• Print Page

Over three days in April General Motors South Africa smashed 30 existing world speed and distance records for commercial vehicles, and set 30 all-new records in pickup classes that had never been contested before. GAVIN FOSTER looks at the effort that went into the Isuzu 72 Hour Challenge.

“We knew before we even ran our 24 hour preliminary test in November that we’d be able to beat the diesel records set by Toyota in 2003, but we weren’t so sure that our diesel bakkies would manage to surpass the overall bakkie records set by their 2.7 litre petrol pickups,” says General Motors’ vehicle engineering manager Rob Deas. In the end they did though, with the latest Isuzu three litre KB300 diesel covering 12,243.38 km at an average speed of 170.047 km/h, compared with the 3-litre diesel Toyota’s 11,024.838 km at 153,123 km/h and the petrol version’s 11,520.664 km at 160.009 km/h in 2003.

As it turned out, even the lower-powered Isuzu KB250 diesel bakkie not only beat the Toyota 3-litre diesel’s average speed by 5 km/h and 470 km, but came within a hairsbreadth of bettering the petrol version’s 2003 overall time and distance records, with 11495,567 km passing by at an average of 159,661 km/h over the 72 hours. Records tumbled throughout the event that used 1, 3, 6, 12, 24, 48 and 72 hours as landmarks in time and 50, 100, 200, 500, 1 000, 2 000, 5 000 and 10 000 km as targets in terms of distance.

The Isuzu 3-litre KB300 smashed all fifteen records in the 3-litre diesel class as well as the same number in the overall class for pickups, for a total of 30 World Records established. Add to that the 15 records each set by the Isuzu KB250 and the newly christened Chevrolet Corsa 1.7Dti in their classes, neither of which has been previously contested, and General Motors scooped 60 world records along the way. The little 1.7 litre Chevrolet diesel utility proved to be GM’s joker in the pack, though, covering 11096,67 km at 154,12 km/h in the three days – that’s 72 km further and 1 km/h faster than Toyota’s eclipsed three-litre diesel record - in establishing an inaugural record in its newly recognised class.

While the event wasn’t a race for drivers pitting themselves against each other, each one of them had to be capable of lapping non-stop for two and a half hours at a time, foot flat on the gas pedal the whole way, and keep on doing that in the middle of the night in a thunderstorm if necessary without getting in the way of faster traffic or shunting the slower cars out of the way.

“What surprised me is that we had a lot of hotshot young racers there who are used to driving very fast machinery around racetracks, and I was worried that they’d come in after one stint and say that this wasn’t for them – it was too boring. As it turned out, they all loved it, and the opposite happened. Some of them came in and asked if there were other shifts needing drivers.”

There were also some interesting moments when bored marshals started aiming coloured lights at the cars as they swept past at between 160 and 190 km/h on the banking in the middle of the night. “We didn’t know what it meant, and worried that we were being warned about something or other, some technicality that could get us disqualified. Eventually we sorted it out on the radio and got them to stop!” remembers GM’s commercial vehicles marketing manager Ryan Visagie.

Spares were not as much an issue as you would think. “We were only allowed to replace things considered as consumables,” says Rob Deas. “Oil, tyres, filters and things like that. Other parts, things like radiators, could only be replaced if they were damaged in an accident. The only modifications allowed beforehand were that we could change wheel alignment on the Isuzus to suit the oval track with its banking, and we could modify the fuel tank breathers to allow faster refuelling. Because our bakkies service intervals are 15,000 km we didn’t need to change oil and filters during the event, and the vehicles used no oil at all so we didn’t have to replace any.”

At each pit stop the outgoing driver would be hauled out of the car before the crew checked oil and tyres, cleaned the windows and headlights, refuelled the vehicle and strapped the replacement driver in. All of this took just over a minute each time, even if a tyre needed to be changed, with the lengthiest part of the process being the refuelling. Time in the pits was hugely important, because off-track time affected speed and distance figures negatively.

“We couldn’t do much to the bakkies before the event either,” Rob says. “The rules allowed us to change wheel alignment in the Isuzus to reduce tyre wear on the banked corners, and we could modify the fuel tank breathers to allow faster refuelling, but that was it.”

Events company 360 Degrees did a sterling job of making sure everything happened as planned. Assistant project manager Marie-Jean Butler reckons things went surprisingly well when you consider that the pit area consisted of an empty field and a brick building inside a banked oval when they arrived. “We brought in generators, toilets, a media centre with air-conditioning, computers, printers and a radio link to the internet, marquees, the masseuse ladies with their equipment, the dancing girls, a Link race-car simulator… we didn’t have any real problems though – the only thing we had no control over was the rain. It turned the grass into a swamp but that added to the charm of the event.” And that it did. Five minutes before the start at 14h00 on the Tuesday Gerotek was hit by a torrential downpour that drenched the dancers as they went into their routine on the starting grid.

The rain stopped as the starting flag dropped and apart from the odd insignificant shower during the next 72 hours, stayed away until half an hour after the finish on Friday. Then it came down in bucket-loads, accompanied by a few minutes of hail.

Piet van der Schyff’s crew from Gerotek looked after the catering, providing more than 4000 meals over the five-days that the track was booked. Apart from the usual breakfast, lunch and supper, there was a full braai laid on at midnight for the drivers and crew who were working at that time each day.

The Isuzu and Chevrolet bakkies did more hard work over the three days the event was run than most people would expect them to do in a lifetime. The only time they dropped below top speed was for about two minutes every two-and-a-half hours, yet they gave absolutely no trouble at all. The wheels of the leading 3-litre KB300 rotated nearly 5,8 million times each, and each of its engine’s pistons went up and down the bores nearly 16 million times. The KB250 was a little less busy, but not much, while the little Corsa slaved away producing over 6 million wheel and 18 million crankshaft revolutions over the 72 hours. The seven vehicles chewed up 60 new tyres and swallowed a total of 11,237.44 litres of diesel while doing a combined 81,626.75 km, with the three-litre pickups averaging just over 16 l/100km, the KB250s around 14.5 and the Corsas a very frugal 9.5 l/100km.

Time (hours)

Distance Avg. Speed Covered (kms)

Previous

Isuzu KB 300

00h 18m 02.688s

00h 17m 36.968s

50.000

50.000

166.253

170.298

Previous

Isuzu KB 300

00h 36m 38.463s

00h 35m 12.746s

100.000

100.000

163.751

170.394

Previous

Isuzu KB 300

01h 00m 00.000s

01h 00m 00.000s

162.425

170.041

162.425

170.041

Previous

Isuzu KB 300

01h 14m 01.715s

01h 10m 19.353s

200.000

200.000

162.099

170.642

Previous

Isuzu KB 300

03h 08m 29.388s

02h 57m 01.073s

500.000

500.000

159.160

169.474

Previous

Isuzu KB 300

03h 00m 00.000s

03h 00m 00.000s

477.516

509.066

159.172

169.689

Previous

Isuzu KB 300

06h 15m 49.102s

05h 53m 35.711s

1000.000

1000.000

159.651

169.686

For further information on the Isuzu 72 Hour Endurance Event and a details of the records

set visit the Isuzu Endurance event website: www.isuzurecordbreak.co.za