17-9-76 Stobilisers Air so sor elinection trumpets rolle en protection built in) Rect YonS Trim teb Full harness safety beit Mirrors Bottom part of lameproof headgear low profile tyres Radiator inteke Flexible call Spring fuel tanks amper uni built in Front suspanslo wishbon Trim tab ¿Stabilisers Racing cars are designed to go as fast as possible. and today's machines are the result of more than 70 years of development. The main limits on the design of the Formula 5000 machines which will race at Wigram tomorrow are the size and derelopment the engine and minimum weight of the car. The engines must have a capacity of no more than five litres and must be standard production blocks with overhead valves-no overhead camshafts are allowed. But with fuel injection. special pistons and other refinements these units produce more than 500 brake horse power, and the object is then to transfer that power on to the road with the minimum of heeispin. The 15-inch rear tyres ("slick," or without tread for the day, treaded for the wet) give the cars remarkably good traction, but the grip is improved by the "prings" at the front and reat. The most pervasive influence in design recently has been the increasing awareness of the need for aerodynamic efficiency, and few racing cars are designed without the help of wind-tunnel tests and computer aids. As air passes over the wings, pressure builds up and forces the car more firmly on to the track, improving traction and stability. Infinitely adjustable trim tabs are used, and because of the similarity to aireraft practice, aircraft engineers are often recruited to design the wings and tabs. Because of the design of the all-independent suspension, the cars hardly roll at all during cornering. The car in the photograph is cornering very hard, but the only indication is the compressed right spring, and the extended left spring. The soft rubber compound of the tyres helps them hold on to the road, but the dividing line between traction and a slide is so thin that if a driver "loses it" the car almost inevitably spins. Because of the low centre of gravity the car is most unlikely to roll over, unless the wheels hit a kerb. The designer aims for the smallest possible frontal area to limit air drag, and, as the tyres cause the most air disturbance, most cars run fairiy small front wheels, with tyres of very Iow profile. Tyre development continues, but the aim is always to put as much tyre surface as possible firmly on the track at all times. The efficieney of acceleration, braking and cornering denends on this. Traffic routes Traffic arrangements for the Lady Wigram meeting will be slightly different from previous meetings. The main difference is that the Main South Road Enttrance to the public carpark on the north side of the circuit will be closed. Rather than have all northlemn traffic coming over the Sockburn overhead bridge, the Ministry of Transport re- ¡ quests spectators from the city and north-west suburos to use an alternative route. which will be clearly signposted. 'What we are trying 1o avoid is all the traffic converging on the Main South Road and Symes Road," a Ministry of Transport spokesman satd. Hence traffic travelling along Blenheim Road and the Main South Road • are requested to turn left into Watis Road. across the railway line. then right into Mc- : Alpine Avenue. right again ; into Haytons Road, then via Washbournes Road to north carpark. Spectator traffic irom the I south may either continue past the main gate, and turn right into Symes Road, and from there to the north caripark. or should tum from i Springs Road. right into Awatea Road to the south-west carpark. South-east suburbs traffic may come trom Lincoln ¡Road, up Annex Road and ileft down Wigram Road to the south-east carpark, into one of the other carparks. No clear favourite for Lady Wigram By RUSSELL JONES) The man to beat in the Lady Wigram airfield circuit tomorrow is Bruce Allison. in his first year of Formula 5000 racing. Trophy Race on the a young Australian Allison, who _Max Stewart, who won atiproved reliable. so Recinan driven his Lola T332 in-l Manfeild and led the Grand should expect to be among second and third Prix for a time, has, accord the first few to finish. And to ing to: Brian Redman. theihe, ton. could win. places in the first twel only fully-sorted Loia T400 rounds of the Peter world. Stewart has! Advantage Stuyresant series, leads offered to let Redman do al Of the other competitor: the other drivers by one few laps in the car during: Ken Smith will be trying the practice, which should be in- ¡hardest. His Lola 1332 hapoint. teresting. proved reliable and his wir However, he is unlikely to in the Grand Priz has given at Could win Thim an enormous psychologibe the fastest driver Wigram. Graeme Lawrence. the тасе. Stewartical advantage in the series the 34-year-old New Zea-should be among the first He knows he can min lander who iron the Tasman three, and will be driving to Wigram. series in 1970. and Kevin Bartlett and Paul close second last year, was albe there at the finish. Fle could well win. Bernasconi (Australia) canthe Pukekohe and Redman. on the othet|not be discounted, although rounds of this rear's semes hand. whose Chevron Be their performances so far before mechanical troubie gives away three litres to bave not suggested a winput him out of contention. the F5000 cars, is an expertining edge. Jim Murdoch. Lawrence needs to win to-jen last circuits and can be from Southland, was fifth in fast circuits and morrow to hare any chance expected to drive to the veryithe Grand Prix, did not start of winning the champion limit of both his, and • histar Manfeild, and has worked to car's, capabilities. The BMW see him set one of the fast-!engine in the machine, nich Sego 018. He will drive as est times in practice today, has titanium connecting rods hard as ne knows now. but if not gain pole position. 21900 a set. has!so far has not convinced anyone that he is capable of Wigram changes Tito important change. have been made for the running of the 1976 Lady Wigram Trophy race meeting at Wigram tomorron. The pits, which in past years have been on the infield near the start-finish, have been moved to the outfield just past the hairpin. This position will be more convenient for the drivers. and should be safer. The other change the Motor Racing Club has made is to begin all races, rather than just the trophy race, with a rolling start. pace car will lead the field around the track slowly, and will put ot just belore the start line, where the cars will be flagged away. Rolling starts cause a lot less wear and tear on machinery and should lessen the chances of major incidents in the first two corners. Spectators around the circuit will appreciate the chance to see the cars travelling at a relatively slow Ispeed on the paced lap. winning. If it rains, of course, Redman will become the favourite. but many of the drivers showed commendable steadiness in the wet at Mansfield and the Englishman would have to work hard to win. No matter who wins the trophy race, it is safe to preevents most exciting racing seen in New Zealand. Allan Moffatt's Cher :Monza must be one of the favourites, but anyone who overlooks Jim Richards in the Sidchrome Mustang will do Iso at their peril. And Leo Leonard will 'be right there with them. Marte Many people will be disappointed that motorcycles are running this year. and remains to be seen whether go-karts can provide an interesting spectacle. •The race for historic cars is always interesting event, but one driver will be racing in earnest. Gavin Bain has taken a bet from his brother, David, that Gavin's restored Ferrari 375MM V12 can lap Wigram faster than David's machine.