Bentley is a quarter-million dollar automobile, people who can afford a Bentley don't mind dropping $40 for fuel every other day, or the several thousand dollars that any major repair would cost. GM would have no trouble making a raging beast out of a 350, but they have to sell enough of them to make money, too. If you're wealthy, fuel economy and insurance costs are distant consideration, but then if you're wealthy, you don't buy GM automobiles. Ergo, GM has to develop products that appeal to the sensibilities of consumers who don't have deep pockets, but want a little kick under the hood.
Here's how Buick came to slap a Garret Turbo on their V6. Buick had the official Pace Car of the Indy 500 back in 1975. They used a 1975 Buick Century Custom with a modified 455cid big-block monster. It was too slow. Yes, too slow. Low-end torque was brutal on the 455, but the requirements of an Indy Pace Car dictated that the car be able to achieve certain high speed and acceleration characteristics; 90MPH out of turn three, 110MPH out of turn four, and it needed to hit pit entrance at 120MPH.
The 455 "Free Spirit" Century Custom could accomplish these requirements alright, but it required dropping the accelerator to the floor and standing on it. It was clear to Buick engineers and the Indy Pace Car Team that the 455 was simply out of its element in high speed situations.
So when Buick was again handed the Pace Car duties for 1976, Buick engineers wanted to showcase Buick's engineering talents. Having the Pace Car presented an outstanding opportunity to promote your stuff to the public back then, probably much more so than is true today. There was a palpable "buzz" over the Pace Cars back then that doesn't exist today.
Buick wanted to present something fresh and out of the ordinary, and 650lb large displacement gaz-guzzlers didn't fit that bill in 1975. Everyone offered a large fire-breathing V8 that cost more to put gas in than the purchase price of the vehicle and insurance companies were severely penalizing powerful V8 cars.
A couple years before, Buick purchased its V6 back from AMC-Jeep, which it had sold to in the 1960's when interest in the V6 was low. Buick was determined to make this engine successful as it needed a smaller displacement engine that it could leverage in the economy-conscious markets.
An Explorer Scout Post supported by Buick had already been experimenting with turbocharging when the call went out to do something different with the Pace Car. The project leader had contact with Buick higher-ups and reported some interesting results by turbocharging a V6. The rest is history.
Buick managed to put together a turbocharged V6 for the 1976 Indy Pace Car (same Century body but with minor model changes) that delivered 306HP and 370ft-lbs of torque. High speed acceleration times from 90MHP to 120MPH were cut in half over the 455cid behemoth while getting better overall fuel economy.
When you can start a fire with a piezo ignition device, why wait around for lightening? Technology is good, embrace it.
