A new build always has issues.

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The first test of the Porsche 917 went really well. We had some small issues that we needed to sort out. One of the issues was bump steering. On the track, we tested there was a slight bump in the road just before the end of the long back straight.

Killarney International Raceway in Cape Town South Africa

When the Porsche 917 went over the dip it felt very aggressive and the car would snake. The cars behind the Porsche would say it looks like the car is bouncing around on the track. After some investigation, we found that the bump steer wasn’t set up properly. We also found that there wasn’t any droop on the rear suspension. What this meant was when the car went through the dip the rear wheels would lift off the ground and cause the snaking effect. This was as scary as hell.

The fix for that was to put in helper springs on the back. The helper spring is fully compressed under the weight of the car. When it goes through a dip the wheel would follow the ground. The only way to get a race car to control well is to keep the rubber on the ground.

First race event

We entered the Porsche 917 in a historic David Piper race weekend at Killarney raceway. This was a big event and race cars would come from all over the country to compete.

The Friday during practice my boss came in from the track saying that the car has fuel starvation issues through the turns. This was not good. The two fuel tanks were fitted with sponge blocks. This would stop the fuel from moving around too much. We also had a surge tank fitted that the two pressure fuel pumps would draw from. A Holley RED pump was filling the surge tank. All the flow rates were correct so I had to investigate a bit. With my boss driving in a bit more anger the issue showed its face.

After a while, I found the issue. The fuel return line was connected to the main tank and not the surge tank. The pressure pumps would lower the fuel level in the surge tank and it would suck air in hard turns. This would cause the car to bog out in the turns.

That was a quick fix. On startup, I noticed that the engine oil pressure light was on. I switched the engine off and had a look in the engine bay. The belt that drives the oil pump was laying on the floor of the engine bay. There was no pulley on the Morosso oil pump. My boss drove the car in from the track to the pit garage without any oil pressure.

The fix

Luckily I had modeled the pulley on our CAD software. I phoned my one friend that also worked with me and asked him if he would help me out with the machining of the pulley. This was already late afternoon and everyone at work has gone home. I met up with my friend at work and I gave him the CAD model. The pulley was done a few hours later.

I took the pulley back to the track. It was very late in the evening. I fitted the pulley onto the shaft and got the belt back on. It was round about 2:00 the morning when I started up the car. The engine was running smoothly and revved cleanly. I sent my boss a message saying the car was ready for the race.

Race day

We were early at the track in the morning. I wanted to do some last check before the care went out for Qualifying. Everything was good. The car went out and ran beautifully without major issues. We have noticed that the coolant temp would spike to 120 Deg C on the back straight but would drop as soon as you take the power off. We were happy to run the car like this and address this issue once back at work.

The Porsche 917 went out for its race, on the 4th lap the car came into the pits. My boss said the back end of the car became loose through the turns. It wasn’t driveable. He just couldn’t control the car. We jacked the car up and found the one rear wheel was loose. The wheel nut was torqued down properly but the wheel had a lot of play.

I took the wheel off and found that the driving pegs that keep the hub assemble together came loose and broke off 3 off the studs. The wheel was hanging on a thread. If my boss had continued the race like this he would have lost a wheel and had some big damage. This wasn’t something we could fix at the track so the car was out for the rest of the weekend.

We packed up the car and took it back to the shop where we would address all the issues we had.