STP Paxton Turbine Special

Browse pages
Current page

1

Current page

2

Current page

3

Current page

4

Current page

5

Current page

6

Current page

7

Current page

8

Current page

9

Current page

10

Current page

11

Current page

12

Current page

13

Current page

14

Current page

15

Current page

16

Current page

17

Current page

18

Current page

19

Current page

20

Current page

21

Current page

22

Current page

23

Current page

24

Current page

25

Current page

26

Current page

27

Current page

28

Current page

29

Current page

30

Current page

31

Current page

32

Current page

33

Current page

34

Current page

35

Current page

36

Current page

37

Current page

38

Current page

39

Current page

40

Current page

41

Current page

42

Current page

43

Current page

44

Current page

45

Current page

46

Current page

47

Current page

48

Current page

49

Current page

50

Current page

51

Current page

52

Current page

53

Current page

54

Current page

55

Current page

56

Current page

57

Current page

58

Current page

59

Current page

60

Current page

61

Current page

62

Current page

63

Current page

64

Current page

65

Current page

66

Current page

67

Current page

68

Current page

69

Current page

70

Current page

71

Current page

72

Current page

73

Current page

74

Current page

75

Current page

76

Current page

77

Current page

78

Current page

79

Current page

80

Current page

81

Current page

82

Current page

83

Current page

84

Current page

85

Current page

86

Current page

87

Current page

88

Current page

89

Current page

90

Current page

91

Current page

92

Current page

93

Current page

94

Current page

95

Current page

96

Current page

97

Current page

98

Current page

99

Current page

100

Current page

101

Current page

102

Current page

103

Current page

104

Current page

105

Current page

106

Current page

107

Current page

108

Current page

109

Current page

110

Current page

111

Current page

112

Current page

113

Current page

114

Current page

115

Current page

116

Current page

117

Current page

118

Current page

119

Current page

120

Current page

121

Current page

122

Current page

123

Current page

124

Current page

125

Current page

126

Current page

127

Current page

128

Current page

129

Current page

130

Current page

131

Current page

132

Current page

133

Current page

134

Current page

135

Current page

136

Current page

137

Current page

138

Current page

139

Current page

140

Current page

141

Current page

142

Current page

143

Current page

144

Current page

145

Current page

146

Current page

147

Current page

148

The first of a new series in which senior racing car designers nominate a machine they didn’t design, but which they admire either for technical ingenuity, elegant simplicity, or sheer results

Ask me to name a car I’d like to have been involved with, and I’d go for one which was almost before my time — the STP Paxton Gas Turbine car which ran at Indianapolis in 1967. Parnelli Jones would have won in it — it led for most of the race until a few laps from the end when a small bearing failed.

It was a very interesting car which only appeared once, in that race. I believe it was designed by someone called Ken Wallis whom! never heard of again — I don’t know what he did after that Its design was unusual in that it had a central backbone chassis with a cruciform front and rear part going round differentials at the front and at the rear for the Harry Ferguson FF four-wheel-drive system. The gasturbine engine was on the left side of the backbone with the driver in a pod on the other side, and there was a bulky but minimalist body which coveted all the mechanical elements.

I liked it because it didn’t follow convention, it took a different route and they got it right. But for that bearing it would have won. The layout of the car was completely different, yet they managed to make a success of it.

The following year STP commissioned Lotus to do a turbine car, and Chapman produced a much more conventional design, the 56, with the turbine behind the driver in the conventional mid-mounted position. It was revised for Formula One, too, as the 56B which Fittipaldi raced in 1971, though he wasn’t very keen because it was a heavy old beast and wasn’t really that competitive. But! liked the first one because it was the path-finder; it was very bold at that time to choose a turbine, four-wheeldrive and that unusual layout Indy suited it perfectly because gas-turbines are best as constant-speed devices, and Indy is closer to steady-speed racing than anywhere else. Of course you could tie a turbine to a CVT (continuously variable transmission) which would keep the engine at a fairly constant speed and let the transmission deal with the variations.

But I think the other thing which probably helped that car is that at that time there was no real equivalence formula between a turbine and a normal piston engine. I think the following year there was some sort of inlet area restrictor on the turbines, but on the car Pamelli Jones drove there was no restriction. I seem to remember a number like 550 shaft horsepower — not necessarily an outstanding horsepower level compared to the piston engines it was running against.

By the nature of the centre spine layout you’re not going to have a high cross-sectional area, and the longitudinal torsional stiffness depends on that, so it isn’t a structure you would choose if you were going to put everything in line. But Wallis could see that the power unit was pretty long, so the whole package would be too long if he put in in line. Once he’d decided to put the engine on one side and the driver on the other, it was logical to hang them each side of a backbone.

I read an article at the time showing how the backbone chassis was at first made of welded stainless steel, but when they heat-treated it it went like a banana; then they got sensible and made it out of rivetted steel and aluminium.

It had almost identical suspension at all four corners — twin wishbones with outboard springs and dampers, and a steering rack and arms at one end and an equivalent fie-rod at the other to lock the steering. I believe it had common hub carriers, hubs and suspension members at each corner too. I suppose they felt that the performance was going to come from the turbine engine and the 4WD, and they wanted to keep the rest of it as simple as possible.

As to cars my designs competed against, I always used to think that although Gordon Murray was not necessarily that interested in the deeper, inner engineering of the cars, he always used to produce very elegant, logical designs. Given the engine they had at the time, the BT5 3 was a very neat, logical car to benefit from the enormous power of the BMW and the fact that it tended to be rather brutal. It was an unusual design that put much more weight over the rear axle than most — very appropriate for the engine’s characteristics. A very neat, clever, simple little car. There were a few of Gordon’s cars that I used to look at and think they were well thought out.

When I started at Lola, there tended to be a much greater diversity of layouts of racing car, and I was involved in a few which were a bit different in my early days. Mind you, the things that departed most from the standard theme were probably the least successful. Nowadays you have a pretty standard layout so you don’t get the opportunity to do anything different.

Just before my time they were doing 4WD Indy cars, and I remember Al Unser Snr telling me that his 4WD car had about 1000hp for qualifying, and of course it had no wings on it. He went over some oil and all four wheels lit up — he had wheelspin on all four wheels! Which with no downforce is not surprising with all that power — must have been quite interesting to drive.

But the layout of those 4WD systems was pretty interesting: when I went to Lola we were doing CanAm cars and one or two unusual Indy cars, so there was more variety than now, but by the mid-Seventies the classic layout of driver, fuel tank behind him and engine behind that had become totally established. Now designers have much less opportunity to have a go at challenging layouts and dealing with unusual problems.

Patrick Head was talking to Gonion Cruiduhank