All this romantic turbo stuff is built around a "very tired" four-bolt main 454 iron block that's currently 0.070-over. "We got one hole that's got something like 0.010-inch piston-to-wall," he says, yet the Camaro still makes plenty of power. There are very few exotic parts on the car except for eight precious metal pieces. David has learned that Inconel exhaust valves are a must when paired with turbo exhaust heat. "We popped the head off an exhaust valve in our boat once and found it stuck all the way up in the turbine housing." After that, David spent the money for the best exhaust valves he could find.
So how much power does this monster make? "I don't know," David opines. "You can't race a dyno, so it really doesn't matter." He will tell you that the Camaro has run 8.62 at 162 mph-hence the need for the rollcage and parachute. He'll also admit that the engine would run much quicker in a better car, a lament we hear quite a bit now that horsepower has become so easy to make. "It makes gobs of torque. The biggest problem is the motor makes more power than the chassis can hold. You can hear the tires squeakin' all the way down the track."
So with all this power, the misconception would be that this is a beast with neanderthal table manners. But cruising down the freeway or even down a deserted two-lane blacktop north of Glendale, Arizona, we quickly discover from the right seat that this car is as comfortable on the road as it is on the track. With 3.42:1 gears, 33-inch-tall tires, and a tight converter, the Rat loafs at around 2,300 rpm at 60 mph.
The streetability question extends even to David's choice of fuel. For a mild night out, the 8.0:1 compression easily supports a pump-gas routine, but David doesn't like the fumes. "We run Av-Gas for a little better octane and because it smells better," he says. That statement made more sense after gaining some seat time. With the turbos sticking through the hood, you still smell the fuel even though it's a blow-through system. By the end of the night, your eyes sting a little from the fuel-rich atmosphere that wafts back past the windshield. As for trackside duties, that's strictly race-fuel territory. He runs Sunoco Supreme NOS fuel, which at an amazing 117 is the highest-octane fuel you can buy. Remember, there's no intercooler on this package, so 16 psi worth of heat stuffed past that carburetor is an excellent reason to run the good stuff.
The Camaro is clean, functional, and eyeball-flattening quick when he applies the turbo boost. The regimen is almost always the same-run it hard, break it, fix it, and run it hard again. To some, that may seem like work. But David does it for the fun, and because he prefers two turbos and no waiting.
What: '67 Chevrolet Camaro
Owner: David Welker, long-time turbo guy
Hometown: Glendale, Arizona, a suburb of Phoenix where there are tons of very straight stretches of two-lane blacktop.
Techs: David gives credit to Joel Britt at Arizona Turbo (602/253-9953) and Billy Carroll at B&B Automotive Machine.