LIMITATIONS ON HOME-BUILT TURBO PROJECTS, PART II

By 460-BBF-Turbo-In-CC (from the legendary Car Craft turbo thread**)

"The man with insight enough to admit his limitations comes nearest to perfection.” – Goethe

4. Fuel quality – The trickest engine in the World is useless if you can’t obtain or afford its fuel. The most obvious limit on the amount of power you can jam out of a street/strip engine is going to be fuel quality. A few lucky Car Crafters have access to E85. An even smaller number will put up with the hassle of using racing fuel. But everywhere else, practical street/strip cars have to burn weak pump gasoline most of the time.

5. Parts quality – It does little good to PLAN a 1000 h.p. turbo engine if you’re using a production block and reciprocating assembly that self-destructs at ~ 600 h.p. So we’ve got to be realistic about how much abuse we can expect the parts we’re forced to work with will absorb.

6. Loyalty and style – Most turbo Car Crafters are going to build a make and model of car that appeals to them for reasons other than pure objective performance. That usually means the turbo project car is going to be heavier, less aerodynamic, and less weight-balanced than optimum.

And our powerplant choices are also often made based on personal history, brand loyalty, or whatever we’ve already got. They’re not usually based on what is the best engine design available to meet our chosen performance parameters. But a great thing about turbocharging is that it can be a huge equalizer for those committed to “obsolete” engine designs.

Moreover, many of the choices we make in crafting a project car are for reasons other than hitting a performance target. As David Freiburger once observed, this sport involves a big fashion component. It also nurtures some fairly strong traditions and peer pressure. Thus, one of our limits will be our self-imposed sense of what looks and feels “right” without regard to objective performance.

The GN/Type-T Regal is a perfect example of a turbo project car that is often picked for reasons other than optimum performance potential. Objectively, they're boxy. They're relatively heavy. They have poor weight distribution. They're saddled with an obsolete two-bolt main six and a cast crank. The cylinder heads are fairly restrictive. The factory turbo system was hardly optimized. And in stock form, they're down about 80 h.p. or more to many modern DOHC V6s.

So from a purely objective assessment of performance potential, there are plenty of better choices for a turbo project car. But over the past 25 years, Turbo Buick Car Crafters have often built these cars to be brutally fast and quick! And we're all glad that they have! The point here is that if you're carrying a torch for something that's off-beat or that has less than optimal hop-up potential, you should be honest about it going in and adjust your PLAN, budget, and performance goals accordingly.

**Reposted with permission of the author.