LIMITATIONS TO BIG-CUBE HOMEBUILT TURBO PROJECTS, PART I

BY 460-BBF-Turbo-In-CC (from the legendary Car Craft Big-Cube Turbo Thread)

A man’s got to know his limitations.” – Harry Callahan, “Magnum Force” (1973).

The Jetfire V8 and recent Indy V8s can only provide limited guideposts for Car Crafters on turbocharging.

The comparison of these engines does show that success in turbocharging (huge torque & massive horsepower) depends on more than just sticking on any old turbo laying around.

But neither the Jetfire nor the Indy V8 would be good street/strip mills. Back in the early ‘60s, Oldsmobile dealers were often busy replacing blown head gaskets or removing Jetfire turbo systems and replacing them with four-barrel carbs. Bore corrosion was epidemic. So the Jetfire stands as a cautionary tale of what not to do.

And an Indy V8 on the street would produce horrible fuel mileage and unsatisfactory power below 5,000 r.p.m., even if you could afford the huge “buy-in,” packaging, and servicing costs. So Indy engines merely suggest general areas for improvement of street/strip turbo powerplants.

Thus, a practical PLAN for turbocharging a OEM production street/strip engine means building within the walls of a vastly different “box” of needs and performance expectations.

But before we identify our performance parameters and goals, we’ve got to take stock of the outer limits. We’ve got to know our limitations.

These limitations should be regularly consulted as we PLAN and build. They are a “reality check” on our turbocharged enthusiasm and creativity.

LIMITATIONS (Part 1):

1. Money – The big limit is always going to be money. While it’s not the same sum for every Car Crafter, everyone has a maximum budget. The only way a home turbo project becomes feasible for most Car Crafters is by avoiding the expense of custom-built parts and costly “experts” whenever possible. Thus, turbo Car Crafters are mostly stuck with mass-produced OEM and aftermarket parts and self-help labor. What is cheap and readily available often trumps what would be best.

2. Time – A close cousin to money is time. Most street/strip turbo Car Crafters are not engineers. Most are not professional fabricators. Most cannot spend every waking hour ironing out build problems or contemplating turbo tuning theory. So something that’s quick, relatively simple, and easy-to-build is almost always better than something so time-consumingly “perfect” that’s never completed.

3. Practicality – If it’s not practical, we won’t drive it very much. It’s that simple. A street/strip machine that guzzles race gas, or idles at 1500 r.p.m., or won’t start when it’s cold, or has to stop for refueling every 75 miles, or takes three hands and three feet to operate, or hides small children behind its giant hood scoop won’t stay attractive for long in the “real world, ” regardless of how “wicked” and “gnarly” it is in our imagination.