GTX5 Mod

[Guest ARkT]

Engine: Six-cylinder, four-valve, water/air-cooled opposed-piston,

turbo engine, four cogweel-driven overhead camshafts

Output: 840 HP at 8200 RPM

Displacement: 3211 cc

Fuel system: Bosch mechanical injection pump, 120 litre fuel tank

Driveline: Four-speed gearbox, no differential

Chassis: Light-metal, tubular space frame, plastic body, independent suspension, coil springs, vented disc brakes

Dimensions and weight: Wheelbase 2279 mm, length 4890 mm, weight 1025 kg

Performance: Top speed 365 km/h

The story of the "Moby Dick" begins in the mid '70s when Porsche first created the 935. The 935

was a silhouette car based on the 911 production vehicle but modified for racing to the prevailing

Group 5 regulations.

The 2.1 litre engined car dominated the 1976 and 1977 world championship for makes in the

hands of the works team and customer teams such as Kremer and Joest.

In the latter part of 1977 Norbert Singer - the creator of the cars, was present at an FIA

meeting. BMW were asking the FIA if they could be permitted to cut the side panels of their

front-engined car to allow the exhaust through. After some discussion, it was agreed that an

amendment could be made to allow this.

Singer realised at that moment that this amendment had created a potential "loophole" that

could be exploited for their 1978 car. They were already planning a lighter aluminium-framed

"Baby" with a more powerful 3.2 four valve six cylinder engine. If it was now permissable to cut

the panels to allow the exhuast through, the car could be made lower by 8 or 10 cm. This would

create a car perfect for the high speed straights at Le Mans.

When the car was finally built, it was a radical departue from the other 935s. The car was indeed

lower which made it look somewhat wider. All new body work was developed to take advantage

of the car's lower profile, for improved aerodynamics, and the tail had been extended much

farther beyond the rear wheels. Other new features included were larger brakes and an "upside

down" transmission. The upside down transmission was used to reduce the severe angle of the

rear drive axles created by lowering the car as much as they had with the larger diameter 19

inch wheels and tyres.

In it's now classic Martini racing colours, the car was stunning.

On first sight, Porsche bosses were concerned at the look of the car. Singer remembers,

"There was a little bit of concern for them because they see that we spend a lot of

money and then if we come to the races and they say it's illegal. Of course, this is quite

a big fear that they had. But I was quite sure this was legal because I was at the

meeting and I knew what they mean and I knew what they wrote. So their meaning

might have been for making a hole for exhaust pipe for front engined cars like the BMW

but what they (the FIA) put on paper was quite a lot of other things which we did."

The FIA were also suprised. "This was the amazing thing, he (Paul Frere) came to

Weissach with President Schild from the FIA commission to make a pre-examination of

the car. And I explained to him what it was, I explained to him what was the letter of the

meeting. And at the end he said, yes okay, you are right. But what concerns him much

more was the double door, this normal production door with add on piece which makes

the door much wider. so we showed him you can take off the outer skin and then you

had the original door. And then I got the passport which was signed by Paul Frere with

the FIA stamp on it and they left.

"Then the FIA working crew came together and they found, this is not legal. But Frere

and Schild had said it was legal. And then we got a telex from the head of the American

group and they said, it's not legal what you are doing. So that's why in Silverstone the

door was cut in the first half so you could see from the outside the original door. And the

front part of the door, which this was the most important aerodynamic part. The rear

part was not so important. So that's why they raced in Silverstone and Le Mans with the

front extension which covers the front part of the door. Then after that, the formal

president of the FIA Commission, Pierre Ugeux, we received a telex from him. And he

said, when the commission was presented by Paul Frere and he decided it was legal and

we got the permission to run like this, then the working crew cannot turn it around. So

afterwards, we got permission to have the original doors legal".

The car was first raced at Silverstone in the 6 hours World Manufacturer's

Championships in May 1978. It was driven to victory by Jochen Mass and Jacky Ickx.

The car stunned the crowd and fellow competitors alike, taking pole with a time less than

2 seconds slower than required to make the grid for the previous summer's British

Grand Prix at the same track. The car would, in fact, have outqualified some of the F1

back markers.

Porsche then took "Moby Dick" to Le Mans along with their Group 6 prototype, the 936.

The calculations had been correct and "Moby" was the fastest car on the circuit,

recording a top speed of 365 kph on the Mulsanne Straight.

But as we all know, Le Mans is not just about speed. The Stommelen/Schurti driven

935/78 was classified only 8th overall in the race which was won by the Group 6 works

Renault. Singer offers this simple explaination , "The problem was, the bigger engine

had a fuel consumption problem and we were refuelling, I think, every 35 minutes. I

think we had, I don't know how many, 39 or 38 pit stops. Far too many. Also the Group

6 prototypes were carrying more fuel."

The few other races that the official works 935-

78 competed in were also dissapointing. The car

would brake down whilst leading.

A 935-79 was planned, improving on the basic

principles of the "Moby Dick" but incorporating

ground effects which had come to the fore in F1

in 1978. A 5th scale wind tunnel model was built

but the project was canned when Martini

withdrew it's sponsorship at the end of the '78

season. Singer still believes that the car could

have won Le Mans the following year.

Moby Dick was retired to the Porsche museum at the end of 1978. But this was not quite the

end of the classic Moby Dick shape. .....

The famous Joest team requested customer 935-78's but was turned

down by Porsche. The team decided to build replicas with the normal air cooled engine which were raced

successfully through the early part of the 1980s in rounds of the WMC, IMSA, Deutcsher

Rennsport Meisterschaft and even Le Mans.

Article reprinted with permission from

http://www.greatracingcars.co.uk/

written by Simon Mallett

Moby Dick

Mesh by ARkT

Physics by Padajacaba

Paint by T-Spark

[Guest ARkT]

The BMW 320 Turbo IMSA 1978

From 1969 onwards, BMW dominated European touring car racing with the 3.0 CSL in various guises. There were countless wins in ETC for the factory Group 2 version, which took the overall championship in 1973. Privately entered cars continued winning championship classes from 1975 through to 1978. A Group 5 version took overall 2nd place in the newly inaugurated World Championship Of Makes in 1976 with wins at Silverstone, Osteriechring and the Nurburgring. The very last win for this car came in November 1976 at the non-championship Wynns 1000 at Kylami. This was the final appearance for the CSL as a works effort.

BMW had introduced the new 3-Series in 1976 and in a press conference in December of the same year, announced a full factory program to race the 320 model in Group 5 competitions the following year. There would be two efforts, a three-car BMW Junior Team for European races, which would be run from Germany, and collaboration with the McLaren team to run 320s in the IMSA series in the United States. McLaren had established a base in America in the late 1960s when it was running its highly successful Can-Am and Indianapolis programs. BMW boss Jochen Neerpasch realised that McLaren had the right facilities and people in place to run the IMSA team.

At the outset, BMW decided not to develop a racing version of the new 3 series’ 6-cylinder engine. The 2 litre, 4-cylinder M12/7 unit from the CSL had been fully developed for racing in Formula 2 over the preceding years and it was lighter, higher revving and used less fuel. This decision may also have reflected the limited time schedule that BMW were working too. With only 3 months to build the cars, many of the mechanical parts that were developed for the CSL were incorporated into the design.

Because of this tight schedule, the engineers at BMW were unable to develop the 320 in the conventional way with a team of designers working on the drawing board. Most of the work was carried out on the shop floor from scratch. Working within Group 5 regulations, the first step of the process was to improve the weight balance. Initially, this meant repositioning the engine 60 mm lower and 120 mm further back towards the front bulkhead. This meant that the driver’s seat, foot controls and steering column all had to be moved and remounted further back. Finally, the battery alternator, dry sump oil tank and regulation fire extinguisher were mounted within the boot space.

A tubular steel roll cage that served to improve the strength and torsional rigidity of the car then complimented the inner production framework. The dramatic glass-fibre aerodynamic bodywork was developed at the Pininfarina wind tunnel in Turin and featured large wheel arch extensions at the front and rear, a separate front aerofoil and rear wing supports. The wing itself was fabricated from sheet aluminium. Although the 3-Series was a saloon car, the racing 320 looked as dramatic as any of the sports car derived machinery it would compete against.

The 1977 three car BMW Junior Team featured an 18 year old Eddie Cheever alongside Marc Surer and Manfred Winklehock – both still in their early twenties. All three cars were raced in identical white BMW Motorsport livery replete with “BMW-Junior-Team” windscreen decals.

As success would almost certainly guarantee a move up to the BMW Formula 2 program for one of the young drivers, competition between them was ferocious.

As the season progressed, the Junior Team battle reached a fever pitch with all three cars jockeying for position, frequently punting each other off the track. This battle became a highlight of the 1977 series and is something of a legend in German motorsport. All three drivers were suspended after one particularly fierce round and BMW boss Jochen Neerpasch responded by substituting the regulars with Hans Stuck and Ronnie Peterson. Acknowledging the less than subtle style of Cheever, Surer and Winklehock, the windscreen decals were changed to read “BMW-Gentlemen-Team”.

Despite the shenanigans, the 320 easily accrued enough points to take the 2-Litre Class by the end of the 1977 season.

The McLaren run operation in Detroit, America took delivery of its cars after the Daytona race. They were basically built to the same spec as the European racers but from the Road Atlanta round in April onwards, the 2-litre engine was given a boost by a Garret AiResearch turbocharger so that it could compete with the near 800 bhp 3-litre Porsche 935. Some modifications were also made to the rear suspension to accommodate the larger 14” wide 19” diameter rear wheels that gave the fire-spitting 320 turbo a much meaner look than it’s European cousin. McLaren engineers also stiffened the car by strengthening the roll cage.

The Atlanta race in April was a promising start with the 320t in the hands of David Hobbs finishing fourth overall despite starting from the back of the grid due to electrical problems. Victories came later on at Mid Ohio, Sears Point, Atlanta in late July and Laguna Seca and this gave the team the overall Manufacturer's Cup. McLaren boss Teddy Mayer concluded that the team had been unlucky not to win more races because the Porsches were simply not ready.

In 1978, it was a different story. Some weight was taken out of the car with the use of new plastics for the body and a new front sub frame assembly. The radiators were also moved rearwards providing improved balance and lower running temperatures. Despite that, the customer-ran Porsche 935s were ‘ready’ this time. “It’s asking a lot for a 2-litre sedan to take on a twin-turbo with 3-litres….and on the fast tracks, the aerodynamics are not comparable to a Porsche. It was uphill all the way”. There were two wins, at Hallet and Sears Point, but Porsche dominated elsewhere. The final standings for the GTX class were Porsche 1st on 136 points and BMW 2nd on 36 points.

The McLaren car ran for another season in IMSA in 1979 boosted by some of the turbo technology that Schnitzer had been developing for its effort in the DRM in the previous year. With the increased weight handicaps placed on the Porsches, the car had a much better season.

BMW’s attention would now switch to the spectacular new 6 cylinder turbocharged M1 sports car. For the first time the company would have a car purpose built to take on the Porsche 935.

1978 IMSA GTX BMW 320i Turbo

Powertrain Layout: Front Engine / RWD

Configuration: Turbocharged Inline-4

Displacement: 2000 cc / 122.0 cu in

Power: 447.4 kw / 600.0 bhp

Transmission: Getrag 5-Speed Manual

Weight: 878 kg / 1936 lbs

Powertrain Layout Front Engine / RWD

Article and research by Simon Mallett

www.greatracingcars.co.uk

BMW 320 Turbo IMSA

Model by ARkT

Paint by Caliban

Rendering by AlexeyK

Photoshop Processing by REVSECT

Physics by Padajacaba

[Guest OPM]

nice to see your mod here:)it is also some kind of touring cars

[Guest Maxx]

now lets see you actually release it

[Guest Bulbhead]

  nice to see your mod here:)it is also some kind of touring cars

I think those cars would rather be classified as prototypes. They have definetely not much in common with any road cars. Group 5 was actually something in between GT and protoypes, but I think those cars were much more prototype like than current FIA GT cars. To say it in different words - brutal racing machines...

[sorry OPM, I know that you know this... ]

Those renderings look great but I guess I do not have to tell you.

@ARkT:

Nice marketing post but of course you and your team are welcome here.

[Guest ARkT]

That kind of marketing was an idea od Revsect the Team Coordinator as soon as we have new articles for each car we are going to post new images. And yes the GR5 cars had their own rules for the transformation taking a serial road car as a base and changing pieces and redoing the car for competition. For that reason the GR5 cars where called Silhouettes. They where not Protos exaclty just variations of the street cars.

[Guest jcvd]

hi,

i'm very happy to see your mod here.

P@T

[VELOCIPEDE]

Please insert your post for F1 Challenge/F1 2002/other Mods to EA Sports Sim dedicated forum. Thanks.

[Berglemor]

che render!!!!!!!!! :shock:

[Guest GTEvo]

:oo: oh holy Shit, what amess, lol, they are just BRILLIANT !!!!!!!!!!

cheers Holger