I have posted this thread on a couple other forums, but I felt like it would be a good addition to RCTech as well. I see this build not only as a resource for those of us who use our RC's for both racing and bashing, but as a kit building resource in general, with basic info about shimming, trimming mold flashing from parts, use of cap head screws in critical areas, etc. For most on this forum, this may seem like basic knowledge, but I have seen so many poorly assembled cars over the years with linkages that would bind, tons of stripped screws, and arms that would flop forward and back when turning, and I thought this would be useful for people who don't really know the basics of kit building for racing and bashing. And being a budget minded build, this build started out with a used buggy purchased from a user right here on RCTech. I also hope that this build can persuade more people to buy used RC's, it seems that many people think buying a used RC is a huge risk and it's better to buy new, which in some cases it is, but in my opinion its always good to look into buying a used RC car instead, especially if one is on a budget, they can afford a nicer RC just by buying a used RC. I also wanted to prove with this build that high end 1/8 buggies are not just for the racing crowd, they make excellent weekend bashers and they are so much tougher, better handling, and longer lasting than a vast majority of vehicles out there marketed to the bashing crowd. So on that note, here it goes....
So as a racer and basher, I demand quite a bit from my RC’s. They need to be tough, but they need to handle well at the same time. Many of us know that this really isn’t easy to achieve with alot of the current offerings for RC’s out there unless you want to drop a ton of money on a high end 1/8 kit. Well I decided I wanted a high end 1/8 kit but didn’t want to pay the price, so I’ve stuck with older cars, like the Mugen MBX5 series. My race truck is a Mugen MBX5T that I’ve built up to be lightweight (weighs in at around 9 pounds 5 ounces ready to go without fuel, only a little heavier than many of the newest generation truggies), and I’ve got it setup to where it handles good and matches my driving style. Problem is, it’s tough, and I end up bashing it too, which tends to making it sloppy or break something and then my race truck is down, so I needed something else……
After watching some youtube videos of 1/8 buggies bashing, I figured what better platform for a super tough, great handling bash car than a 1/8 buggy. The short arms of a buggy still have the same beef as the truggy counterpart but alot less leverage on them in a crash, and lighter overall, which adds up to a tougher car. I browsed the RCTech for sale section for a while and came across a deal for a Mugen MBX5R converted to electric with some extras for $125 shipped, so I jumped on it. Didn’t really know what to expect because the pictures weren’t very detailed, but when I got the box my jaw hit the floor, it weighed in at 34 pounds and cost the guy almost $40 to ship. Opened it up and it looked like I had been sent his entire Mugen buggy collection, easily over $1500 worth of stuff (and probably $200+ of that just in spare suspension arms, tons of Mugen Prospec parts and King Headz parts NIP and enough spares to build 3 more complete buggies with plenty of spares to cover breakage). The buggy itself that came with all of this stuff was in need of some TLC, and I wanted it to be nitro (I love brushless but always have better luck with nitro, so don’t hassle me to convert it again or ask why I didn’t run brushless!), so I figured the best plan of attack would be to rob some parts off the current buggy and build up another one from all the brand new parts that I got with the deal.
This buggy will be built with lightweight parts (lots of CF) and aluminum strength upgrades from King Headz, Fioroni, and Reckward Tuning. The reason? Reduce the weight to help increase the strength. Get rid of excessive beef where it isn’t needed (like the servo tray and steering top plate and center diff top plate, which come stock as aluminum and I am replacing them with CF) and replace with light weight parts and keep the beef/add more where it is needed (like lower hinge pin supports and such), and still have a fuse to prevent worse damage in a bad crash in all the needed areas (like some plastic parts). Everything will be built like the buggy will be raced, meaning shimming everything that needs to be shimmed, de-burring the plastic parts where they break away from the mold tree, properly shimming the diffs, getting the linkages setup to be as efficient and smooth as possible, and get the handling dialed in. For the setup (like link positions and such) I am going off of a combination of Mugen’s stock setup sheet for the MBX5 and MBX5R Prospec (the MBX5R does have some slightly different parts and this is a 5R so thats why I am using both setup sheets to get 1 baseline setup). There is nothing extraordinary here that the average guy with a 1/8 buggy can’t do, as I am not going to have any custom made parts on this buggy, everything can be purchased for this particular buggy, and really the same applies for most 1/8 buggies out there because of similar design.
Here are the details for what running gear it will be getting….
Engine – Werks B5 (was planning on using my old Picco P3-28 but you’ll see why that changed in the pics below)
Servos – ACE/XP DS1015′s on throttle/brake and steering
Radio System – Futaba 3PM 2.4GHz FASST
Rx Battery – Protek 1700mAh LiFe
Fuel – Byrons 30%
Now for the pictures….
The MBX5R that I bought next to my MBX5T (5T has a broken front lower arm, don’t mind that),
And of course, the mandatory nude picture!
Previous owner of this MBX5R must have been an amateur machinist like myself as the chassis that it was on had been pretty heavily machined and didn’t seem like it was machined in the right places for use with a nitro setup, so that chassis went into my aluminum scrap. This picture shows some of that, along with the Elite RC MBX6 motor mount and Tekno battery tray
Here is why plans changed on using the Picco P3-28, and I just want to note that it was still running, and I thought I better check it out just in case before I put it in the buggy and I’m glad I did. Must have been a factory fluke or something, but the rear bearing failed and was letting the crank slop up/down/side to side, exactly what it shouldn’t be doing, and it was enough to allow the piston to come into contact with the head button. Amazingly though it was still running, but I think it’s just going to be used for mock up purposes now, no sense in going through the trouble of putting it in the buggy if eventually it’s just going to grenade.
Tear down of the (filthy) MBX5T. Took the Picco out, and removed the servos from the MBX5T’s servo tray and put them in one of the brand new CF trays that came with the MBX5R.
MBX5R chassis torn down. front and rear assemblies removed, center diff and motor mount removed. You can see the parts from the completely disassembled Picco in the upper right corner. Also note the machine work done to the chassis by the previous owner, definitely not up to my standards and it looks kind of hack and I thought the chassis felt way too flexible when the buggy was still together, so it’s getting a lightly used factory replacement.
Just wanted to show these off, a brand new unused set of aluminum center diff mounts, I believe they are Mugen Option parts, as I’ve never seen a set before, but I am wondering if they are aftermarket because the anodizing color isn’t the same as any of the rest of the Mugen parts. I am not using these for this buggy build because they are a little too nice to throw in a basher and I plan on machining them to make them lighter and use them in another build eventually. But they are really nice so I figured they’d make some good eye candy for the build thread. Anyone out there happen to know what brand these are?
Then I started putting things back together… got the front bulkhead put together with the diff (brand new diff, filled with 4K weight fluid) and got the diff shimmed up. Put it together with the Mugen stock #0 front hinge pin support (optional ones include a # -1 plate which drops the front kick-up angle of the arm down, also known as anti-dive). For the front lower block (the one in the picture below) I started with a King Headz 1°, but I think their machining must be off, as you can see in the picture below it made the bulkhead sit off of the chassis. I compared this chassis to a couple others I had and it is not bent, so I swapped the King Headz front lower block for a Fioroni 1° block and everything sat down on the chassis like it was supposed to -
Here it is now with a brand new front shock tower on, and the Fioroni 1° front lower block, which let everything sit like it was supposed to down on the chassis.