Jackie Oliver’s Shadow DN6 Chev on its way to 2nd place, Road America, 27 July 1975. (Richard Dening Jr)
Exactly 12 months later Oliver goes one better in the Dodge engined DN6B, winning the Road America race on July 25 1976. (Richard Dening Jr)
Jackie Oliver takes an historic win in his Shadow DN6B Dodge at Road America on 25 July 1976…
Chev engines won every championship F5000 race in the US from Riverside on 25 April 1971 when Frank Matich took a Repco Holden win in his McLaren M10B through until Oliver’s long overdue Shadow victory, the Lola T332 Chevs of Al Unser and Vern Schuppan were second and third.
Whilst the Dodge was more powerful than a Chev it was also heavier making the packaging of the car and its big cast iron V8 a challenge for designer Tony Southgate.
The Lola T332 was their 1974 production F5000 but was continually developed, the subsequent Lola T400 and T430 not quicker cars, a good 332 was as quick as an F1 car on the common circuits upon which both categories raced in North America. ‘Twas a remarkably good, very fast racing car the Shadow was competing against driven by the likes of Brian Redman, Mario Andretti, Alan Jones, Al Unser and others…
Shadow DN6 Chev. Car based on Tony Southgate’s very quick DN5 1975 F1 contender. Aluminium monocoque chassis. Front suspension lower wishbone and top rocker actuating inboard mounted coil spring/damper. Rear single top link, lower twin parallel links, two radius rods and coil spring/dampers. Adjustable roll bars front and rear. 5 litre cast iron OHV Chev here, Dodge V8 from the Road Atlanta round in August 1975 , Hewlands TL200 gearbox, developed as an endurance racing tranny used rather than the F5000 standard, the ‘brittle’ DG300. Road America July 1975. (Richard Dening Jr)
5 litre cast iron, mechanical fuel injected, OHV Chev V8 engine developed circa 530bhp@7800rpm. Rocker covers removed here for Road America July 1975 prep, one rocker missing. Magneto, its yellow ignition leads and fuel metering unit all visible. (Richard Dening Jr)
The Shadow DN6 was based on Tony Southgate’s very competitive DN5 F1 design and was first raced in 1975 powered by the ubiquitous Chev V8. Oliver took 4th place in the championship won by Redman’s T332, the car raced well at both Watkins Glen and Road America.
Gordon Kirby in his 1975 season review in Automobile Year said; ‘Almost immediately the Shadow proved to be competitive and in the last part of the season (the last 4 races) it became even more of a threat when after a long development program the team switched to Dodge engines, based on the same powerplant used in NASCAR by Richard Petty’. (in 1975 the Grand National Stockers were compelled by a carburetion ruling to use 355 cubic inch or 5.8 litre engines). The Dodge developed some 30 bhp more than the Chevys’ but was much heavier. The Shadows were not completely tuned and set up and did not win a single race. The whole of the 9 races were taken by the Lola Chevrolets.’
Jean-Pierre Jarier lines up on the Watkins Glen grid with Brian Redman 13 July 1975. Shadow DN6 Chev and Lola T332 Chev. JPJ DNF with a broken oil line, Brian was 1st, Oliver in the other Shadow also DNF with a blown Chevy. (Gary Gudinkas)
F1 drivers Jean Pierre Jarier, Tom Pryce and Jody Scheckter each raced a second car in three rounds at Watkins Glen, Long Beach and Riverside respectively.
All three qualified in the top 5 but retired with mechanical maladies.
Business end of the Shadow DN6 Chev. Engine magneto and fuel metering unit, Hewland TL200 gearbox to which the wing is mounted, neat duct for inboard disc and additional oil cooler all visible. Road America July 1975. (Richard Dening Jr)
The following Shadow press release written by Rob Buller prior to the Mosport round, the second of the 1976 season, reproduced on the My Formula 5000 website outlines changes to the car and program over the 1975/6Winter.
‘Development work on the DN6 5000 car has continued over the winter under the direction of Chief Mechanic Ed Stone and Engine builder Lee Muir.
Stone joined the 5000 effort late in 1975 and immediately set about making chassis and suspension changes.’Basically the 1975 season progressed with little development, there wasn’t much time.’ Stone said in a recent telephone interview, ‘I was asked to make some suspension changes and the car was more competitive at the last 1975 race at Riverside with Jody Scheckter driving.
Oliver in the Road America pitlane, July 1976. Shadow DN6B Dodge. (Richard Dening Jr)
‘But the heart of the Shadow development is the new Chrysler power-plant, a joint venture between Shadow and Chrysler’s Plymouth Division. The engine starts life as a 340 cu. in. stock block that is down-stroked to 305 cu. inches. It is fitted with the same injection system that is used on Richard Petty’s NASCAR Dodge.
Chrysler, which is heavily involved in NASCAR and Drag Racing, is new to F5000 racing, a class that has been dominated by the rugged Chevrolet 5 litre engine. As a part of their new kit-car package now under development, Chrysler has contracted with Shadow to do the engine development and sorting.
They supply the engine components to Shadow engine expert Lee Muir, who then hand builds and dyno tests each engine. Chrysler also helps with technical information and advice to Muir, who came to Shadow from McLaren’s engine department.
Race debut of the Dodge engined Shadow DN6 chassis ‘2A’ at Road Atlanta 31 August 1975. Oliver 4 th, race won by Al Unser’s Lola T332 Chev. Specs; Dodge 340cid V8 taken back to 305cid by reducing the engines stroke. 5 litre cast iron, OHV, mechanical fuel injected V8. Bore/stroke 4.04 inches/2.96 inches, power circa 550bhp@7800rpm. Hewland TL200 ‘box. (unattributed)
‘The first outing in 1976 for the Shadow Dodge DN6 was at Pocono, Pennsylvania for the Series opener. Although they weren’t quite ready for the Pocono race, they were very encouraged with the results. Oliver was lying third in his qualifying heat when a connecting rod developed terminal stretch. As they only had one dyno’d engine a spare practice unit was installed for the feature. However, a fuel pump seal split on the grid and it took 5 laps to change. By the time he joined the fray Oliver was hopelessly behind but by charging hard he was able to run with the leaders.
With that encouraging performance Stone and Muir returned to Phoenix Racing headquarters in Chicago and started preparation of the Shadow for the Mosport race. Further chassis mods have been made utilizing new springs, roll bars and revised suspension settings. To help weight distribution, the water rads have been moved forward a la McLaren Indy car. Muir will have three completely dyno’d engines ready for Mosport’.
‘Sponsorship for the F5000 effort is a problem for Shadow. Since the departure of UOP, Nichols has been unable to get the full 5000 program underwritten. Various sponsors are now supporting the Formula One effort on a per race basis while only Goodyear, Valvoline and, of course, Chrysler are behind the 5000 effort. Thus Shadow must watch their budget closely and this, the team feels, will restrict the amount of development they can attempt. Nonetheless the 5000 effort has Don Nichols full support and he won’t field cars unless he can be competitive. And with the driver, new engine and chassis changes he plans to be competitive’.
Oliver lead at Mosport but was held up by a backmarker, Alan Jones snaffling the win, inevitably in a Lola T332 Chev.
Three weeks later he lead at Watkins Glen but a cracked sump ended his race, the Shadow finally won at Road America, Elkhart lake, Wisconsin. It was a good win as Ollie had to overcome diff and flat tyre problems in his heat which meant he started 14th on the grid of the final.
Oliver on the way to victory, Road America July 1976. Shadow DN6B Dodge. Behind is Al Unser’s 2nd placed Lola T332 Chev. (Richard Dening Jr)
After 16 laps he was 3rd, within 3 laps he was past the Lolas of Al Unser and Brian Redman and took a strong win for the team.
Oliver took 2nd place at Mid Ohio on 8 August 1976, Shadow DN6B Dodge. 1976 champ Brian Redman won in a Lola T332C Chev. (Richard Dening Jr)
Two second places at Mid Ohio and Watkins Glen secured third place in the championship again won by Redman’s Haas/Hall Lola T332.
With the demise of F5000 in the US at the end of 1976 and its evolution into 5 litre central seat Can Am from 1977 the Shadow’s raced on into 1977 and 1978 but without success, Lola’s T332/T333 the dominant cars in the early years of the class.
Jack Oliver ready to go Road America 1975. CanAm Champ for Shadow in 1974. (Richard Dening Jr)
Road America pitlane on a beautiful July 1975, Wisconsin day. Redmans Lola T332 at front. (Richard Dening Jr)
Comparison of the specs of the F1 Shadow DN5/7 and F5000 DN6 from the 1975 Long Beach GP race program. (Fred Bernius)
Jackie Oliver Fan Club President? Road America July 1975. (Richard Dening Jr)
Photo and other Credits…Richard Dening Jr, Gary Gudinkas, Fred Bernius, My Formula 5000 website, http://www.myf5000.com/index.html, Peter Brennan and Glenn Snyder for research assistance
Other F5000 Articles…
Elfin MR8 Chev & James Hunt.
Frank Matich and his F5000 cars.