Small center differential with light spur for MP10/MP9

Latest option for Kyosho MP10, MP10e and MP9: light center spur gear with 45 or 46 teeth.

I have been working on the traction of the car for several months now and found that this large center differential (stock on MP9, MP10, MP10 TKI2, MP10e) was not optimized.

Indeed, the volume of oil is really great to have more consistency in the central differential and a lowered oil temperature.

However in practice, with the centrifugal force, I still have the impression that the oil is always projected against the case inside the differential and does not necessarily go between the gears to provide the resistance necessary for the transmission of the power.

In theory, if the differential is 100% full without any air bubbles, that shouldn't change anything, but we all know that unfortunately it never does. In addition, this larger volume of oil is also heavier.

This is why several months ago I asked the Kyosho R&D team to be able to test the small differential (identical differential body at the front and at the rear, reference IF403B with a suitable crown) .

In my testing, I noticed that the traction and power output are much higher with this small differential and the car also has a more directive behavior.

With these crowns (reference IFW634-45S for the 45 teeth and IFW634-46S for the 46 teeth), you will be able to appreciate a faster but also more responsive car. The weight gain with the full differential is around 10g, which is huge on the car's center differential.

If you like a smoother, easier car that is also more balanced in the bumps, you can obviously keep the original center differential.

On the other hand, if you choose this new central combination (IF403B and new crown) I advise you to keep the differential setting that you used to have. 7000 for a start.

In difficult track conditions (ruts, holes) do not hesitate to go lower in oil than with the original differential (down to 3000 if necessary).

Indeed, with this new combination you will still have the feeling of a harder center differential and a more efficient car.

Talking about consistency, I have already achieved several 45-minute finals without noticing any premature degradation of the oil or a drop in performance.

See you soon for a new episode!

The Shark

Reno Savoya