Big Jon

The Pro-Line Big Hit is super burly, and has a lot of travel, too.

Believe it or not, the Axial, RC4WD, Traxxas, ECX, whatever, 20T motors are probably exactly the same, because they're just off the shelf commodity motors. The vast majority of sealed can motors are used in a wide variety of consumer and industrial applications, where they're understressed and provide long reliable lifespans. Even the Technipower was used in industrial applications first, which explains the leaf spring brushes. There's also a huge production variance, so performance varies widely, which is why racers and tuners buy sealed motors by the case and test them. The open endbell motors started as serviceable industrial motors, and hobbyists quickly realized the performance potential in serviceable brushes, springs, timing, and all of the little tweaks. There were a lot of slot car guys in the industry at the time. Last year, I found a letter from Mike Reedy last year submitting Yokomo open endbell motors for ROAR competition, for example, and Trinity was a slot car company first. So was Associated, Parma, and many others.

For some reason, the 20t is a dog. Maybe it's a lack of timing, maybe it's the brush compound or spring tension, but it's not much faster than a silvercan. The Sport Tuned seems more powerful, kinda like how the old ROAR stock 27T motors were faster than say, the old 21T budget modified motors. There's a lot more to brushed motor power than the turn count.

The Dynamite 20T isn't nearly as fast as the Tamiya 23t, so there's a start. The two vehicles both use fairly efficient transmissions of similar design, so should be about equal assuming equal rollout, with the 'Box being slightly slower due to weight. Rollout is how far the vehicle moves per motor revolution, and is a great way to compare final drive ratios between dissimilar vehicles or when changing tire size. One of my rigs uses a 3800kV motor on 3S high voltage lipo, and is easily outrun by a buggy with a 17.5 on 2S. I don't know the rollout on either, but the truck has about a 45:1 FDR, and the buggy has about 8:1. Finally, when dealing with low power levels, every little bit matters. BITD, we put a tremendous amount of effort into reducing friction and rolling resistance, motor tuning and maintenance, minimizing voltage drop, etc. Look at some old pics of race cars, and you'll see three wire speedos directly soldered to motors and batteries, no connectors. Small improvements in efficiency have big results in low power applications.

I've done a few Mamba X speedos in the XV-01, but I don't have any pics on this phone. I used "low profile" bullets for neatness, though, with the wires at 90°, not vertical.

Most of the Quicrun ESCs are setup with a program box or the setup button on the switch. There's more stuff to tinker with.

Definitely. Or at least release some prototype bodies. I'd buy one if I had, say, a 917-30 or a 787B to put on top. The Formula E body is really neat, and is probably the 959 of our era, though, so I'm tempted to do a runner and a shelfer. It'll probably take me more than two tries to make the body properly.

The Yeah shocks are getting pretty close to TRF quality. The springs and o-rings aren't even close, though, and the plastics aren't quite as good, but, with an o-ring and spring change, I can't tell the difference between the two in performance, they're cheap, and always available. Totally worth it.

Glad it worked!

If you remove the fan from the Mamba X and use a 300mm sensor wire, it'll install nicely in the front of the electronics box, and you'll only have to widen the wire exit slot slightly for the extra wires. You can install a 30mm fan in the lid if you feel that the extra airflow is necessary. For reliability, I ALWAYS remove the switch on Castle ESCs.

Try reinitializing the ESC after setting throttle trim to neutral. If that doesn't work, check the ESC programming to make sure that reverse is still turned on. I can't remember if the Max 10 defaults to "race/no reverse" but the Xerun ESCs don't have reverse as the default.

The droop screws are the easiest way to prevent the steering from fouling. I'm not entirely convinced that these cars need a whole lot of extra travel. The Long Damper cars in our group are no faster than the standard cars, and are much more difficult to get handling properly. They also suffer from traction rolls and snap oversteer, even with stiff swaybars, which make them darty through the rough. Unfortunately, all of our cars are setup and spec'ed so differently that a direct A to B comparison is impossible. I can't afford to build a Long Damper version of my car, or I'd do the testing myself. I was, however, able to solve some handling issues on my MST XXX-Rally by reducing down travel significantly and lowering the ride height to 15mm. Due to the wide variety of surfaces on a single course, everything is necessarily a compromise, so my "fast setup" might be too aggressive or a sloppy pig to someone else. One of the guys was usually faster than me with a nearly stock 4Tec 2.0 (long shocks, a little grinding on a VXL model, good electronics), and I could barely get the car around the course because it was so aggressive. We're starting a '21 rally season in March after talking a COVID hiatus in '20, so we've all been doing our R&D again. Hopefully, we'll stumble across something fast! BTW, one of our consistent top 5 guys was driving a completely stock XV-01 Subaru with a silvercan, 1060, and Savox 1251. The only "modification" was a High Torque servo saver. Stock oil, manual setup. Yes, he's a very skilled driver, and yes, he was faster with my car.

I'd toss the stock servo saver right away, and replace it with a High Torque or Kimbrough. The stupid plastic "spring" is too weak and sloppy to center correctly and consistently after a hit, and decent metal gear digital servos center pretty well. You won't have to worry about the servo gears - if that servo can withstand a 12 lb crawler cartwheeling down a long hill, it can withstand a 3 lb buggy bumping curbs - but the stiff servo savers will protect the plastic suspension and steering parts. Most of the "steering won't center" issues I see are weak or worn-out servo savers; the rest are either bent steering parts, binding suspension, excessive slop, or a failing servo.

I really like the Tamiya High Torque with an aluminum horn, or the X-Ray Extra Stiff.

Yeah, those rings are to prevent the out drives from spreading. Beautiful build, beautiful body set. TB02 was a great chassis, and should be rereleased in R form.