Vintage Thing No.42 - the Tonkin-VW Special

Another vehicle that I liked at the Launceston trial was this neat VW buggy entered by Ryan Tonkin. Its workmanlike appearance caught my eye and it had obviously been recently painted. I noticed a couple of tell-tale scrapes along the sills and, in talking with the crew, I discovered that it had already seen quite a lot of action, despite having only been completed the previous summer.

Ryan Tonkin bought it already converted into a buggy but substantially reworked it to make it more competitive. His passenger (sorry I didn't catch your name) showed me a picture on his mobile phone of what this machine looked like before the rebuild. It was certainly distinctive. Some would say it was cosmetically challenged. To me, it looked like the result of an unnatural act between an agricultural tractor and a submarine. I hope they get to see this blog and maybe they'll send me a picture of it in its original form. As it currently stands, it looks a whole lot better and is also substantially lighter.

Again, this is one of those vehicles that the more you look at the more you see and, through chatting to Ryan before the start of the event, I was able to learn about some of his other mods.

The first thing that caught my eye was the front disc brake conversion. Ryan designs programs for CNC machinery that has to have a well-equipped workshop just to make sure his software controls the hardware properly. Consequently, he made converting Volkswagen front axle to taking a disc brake sound easy but that is often the gift of the gifted. Although it's not a particularly good photograph, if you look closely you can see how close the bolt heads are the disc itself. Ryan had to skim them down to fit. I can't remember what discs and hubs he used but the drop of machining down the stub axle to accept the new bearings for the hub was a relatively easy job in comparison to get on the discs to physically fit into the space available.

The bodywork is all new and made a much lighter frame than the original structure, which, from their description, sounded more like ballast than anything with any strength. Compared to some buggies, the driving position is quite high up but visibility and comfort are major plus points.

I regret that I didn't question him much about the chassis but, to my eyes, it doesn't look as if it has the conventional VW floorpan underneath.

What I did notice, were the fancy looking dampers mounted on the rear bulkhead. These are adjustable air shocks from a high spec Range Rover. They are linked from side to side, not unlike the Hydragas system on an Austin Metro but the whole raison d'être is to keep both rear wheels on the ground much as possible. As the wheel on one side gets pushed up, the one on the opposite side gets pushed down. Combined with the rear engined layout, this makes a traction control system pretty well superfluous.

Then Ryan casually mentioned that he had done a similar disc brake conversion on the back and -- low, and behold -- there were the rear disc brakes. Again, he made that sound easy but then I suppose if you know you're doing then it is easy. I can't remember what these discs originally fitted but he did mention VW Transporter parts in passing.

Despite doing such a neat job on this VW buggy, which for want of a better name I have christened the Tonkin-VW Special, Ryan is no fan of VW engines. The present unit is a 2 litre with a vertical fan but Ryan has a Peugeot 205 GTi engine and gearbox sitting around doing nothing so it's only a matter of time before that gets installed. He reckons that at present there is too much rear overhang and a transverse powertrain will improve his performance even more.

In the meantime, he's made his own fuel injection system -- like you do -- using Rover 400 injectors. I think this might be a proprietary kit, possibly along the lines of a Megasquirt, but I find the idea of making your own tailor-made injection system hugely appealing, although a little daunting at the same time. I suppose the principles are simple enough and if you can do an Excel spreadsheet I don't see why you can't program the system. I can remember fantasising about fitting the fuel injection system of the then brand-new Kawasaki Z1000 to my Morris Minor. Starting from scratch actually sounds easier than trying to get the factory supplied injection and ignition systems to work in your special.

A 1970cc (94mm x 71mm) "suitcase" engine from a VW Transporter (with the fan on the end of the crank) puts out about 70 bhp and nearly 100 lb ft as standard with a 7.4:1 compression ratio and twin Solexes. In the VW-Porsche 914, the same engine put out 100bhp with fuel injection. Many people have disproved the age-old maxim that you can't tune Vee Dub motors but if you're not obliged to use them in your chosen formula of motorsport there are easier (and cheaper) ways of finding power.

Although Ryan didn't win the Launceston trial, I believe he had a good event. Certainly our little section didn't tax the Tonkin special very much. I'll watch out for him in other local trials and see if that Peugeot engine gets fitted soon.