1978 USAC Mod | Readme

The 1978 USAC National Championship was one of high turmoil and important changes, some even tragic. For some time already, the racing team owners had been increasingly vocal and dissatisfied about the way the USAC board was managing the series since the early 70s, with constant rule changes in a effort to slow down the cars, ineptitude to control the cheating and questionable decisions. The final straw was the introduction of the DFX Cosworth engines by Parnelli Jones, which quickly became the dominating engine and effectively rendered the Offenhauser obsolete, since the four cylinder classic could never be competitive under the strict fuel and boost limitations imposed. To further aggravate the problem, the DFX Cosworth had only limited production runs, meaning there was a long waiting list, and was incredibly more expensive than the veteran Offy, thus increasing the gap between the poor and the well funded teams. The whole season was thus marked by a constant wrestle between USAC and the Offenhauser equipped teams, whose protests increased to the point of threatening with boycott in several races. To mitigate the problem some concessions were made, and the four cylinder cars were allowed mid season some more boost and fuel use, but the writing was on the wall and an airplane accident that killed nearly the full USAC board and left the organisation beheaded precipitated the events, with several important team owners departing the series in 1979 to form CART (Championship Auto Racing Teams).

All those external circumstances obscured what was otherwise a truly fantastic racing season, with many important achievements. Tom Sneva managed to defend successfully his title, but Al Unser fought till the last race, clinching the only ever triple crown on the way, and most races were quite open, with winners alternating. But probably the most spectacular and sensational performance came from reconverted former drag racer Danny "On the gas" Ongais, who showed some incredible skills and speed, being letdown only by the reliability of his equipment.

The season also marked an historic point when staging two races in England, at Brands Hatch and Silverstone, plus another road course at Mosport, consolidating its return to road racing after many years of only turning in circles.


A large variety of chassis was present due to the usual combination of state of the art cars and old models updated and kept in service.


Penske PC6:

Newly designed and constructed in England, it is very quick and balanced. A solid oval car that will challenge for victory in any track. Exclusive to the Penske team.


Parnelli VPJ6:

A reconverted Formula 1 design, it was blistering quick but much more nervous. The car to have in road courses while still a preference in superspeedways - provided the driver's reflexes can cope with it. The car was field by Interscope Racing, born from the ashes of the Vel's Parnelli Jones team, but later AJ Foyt acquired one and was ecstatic about its performance in the three races it took part.


Lola T500:

Fielded only by Chaparral Racing directed by Jim Hall, the car was planted but not as quick as the top ones. Al Unser pushed it to higher results than deserved, and clinched the triple Crown with it, displaying an unexpected reliability at 500 mile races that completely missed at the shorter tracks, where the car was plagued by failures.


McLaren M24:

Another F1 design adapted to racing in the states, resulting in a more agile ride than the dedicated oval racers. Rutherford had a lackluster season in the factory ride due to reliability issues, but the car had potential for victories. Customer cars were fielded by Jerry O'Connell and Dayton Walther.


Penske PC5:

A clone copy of the McLaren M24 as an exercise by Penske in 1977 to understand car building process and proper quality of finish in preparation of their first in-house design. The car was sold to a private team that fielded it in 1978, being otherwise identical to any McLaren M24.


Eagle 78:

The first new design from AAR since the iconic Eagle 72, it arrived late in the season just for Indy and never had the pace to challenge for victories. Bobby Unser drove it to some top-fives and scored respectably, but the car lacked speed. It looked stunning though, with one of the most elaborate and artistic liveries ever seen in USAC.


Coyote MK7:

Still fielded with continuous minor updates since designed by Bob Riley in 1973, the car had won the previous year's Indy 500 but was already clearly ageing. Very sleek and aerodynamic thanks to the shovel nose, it could still be competitive on superspeedways despite the weaker Foyt V8 but otherwise only Foyt's supreme driving prowess made it look more brilliant than it was. Easy to drive and now much more adjustable thanks to several different extra front winglets, it is still a good car for long races.


Wildcat MK2/3/4:

Pat Patrick hired Bob Riley to design custom cars for him, and the result were the different iterations of the Wildcat. The MK2 started on the shovel nose theme used by Riley in the early 70s and handled quite well. The MK3 was an effort to couple a conventional front and wing on the previous model, all the rest being the same, but it did not result in any gain. The MK4 was an adapted version for the new Drake V8.


Lightning MK1:

Decent and uncomplicated, it was the customer car of choice for most private or mid-funded teams. Its pace may vary depending on the engine equipped, but overall a balanced and simple car than can pay dividends over a whole season.


Vollstedt 77:

Brilliant engineer Rolla Vollstedt kept pumping out new designs during the 70s for cars that never failed to be solid and easy to drive, but usually lacked funding to be equipped with top engines and material. In the capable hands of veteran Dick Simon the car was always a mid field contender.


Watson 77-78:

The Watson 77 was a clone copy of the Lightning MK1 but with a custom rear wing with extended side plates, the Watson 78 a new design with the same rear wing but not improving the performance. A mid field car that feels more nervous and agile, which should be helpful in short tracks and road courses.


Dragon 76:

Unique design fielded by Grant King at Indianapolis copying (As usual in King) parts of other designs and resulting (As usual in King) in mediocre results.


McLaren M16, Eagle 74, Rascar-Atlanta, Finley-Eagle, Kingfish:

Old models pressed into, or kept in service with different updates and modifications by the most underfunded teams, one could have been misled into believing it was -as in sportscars- a different class in the races than the top cars. Nevertheless, the abundance of these older cars meant they were never alone in the track and always fighting each other for points.



By 1978 the main concern for the teams was the fuel use, as the restrictions imposed by USAC meant that the driver had to play during all the race with the boost knob and watch the temperatures if running too lean, which resulted in many failures and breakdowns. For the purposes of our simracing season and due to the limitations of the game engine, there will be 5 boost settings adjustable from cockpit. The cars should be able to do the race in principle only on the first two ones, and depending on the driver's ability to save fuel thanks to his driving technique, draft, or the amount of caution periods, have more or less leeway to be liberal with the boost for overtaking or towards end of the race.


Cosworth DFX V8:

The engine to have. Up to 900 HP in qualifying trim and good fuel consumption, the only Achilles heel was its more peaky nature, lacking the mid range punch of a four cylinder.


Foyt V8:

Still maintained by Foyt, the former 1972 Ford V8 design was at the peak of its possibilities and quite comfortable on the boost restriction of the late 70s. In all aspects similar to the DFX but with some 50 HP less at 850, although the sleek and aerodynamic design of the Coyote made up for a big part of that difference.


Drake V8:

The swan song of the Offenhauser factory, it was a desperate move to stay in the game with a completely new design of V8. It had some brilliant ideas and went in the right direction but it was too little, too late, and with the rather bad reliability of an untested fully new design.


SGD 4L:

Based on an idea from Art Sparks implemented by Leo Goosen and Dale Drake of Offenhauser, the angle between valves was reduced and the combustion dramatically improved, resulting in a respectable 850 HP on the strict USAC fuel and boost rules. While not enough to qualify at the top, the combination of the Wildcat chassis and the mid range punch made it quite efficient at short tracks, where Gordon Johncock scored victories and podiums, as well as in road courses.


Offenhauser 4L:

So good was the base design that this venerable four cylinder would have been able to continue dominating the field had it enjoyed unlimited boost and fuel use rules. But on the limits imposed by USAC it had at best a 75 HP deficit to the Cosworth with similar or higher fuel consumption, and was hence hopeless.


AMC V8 stock block:

American Motors Corporation promoted itself heavily in US motorsports of the early 70s, taking part in the iconic Trans Am series and also venturing into NASCAR, but also kept an eye on the top series of USAC racing. When the rules for stock blocks relaxed, they decided to enter some "experimental" engines, which actually did perform quite well thanks to the increased displacement. But by 1978 they had not gone any further than how they started, and veteran Roger McCluskey only entered part of the schedule in an old Eagle 74 equipped with the 208Ci stock block. The engine propelled the car to quite decent pace, but the rest of the combo meant it never was able to materialize the potential. 

By 1978 Firestone had left the competition and Goodyear was the sole tire provider. As it usually happens, this immediately resulted in a quite conservative approach with safe hard compounds, to the point where double stinting the tires was the norm, as fuel decreased much quicker than tire grip.


3D models & Skins: David Sabre, Jason White
Physics: Richard Wilks, Alberto Ibañez
Sounds: Richard Wilks