Turbocharging was never the hard sell in aircraft, locomotives, or heavy diesel work. The need was obvious: as air density drops, power drops with it. A turbo puts the air back. The real fight came on gasoline engines for passenger cars, where detonation, uneven fuel distribution, cold-start behavior, and emissions compliance all had to be controlled at the same time. That is why turbocharging existed for decades before it became common in production cars. Once fuel economy and emissions rules tightened, the question changed from whether a turbo worked to whether the whole engine system could be made to work every time. Detonation sensing, better air-fuel control, and more precise fuel delivery were the keys that moved turbocharging from race, marine, and experimental programs into real vehicle development. Europe got there first. The U.S. took longer. But the path was the same: solve the combustion and control problems, and the turbo becomes the right tool.
In this episode of Speed School, Gale Banks continues his long-form conversation with Walt Ware, a friend and engineering colleague he has known for more than 50 years. Banks frames the discussion as a continuation of the previous episode, which covered Ware's early career and his work on engine development and testing for the SR-71 Blackbird. This installment shifts to Ware's move to Garrett and the beginnings of his turbocharger career.
Banks emphasizes that Ware's role in turbocharging had a direct impact on Banks' own work. Their careers repeatedly intersected around turbocharger development, racing, marine engines, and production vehicle programs. The episode is structured as a technical recollection rather than a formal history, but it preserves a clear engineering thread: how Garrett evolved from an aerospace company into a major turbocharger supplier, and how Ware became one of the engineers pushing turbocharging into automotive use long before it was widely accepted.
Ware explains that Garrett Air Research was far more than a turbocharger company when he joined it. The company had deep aerospace roots and worked on jet engines, auxiliary power units, hydraulics, space-program hardware, pressure suits for SR-71 pilots, and even unusual government and medical projects. He recalls that the company had a uranium centrifuge operation in a basement department and had also worked on an artificial heart in the 1970s. To Ware, Garrett was a playground for engineers who refused to accept that something could not be done.
Garrett's culture was shaped by unusually broad technical capability. The company made aircraft systems, propulsion hardware, and turbo machinery, and it attracted engineers who were comfortable crossing disciplines. That environment appealed to Ware, who had already worked in advanced engine programs and wanted to stay close to difficult, state-of-the-art machinery. Although Garrett would later become closely associated with turbochargers, Ware entered a company whose identity was still rooted in aerospace engineering and experimental development.
Ware says he left Pratt & Whitney after concluding that the career path he wanted was no longer available there. Garrett was recruiting aggressively for an advanced small turbofan program, drawing talent from Pratt & Whitney, GE, Rolls-Royce, and elsewhere. He was recruited into that effort and joined Garrett in late 1968, reporting in early 1969.
The engine program he joined was technically ambitious. Garrett had not previously built a turbofan of this type, and the design used a three-spool architecture at a time when single-spool engines were still common. The front of the engine used axial-flow compression stages, followed by a centrifugal compressor that functioned much like a turbocharger's compressor stage. The high-pressure section also used a radial-flow turbine. Ware describes the engine as turning the air through a total of 720 degrees from inlet to exhaust while extracting substantial work from the airflow. The program also introduced what he identifies as the first full-authority digital engine control, around 1968, requiring synchronization of three rotating groups. That was a major leap beyond the analog and hydraulic control systems then common in propulsion.
Ware also notes that Garrett's engineering bench included several German engineers brought to the United States after World War II. Some had worked on advanced turbo machinery, diesel submarines, and jet engines in Germany. He remembers interviewing and working under men with deep prewar and wartime turbo machinery experience, including engineers who had to evaluate problems with little more than a slide rule. That background reinforced Garrett's strength in turbomachinery and helps explain why the company was well positioned to expand into turbochargers.
Banks and Ware place Garrett's turbocharger work in a broader historical arc. They trace turbocharging back to Alfred Büchi in Switzerland, who developed the concept to restore air density for diesel engines operating at altitude, including railroad and marine applications. The underlying problem was simple: as altitude increases, air density falls, and naturally aspirated engines lose power. Turbocharging restores density and therefore combustion capability.
They also discuss early American aviation turbocharging. Banks references Sanford A. Moss and wartime turbo-supercharger development, noting that turbocharged aircraft engines dramatically increased altitude capability. A naturally aspirated aircraft engine that might have been limited to the high teens in altitude could, with turbocharging, operate in the high 20,000-foot range. That capability mattered in World War II, where aircraft such as the B-17 and B-24 used turbo-supercharging to carry heavy bomb loads at altitudes difficult for enemy fighters and anti-aircraft artillery to reach. The discussion reinforces a central engineering point that runs through the episode: turbocharging is fundamentally about restoring or increasing air density, whether for locomotives in the Alps, bombers at altitude, or automotive engines constrained by emissions and fuel economy.
Ware's transition from jet engines to automotive turbocharging came through a General Motors contract. Around the early 1970s, as emissions regulations and CAFE fuel-economy pressures began to reshape the industry, GM gave Garrett an early 1972 Monte Carlo and a group of Chevrolet 350 small-block engines. The assignment was to determine how turbocharging could preserve or improve vehicle performance while meeting emerging fuel-economy and emissions requirements.
Garrett did not yet have a complete automotive development infrastructure, so Ware became deeply involved in building the capability. He had previously acquired a large Lomita facility with multiple test cells, and that site became central to the work. The program required both engine-lab development and full vehicle emissions testing, including cold-start and drive-cycle work using Horiba emissions equipment. Ware describes the challenge as multidimensional: the engine had to maintain performance, improve fuel economy, survive detonation, and pass emissions testing repeatedly, including after a 24-hour cold soak.
At the time, detonation control was still primitive. Ware recalls propping open dyno-cell doors with a broom handle so engineers could listen directly for knock, despite the obvious safety and hearing risks. He then developed an instrumentation-based approach using accelerometers and filtered oscilloscope signals, focusing on the characteristic detonation frequency around 5,500 cycles per second. That allowed the team to detect incipient detonation before it became destructive. The work paralleled similar efforts at GM, where Jim Curry was developing a detonation sensor. Ware's conclusion from the Monte Carlo program was straightforward and, at the time, controversial: cars should be turbocharged. He wrote a major internal report to that effect, but management did not yet believe the market or the technology would support it.
Although Garrett management remained skeptical about turbocharged gasoline passenger cars in the United States, Europe moved ahead sooner. Ware notes that Garrett was already supplying turbochargers for European automotive applications, including Volvo, Saab, and German manufacturers, before turbocharging became established in the U.S. market. Banks adds context from his own work with Volvo and Bosch, particularly around oxygen sensing and closed-loop mixture control.
That European lead mattered because turbocharging gasoline engines successfully required more than just a compressor and turbine. It depended on air-fuel management, detonation control, and increasingly on fuel injection. Banks contrasts draw-through carbureted systems with pressurized carburetion and fuel injection, pointing out the mixture-distribution problems that occurred when atomized fuel passed through a compressor and then had to negotiate turns in the intake tract. He describes how fuel could centrifuge out of suspension inside the compressor and discharge in a helical pattern, creating uneven cylinder-to-cylinder distribution. Those issues contributed to durability problems in early turbocharged production engines.
The discussion also touches on Buick's early turbo V6 efforts. Banks recalls that the first pace-car-era Buick turbo systems used a carbureted draw-through arrangement and suffered from uneven mixture distribution, especially with rear cylinders running lean. Later fuel-injected versions improved the concept and eventually used Garrett turbochargers. The broader point is that Europe adopted turbocharging earlier because it was willing to integrate the supporting technologies-fuel injection, sensing, and calibration-needed to make it commercially viable.
While production automotive turbocharging advanced slowly, racing and marine applications moved much faster. Banks explains that he and Ware first connected through A.K. Miller and the Southern California performance community, where turbochargers were being used to set records and win races before Detroit fully embraced them. Ware supplied Garrett hardware into these efforts, sometimes informally, because he believed in the technology even when corporate priorities did not.
Banks describes using Garrett TE06 turbochargers, originally associated with Indianapolis Offenhauser applications, on twin-turbo marine engines. In one notable example, a twin-turbo alcohol-burning big-block Chevrolet in the Hondo jet boat Hurry Around Hondo proved overwhelmingly fast. In its first race, it was half a lap ahead by the end of lap one before a jet-drive thrust failure swamped the boat and sank the stern, exposing the hot turbo system to saltwater. Even so, the test demonstrated the enormous power potential of properly matched turbochargers. Banks says the Garrett units matched the engine so well that the wastegate could not bypass enough exhaust flow, forcing him to limit throttle travel mechanically to about 5/8 throttle while still outrunning the field.
The marine work also drove hardware innovation. Banks recalls receiving early water-cooled turbine housings from Ware, including aluminum versions, at a time when such components were not commercially available. Ware explains that turbine-wheel materials had to keep improving because gasoline engines ran much hotter than diesels. Garrett moved through progressively stronger nickel-based alloys, including 713 and MAR-M-type materials, to survive the thermal environment. Compressor-wheel retention also became an issue in severe transient use, such as marine acceleration, leading to improved shaft and wheel-drive geometry, including a tri-cordial shaft form that prevented the compressor from slipping on the shaft.
After the Monte Carlo program, Ware expected to continue pushing automotive turbocharging. Instead, Garrett management redirected him toward Caterpillar, Garrett's foundational turbocharger customer. Caterpillar had originally helped launch Garrett into the turbocharger business by asking the company to evaluate and improve an early turbocharger design. By the time Ware was assigned to the account, Caterpillar was deeply committed to turbocharging for diesel power density and productivity, but it was dissatisfied with aspects of Garrett's new TV-series turbochargers.
Ware did not want the assignment at first. He preferred gasoline engines and automotive work, while diesel engines seemed slow and unexciting by comparison. But Garrett's president pressed him repeatedly, and eventually Ware accepted. Once involved, he discovered that Caterpillar's expectations were exacting. The company ran its own destructive tests, including burst-containment evaluations, and challenged Garrett on durability, design details, and production readiness. Ware had to absorb the complaints, return to Garrett leadership, and then propose concrete corrective actions. He describes a pivotal debrief in which management told him to stop merely reporting Caterpillar's dissatisfaction and instead come back the next day with a plan to fix it.
That assignment became a defining part of his career. Ware ultimately satisfied Caterpillar and built a strong relationship with its engineering organization, but the success came at a cost: he never fully escaped the account. Even later in his career, including leadership roles and time in Europe, Caterpillar remained tied to his responsibilities. At one point Caterpillar told him Garrett had reached about 85 percent of its turbocharger business, exceeding Caterpillar's internal rule against allowing any one supplier more than 50 percent share. That comment underscored both Garrett's success and Ware's influence on the account.
By the end of the episode, the engineering story has reached an important transition. Ware has moved from aerospace propulsion into automotive turbo development, then into heavy-duty diesel turbocharging through Caterpillar, while Banks has been applying Garrett hardware in boats, record cars, and prototype vehicle programs. Their recollections show how turbocharging spread not through a single breakthrough, but through overlapping advances in materials, controls, sensing, emissions testing, and application engineering.
The conversation closes by pointing toward the next major chapter: John DeLorean's interest in winning Indianapolis with a small-block Chevrolet, along with the involvement of Smokey Yunick and Herb Fishel. Banks presents that as the next pivotal moment in the Garrett turbo story. This episode therefore serves as the bridge between Garrett's aerospace and diesel roots and the more visible racing and performance programs that would help turbocharging gain credibility in American automotive engineering.