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Porsche 917K81

Competition Group: Provisional LeMans

Constructed For: Kremer Brothers

Engine Specification: 4.9 liter

Ownership History: Kremer Racing (1981), Bradley (1991)

Competition Highlights: Competed at LeMans 1981

Chassis Notes: (courtesy Rick Wilson, Maison Blanche)

After an ultimately successful closed course lap record attempt in 1975 with the 917-30 Can Am car, that might have been the final chapter in an extraordinarily successful career for the 917 in it's many shapes and guises. However, one 'last blast' (or two as it turned out) was yet to come.

The Kremer brothers, famous for their successfully modified Porsche 935s (the most famous of all being the K3, which had won Le Mans in 1979), had been collecting parts for a planned one-off 917, intended as a show/concept project. Sufficient parts were in hand when the 1981 Le Mans regulations were released late in 1980. This was to be an interim/transition year between the old Group 6 and the new Group C categories, and as such created a loophole whereby a closed car could run in Group 6 as long as there was some sort of permanent opening in the roof. This was incorporated into the design of the 'new' 917 to see the roof mounted rear view mirror.

Kremer approached the ACO who were very keen on the idea, especially as it would create substantial interest for a year that had little else to offer, despite a country still riding high after Rondeau's win in 1980 and the little local WM team running four cars, two of which were running to provisional 1982 regulations and as such were the first Group C cars to officially enter Le Mans as they had their own category. Managing to also attract sponsorship principally from Malardeau and BP, the project was on. Drivers were to be Xavier Lapeyre (contacts with Malardeau), Guy Chasseuil and the very rapid Bob Wollek.

The concept and basis of the project was to take the original design, update it to incorporate current technology and build the new car from scratch at Kremer's workshops in Cologne. The Porsche factory co-operated by allowing the brothers to use the original drawings. The pay back for the factory would be lessons learned with reintroducing coupé aerodynamics as 'spyders' had been to the fore since 1972. Porsche themselves were well advanced with the Group C 956 programme but any information gleaned would be most useful, even at that stage. Kremer had even managed to 'borrow' an ex-Pedro Rodriguez Gulf 917 from the Midlands Motor Museum in England and had it in their workshops for reference during the build.

The new chassis, still tubular, weighed in at around 65kg, much more than the 1970 version at just under 50kg. The main reason for this increase was the incorporation of several 'diagonals' to substantially improve torsional stiffness, as with 1981 aerodynamic improvements, forces exerted on the chassis would be far greater, both at speed and particularly whilst cornering. The overall weight when the car was presented at scrutineering for Le Mans was 893kg, which compared with 850kg for the original 917Ks. Interestingly, the Langhecks used to average around 900kg. A particularly problematic area in the redesign was adapting suspension geometry and components to cope with the huge increase in tyre technology in the 10 year gap.

Porsche came up with two different engines for the project, both in keeping with the original format. Early 917s use a 4.5 litre flat 12 powerplant, while later versions user 4.9 litres. Kremer opted for the 4.9 litre, assuming that the increased power but poorer fuel consumption would be a better bet against the turbocharged cars that would use more fuel anyway.

With the project always running close to schedule, little time was devoted to the aerodynamics; the team concentrating more on the engineering side (similar to Porsche when they developed the 'Moby Dick' 935-78, hence the particularly long wing endplates on that car - they never had time on the track to evaluate trimming them up!). Body styling of the 917K81 was of course pretty much already done for the overall look but Kremer 'guessed' the rest, choosing an almost flat rear deck with a full width rear wing mounted on endplates integrated into the bodywork. Also gone were the rounded sides, latest 'slab' sides were introduced to assist the whole 'ground effect' underneath.

At Le Mans, the car was woefully lacking speed in a straight line, pulling only 300 km/h on the Mulsanne during qualifying, although this was also partially due to a bad choice of gear ratios. Once rectified, the car would pull to 8,000 as opposed to 7,000 before, but only managed to qualify a lowly 18th (9th in class). The car's time was set, of course, by Bob Wollek at 3'46"54. This was over seventeen seconds off the class leading and pole winning Porsche 936-81 .. some advantage to make up over the turbos!

Come race day, the weather was blisteringly hot and maybe the drivers had more than one reason for wishing they had a 936. Once the race got under way, the car ran steadily in the hands of Bob Wollek for the first hour before he handed over to Lapeyre. After three hours, the car was running in ninth with Chasseuil at the wheel. Lapeyre took over again as the car fell steadily back as earlier delayed cars regained places. Whilst lapping a slower car, Lapeyre managed to put the car off the track, which fractured an oil line in the process. The leak steadily got worse and the car was retired just before the seven hour mark.

So the adventure was over. The 917 had had an unspectacular and rather disappointing retirement party at Le Mans. Feeling the car had not shown its true potential (or rather, reflected poorly on Kremer's engineering expertise), the team decided that just one more race had to be done to verify the competitiveness and justify the effort. The race was to be the last World Championship race for Group 6 regulations; the Flying Tiger 1000kms, round 15 of the World Endurance Championship at Brands Hatch, England on the 27th September 1981.

The overall drivers title had yet to be decided. The drivers in contention were Bob Garretson, Harald Grohs and Edgar Dören. Ultimately, Garretson would take the spoils with a steady second place.

Star of the show was, however, not the Kremer 917 but the first race for the new breed. Ford had decided to début their new C100, albeit in interim Group 6/C form. (The car to grace the tracks the following year was a completely different animal.) The Klaus Ludwig/Manfred Winkelhock driven C100 took pole by over a second from the ultimately race-winning Lola T600 of Edwards/de Villota and led until the first fuel stops. Thereafter running third, the car retired with shaft failure in the gearbox. Nevertheless, Ford had made the impact they desired.

The 917K81 looked stunning again, despite the addition of some heavy handed striping in the absence of major sponsorship. Driving again was Bob Wollek, this time partnered by Henri Pescarolo .. what a pairing! During the early, wet stages of qualifying, Wollek had been fastest by a substantial margin and was only overhauled in the later stages by Winkelhock and in the last minutes by a spectacular effort by Guy Edwards in the Lola.

Once the race got under way, Wollek eased the 917 past the Lola which steadily dropped back. The 917 shadowed the C100 all the way until an accident necessitated the deployment of the pace car. Wollek maintained second behind the pace car for one lap before diving into the pits, rejoining on the same lap at the tail of the queue, but with full tanks. Once racing resumed, Wollek was quickly up to fifth. Then it began to rain.

Running in third before the rain was Hans Stück in the BASF BMW M1, a master in the wet, quickly reeling in and passing Edwards' Lola for second. The rain was a shower and once the track started drying, Edwards was back ahead. The other BMW M1 in the race was the Michael Cane Racing car, driven by Derek Bell and Chris Craft. This car had raced at Le Mans that year as well, driven by David Hobbs, Eddie Jordan (yes, that Eddie Jordan) and Steve O'Rourke (finished fourth in '98 .. seventeen years on!!). This was a modified 'Procar', whereas the BASF car was purpose built and substantially lighter as a result. Running a safe second in the later stages of the 1000kms, Hans Heyer in the BASF M1 had an unavoidable accident (wrong place, wrong time) collecting a spinning 935 passing the pit entrance. The EMKA sponsored car finished third.

Wollek was by now hot on the heels of the leading Lola and on lap 43 showed his intentions. Edwards was driving superbly and it wasn't until the Lola pitted that finally, at long last, a 917 was leading a World Championship event once more. It couldn't last; all Wollek's hard driving on the twisty Kentish circuit came to nought as the suspension failed, leaving car and driver stranded 'out in the country' at Dingle Dell. Seems the suspension hadn't been beefed up enough to cope after all. Pescarolo never even got to drive.

The car was retired to the Kremer factory and then sold to a collector; the 917 has finally run its last top level race. Historic meetings aplenty will ensure the 917 never leaves the track, but a chapter is now closed forever.

917K81