The car is being built on the shell of a 930 Turbo race car. It already has a roll cage, up-rated brakes, a fuel cell and nice suspension. Its bodywork looked tired but this doesn't matter to us as we are taking it all off. Clearly this will be a more efficient way to the ultimate RSR recreation than starting with a bare tub.

The panels are being fitted to the car at this moment. When we have made some progress we will post some photographs.

The engine is at the engine builder and we have found an original kkk turbocharger. The turbo is similar to the ones used on Caterpillar diesel engines; it is huge. We expect to have about 600 horsepower though we could up this at the cost of reliability. Pectel engine management will provide the control we need. We plan on being able to switch power between road and race and possibly wet settings.

The plan is to try and get the car ready for the Porsche open day at Hedingham Castle on Sunday 7th June, although building a race car from the ground up in only six weeks is a tall order. This is an exciting project and we hope you will keep abreast of developments.

We may have written a little about this before but let's cover it in a little more detail. We have just commissioned it, so this is how it is supposed to work:

- The lift pump sucks fuel out of the tank and fills up a swirl pot.

- The swirlpot allows a constant supply of fuel when the car is generating high G forces. The pick up point in the fuel tank will run dry during high 'G' forces. Cornering being the most common place to have the engine die due to lack of fuel.

- Two high pressure pumps suck the fuel from the swirl pot. They can generate 100psi of pressure. Thats enough to shoot a geezer of fuel on the ceiling of a race shop. We know; it just happened. The fuel pressure regulator was on back to front. More of that in a para.

- The high pressure pumps push the fuel around to all the injectors. Which in turn feeds the car's throttle bodies. However it is quite possible to generate too much pressure and the fuel pressure regulator has a bypass valve that returns unused fuel back to the tank.

Why have we told you all of this? Because it's not quite perfect. Currently it's providing 6.6bar of pressure and we need only 6bar. Though this might change when we actually run the car. It may be the case that we need to use fuel pressure regulators.

The good news is that the fuel pressure guage works. It was this guage that indicated we might have a problem. With the regulator mounted backwards there was no flow of fuel and the pressure was building up to very dangerous levels. Anyway, all is resolved. It shows the necessity for careful commissioning of each system.

Every job completed is one more off the list. A few days of attending to little tasks shortens the 'to do' list very nicely. Though each one inevitably takes a lot longer than planned. For example making the engine's air-box took ages. A V12 engine is longer than most and finding an off the shelf air box was not possible. Eventually we had the notion to try and convert the nose cone of a dragster. It's the right shape and material and in theory it's a lot easier than starting from scratch.

One can be wrong from time to time. In the end, we have had to cut and bond and re-cut and reshape this wretched dragster nose so many times we don't even know where we began. The damn thing fits now but it needs to be given lots of attention to make it look as good as it should. If anyone offers to make you an air-box then accept gladly.

The car loom is now in, though the dials are not all connected. The fuel pressure guage has been run into the fuel system. We need a number of sender units to talk to the instruments. These will come shortly. The engine loom is next on the list.

Talking of the engine the throttle return springs are attached in such a way that they fly off. It would be disconcerting to have 620bhp pushing you along just when you don't need it. We now need to create a new throttle return mechanism. Another small job that will take longer than expected.

The radius arms that connect the car to the uprights are complete and installed.

A new roll over bar has been fabricated and welded in. The new roll over bar carries a number of braces that stiffen the chassis. Incidentally also improving safety.

The fuel system is complete and has been dummy fitted. It must all come out and be put back in more permanently. Braided fuel lines with dry break couplings. A dry break coupling allows us to drain the fuel tank and replace only the fuel we need for the task. Every litre has a detrimental affect on lap times.

At some stage we will have to tackle the gearbox. It is a new box and we don't know what gears are in it. More importantly we don't know what crown wheel and pinion it has. This determines the top speed of the car. The lower the top speed the greater the acceleration. Vanity may say that 260mph sounds cool. Good sense tells you that if the top speed of the circuit is 150mph then one is better off with the improved acceleration. Gearing on a car with such a narrow power band is essential. If the gap between each gear is too much the engine won't manage to pull the car along. Slide rules and graph paper required. Patience too.

Fuel tanks templates have been made and the tank will be created from this in a little while.

One wheel seems to be porous, though this might be a hole in the tyre. Sods law might come into play.

This has come on enormously over the last few years. Now there is no need for that bush of wires in the back of a dash. Well not if you know what you are doing. We don't, so we leave it in the hands of someone that does. Though we do appreciate good work. It takes a long time to make a loom this neat. If you look behind the dash now you barely see anything. Not only is this neat but it cuts down on the potential for fires.

The corners are now on the car, though we still need to connect brakes etc.

Drive Pegs

Whilst we were taking the front wheels off we noticed that the drive pegs had all but been obliterated. The drive pegs keep the wheels attached to the brakes. Without them there would be no front brakes. Over 70% of the braking force comes from the front. This could have been a disaster. It looks like we were down to a few laps from certain catastrophe. Races are won by putting the brakes on at the last moment. There's little room for brake failure. We have uprated this component to cope with the strains.

Exhaust Pipe

The exhaust pipe is starting to get fabricated. We wanted a pipe that looked period correct. There are plenty of excellent exhaust people who can bend pipes. There are very few who can make a pipe that tapers into a megaphone from the header back. Dave Tylor is the 'snake-charmer' of choice for many of the top racers in England. Though it does take him a year to get you a system, and then it will take plenty of fettling to fit in the constricted space we have.

The throttle bodies on the new engine are vertical and this has meant that they collide with some of the rear bodywork just bellow the rear screen. We have opened up this part of the body to accommodate the new engine.

On the subject of new engines.. Arghhh. Our new engine has emulsified oil in the crank case. This indicates that there is a water leak into the block. We will report more when we know.

The chassis has been placed on a flat plate. The plate is marked out with a grid. In this way you can easily ensure that the car is squared up correctly. The corners are in the corners and the engine is in the centre. Sounds simple. Get this wrong and you spend months trying to work out where it went wrong. Is the engine in straight? are the pick-up points for the suspension out of true. Eventually you don't know if you turn around a wheel and it's standing still. Or the wheel turns and you're standing still.

Time on a computer can cut the process shorter. But, computer time isn't so cheap either. We decided to plot the suspension geometry on the computer and thus get the car in the correct ball park for a set up. While we are doing this there's plenty to be getting along with.

The fuel system operates on 5bar of pressure. We are told this is enough to slice your finger off. We'll believe them. So we need to make a collector that can carry enough fuel for a long corner. Fuel tank surge can drive the fuel away from the fuel pick up and the car runs lean. A tank that is slender and upright is less prone to this problem. The fuel gets to the collector tank with a lift pump. You will have head these going tap, tap, tap. After the collector the fuel goes to two high pressure pumps. These whirr in a sporty way. And from here to the fuel rail. Lastly a fuel pressure regulator returns any unused fuel back to the tank.

That was easy, now lets squeeze all that into a space not large enough for a box of cigarettes. Not large enough to squeeze the hand of a double jointed child. There's no room for a wallet in the P4. Good thing too because by the time we have finished this there will be no funds left to spend.

- Special projects
- Rebuilds
- Development

My P4 has had ten hard years of racing and a lot of development. It is time to do a full rebuild of the rear end of the car and incorporate all that we have learnt.

What have we learnt?

Suspension

Primarily this: wishbones are not ideal on a car with a chassis of this type. The very wide tyres have sufficient grip to cause the chassis members to twist. This is bad for two reasons. Chassis flex is uncontrolled by the suspension. It makes the car unpredictable. The other more pressing reason is it causes the chassis tubes to snap. We had noticed a drop off in lap times using identical set ups for the car. Either my driving was degrading over a few dozen laps or something in the car was flexing badly. An inspection of all the chassis tubes showed that over 50% had fractures in them. Either we go back to skinnier tyres or we change suspension set up.

P4 suspension & engine rearshot
In period the cars used radius arms. The arms locate directly to the back of the tub. This means that the forces are transferred away from the chassis at the rear of the car. It seems whenever we develop something on the P4 we are better trying looking hard at what the original engineers did. So we chose to rebuild the rear of the car with radius arms. Apparently they take a lot of setting up to get right. Though they are very good when this is achieved.

Whilst we we're taking the rear of the car off, the oil system has been removed along with the cooling, the brakes and relevant piping and the wiring. We figured that keeping these things was stupid when we were taking so much of the car apart. A small electrical fire might write off a few hundred thousand pounds of development work. The car did catch light once, albeit briefly because the marshals put it out. That was caused by a fault in the wiring.

Engine

Why do all this work to the chassis and not try for more power?

So we located a V12 F1 engine with 619bhp at 11,000 revs. Enough about lineage. Suffice to say that it's bought and paid for legitimately. The engine needed a full rebuild which was done. We don't need air valves and they are a little unreliable. We have spring valves and they are perfect for our purposes. It's a very compact engine and a 3.5ltrs. This is going to be it's Achilles heel. A well tuned Lola T70 has two or three times the torque. This matters because it's torque that gets you through the rev range and thus it's critical for acceleration. We will need to be spot on with our gearing if we are to liberate all that horsepower.

Gearbox

The DG300 is on the upper limits of its ability with 400 ponies. The jump in performance is not going to suit it. We will keep an eye out for an upgrade. Perhaps and DGZ or an LG600.

Rebuild time

Taking a car apart will take about 1% of the time it takes to put back together again. Gravity is a free labourer. Precision is not required. Wiring can be clipped and pulled out. Suspension cut off. Reducing a racing car to it's few major components is easy.