Wow, didn't think it would make that much of a difference. Guess I'll leave it as is and just get a couple of different spur sizes.

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

"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."

Not quite. Yes, 32, 48, 64 and even 84 pitch are "common" imperial pitches. Metric pitches are described as "module". Tamiya (and some other asian brands) use .4, .6, and .8 mod gears. They are not "metric 32" pitch. Amusingly, mod .6 and 48 pitch are pretty darn close, close enough to work for a while, but wear goes through the roof.

Bigger teeth are harder to damage. Bigger teeth have greater difference in shape of tooth, and have more friction. Smaller teeth have less friction, but are harder to setup right. Higher numerical pitch gears also give you a wider selection of available gear ratios. Since the OP is asking, go with 48 pitch.

Thank you both. I really appreciate the info.

As far as what motors will be run, these guys won't do the whole motor of the month thing. Tekin and HobbyWing will be the motors/esc of choice.

I made it very clear to them the body needs to resemble a production based racecar. No goofy tribal paint schemes.

Track we will most likely use is at Trains and Lanes in PA as it's the closest outdoor on-road course I currently know of. Looks to be kept clean. Since it's not out of the realm to use 48 pitch gearing, I'll go with that since I have a ton of spurs laying around from when I used to have HPI Sprint 2s. They know about Gravity tires, and spoke wheels. They love stuff like this. We follow a similar setup for our parking lot 13.5 cars. No T/C blobs, slicks, or crazy ESC timing. We all love door to door racing.

Only info I find on the TF7 is from Kyosho, says internal ratio is 1.9. I'm not entirely sure how large the Trains and Lanes track is, so I'll have to wait until spring when we go to find out.

Anybody at Cleveland Indoor Race have a USGT Spec Motor they would like to sell? PM me. Thanks.

Everyone is keepign them as most tracks are switching ot them. I have a bunch in stock still.

EA

following thread, building my first USGT. thanks in advance for all the knowledge.

Hopefully the 360v2 USGT program will switch to the Motiv Usgt motor very soon.....
Rc racing's biggest class is about to explode !!!

My tires just came in. Those things tend to be difficult to get don't they, lol. Just picked out a body, Audi R8 LMS from either Charisma, or Tamiya. Not sure which one yet. Anyone used either have any input?

Here is the rules list for USVTA, USGT, and F1. Might want to check with your local track to see how closely they stick to them. There is a USGT body list. I don't recall any Carisma bodies on it, but haven't looked recently.
U.S. Vintage Trans-Am R/C Racing Series

Not sure I'd actually compete. It's just a group of us who plan on doing USGT style cars and going by ourselves. But I will definitely look at the list to see what on it, might change my mind, lol. As I read previous posts, it was always stated any body 190/200mm body. I figured, it's a model of an actual race car so it would fit in.

The Build RC has the Audi R8 body and they are on the list. I've just order one for myself.

The Build RC 1/10 AUDI R8 PC Transparent 195mm RC Car Body - Option parts & accessories - Cars The Build RC

Ordered a couple of bodies through my local store. Whichever I take, the rest of the group can pick from, lol.

Curious, what timing does the new Motiv Spec USGT motor use? What kind of gearing does it like on a med fast (60 x 140) asphalt track? Right now I have my R1 V16 geared at 3.91.