| Super Twin21 Baja |
| When the Twin21 truck was complete, I had fun driving it around. Unfortunately all too soon I quickly found its weaknesses. Based on the chassis of a Ho Bao (Ofna) Hyper-7 buggy, the platform just was not strong enough to handle the weight (11lb) or power (pushing 5HP). This meant that I had to exercise a level of caution when driving the truck, which I did not like! I still ended up with a bent chassis, bent centre driveshaft, stripped rear diff gears (twice) and crumpled front transmission housing and bulkhead. All these from fairly minor incidents which would not harm a normal RC vehicle, so I certainly was not going to tolerate it in this 'super truck'. It became obvious that the 1:8 scale platform is simply too small to have proper stability with this power. Plus, I needed all-metal transmission housings to stop the gears de-meshing under high torque, which was the root of my stripped diff problems. This has lead to the development of the SUPER Twin21 idea. Too large for any standard lexan bodies to fit, even the one from the new AE Monster GT (yeah at �50 a piece too expensive anyway), it would have to be a home-made cage style body. That got me into thinking about TRUE off road racers, the Baja desert buggies that spawned 1:10 off roaders in the late 70s and early 80s. Design In keeping with my previous ethos, I had to design in many features you do not see on production RC vehicles. Now you can get twin-engine production models, I have to go 'one better'. No, not three engines :), but mine are now laid-down like a flat twin. This pulls the centre of gravity down lower than is possible when you stand the engines up, making me wonder why you don't see it done more, especially on 1:10 nitro touring cars which are obsessively designed for a low centre of gravity. |
| WHY BUILD IT? |
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| UPDATE 11-08-05 Its becoming difficult to independently update every page of the web site, so I will mostly place updates here for now. I have almost finished the project, at the moment all I have left to do is the enfgine cage and the body panels. Over the 20 months it has taken to build the buggy I have honed my ideas of what it is exactly going to be like. I have become more interested in it being like a true desert race buggy such as those produced by Jimco, as well as retaining the designed high performance levels. Since I started the project, lots of things have changed on the nitro RC scene. The Losi LST has been released which uses single shocks per wheel, which I believe is a good move. The Kyosho Giga-Crusher and Hot Bodies Lightning trucks have both come out with twin engine set-ups. And the Traxxas Revo with its huge suspension travel has been released. I still believe I am making the ultimate off-road nitro vehicle. The current twin engine trucks are too small for the power, and the Revo does not look right because it is too far from a scale model for my liking. Too much suspension, tyres too low profile and body too small in my opinion. Anyway, here's a pic of her almost done... |
| Almost finished Twin21 super buggy. What you can see: carbon fibre Baja impact bumper; 4" fluid damped front suspension; tubular brass hood section; 1/4 scale digital steering servo; independent cable operated 4-wheel disc brakes; twin fuel tanks and pressure lines; tube brass side pods with direct access to air filters and engine heads for cooling; carbon fibre tubular body with machined aluminium lugs - cab section hinges forward for access; twin Hyper-21 engines with central throttle servo; on-board glow; twin linear exhaust manifolds and twin RB Concept 086 polished tuned exhausts; 2 mm aluminium undertray. AUW: 15 lb, as predicted! |
| BAJA BUGGY FACTS AND INFORMATION Insane tube-frame buggies raced mainly in Arizona, Mexico and Baja California areas. These should really get more coverage on UK TV. When I first saw videos of these on the web I was blown away by the stuff they go over, and at mad speeds. The races are generally long, 250-1000 mile events over American desert terrain which is dry and sandy with lots of big ruts, bumps and jumps. I am talking about bumps and ruts big enough to fit a standard 4x4 vehicle into, none of your small crap. These buggies fly through this sort of terrain at speeds well over 100 mph! The buggies come in several different performance classes, top of the heap being the Unlimited Class-1 cars. As far as I can understand, they generally have engines running about 750 HP, 24-38" of wheel travel and 2wd drivetrains. They normally have live axle rear ends and independent front suspension. The construction is tubular steel for the chassis, normaly 4130 chromoly, with a number of different ways of doing the suspension. The best I have seen has to be the Herbst Truggy with welded steel monocoque lower arms and solid billet aluminium uppers - these look just like the arms on the project buggy. These cars are some of the coolest vehicles I have ever seen, RC models claiming to be 'Baja' just don't seem to convey this scale of awesomeness. The closest thing is the early Tamiya stuff like the rough rider, but they didn't exactly have the performance to match :) |
| GEN I CAR FINISHED! Go to the finished page here or check out the individual build sections <--- GEN II CAR DESIGN Starting the enhancements |