Part 1

Its been a while since I gave an update on what has been going on since the season finished back in October. After a very successful season with the Radical and its little 1100cc engine, which was the smallest on the grid, I am aiming to go back next year but with the same car but with bit more of a sting in the tail.

At the end of the season we were running the Kawasaki 1100cc engine in the Radical which gives around 150-160bhp and 70ft/lbs of torque. With this modest setup I was able to get the car to lap Castle Combe in 1:09’s. A lot of this time was gained with setup of the chassis/suspension over the season.. So with that in mind for the 2007 I am going to leave the chassis setup as is and turn my attention to the power-plant. The main thing I need is a engine that is going to be reliable, this means that I am not looking to run stupid power that will require frequent rebuilds and cause lots of stress on the engine. As I’m concentrating on the Castle Combe GT’s again next season I am going to tailor the car to suit this championship.

This is where the fun beings, the plan is to replace the Kawasaki engine with a Suzuki GSX1300R(Hayabusa) engine. Of course in an ideal world I would be able to slot a new engine in and off we go. Alas it isn’t as simple as that, in fact the easy part is slotting the engine into the chassis as the mounts can be bought from Radical to do this. So half the job done then? Well not quite.

First of all I need to purchase a engine, after watching the classifieds it seemed that good stock engines were changing hands for around £2000 and upto £2500 with ECU, wiring loom and throttle bodies attached. As usual ebay came to the rescue and I located a complete bike for £3000 which I purchased and proceeded to strip down to its component parts. With the help of ebay I managed to sell on 95% of all the parts on the bike and in doing so generated a shade under £2000. This meant I had a engine, throttle bodies and wiring loom that owed me £1000.

So I am off to a good start here……the next thing to do is decide what specification engine I need. To decide this I looked at the performance of the car over the season to see where it was strong and where it could be improved. The biggest problem I had last season was punch out of the corners. In a number of races I was were able to match larger capacity cars through the corners but lost out on initial acceleration out of them. So first thing on the list is to improve the torque of the engine to provide enough thrust to push the car out of the corner and down the straight. Of course with more torque you get more horse power which is needed for top speed. The old engine ran carburetors, which did performed very well but fuel injection has come a long way in the last 10 years and this was something I wanted to employ on the new engine. The Suzuki GSX1300R comes with fuel injection as standard so the plan is to use the oem injection system on the new engine. Along with the oem fuel injection I are going to stick with the oem coil-on-plug ignition system. I have the option of running the oem Hayabusa ecu on the engine and retro fit a power commander, which is basically a piggy back ecu which allows alterations to the fuel and ignition map. I looked at doing this but decided to run a proper dedicated ECU to control the engine, I turned to the company that I used on the Elise for this called Emerald. Emerald’s support is second to none, they are always happy to answer any silly questions I might have and are always on the end of the phone/email. I contacted them and explained what we are doing, they made some useful suggestions with regard to running the engine. I had already purchased a ECU second hand but this had to be returned to Emerald to be upgraded to support the Hayabusa ignition system, this was done FOC which is a testament to their customer service.

So to recap I have a engine from a motorcycle with the stock injection and ignition system fitted. To drive the engine we have the Emerald ecu. Next step is wiring. I had a design of the wiring loom that included the ecu plugs, all the sensors required and the dash board layout. I thought finding a company to make the loom would be a simple task. How wrong, the initial companies I contacted considered the project to complicated and turned down the work. Running out of options I put a plea out on the internet forums and got a couple of recommendations. One of the recommendations was from a chap that I helped to purchase a Radical back in the summer, his uncle ran a motorsport wiring company. A email was sent off to Tim Mason Motorsport explaining what I wanted, almost by return mail I got an answer and he got the job. Basically I was ripping out all the old wiring and installing a new loom to support both the dash and the engine. There were some quirks with the Radical like the electronic reverse that had to be incorporated. I arranged to take the car up to Tim, once in his workshop we set about confirming the details. One idea was to remove the old mechanical cut out switch for something more reliable. Tim was already on the case and had designed a system using a relay. This system would give me a master cutout on the dash and the rear bulkhead for the marshals to pull. A number of other enhancements were added to the loom design and Tim set about working on it. About a week later I get a call saying the loom is ready and the car can be collected. Back at Tim’s workshop the loom is loosely laid on the car and it looks amazing (yes I know getting excited about a bunch of cables is a bit sad). Tim had also installed a proper gear indication device from Geartech that runs off the gearbox on the Hayabusa engine. The whole loom was a work of art, almost a shame to fit it to a car.

I am making progress, I now have an engine, ignition, injection and a wiring loom. Next step is the fuel tank, why change the fuel tank you ask? Well firstly I need to make some room so I can install the new ECU away from the engine bay. The standard Radical tank takes up the whole width of the car and holds about 45litres. As I am only running at Combe I decide to reduce the tank size down to 20 litres. I spoke to Spec-R based just south of Bath to do this work, I dropped off the old tank as a pattern and explained the new size required. With in no time I had a call from Spec-R saying the tank was ready for collection. I return to Spec-R and I’m greeted by this fuel tank that is about a 1/3^rd of the size of the original one. I ask a number of times if it is 20 litres and they say yes…..being the suspicious type when I get home I try filling the tank with petrol, and sure enough its 19.5L (half a litre taken up by the baffle foam). This new tank saves me a few Kg over the old one and also provides loads of room on the bulk head for the ecu and also space to install the new high pressure fuel pump.

Ok so I have now got a engine, injection/ignition, ecu, wiring loom and fuel tank. Things are starting to take shape.

With the new loom, additional switches etc I need to redesign the dash board on the car. I spoke with MVS Racing who provide all my carbon bits and they supplied me with a couple carbon sheets to use as the dash board. With the fuel injected engine I’ve added an additional switch for the fuel pump and also I need to accommodate a master cut off on the dash as well. I have also purchased a gauge for water temp as the old "needle type" had a real problem with the revs of the engine went over 7000rpm. I decided on a SPA dual LCD one like I’ve got for oil pressure/temp as this has been ultra reliable this season. I took the advantage of the redesign to move the gauges around so they are easier to read when on track. There are a few things I can’t do until it is back on the car and the engine in position but the dash is 90% complete now.

The final trip for the rolling chassis was up to GH Racing up near Rockingham Speedway for a new exhaust manifold. I had to change the manifold as the Kawasaki one won’t fit the Hayabusa engine. Radical wanted silly money for their mild-steal manifold and GH Racing was recommended to me. They set about preparing an exhaust that would provide good torque as well as out and out horse power. The finished article is again a work of art, all made from stainless steal and incorporating some excellent welding. The design is a 4-2-1 for torque and looks like it should produce the goods.

Now I am sure you’ve got to this point and thought….but what about the engine? Ok did you really expect me to install a completely stock engine? Really? Well you’d be right I am going to play with the engine. The idea is to build an engine that matches the characteristics outlined at the start of this project i.e. reliable power with a ample dollop of torque. How am I going to do this? Well you’re gonna have to wait for part 2 to find out.