Mugen MBX4-XR Conversion?

[SilveradoHD]

I have an old Mugen MBX4-XR and another parts buggy in need of a powerplant. I am looking to convert it to brushless. I was wondering if the RC Monster motor mount for mugen will fit in the MBX4XR series of buggies. I am not sure if the diff mount is the same as the MBX5. I already have a v2 MMM that I run in my drag rustler that I could use in the buggy. I plan to do this on a budget and use the cheap zippy packs. Would a 4, 5 or 6s battery be better to use on a Medusa 2000kv? Which pinion should I get for bashing? I will mostly be bashing this car as this old Mugen is built like a tank, but would also like to drag race it. Would the Medusa 2000kv motor be sufficient to move around an 8th scale buggy?

[Arct1k]

I believe mikes stock mugen mount works:

http://www.rc-monster.com/proddetail...=RCMmugenmount

A 4s 5000mah lipo with a Medusa 60mm 2000kv would work fine - Bashing aim for about 40mph - 16T pinion would work.

Use this script: http://scriptasylum.com/rc_speed/_top_speed.html

Differential Ratio: 3.3076923076923075
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 16
Total Voltage: 14.8
Motor KV: 2000
Tire Diameter (inches): 4.5
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 2.88 : 1
Total Ratio: 9.50962 : 1
Tire Circumference (inches): 14.14 inches (359.08 mm)
Total Motor Speed: 29600 RPM
Vehicle Speed: 41.67 mph (66.94 km/h)
Estimated Adjusted Speed: 39 mph (63 km/h) - 5% loss
Effective KV Value: 2000

PS There are quite a few stickies and the search thing works well on the site if you want to research batteries and trays etc

[BL_RV0]

I did a comversion on a MBX4-RR. Link is in my sig. The MBX5 mount bolts up perfectly.

[SilveradoHD]

Originally Posted by BL_RV0

I did a comversion on a MBX4-RR. Link is in my sig. The MBX5 mount bolts up perfectly.

Awesome, after converting my Rustler to a drag racer I have an itching for a reliable basher and I think my old MBX4-XR would do the trick. I know parts are getting hard to find but nitrohouse.com still stocks parts, ebay, and I already have another parts buggy. I think I am going to run the Medusa 2000kv-60 on a 5s. What pinion should I order with it to keep it cool? What about the Medusa motor with the heatsink? Would there be enough clearance for the heatsinked motor to fit?

[SilveradoHD]

Got all the parts in today for my MBX4-XR conversion and hit a few snags. The RC-Monster Mugen motor mount fits, but it is a tad too short. The older MBX4 diff sits about 2mm higher. This causes the center diff to sit at an angle if no spacers are used under the RC-Monster mount. It seems that 2 brake calipers without pads are about the perfect height to remedy the problem, although this is kind of rigged and I would prefer the mount to sit flush on the chassis. Would it be possible to get a 2mm spacer custom made to fit perfectly to the mount?

Also, for anyone else doing this conversion on an MBX4. The stock rear chassis brace gets in the way of motor adjustments. I can not get my 13t pinion to work because of this. I had to dremel some plastic off just go get a 16t to work. I may try locating the aftermarket all aluminum chassis brace and this may work better. Also, the included servo mount tray will not work for the MBX4. I may try to mount this somewhere as a ESC mount.