 06:42 PM   #15
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My current track is 105'x57' and I'm running a 3.68 fdr. It set to run to the very limit of a race plus a couple of warm up laps. This is also an asphalt track.
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