Turbomachinery in Racing

While Formula racing is well known for its use of standardized turbocharged V6 engines in all races, they’re certainly not the only races where turbocharged engines are used; and in some cases, the vehicle isn’t even a car! Today’s blog is going to look at turbomachinery in racing, starting with the origin of their usage, and looking at some of the different applications where these machines are found.

As we covered in recent blog, turbocharging has been around since the turn of the 20th century, however its applications was limited for a time to heavy-duty marine applications; high-end cars and trucking; and military aviation. By the 1950’s that had changed thanks to Cummins’ entry in the Indy 500, with their advanced turbodiesel engine raising eyebrows until it catastrophically failed. The point was made though, as Indy banned turbodiesels from the races going forward.  Current IndyCar engine specs call for a 2.2 liter V6 engine that is twin-turbocharged with a fixed boost level. These engines can crank out an astonishing 700 horsepower at full chat, which is around 12,000 RPM. If you’re curious about just how Honda is getting this supercar levels of horsepower out of such an engine, I definitely recommend having a look at the magnificent explanation done by Jason Fenske from Engineering Explained.

On the left #28, the Cummins Diesel special which had the famed turbodiesel engine, and on the right, the 2.2L Honda IndyCar engine. Images courtesy of Truck Trend and Engineering Explained respectively.

We’ll circle back to turbocharged road racing in a moment, but let’s talk about jet engines and the H1, first. Started in 1946, H1 Unlimited is a racing league where teams compete using hydroplanes (not to be confused with the extremely dangerous condition that occurs on wet roads). These hydroplanes rely on lift as opposed to their buoyancy to maintain high speeds and maneuverability. After World War II, the surplus of aircraft engines like the famed Rolls-Royce Merlin V12, discussed in an earlier blog, found their way into these high speed watercraft.

The Lycoming T55 turboshaft engine, powering everything from Chinooks, to race boats. Left image courtesy of Mr. Z-man

In modern times however, H1 Unlimited has now standardized the engines used in competing hydroplanes, and all craft must now use the Lycoming T55 turboshaft engine, which was originally used in the famed Boeing CH47 Chinook helicopter.

The T55 is a versatile engine used in a number of different aircraft and applications outside of the Chinook, including in turboprop applications such as the Piper PA-48 Enforcer, and other small aircraft. The commonality of this engine and its parts more than 60 years after it was first introduced makes it a great choice for the H1 Unlimited Racing league.

In the 1950’s and 60’s the gas turbine was making its rounds in automotive R&D. Chrysler had offered the Turbine Car to the public in 1963, while General Motors was turbocharging some of the engines in its lineup. Both companies found limited success. In racing, however, the gas turbine hadn’t won any races yet. That was all about to change with the debut of the Howmet TX.

The TX, a racecar prototype which stood for “Turbine eXperimental”, was created in 1968 by Ray Heppenstall, using a chassis provided by McKee Engineering, a gas turbine engine from Continental Aviation and Engineering, and financed by the Howmet Corporation (1). Although this would not be the first racecar to use a gas turbine engine, Heppenstall, with the help of the Howmet corporation, would make history. The engine from Continental was originally to be used in a light observation helicopter for the US Military, however Continental had lost the bid. The engine was the TS325-1, a turboshaft engine similar in purpose and function to the Lycoming T55 we discussed above. This smaller engine put out a respectable 325 shaft horsepower, with 650lbs feet of torque at stall, and weighed only 170 pounds, a fraction of the weight of an equivalently sized three liter piston engine (1). The engine equivalency formula used put this engine in the three-liter piston class, and rated it to 2960CC, or just under 3 liters (1). By using a wastegate between the gas-generating and the power turbines, Heppenstall was able to overcome the turbine lag which causes poor throttle response in turbine engines, and one of the largest disadvantages for turbine engines when pitted against reciprocating engines.

The TX's secret to success, a turbine engine fitted with a wastegate, mounted on a space frame chassis.
The TX’s secret to success, a turbine engine fitted with a wastegate, mounted on a space frame chassis. Image courtesy of Peter Stowe.

Circling back to Formula racing, the engines used have come a very long way, from screaming V12 engines, to the modern turbocharged V6 engine which is now the standard. But how did this come to be? How did we go from 12 naturally aspirated cylinders, to 6 forced induction cylinders?

Well, like so many other things in life the changes were gradual and progressive. By the late 1970’s Federation Internationale De L’Automobile (FIA) allowed naturally aspirated engines to displace 3 liters, while forced induction engines were to be no bigger than 1.5 liters. While superchargers had long been the “go-to” option for compressed engines, it was about to change in 1977, when Renault entered the ring with the R01 car, and the RE20 engine by Renault-Gordini (2). Although the investment was significant, the engine’s performance spoke for itself, and soon every other F1 team was jumping on the turbocharger bandwagon.

The Renault Gordini turbocharged V6; the first step toward complete forced-induction in Formula 1. Image courtesy of Formula 1 Dictionary.

Just 2 years later, a turbocharged engine won a world championship Grand Prix; it was a Renault, driven by Jean-Pierre Jabouille, at the French Grand Prix in Dijion (2). It wasn’t long before other teams got in on the turbocharger game, with Ferrari and Ford following suit. Most of these engines were twin turbocharged V6 engines, however there were exceptions such as Alfa Romeo’s V8 and BMW’s inline 4 engine. These turbocharged engines were boosted to unprecedented horsepower and in turn speed levels. As a result, FIA limited turbocharger boost levels in 1987, and then outright banned turbochargers in 1989, putting an end to the “free reign” of turbochargers in Formula racing.

Fast forward to 2014, and turbochargers were now allowed in Formula racing again albeit in V6 engines as opposed to the traditional V8’s and other larger displacement and cylinder engines. Although the turbochargers aren’t directly governed, the fuel consumption of these engines is significantly lower than in previous generations, and as a result these engines and teams are having to find new ways to improve turbocharger and engine performance with what resources they have.

This is where R&D tools such as AxSTREAM for turbocharger design and performance map generation, GT-POWER for engine simulation, and STAR-CCM+ for advanced aerodynamics analysis come in. Using these tools, a team is able to determine just how to best run their engines, and how to nab first place in the next Grand Prix. So whether you’re at Le Mans, Indy, or you’re out on the water, if you want to go faster, consider turbomachinery for everything from turbocharger boosting to jet engine power!

If you’re working on an R&D project where a turbomachine is being used, what are you waiting for? Reach out to us at info@softinway.com and see how AxSTREAM can help you now and with future projects.

References

  1. Stowe, Peter. “The history of the Howmet TX turbine car of 1968, still the world’s only turbine powered race winner”. Web.
  2. Formula1 Dictionary.