Weird and Wonderful Indy Cars: March 86C Cosworth

Published On January 4, 2017 » 7654 Views» By Marshall Pruett » Blogs, IMS History, Indy 500

Regular #SpeedRead readers will recall Marshall Pruett’s eight-part series on “Weird and Wonderful Cars of the ‘500’” that appeared in the weeks leading up to the 100th Running of the Indy 500 presented by PennGrade Motor Oil. Now, the feature continues with one car featured regularly.

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Bobby Rahal

There was something special about the red 1986 March 86C chassis that carried Bobby Rahal to Victory Lane at the Indianapolis 500. Its advanced aerodynamics and finely tuned suspension gave Rahal the balanced handling required to run up front. And its 2.65-liter Cosworth V8 turbo blended great power with impressive reliability to keep the Jim Trueman-owned, Steve Horne-led car in the hunt for most of the 200 laps.

But it was one small component—something that received a special touch from March—that caught the eye of many at Indy in 1986, including the future (and current) president of the Indianapolis Motor Speedway.

“There were so many things about Bobby Rahal’s car that caught my eye that year, and one of them was a so unique—it was the pointed, chromed roll hoop on the 1986 Marchs,” said Doug Boles. “It was just one little aspect, but it made the Marchs stand out from the other cars and it always stuck with me.”

As Boles noted, the Marches were easy to pick out from the Lolas and Penskes in the field because of their roll hoops. Beyond the novelty of that safety item, the March chassis was also the car to have in 1986 after receiving the full design attention of the great Adrian Newey.

Best known today as the designer of countless Formula 1 world championship-winning cars, Newey’s 1986 March hinted at the Englishman’s slavish devotion to slippery aerodynamic shapes, including the narrow, tapered tub. As Rahal recalls, the March’s comparatively tiny nose and forward chassis section might have been a winner while cutting through the air at 200-plus mph, but it made more than a few enemies in Gasoline Alley.

“I remember the guys were always bitching about changing the springs in the front of the car because Adrian was always about making the car as small as possible, and of course that was great for aero and everything, but it wasn’t great to work on,” Rahal said. “And everybody bitched about it. But it was typical Adrian. Okay, here’s the profile, how can we make it better? It was always about making it smaller and more aerodynamic.”

Rick Mears

(ABOVE: The 86C’s pullrod front suspension and small, square access hatches made shock and spring changes a long and frustrating experience for mechanics.)

Roger Penske split his Indy 500 effort in 1986 as Rick Mears and Danny Sullivan were given the same March-Cosworth package Rahal used and Mears duly placed it on the pole. The third Penske teammate, Al Unser, was equipped with a Penske PC-15 chassis and a brand-new Ilmor-built Chevy.

Al Unser

(ABOVE: Sleek and different, the Penske PC-15 equipped with the new Ilmor Chevy engine would evolve into the package to beat by 1988.)

Among the sea of Marchs, Lola’s new T86/00 was also present in the hands of Mario Andretti and Al Unser Jr, among others.

(BELOW: Andretti’s Lola lacked the crisp details that made the March a standout performer at Indy.)

Mario Andretti

Danny Ongais even had a volcanic Buick turbo at his disposal to give the race three unique chassis and engine manufacturers.

Danny Ongais

(ABOVE: Ongais was the highest-placed Buick runner in 23rd. His day ended with engine problems after 136 laps.)

There was, however, no escaping the fact that with 24 Marchs on the grid, and Rahal’s Truesports team was more than ready to take on Mears, Andretti, and the best the 1986 race had to offer. Like the successful single-car Rahal Letterman Lanigan Verizon IndyCar Series team he runs today, Bobby points to engineering strength as a key differentiator between his No. 3 Budweiser 86C-Cosworth and the rest of his rivals using the same package.

Add in Newey’s fine work in the drafting room and the solid Cosworth powerplants delivered by VDS engines from Texas, and a winning combination was formed.

“’85 was Adrian’s first real 100% responsible design, and then of course ’86 yet again,” Rahal said. For me, certainly, after the ’85 year, which we had a very good year, then Adrian left, which really bothered me to no end. [For 1986] we had a great engineer, [but] not a lot of people know about Grant Newberry who was a young guy and got thrust into the limelight, so to speak.

“Grant, we worked well together, and we really had a good feel for that car. Those days you carried 40 gallons of fuel. And so the car would really change dramatically over the course of a fuel run. So you really had to make a decision where [do you] want the car to be best? At the beginning of the fuel run or at the end of it? And we really had a good feel for what we wanted in the car from the start of the race. And it was just getting better and better as the race went on.

“[And] Our engine … from the day I started in Indy cars in 1982, our engines were always built by Franz Weiss [at] VDS engines. Franz had been Chaparral’s builder from the 60s, Chaparrals with Chevy V8s. Franz, I think, and his guys are the best. Mario had Franz Weiss engines as well. I don’t know if we had the most power, I mean, it certainly was competitive, for sure. But I think we had more drivability, and we certainly had more reliability.”

(BELOW: Of the interesting differences between Marchs, many used a large cooling duct at the base of the engine cover that fed multiple sources.)

Bobby Rahal

(BELOW: And some, like A.J. Foyt, ran without it and made modifications of his own to the engine cover.)

A.J. Foyt

Although the March 86C was the class of the field at Indy, Rahal says the car wasn’t perfect. Treat the steering wheel with too much aggression and the consequences would be revealed on the stopwatch.

“I remember Indy in ’86, Rick [Mears] and I, we were racing from about one-third of the ways through the race to the end, and Rick was always faster than I was in the first part of that run and each run after a fuel stop,” he said. “But then as the fuel load burned off we would catch him. That is kind of what we did all year, everywhere we went. If we were going to cheat the car a little bit we’d always cheated in the beginning. You have to be careful not to burn the front tires off.

In fact, I remember in Michigan in 1986 where we won—I mean, you literally could not, if you leaned on the front tires they would just go away within a few laps. You had to be patient because it was hard to watch Michael [Andretti] take off and run. But sure enough, 10 or 20 laps into the fuel run, here he comes.

“So just really, you really had to know where you wanted the car to be best and tune the car that way. And we were able to do that, there was no question that is why we did as well as we did that year, is Grant Newberry did a great job with the whole team and together we generated a lot of success.”

(BELOW: At the back of the car, Newey put together a tidy suspension and damper package that used rocker arms and bell cranks to operate shocks placed atop the transmission.)

Engine Hub

Rahal would go on to lead 58 laps and head a March 1-2-3-4 to the finish line. More than 30 years later, he still marvels at the shape and advanced performance attributes Newey’s 86C had to offer.

“That car, it looked fast standing still,” he said. “That was just one of those deals where—when that car showed up it looked like it would have been more than one year between the evolution of that and the 1985 car, it looked like it was about five years’ difference.”

Listen to the full Rahal interview about his 1986 Indy 500, the 86C, its engines, and whether he believes his son Graham is capable of capturing another Indy 500 win for the family.


About The Author

Marshall Pruett

Marshall Pruett transitioned from more than 20 years as an open-wheel and sports car mechanic, engineer and team manager into his current role as a writer and reporter in 2006. Follow him @MarshallPruett []