Originally Posted by
Knockoffracer
Just finished reading all 634 pages....😳. Lol.
My group is definitely interested in the idea of USGT. There are 10 in the group. We don't compete, we run for fun. No transponders or lap timers. Grass Roots parking lot racing. It's a competition of who can stay out front the longest.
We've been running 13.5 T/C in a large "L" we set up in a parking lot. Since then we've added a stock 4tec class, and they have all decided to go with a scale type car. I suggested USGT as a guideline for it. They are on board with this. So I've come here, read the entire thread, and let them know USGT rules. They love it. Race liveries and all. They've all picked out their bodies and are starting their builds. I've stressed difference in this area.. in our 4tec class, 6 people run the PF 71 Camaro since it's easy to get. Rather not have that happen with our USGT cars.
With that being said, I've begun to piece together my car. I've picked up a Kyosho TF7 super cheap, going with Tekin ESC/Motor. What I'm having trouble with is the gear ratio, I didn't realize these cars use 64p gears. Where do i go with gearing? I've never used 64 pitch gears before.. kind of lost, lol.
The track quite large, it's in a parking garage local to us. I have YouTube videos of some of our runs, can share a link if any are interested.
thanks in advance for any advice.
The pitch of gears used is a personal choice and what really matters is the
Final Drive Ratio (FDR). There are many gear pitches out there from the very old school 32 to 48, 64 and then there are the odd Tamiya metric 48 and 64 pitch gears. I even recall a hybrid pitch in between 48 and 64 that I believe was from Losi. No matter, what you need to focus on is FDR.
If you all plan to run USGT class cars and will use the USGT rules as a guideline then I assume you'll all run 21.5T brushless motors with 'blinky' speed controls (No software boost or turbo), the Gravity RC rubber tires/rims and a proper sport car body and minimum weights. All pretty equal there unless someone just has to spend $200 on a super duper 21.5T motor. Let's not go there.
I run USGT as well as VTA in local club events indoors on carpet and I use an FDR of 3.80 as my base. To calculate FDR, you need to know the internal ratio of your particular sedan. I run an old TC3 sedan in USGT and it has an internal ratio of 2.5 and I run 73T spur with a 48T pinion which gives me an FDR of 3.802. The math is
Spur / Pinion x Ratio. In the VTA class I run an old Tamiya TA-05 that has a ratio of 2.0555 and I use 88T spur and a 48T pinion for an FDR of 3.768.
I run indoors on a carpet track and 64P gears as there is little worry about pebbles or other dirt getting into the gears causing issues. I also used 64P outdoors on asphalt when we had a place to race as our track was always swept clean and sprayed with sugar water to help with traction. With the finer 64P, I am able to make smaller adjustments in my FDR when necessary.
Hope this helps