15.5T What is this madness!

Shibata is always coming out with unique, cutting edge products. The latest to appear in the lab is the new, Shibata 15.5T motor. I had received it last week, but since I was going out of town, I was unable to give it a try. Now I’m back and I was able to see what this new motor is all about.

It definitely looks good

A little background on myself
Back when I started drifting, I had read a write up by Atsushi Mizunaga, Mr. Tetsujin. One take-away that really shaped my path was not to rely on curves and electronic adjustments, but rather to work on training your finger. This way, you can drive anything and are not limited by different settings. This really spoke to me on a deep level, and I made it a point to not give into the easy path, but rather to learn to fine tune my hands. This has worked out well for me, and actually gives me a pretty good place to test different components from.

My Motor Preferences
I have gone from running 9.5T, 10.5T, 13.5T, then back to 10.5T with a torque rotor. The last setup has been my go to setup for the past few years now. I am really comfortable with any listed though.

I dropped it right in to my current chassis. What better way to test, than to just swap it into a chassis I have been driving non-stop. Forgive the dust and dirt, I didn’t even take time to blow it off yet.

The 15.5T
I found myself to be very curious about this motor. First, because I know Shibata / R31 House does their homework, but also because I had tried a 17.5T years back, and it honestly wasn’t bad. I prefer to drive with a lot of RPM when I hit boost and turbo, but only because I’m set up that way. The 15.5T should have good torque, a broader useable powerband, and lower top end RPM than my current setup. I decided to test this motor by simply swapping my 10.5T w/Torque Rotor Acuvance Fledge with the Shibata 15.5T motor. It would be driven by an Acuvance Xarvis XX. All installed in a Rhino Racing Shark conversion.

How Does It Drive
As soon as I hit the throttle, it had a noticeably different feel. The chassis felt more grippy due to the lack of wheel spin. I proceeded to put on a few more laps without putting much thought into it. I just wanted to warm up the tires so I could get a good feel for what was going on.

Right away I felt right at home with it. It wasn’t hitting the high RPMs like my 10.5T, but it’s not supposed to. I noticed I had a lot broader stroke in the “grip” area of my throttle pull. I would have to say it felt almost like 50% more pull for the same RPM. So it allows for a finer adjustment in wheel speed. Since we have a long sweeper on our track, I am able to test really long, consistent drifts. It was very clear that adjustments in wheel speed were very crisp and exact. I would liken the difference from my current setup to this as almost a feeling of Belt Drive to Gear Drive. It’s almost as if the 10.5T has a bit of a “springy” feel, where as the 15.5T feels directly connected to the throttle. I only notice this when comparing the two. Although the 15.5T doesn’t achieve the same RPM Level, 87k vs. 66k for the exact same ESC settings, it is more than enough for what I need.

The Test Mule – Acuvance Xarvis XX ESC, Acuvance Blaze Capacitor, Futaba CT700, Futaba GYD550, all in a Rhino Racing Shark Conversion.

Overall, I would say it would give the chassis some extra speed if you are running a hotter turn motor and tend to be a little heavy on the throttle. It seems to have a good amount of room in the lower RPMs where the traction is when coming out of the corners, so modulating the throttle is a lot easier when you are searching for that extra little bit of grip. At the same time it has enough RPM to keep those wheels spinning, and enough torque to make those RPM changes really precise. It does however lack the smoothness I have become accustomed to with my Acuvance setup. I wouldn’t hesitate to run this motor for a second, as it feels about as smooth as the Yokomo motor offerings, which is not a bad thing at all.