aero car article from nascar.com

[held1823]

http://www.nascar.com/news/120614/maumann-cglotzbach-ballison-first-restrictor-plate-race/index.html

Yarborough falls short in first restrictor plate race

Fords had fuel mileage advantage in race at Michigan, but Dodge takes the win

By Mark Aumann, NASCAR.COM
June 14, 2012  

With speeds during April's tire test at the newly-repaved Michigan International Speedway well in excess of Ryan Newman's track record, crew chief Todd Gordon believes someone might turn a 200 mph lap in qualifying.

But it's not the first time there's been talk in the garage about speeds at Michigan being too fast. Consider the 1970 Yankee 400, when some of the top drivers of the day suggested NASCAR do something about escalating speeds, which resulted in the first restrictor plate race.

That was the year the wildly inventive -- and controversial -- high-winged Plymouth Roadrunner Superbirds and Dodge Chargers burst onto the scene to challenge the Ford Torinos and Mercury Cyclones.

Suddenly, aerodynamically superior cars were creating a rapidly escalating speed war, touched off by Cale Yarborough's 194.601 mph lap at Daytona in February, and peaking with Bobby Isaac's a-tick-under-200 mph lap of 199.658 mph at Talladega in April.

It was obvious the cars were too fast for the tire compounds of the day. So Isaac, David Pearson and Bobby Allison were called on to do testing to find a safer speed. With their input, NASCAR officials mandated the use of a restrictor plate on superspeedways, beginning with the August race at Michigan.

Unlike today, when identical plates are used for every car in the garage, the rules then were specific to manufacturer and engine size. Small block engines were exempt from needing a plate. And because the Dodges and Plymouth hemi engines had dominated most of the season, they were given a more restrictive plate than the Fords and Mercurys.

Even with the plates on, the top three spots in qualifying were captured by Mopars: Charlie Glotzbach and Isaac in Dodges, followed by Richard Petty in his Plymouth. Yarborough, driving for the Wood Brothers, qualified fifth.

Glen Wood, the braintrust for the Wood Brothers operation, knew the Dodges and Plymouths were having to use more fuel to keep pace with the Ford teams. Wood did the calculations and realized Yarborough could conceivably make the 400-mile distance on three stops, compared to four for the Dodges, negating any speed advantage they might have on the track.

Even if the Dodges could put together four perfect stops, Wood believed his crew could build a big enough advantage with just three good ones. If this was going to be a high-speed version of the tortoise and the hare, Wood was confident the tortoise would prevail again.

When the race began, Glotzbach, Petty and Bobby Allison -- all in Mopar equipment -- immediately went to the front and began pulling away. But when they each had to pit, Yarborough stayed on the track and built a sizable cushion.

Glotzbach's speed advantage eventually allowed him to catch and pass Yarborough, but he realized he'd have to stop again for service -- and Yarborough would get the lead back. And the lead leap-frogged that way all afternoon.

However, Glotzbach eventually figured out how to keep Yarborough from tucking back up behind his No. 99 Dodge, which allowed the slower Ford to conserve even more fuel in the draft.

"I watched Bobby run the track, "Glotzbach said. "He was zig-zagging to break the draft. I had never tried that before but I did today.

"I had a problem early in the race trying to get away from some of the guys. Then I saw [Allison] and did the same thing. I would drop low and under them and cut them off. It worked."

Once all of the scheduled pit stops had been completed, Yarborough led Glotzbach by a large margin, with Allison in third as the only other car on the lead lap. While Glotzbach was making up time on every circuit, it appeared Yarborough might have just enough of a lead to hold him off.

Yarborough was ahead by eight seconds with nine laps to go when the engine in his Ford hand-grenaded in the first turn, pouring parts, oil and fluid all over the track. That handed the lead over to Glotzbach but also allowed Allison to not only pit twice for fresh tires, but to close directly behind Glotzbach for the ensuing restart.

Except there never was a restart. The final eight laps were run under caution as track workers feverishly worked to try to sop up the mess. As a crowd announced at 34,500 voiced their displeasure at not getting to see a full-speed sprint to the finish, Glotzbach took the checkered flag, his first win in two years.

Allison was philosophical afterwards.

"What can you say? That's all a part of racing," Allison said. "I would much rather have finished under the green if it had been possible.

"There's no way to tell how it would have come out if Charlie and I could have run for it."

NASCAR tinkered with the restrictor plate rules for much of the next three seasons -- mainly at Daytona and Talladega -- before shelving the project. Speeds then gradually climbed in excess of 210 mph at both tracks before a harrowing accident involving Allison at Talladega in 1987 forced the reintroduction of engine restriction.

[odcics2]

2nd race I ever saw. Cale really dumped the engine! "Grenade" described it to a "T"...   Maybe he was running a little too lean to get better mileage?
All those engines got around 4 mpg, give or take.   Till this day: restrictor plates suck.