UltimaX MRB - another mid convertion

[Alex H]

Hello racers!

There are some homemade kits out there and I wanted to do one myself. Inspired by Fabs and Mr Pink.
First things first. NO 4 GEAR TRANNY. Wanted to make one myself and I am going to eventually, but just to evaluate. Have seen MR Pinks creation in real life and he is doing really well with it. It accelerates strait on slippery surfaces and turns like nothing else. And on turf, don't need to say more.

I did my transmission differently than him tough. I simply made a hole on the opposite side and reversed the axel. Put in some shims here and there and Volà. The bearing sticks out a 0.5mm. I solved that by making a 6.1mm thick CF fixture with a 10mm alutube inside that holds the bearing in place. Everything is then attached to the motorplate. The bushing are made out of 3*5mm brasstube. The whole motor/motorplate is shifted towards the right to create perfect balance L/R. Seen from behind that is. About 2.1mm shift.
The screws from the lower suspension holder (will be blue alloy soon) are longer and screwed into the brass bulk and from top as well. The lower part of the shocktower (CF of course) will be attached into it as well. Some sort of brace will also be made to support the higher end of the tower. The CF on the gearbox is for supporting the plastic and strengthen it.
Just waiting for the CF sheets to arrive so I can start on the chassi and tower. There will be no top-deck and side by side liposaddles only.
More to follow soon.

[OldTimer]

Looks good so far

[Alex H]

Thanks.

I forgot. I am going to steal your CR2 chassis solution with CF screwed together Jonathan.

[RogerM]

Is there a webcam in my workshop??? Rear end looks similar to the car I am looking at right now but with the motor plate on the other side and a 4th gear (similar to the CR2 idler gear mod).

Question is do I take it to Petit or not?

[Fabs]

Alex,

Looks good mate, but I have a question: where does the shock tower go??

Roger:

Of COURSE you bring it !

[Alex H]

Originally Posted by Fabs

Alex,

Looks good mate, but I have a question: where does the shock tower go??

Thanks Mr Mid Ultima Custom special!

If you look closely, you can see the brass bulk between the upper suspension holder and the rear arm mount. Going to drill 4 holes in that. Going to use 3mm Cf for the tower and mill 1mm off where the upper shock holes are to 2mm. This straitens up the shocks and they clear the turnbukles better. Then I have a solution for another 2 holes a little higher up on the tower for greater support so the transmission does not break easily. The 4 holes in the bulk is not enough I think.

What's great with this tranny mod is the fact that there is very little preparation on the gearing house ones you figured out what spacers to use and what holes to make. Only had to reem up the new opening to 10mm and shims it correctly. If the transmission case breaks it will only take a few moments to make a new one.

Have another idea too. The Durango Dex410 front shocks are not that much shorter than the Kyosho rears. Perhaps 10-12 mm. Have not messured yet. This could mean lower CG and improved airflow over the wing. Got enough Cf for an optional shocktower....