KITS AND PIECES

TAME TO INSANE, THE CHOICE IS YOURS

During the 1970s, Rhubarbs were a wellknown sports racing car on New Zealand race tracks. In total, five cars were constructed between 1970 and 1977, made by four good friends: Adrian and Roger Rimmer, Colin Smith, and Bruce Hancett. These guys loved cars. Each Rhubarb was an improvement on the one before. At the end of 1977, the four headed off on their big OES, trips that would include a strong bias towards motor sport. Adrian was the first to return after about three years, with Colin and Bruce following a few years later. Roger took 30 years to return, but, by the late 2000s, all of them were back in Tauranga hanging out together. Not much had changed apart from the addition of some bald spots and grey hair.

Last of the Summer Wine

Bruce Hancett’s wife refers to their group as the ‘Last of the Summer Wine’, and it was my privilege to spend a morning with them. Naturally, the guys shared stories about their good

old days, before we got on to the modern Rhubarbs, and how they came to be.

These Rhubarbs started with a trip to the Hampton Downs race track. While sitting watching the racing action, another good friend, the late Kevin Clark, suggested that they should get back into building cars. Nothing was done at the time, but the seed was planted. At the time, Adrian also owned a couple of MX-5S — a car that he believed was one of the best-made sports cars of modern times. It was not too big a jump from there to decide to build a car using the best of the MX-5 bits and some creative Kiwi ingenuity. There are thousands of MX-5S in New Zealand, which ensures a readily available supply of donor parts. On top of that, there is a huge aftermarket of go-faster bits that can be added to the car.

In 2012, a written-off MX-5 was purchased from a local panel beater and stripped of its body, leaving just the basic subframe that is connected front to rear by what Mazda calls a ‘power plant frame’. Right from the start, their intention was not to build just another Lotus Seven replica but something totally different. It was decided to build a strong, rigid space-frame chassis with the emphasis on safety, and which would comply with the Low Volume Vehicle Technical Association (LVVTA) requirements.

Using this as the starting point, Adrian and Bruce designed and built what can be best described as an ‘exoskeleton’ chassis, similar to what is used for the well-known Ariel Atom. Although, apart from an external chassis, the Rhubarb is in no way a copy of the Atom; the Atom is mid-engined while the Rhubarb is a front-engined, rearwheel-drive car. Even if you cross your eyes and squint real hard, there is no way this car can be confused with the Atom.

Simple as possible

Using the LVVTA’S New Zealand Car Construction Manual as the builder’s bible, they set about designing a kit car that would not only be not too challenging for its future builder but also use only one donor car, a car that could be bought for as little as $2K. The only parts that cannot be used from the MX-5 are the radiator, the fuel tank, the top wishbones, and the coilover shocks, all of which are supplied in the kit.

Right from the start, this car was only ever intended to be sold in kitset form. This was at the forefront of their minds as they created brackets and set up the chassis so that MX-5 parts could be easily taken off the donor car and attached to the Rhubarb. All the builder would need would be a bit of mechanical know-how and a few spanners.

Once the chassis was complete, the next task was to design the ‘ functional’ fibreglass panels to keep the worst of the weather out. This was achieved over many Saturday working bees when the bucks for the various parts were made and the moulds taken from them. Fortunately, the shed in which these cars are built is located on a very quiet back-country road, so many hours of wind-tunnel testing could be carried out in a practical way — using wind but no tunnel!

To maintain the illusion of a roadgoing race car, a windscreen was never considered, as it was deemed to be an unnecessary requirement that would add cost and complexity to the build, which they wanted to keep as simple as possible. There is, however, a wind deflector designed to keep the wind in your hair and the insects off your face.

The end result is a minimalist vehicle that a builder could easily adapt to suit his or her needs. Money saved by the body’s simplicity can be added to the important job of making the car go fast. With the huge range of aftermarket bits available for the MX-5, power can vary from 86kw to somewhere over 298kw — at which point, traction is purely optional. Not surprisingly, the boys at Rhubarb Cars believe that 298kw in such a light car is a bit over the top. With such a high power-to-weight ratio, it would take an exceptional driver to keep the rear wheels from constantly trying to overtake the front ones.

If a potential builder wants to see what is involved in building the car, then the Rhubarb Build Guide can be viewed at any time on the Rhubarb Cars website, rhubarbcarsnz.com. If this guide is followed in conjunction with the New Zealand Car Construction Manual, then there will be no problems with certification. Each of the four cars shown here sailed through certification with no hiccups. It is estimated that the cost to build these cars ranges from $25K to $35K, which includes the estimated cost of a deregistered NA or NB MX-5 donor car purchased for around the $2K mark.

Difficult decision

At the end of the interview, I was asked which of the four cars I wanted to drive. What a difficult decision. The first I decided against was the red car (186kw, intercooled-turbo Mazda 1.6-litre) of Roger Rimmer, because, with its fully enclosed body, it seemed a little overdressed compared with the others. Which left the three exposed exoskeleton cars.

The next to go was Adrian Rimmer’s black car (198kw, 3.0-litre Honda VTEC), mainly because the thought of keeping a 3.0-litre V6 on the road made me nervous. Also, not being a Mazda, it was not a typical example of what most builders would construct. I asked Adrian why he’d chosen the Honda engine. He said that he did it just to prove to himself that it was possible.

Which left the blue car of Colin Smith (164kw, supercharged Mazda 1.6-litre) and Bruce Hancett’s grey car (239kw, intercooled-turbo, Mazda 1.8-litre). In the end, I chose the grey car. The theory was that, if I was going to be scared witless, I might as well do it properly.

With Bruce in the co-pilot’s seat, I headed off down what can best be described as a typical New Zealand country road. It was narrow; windy; and, thanks to its regular use by milk tankers, a bit bumpy in places, especially on corners. Bruce told me that any buyer who has any doubts about building a Rhubarb will have them blown away, literally, once they drive the car.

Having driven the car, I can fully understand that sentiment. The wings on the front and back are there for a reason. Almost immediately, the racing experience of the vehicle’s designers is evident. These cars are very well set up. I hopped into the car expecting to have a few collapsed vertebrae and the fillings in my teeth fall out, due to the car’s stiffness and rough ride;

In the end, I chose the grey car. The theory was that, if I was going to be scared witless, I might as well do it properly

instead, the suspension absorbed all the nasty bumps, and it was quite a comfortable car to drive. Having driven a supercharged Jaguar XKR a couple of days earlier, I found the difference between these two cars extreme. In the Jaguar, you are closeted away from all the harshness of what is happening around you, but, in the Rhubarb, it is like being in a four-wheeled motorbike, without the need for a crash helmet.

It is a totally raw and visceral experience. The sensation of speed is pure and in your face. As I moved the steering wheel, I could see the wheels turn in front of me. I had no idea how fast I was going, as I never took my eyes off the road in front of me, not even for a split second. Bruce was chatting away in the seat beside me, but I had no idea what he said, as I was enjoying myself too much to listen. The car simply obeyed my every input without hesitation or drama. I have driven many MX-5S — this was so much better. Somehow, they have not only improved its handling, but they have also given it supercar performance as well. Anything it lacks in the creature- comfort department is made up for by adrenaline-pumped exhilaration.

Pulling back into the driveway, sporting a very different hairstyle, I felt I could honestly say that the guys at Rhubarb have done what they set out to do — build a car that would be as much fun on the road as on the track. This is a car built by enthusiasts for enthusiasts. It is an ideal car for those who are starting to feel a bit fragile on their motorbikes but do not want to lose out on that weekend drive experience.