Whether a drag-racing bully with a supercharger bursting through its hood or a Trans-Am road racer, modified Camaros embody everything a fast car should.

“I like the wheelbase and stance of the first generation car,” explains Mark Stielow, 48, whose hobby is modifying 1967-1969 Chevrolet Camaro coupes into Porsche-slaying supercars. “I do one car at a time. I get an idea, a vision, and I do that for 18 months in my shop.”

The Stielow-built Camaros are not old cars with some hop-up parts bolted on. They are fully re-engineered, monstrously fast, 800-horsepower beasts. And Stielow himself is no mere mechanic sneaking in projects between tune-ups and smog tests. He is a trained engineer  whose day job at General Motors (GM) has recently consisted of shepherding the development of the new 2014 Camaro Z/28 – the limited-edition muscle car that debuted at the 2013 New York auto show.

Whether old or new, the best of all Camaros converge at the  feet of Mark Stielow.

Over the last 25 years, Stielow has built 14 Camaros in the shop behind his house in Royal Oak, Michigan, sourcing clean, rust-free donor bodies primarily from California. Each build is more refined and faster than its immediate predecessor. His first car was lightly modified – a traditional street machine in the Car Craft magazine tradition – but  his latest, called Mayhem, is a 1967 Camaro built around a chassis that uses a custom, hydro-formed front subframe, a rear axle located by Stielow’s own coil-spring suspension system and a stupendous 800hp engine that is, to oversimplify, the bottom end of a Corvette Z06’s 7-litre LS7 V8 mated with the supercharger system and cylinder heads of the Corvette ZR1’s LS9 V8. Throw in huge disc brakes with their own anti-lock system, a carbon fibre hood to knock some weight off the nose, a rack-and-pinion steering system developed through obsessive trial and error, massive 335mm-wide rear tires and 10,000 details that only Stielow would notice, and you have a car that will vaporise almost any racetrack.

Stielow’s 13th car, a 1969 model named Red Devil, is mechanically similar to Mayhem, though it lacks the carbon fibre diet. It roars to life but settles quickly into a smooth 750rpm idle. Even though it is likely the most well-wrought ‘69 Camaro on earth, it is still a raw machine. The engine torque rocks the car when the throttle is blipped, and it takes a manly shove to put the six-speed manual transmission into first gear. It is a hot rod, not a car for impressing your date while club-hopping in Miami Beach.

And it is blisteringly quick. Think zero to 60mph in under 4 seconds, with the quarter-mile flying by in under 12 seconds at over 125mph. It pulls more than force of gravity on a skidpad and will hang with many of the world’s most exotic track-day specials.

Stielow is starting work on his 15th Camaro project in his shop. His previous cars have been sold, even though he is not really in the customer car business. Maybe when it is done, he will sell number 15 to you – if you have around $250,000 and can beat everyone else to the front of the line.

Theoretically, you could build one yourself. But admit it: you’re no Mark Stielow.

Then again, you could just go to a Chevy dealer and order up a copy of Stielow’s other Camaro.

Then try…

As an experienced suspension engineer with a passion for Camaros, Stielow was a natural choice for GM to appoint as program engineering manager for the Z/28 – basically the guy who pulls together the resources and talent necessary to get the car into production.

“The fifth-generation car has really grown on me,” says Stielow about the current Camaro. “I’m extremely comfortable with them and they’re built like tanks. They’ll take a hit and I feel secure with going very fast in them. The Z/28 is a balanced package, like my hot rods. You kind of touch everything to make sure it all works together.”

Optimised for on-track performance, the Z/28 uses the hand-assembled, naturally aspirated 7-litre LS7 V8 from the Corvette Z06, which produces more than 500hp. That is down from the 580hp in the supercharged Camaro ZL1, but it is a lighter weight engine, and altogether the Z/28 weighs about 300lbs less than the ZL1 and 100lbs less than the far more ordinary Camaro SS. Under hard acceleration, the exhaust system bypasses the mufflers, promising a momentous V8 sound. The only transmission available is a version of the same Tremec six-speed manual Stielow has used in his hot rods.

“The whole thing works in context,” says Stielow of the Z/28. “We put a big 11in-wide wheel on the front of the car, and we kind of pushed the engineering envelope to put it into production. It’s a very form-follows-function car.”

Beyond the inherent technological advantages of the new car – including independent rear suspension and a vastly more robust structure – the new Z/28 has thumping 305/30ZR19 Pirelli tires at each corner and huge Brembo carbon ceramic disc brakes. GM claims it laps some road courses three seconds quicker than the more powerful ZL1 (but is being intentionally vague about exactly what courses those are). And thanks to careful air management that keeps those brakes cool despite hard use, it should be able to do it lap after lap.

When the Z/28 enters production this fall, it will be the most narrowly focused of all Camaros. It can run on streets, but it is built for racetracks. It won’t be the raw-nerve machine any of Stielow’s hot rods are, but it will still be hardcore and come with a warranty. And as long as you have about $60,000, it is vastly more accessible than those other Stielow builds – if not half as maniacal.