I am going to hopefully improve the driving feel of the XV-02 RS Pro.

I have got the centre differential gear, and this will allow me to tune how the car handles and also allow me to use the front bias overdrive gear.

The standard XV-02 Pro uses the same sized diff crown gears that you get in a TT-02. They have 39 teeth - but this kit gives you the option of using a 40t gear in just the front or rear.

What this essentially means is that you can make the front or rear wheels (depending on where you put the larger gear) spin slightly faster by approximately 3%.

The centre diff gearrequired is linked here, but is also required to be used in connection with a TT-02 oil diff.

I had a spare diff set with my kit as I used the optional spool on the front.

Using the spool in the front diff (39 teeth the same as a stock diff gear), and the overdrive 40 teeth gear in the rear, my car's front wheels are spinning slightly faster as it has front-drive bias.

I like the idea as it will pull hard out of a corner and behave slightly more like a front wheel drive car, meaning it will be very stable and hopefully predictable.

This is the XV-02 diff I had spare to use in the centre (the TT-02 diff is exactly the same). The option HC-22050 is simply just a spur gear and different casing.

The XV-02 manual has a separate page going through how to build and install the centre differential.

You need to use 30k diff oil, although the great thing about diffs is that they can be tuned to meet your driving style. However, if you are using the overdrive gear then I would not recommend going too high as you need there to be a certain degree of slip to avoid drivetrain damage.

All installed and ready to go - I used a 28t pinion and it all fits together beautifully. One thing I did notice was that there was a bit of annoying slop in the bearing for the centre diff when in the diff housing.

I solved this by sticking a tiny piece of aluminium tape down to sit the bearing onto.

This seemed to get rid of it completely - it would probably have been fine anyway, but an 8.5t motor with boost is quite quick so I didn’t want to take any chances if possible.

The battery fitment on this car is designed for a Nimh or round case lipo. I wanted to use a shorty pack as they give much more punch (7.6v) and are smaller and lighter.

Note to XV-02 users… A shorty will fit perfectly in this car with a bit of modification.

You need to use a foam block at the front end of the battery tray, and you will notice that the tubes in the battery line up perfectly with the gap between the spur gear casing and the servo mount.

So with a bit of cutting and fiddling…

There we go - use a bit of foam tape to line the edges where the battery sits, and make sure it is a fairly tight squeeze onto the foam block at the front and the battery is every bit as secure as a Nimh pack would be.

I used some of the plastic-covered slimline tube connectors and they fit in the gap pictured very nicely.

The car is now ready to test!