Test Results:
1) Is the TT-01 a competitive racer?
2) What upgrades are required to run at a competitive level?
3) Future tests?
Introduction:
Just completed running a TT-01 at the Aliso Viejo TCS event in the GT-3 class. GT-3 requires a Tamiya tub chassis and a silver can motor and is predominately run with highly hopped up TA-05's. 29 of the 35 cars were TA-05's, probably 20-25 of these were so heavily hopped up that clearly costs in excess of $350-$400. I also saw 2 TA-04's, 2 FF-02's, 1 TB-02, and I ran the only TT-01. I ran a highly upgraded TA-05 in last years TCS. I sold the car, but got the itch again this year to drive another class so that I'm not sitting for 2 days driving my Mini in only a handful of races.
1) Is the TT-01 a competitive racer?
I started with buying the cheapest kit Tamiya makes, the Enzo TT-01, and tried to make it work, only buying upgrades as needed when testing showed without it I would be uncompetitive. The only upgrades from box stock on race day were bearings, gears, and tires.
I finished in the middle of the B-main; Watching the A-main and the top B-main drivers made me realize that I was not held back by the chassis. With a better motor and a lower drive ratio I might have finished a couple places higher, but that was it. If I had been allowed to run my Corally Phi with the same motor and gear ratio I wouldn't have been in the top portion of the B. This chassis is fine for silver can racing without a lot of mods.
2) What upgrades are required to run at a competitive level?
a) Bearings are a must. I bought the $18 Tamiya bearings for the TT-01. I soaked then in motor spray overnight to flush out the grease, soaked them another day in thin oil. After this they spun very freely. This may cut down on the life of the bearings, but you want a free drive train; that’s the price we pay for racing.
b) The 19T pinion and 61T stock spur is for beginners in the Spec class. I'm fairly advanced so I wanted whatever drive ratio gave the best time for the track. Some people ran silver cans at drive ratios of 3.8, I suspected that the mid 4's were optimum. Tamiya sells options for getting the drive ratio as low as 5.7 (25T pinion / 55 spur) so several of us on this thread have done research to improve this. See the table below for how to target the gear ratio you need. I ran the 52T spur, the largest pinion I had was a 28T; if I had the 29T or 30T I would have used it. No single best answer here, your track will require a different solution.
In an earlier post I mentioned motor heat as a problem. Found I had some rubbing going on in the back diff; once that was solved my motor never got hot through-out the whole day.
I’m not going to say much about silver can tuning other than to say it was clearly being done by good motor guys; I had a strong motor in my Mini but decided to run this car with what a beginner could do. I ran with an underwhelming 12.3k rpm @ 5v motor and guys were getting disqualified all day for going over the 15k limit. Nuff said.
c) I ran the Tamiya B3 tires I had left over from last year. Decided not to even try the kit tires; kit tires wear so quickly that I would have worn them out in 1 practice. The cost of replacing kit tires over and over makes no sense. Since this doesn't differentiate between car models it didn't bother me to run the non-kit type; any chassis will have this issue.
Now for what didn't need upgrading:
d) Did not use oil shocks; used the friction shocks. This was the closest call as upgrades go; with the friction shocks the car had a lot of bounce and that doesn't look pretty, but with a silver can motor I don't think the performance was affected. I had to run the car at 1500 grams, that was a lot of weight to add and the friction shocks didn't like it. Maybe the car would have done better with oil shocks, but you should see the look on peoples faces when they found out they were the stock shocks!
e) Did not use an upgraded ESC; Silver cans don't need it; I would reconsider if the motor is stronger.
f) Did not use the aluminum drive shaft. Silver cans don't need it; I would reconsider if the motor is stronger.
g) Did not use 2 degree rear hubs. Silver cans don't need it; I would reconsider if the motor is stronger.
h) Did not use adj Toe or Camber links. Silver cans don't need it; I would reconsider if the motor is stronger.
i) Did not use ball differentials. I packed the front gear diff with anti-wear grease, left the rear gear diff free.
h) Did not use any stiffeners. Silver cans don't need it; I would reconsider if the motor is stronger.
3) Future tests?
a) ROAR is now moving to the brushless 17.5T being the new stock, and my local tracks are talking of moving that way. I run a 13.5T sintered with advance timing in my Corally Phi and I really don't think the TT-01 can handle that kind of power without major expensive upgrades. But I'm wondering about the 17.5? Brushless also like very low drive ratios so all the gearing research will still pay off.
b) Setting droop to control the weight transfer is a very critical adjustment that I make a lot of use of in all the sedans I've owned. The TT-01 does not have droop control and it would have to be done by shimming the shocks (not easy to adjust on the fly!). Where the lack of gearing was the main limiting factor in silver can classes, lack of good droop control I suspect is the main limiting factor in the stronger motor classes.
Conclusion:
The TT-01 is a great car for the Spec or silver can type classes.
I'll keep playing with it for stock classes and keep posting.
Resist the urge to plow a lot of upgrades into the car, it probably needs less than you would think. Bling is fun, I’m not trying to knock it, just looking to see if a $100 car (including upgrades) can work; Yes it can!
Below is a table for all the gear combos without modifying the chassis, and a couple of pictures of the car.