By: Paul Fearnley 5 hours ago

Dan Gurney’s favorite Indy car was the 1981 Pepsi Challenger, or the Eagle 8100, to give it its official nomenclature.A year earlier, Gurney had turned designer John Ward loose, and the result was a radical, striking piece that didn’t look like anything else in Gasoline Alley – and didn’t work like anything there, either.While others went the conventional ground-effects route, based on venturi tunnels under the car, Ward, plus Trevor Harris, egged on by Gurney’s no-holds-barred mindset for innovation, conceptualized and built a twin-vortex generating body shape which energized flow over the rear wing (aided by exhaust flow – how ahead of its time was that!) and produced significant downforce. Significant.“Dan was all in on getting answers and not at all concerned with conformity,” recalls Ward. “The ground effects or BLAT [Boundary Layer Adhesion Technology], as Dan liked to call it, was inspired by the shed vortices on the top of an F-16 fighter jet wing, which could fly at extremely high angles of attack, hence BLAT. If you turn an F-16 upside down, you have the ’81 Eagle!”Ward made some refinements for 1981 and the 8100 was even zoomier as Mike Mosley stuck it in the middle of Row 1 at Indy, out-pacing the turbo Cosworth DFX hordes with a stock-block Chevy V8.“Dan was extra proud of that engine and it was a great month because I think we surprised a lot of people,” says Ward, who’d created a tenth-scale wind tunnel, complete with rolling road, at Gurney’s All American Racers shop to accelerate their learning curve. “And he was proud of our team – I think we only had 15 or 20 people at AAR and we did the car and engine in-house. Dan loved that car. We all did.”After an engine failure at IMS, Mosley went from last to first and lapped the field to win at the Milwaukee Mile – the final victory for AAR in open-wheel competition and the last time a stock-block pushrod engine scored a victory in Indy car racing.“It was a great car on an oval and a great car on a road course,” said Gurney back in 2013 while poring over photos of Geoff Brabham and Rocky Moran leading races in 1981 at Riverside and Watkins Glen, respectively. “Then the bureaucrats took over and ruled out our car.“An American car with an American engine that won a single race and they were scared of it, so they arbitrarily threw it out. That stuck in my craw for a long time.” Ward will always treasure his time at AAR with The Big Eagle.“Dan so was so curious about how things worked,” he says. “He would always ask the right questions to make you think and he made us feel like we could do anything.” Get the full version of this story in the 2018 Heroes Issue of RACER magazine, on sale now.