Mercury Cyclone Spoiler II That Got Its Owner Into the 150mph Club At Bonneville

Retired printer Michael Callahan wanted to join Bonneville’s 150mph Club under his own power, and found his answer in a 1969 Mercury Cyclone Spoiler II, one of roughly 503 built purely to satisfy NASCAR’s homologation rules. Most muscle car fans have never even heard of the car, despite its 8 Grand National race wins tying the far more famous Plymouth Superbird. Read on to find out how an obscure aero-war special ended up chasing land-speed records decades later.

Somewhere in a garage in Cincinnati, a retired printer was chasing a number most gearheads never even attempt: 150 miles per hour, under his own power, no trailer, no support truck, just drive there and drive home. Michael Callahan had already flirted with triple digits in a Bondurant-built Crown Vic packing a Jack Roush-tuned Mustang Cobra valvetrain, but that car was never going to crack 150. What he needed was something aerodynamically slippery and mechanically willing to be pushed, and in 2015 he found it for sale in California: a 1969 Mercury Cyclone Spoiler II, one of the strangest and most overlooked homologation specials Detroit ever built. Most muscle car fans have never even heard of it. That’s exactly what makes it worth telling.

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A NASCAR Rulebook Built This Car, Not a Marketing Department

In 1969, Ford and Mercury were locked in NASCAR’s aero wars with Dodge and Plymouth’s winged cars, and the rulebook was blunt: if a manufacturer wanted that slippery long-nose bodywork on the superspeedway, it had to sell a version of it to the public first. Mercury’s answer was the Cyclone Spoiler II, and Mercury built almost nothing of it — roughly 503 units total, though some sources push the figure to 519, split between about 285 Cale Yarborough Specials finished white with red trim and roughly 218 Dan Gurney Specials in white with blue. That split between the two special editions gave Mercury a way to court both NASCAR’s Southern fan base through Yarborough and its more cosmopolitan road-racing following through Gurney, all from a single homologation platform.

Every Street Car Left the Factory Tame

To satisfy the letter of the homologation rule, every one of those street cars left the factory with a 351 Windsor, a column-shifted automatic, and a front bench seat — about as far from race trim as a ‘race car’ gets on paper. And there was no factory way around it: unlike the regular Cyclone CJ with its 428 Cobra Jet, the Spoiler II was never offered with a big-block at all on the street version, so every single street copy left the line tame next to what showed up at the track that same season.

Raced Different From What You Could Buy

The cars Mercury actually raced barely resembled what sat on dealer lots. Early in the ’69 season, Cyclone Spoiler IIs ran Ford’s FE 427 side-oiler, the same warhorse racing engine Ford had leaned on since 1963, before NASCAR finally signed off mid-season on the Boss 429, giving Mercury’s race team a genuine power upgrade partway through the year without requiring any change to what customers could order at a dealership.

Eight Wins and Almost No Credit for Them

It paid off: Cyclone Spoiler IIs won 8 Grand National races across the ’69 and ’70 seasons, tying the win total of the far more celebrated Plymouth Superbird, despite getting a fraction of the recognition in muscle car folklore today. That obscurity is part of the appeal — a genuinely rare, genuinely raced piece of aero-war history hiding in plain sight among 500-some survivors that most collectors have simply never heard of. Considering how much less marketing muscle Mercury put behind the Spoiler II compared to Chrysler’s aero cars, an eight-win tally over two seasons represents a genuinely disproportionate return on a car most fans today can’t even picture.

Chasing 150 Miles Per Hour the Hard Way

Callahan’s goal wasn’t just owning a rare piece of NASCAR history — it was proving the car could still do what it was originally engineered to do, at genuine speed, on the salt at Bonneville. That meant treating the Spoiler II’s factory aerodynamics as a starting point rather than a museum piece, modifying it further for the specific demands of land-speed racing while keeping it street-legal enough to drive there and back under its own power.

A 130-Mph Warm-Up in a Bondurant Crown Vic

Before the Cyclone, Callahan had already proven he could hit serious speed in something unconventional — a 1999 Ford Crown Victoria originally built for the Bondurant Driving School and fitted by Jack Roush with a Mustang Cobra valvetrain, which got him into Bonneville’s 130mph Club. But he knew from the start that particular car had a ceiling well below 150, which sent him looking for a different platform entirely once he retired and had time to chase the bigger number.

Why the Spoiler II Made Sense for the Job

Callahan wasn’t hunting for any specific car when he started looking — his parameters were about what he could modify aerodynamically and performance-wise, not brand loyalty. The Cyclone Spoiler II’s factory-designed slipperiness, originally engineered to win NASCAR superspeedway races, made it an unusually good starting point for exactly the kind of top-speed project he had in mind, even though almost nobody else was thinking about the car that way in 2015.

An Obscure Homologation Special Finds a Second Purpose

It’s a strange kind of full-circle story: a car engineered specifically to be fast in a straight line on a superspeedway, sold to the public only because a rulebook demanded it, ending up decades later on the Bonneville salt flats chasing the exact kind of top-speed record its aerodynamics were always built for, just with a very different driver behind the wheel than Mercury’s factory team ever imagined.

Why So Few People Know This Car Exists

Part of the Spoiler II’s obscurity comes down to timing — it arrived in the shadow of Dodge and Plymouth’s more famous winged cars, and Mercury’s own marketing never pushed it the way Chrysler pushed the Daytona and Superbird. That’s left genuine survivors like Callahan’s relatively affordable compared to their Mopar rivals, at least for now, even though the underlying engineering story is every bit as compelling.

A Bonneville Attempt Rooted in 1969 Homologation Rules

Every run Callahan makes across the salt traces back to a NASCAR rulebook from half a century earlier, one that forced Mercury to build a street car nobody was supposed to actually push to its limits. Share your thoughts in the comments below.

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