MBX5T

Anyone who’s ever driven a Mugen car of any sort will tell you what a great piece of kit it is, but with your Mugen you get a little something extra in the shape of a certain aloofness, a somewhat superior feeling over the competition, a new level of precision and the knowledge that your car is well equipped to do the business on a race track. So there’ll be quite a bit of expectation from the newly released MBX5T Prospec truggy as Mugen dip their toes into the outlaw racing class and I launch a broadside attack to displace Dan’s Kyosho ST-R and prove there is only room for one top dog!

I can’t express just how amazed I am at how the truggy class has come on leaps and bounds in design layouts and the sheer genius of thought behind them. The Hot Bodies LSP started the racing kick but was soon overtaken by the class of the Hong Nor CRT that appeared to be unbeatable till the Kyosho ST-R came along, and now we have the Mugen MBX5T Prospec that threatens to be even better! With Dan and myself building our kits side by side, it was easy to see the differences between the two and as we progressed, how some parts in the Mugen kit were already of a far higher spec than its Kyosho counterpart.

Gentlemen, start your build

It was soon time to open the box, spill out the contents onto my table and with the instruction manual laid in front of me, prepare for the long build ahead. As per usual with most kits, it’s the diffs up first with 46 helical cut toothed crown gears to 10t pinions, 18t bevel gears and four 10t spiders going inside and a 46t spur gear on the centre that when mated to the 13t clutch bell gives an overall gear ratio of 16.28:1. So straight away we can see an improvement over the MSR X5T conversion kit that used a 13t bell/62 spur that has a ratio of 15.90:1, ergo re-gearing the whole truggy so it does away with the huge spur and immediately lowering the centre of gravity of the Prospec by 8mm and also means most of the drive train is interchangeable with the MBX5 buggy! Anyway, as I build on it wants to include some small rubber S3 O-rings into the front and centre diffs, but I since discovered that racers abroad have advised to ignore the use of these because they can wear and make for an inconsistent feedback from the truck and then also have the result of making the drive react as if there were an extra 2k of oil in the diffs, the rear is OK though as this one doesn’t get O-rings installed. The supplied setup sheet says to use a 5k-2k-2k arrangement, but I had to disagree with that as it would unload far too much power to the front end and so I used 7k-10k-2k oils as my starting point.

It’s CVDs all round too and making up the centre drives was a synch, even a small tub of super joint grease is included to lube up the UJs. Now with the diffs put into their cases, we see the first of the Prospec parts come into play with the front lower suspension plate being a lovely gunmetal grey 7075-T6 aluminium part over the stock plastic and also the beautifully milled 5mm thick ally shock towers. Standard models here will have “e” clips on their hinge pins but I have a Prospec with captured pins front and rear, except for the two clips on the front upper arm retainers, but they are in a place that’ll not be troubled too much and just a few clips on the whole truck is fine with me as I slip on the 2.7mm thick anti roll bar. Next comes not the long arm of the law, but the well braced long arms of the truggy, the PBS and the extended wheel hubs that make this Mugen the widest in its class by a clear 10mm. Another easy job done that lets me move onto the steering and the 5mm milled ally Prospec steering plate and upside down bellcrank fitted with bearings that’s going to be so easy to adjust should the need arise, but it also has an O-ring inside the adjuster to resist moving on its own and so it won’t require any thread lock to keep it in the right place and thus completes my front end.  

The rear end goes together just as easily and again has good bracing in the arms aswell as some semi-circular braces at the wheel ends for enormous strength where the stress levels are highest. The rear lower arm support is another ally part and matches the lovely gunmetal grey rear uprights before a 3mm anti roll bar goes on to aid stability. Do make sure you put your rear uprights on the correct way with the grub screws facing outwards and the wheel cleaner tab to the rear, get them wrong and you’ll notice how the ends of the CVDs are dangerously close to the end of the diff cups and running them like this will see them pop out and possibly chip the cups.

I’m now looking at assembling the centre diff unit and as I’ve already glued on the brake pads to their callipers, I can screw them straight onto the top parts of the diff casing, yes I said the top part as this appears to have topside access to the centre diff as a standard feature.