Venturi capitalists

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

Current page

149

Current page

150

Current page

151

Current page

152

Current page

153

Current page

154

Current page

155

Current page

156

Current page

157

Current page

158

Current page

159

Current page

160

Current page

161

Current page

162

Current page

163

Current page

164

Current page

165

Current page

166

Current page

167

Current page

168

Current page

169

Current page

170

Current page

171

Current page

172

Current page

173

Current page

174

Current page

175

Current page

176

Current page

177

Current page

178

Current page

179

Current page

180

Current page

181

Current page

182

Current page

183

Current page

184

Current page

185

Current page

186

Current page

187

Current page

188

Current page

189

Current page

190

Current page

191

Current page

192

Current page

193

Current page

194

Current page

195

Current page

196

Current page

197

Current page

198

Current page

199

Current page

200

Current page

201

Current page

202

Current page

203

Current page

204

Current page

205

Current page

206

Current page

207

Current page

208

Current page

209

Current page

210

Current page

211

Current page

212

Current page

213

Current page

214

Current page

215

Current page

216

Current page

217

Current page

218

Current page

219

Current page

220

Current page

221

Current page

222

Current page

223

Current page

224

Current page

225

Current page

226

Current page

227

Current page

228

Current page

229

Current page

230

Current page

231

Current page

232

Current page

233

Current page

234

Current page

235

Current page

236

Current page

237

Current page

238

Current page

239

Current page

240

Current page

241

Current page

242

Current page

243

Current page

244

Current page

245

Current page

246

Current page

247

Current page

248

Current page

249

Current page

250

Current page

251

Current page

252

Current page

253

Current page

254

Current page

255

Current page

256

Current page

257

Current page

258

Current page

259

Current page

260

Current page

261

Current page

262

Colin Chapman was renowned for discovering the next big F1 thing — and the Lotus boss was a sucker for this particular idea, explains Gordon Cruickshank

Downforce without drag — the holy grail of Formula One aero experts. By the 1970s designers knew how effective a wing was in loading the tyres and boosting cornering speeds, but on the straights the effect was like towing a caravan. Driver-adjustable aerofoils could slash drag, but had been banned. This was the conflict which Peter Wright set out to resolve for Lotus in 1974.

Chapman’s team were floundering with its 76, and so he initiated a clean-sheet think-tank, with Wright at its centre doing after-hours sessions in the Imperial College wind tunnel — and if it hadn’t been a rolling-road unit he might have missed the signs. Under the panniers of the mock-up 78, the rolling rubber belt began to lift. Negative pressure was building. A breakthrough.

Tentative experiments with brush skirts fitted to the 77 had hinted at underbody effects, so with cardboard and tank tape Wright deepened the pannier sides, and the downforce soared. The figures were so profound that at first they didn’t believe them.

What came out of that was the Lotus 78 ‘wing car’, which opened everyone’s eyes. But Chapman knew ground effect had been lost translating the 78 into reality, and was determined to win it back. He was more closely involved with 79 than its predecessor, partly because the 78’s designers had both left, partly because he was excited by the new field. “Colin went on holiday to Ibiza,” remembers Wright,” pencilled out the whole thing and handed it to Martin [Ogilvie].”

Ogilvie and Geoff Aldridge were charged with turning Chapman’s scheme into metal.

“Colin took overall charge, for better or worse,” Martin says. “He would get his teeth into one thing, what he called the ‘unfair advantage’, and ignore the other factors.” The result was a conventional but narrow steel monocoque. Airflow through the suspension was crucial to the venturi, so the springs, dampers and rollbar links vanished inboard at both ends, and the exhausts were tucked up high and tight. Fuel tankage, in the sidepods on the 78, was moved behind the driver, pushing him forward, and oil and water radiators went in the sidepod noses. This left most of the sidepod free to form the venturi, the narrow-waisted tunnel which speeds up the air, producing low pressure and sucking the car to the road. Of course, if you allow air to rush under the sides the effect is lost: hence the skirts.

“Colin compromised the structure to leave the sidepods free,” says Wright, “but then nobody knew what the loads would be. We were creeping up on the skirt problem because we didn’t know what was allowed. It was only when Harvey Postlethwaite fitted sliding skirts to his Wolf and they weren’t banned that we realised we could go that route.”

It was these ‘board in a box’ skirts which closed the gap between theory and practice. With full-length sliding skirts instead of the 78’s short flexible ones, the 79 started to generate real suction. Chapman had his ‘unfair advantage’; true ground effect was born.

Testing showed snags — lack of stiffness and inadequate cooling air over the twin exhausts — which would dog the 79, especially in its second season. Nevertheless, Mario Andretti, more technically minded than team-mate Ronnie Peterson, was sure Chapman had scored another jump on the opposition.

With its elegant shape and JPS colour scheme, the 79 was dubbed ‘Black Beauty’ when it was revealed to public gaze. And its first race, the non-championship International Trophy at Silverstone, seemed to confirm the team’s hopes: Andretti put the new car on pole. Those hopes were washed away in a raceday downpour, when Andretti aquaplaned off while leading. But the American loved the planted feel of the car, and when Zolder came around, he sliced a whole second off the field to take pole. And the only guy tailing him was Peterson in a 78 — who despite stopping to change tyres, hoovered up the field for a Lotus 1-2.

It was the same in Spain, by which time Peterson also had the new car. Yet Chapman’s rivals had worked out what the underneath of a 79 looked like and were designing their own versions. Gordon Murray was the first to look like puncturing Chapman’s balloon; his BT46B ‘fan car’ out-vacuumed the 79 and won in Sweden. Immediately, Lotus R&D went into overdrive, working on a twin-fan car, one for each venturi; Chapman said later that if fans hadn’t been banned, he’d have had a fanassisted 79 ready by the British GP

But they were banned, which meant Hethel had a clear year with a car way above the rest. Yes, they also had two of the finest drivers, but the 79 showed how clean its heels were when, after Peterson’s death at Monza, Jean-Pierre Jarier, with no experience of the car, turned in the fastest race lap at Watkins Glen, then took pole and led at Montreal. With six wins and four seconds, Lotus stomped on Ferrari for the constructors’ tide.

But the response wasn’t long in coming — and from an unexpected quarter: Ligier. As 1979 opened, Gerard Ducarouge’s take on the venturi-car hit all the right notes before everyone else, and highlighted the 79’s basic flaw — that flexibility. ‘The 79 was never stiff,” says Ogilvie, “and the torsional strength almost halved after a couple of races as its rivets loosened. We had our doubts, but you just didn’t argue when Colin was on one of his charges.”

The French machine stood up to the high loadings far better than the Lotus, and Chapman’s ‘next big thing’, the 80, wasn’t ready (see page 136). Ligier’s candle burned out quickly enough, but by then Patrick Head’s Williams FW07 (“a stiff 79”, Wright calls it) had the baton. And last year’s cream-of-the-crop Lotus couldn’t grab it back. Worse, nor would next year’s Lotus.

Related articles

Related products