IndyCar is the guiding light for engine manufacturers.
Downsized, turbocharged, high compression ratios, and exotic materials – this describes the 2.2 liter twin turbo V6 specified by the Verizon IndyCar series. These engines are designed, built and supplied by Honda or Chevrolet. The teams select which engine will work for their entries.
These engines have influenced many of the new powerplants that are powering cars on the road today. What is learned on the racetrack is having profound effects on the way automakers design and build engines. These engines include the 2.0 liter Drive-E engine from Volvo, the 3.5 liter D4S V6 from Toyota, the 2.7 liter EcoBoost from Ford and the 3.0 liter twin turbo V6 from General Motors. These four engines epitomize where engine technology is going. NASCAR nor Formula 1 has done what IndyCar has in advancing engine technology.
Let's start with the 3.0 liter twin turbo V6 from General Motors. Since Chevrolet is one of the engine manufacturers for the Verizon IndyCar Series, GM Powertrain development has direct access to the research and development pipeline. As a result, this 3.0 liter engine makes 400 horsepower and 400 pound-feet of torque.
Advanced polymer and metallurgical technology are used to handle the stresses that this engine experiences. Pistons need special friction coating. Connecting rods feature a high copper content. Thermal management is also extremely important. The cooling system must be able to handle stresses like stop and go and heat soak. This engine also uses an air to liquid charge air cooler to reduce inlet air temperature before it enters the cylinders. There is an enormous amount of engineering and calibration that goes into making an engine like this reliable in the unforgiving world of daily driving. On a fundamental level the trials and tribulations of the 2.2 liter V6 that debuted in 2014 and is still beings used today is the progenitor of this engine.
Displacement no longer is the measuring stick of high performance. IndyCars maintained speeds greater than 225 miles per hour out of 2.2 liters of displacement. Horsepower is a digital creation now. It is not based on the mechanical relationship between camshafts, distributors and mechanical fuel pumps. Engines can operate at peak efficiency in a wide range of conditions. With a simple computer retune, an engine like the IndyCar 2.2 liter V6 can be efficient on a road course one day and operate at wide open throttle on a speedway for hours the next. The average life of this engine is 2,500 miles. That doesn’t seem like much, but if you scale back the boost and the speeds and you find yourself staring at the second cousin of this engine, the 2.0 liter Volvo Drive-E engine.
Two liters is all Volvo needs to replace an entire range of engines. Just like the V6 in today's IndyCars, the Drive-E engine is tunable and can be calibrated to meet the exact need of a given consumer. For example, in the 2016 Volvo XC90 T6 with both a turbocharger and a supercharger makes 316 horsepower and 295 pound-feet of torque. The same engine in the Volvo S60 T6 front-drive model only makes 302 horsepower. With nothing but engine calibration they have created a perceived difference in both of these vehicles. Some might say a four-cylinder is improper or unsuitable for a vehicle like the XC90, but is that reality or just a narrative that dates back to the analog perception of power?
Race car drivers are looking for a competitive edge and are less concerned about the perceived prestige of greater displacement to achieve their goal of winning races. Volvo is realizing that power in the 21st Century is more about the perception of the driver while driving instead of the perceived prestige formerly associated with larger displacement engines.
Ford and General Motors have been long time rivals, and it is far from surprising that Ford would see the success of one of its main rivals on the race track and apply it to their own engine development programs. Ford’s marketing for these engines fall under the umbrella of EcoBoost. The engine that shows the most striking similarity to the IndyCar V6 is Ford's 2.7 Liter twin turbo V6 that is found in the Ford F-150 and Edge. This engine delivers 325 horsepower and 375 pound-feet of torque in the F-150 and 315 horsepower and 350 pound-feet of torque in the Ford Edge. This engine uses advanced metallurgy such as compacted graphite iron, a material mostly relegated to diesels, to allow for extremely high cylinder pressures, stratified or lean combustion and high load situations. This engine also has max boost of 17-18 pounds. This is actually very close to the amount of boost pressure used by the IndyCar 2.2 V6 during speedway competitions.
Ford is taking this to the next level with the upcoming return of the Ford GT. The new 3.5 liter twin turbo V6 engine will produce roughly 600 horsepower. Horsepower seems to only be limited by how much a consumer is willing to pay, and how much reliability and drivability is needed from a given engine.
Ford has been extremely successful with its EcoBoost line of engines. Power can now be calibrated exactly to the budget and expectations of their customers while reducing the complexity of their manufacturing process. EcoBoost draws a line between racecar and the engine in your truck, and that is a powerful message that interacts strongly with the consumer psyche.
Dual injection is a main feature of the IndyCar 2.2 V6. There are in-cylinder injectors as well as port mounted injectors. Both of these fuel injectors operate at the same pressure to pump enough E85, the fuel of IndyCar, into each cylinder. Toyota has developed a system known as D4S that features this type of dual injection system. Where IndyCar uses this to solve a fuel flow issue Toyota is using this technology to increase power, drivability and reliability.
Carbon build-up has been an issue with direct injected engines. The addition of injectors in the intake manifold insures that fuel and its detergent package makes contact with the intake valves. While this will not completely solve the issue of carbon build-up it does allow Toyota to benefit from the thermal efficiency of direct injection while increasing throttle response at low rpms and increasing high rpm power due to increased fuel flow while reducing some of the systems inherent limitations.
IndyCar is one of the most challenging environments for an engine to exist in. These challenges come from drivers needing to operate at the physical limits of the car and their own personal limits. The life on an engine on the road today is difficult for other reasons. Instead of having a dedicated team of engineers and technicians whose sole purpose is to properly maintain their race car, normal car ownership can be quite a bit messier.
Engineers at General Motors, Ford, Volvo and Toyota as well as all other manufacturers are putting advanced technologies, tested on race tracks around the world, into production cars. Exotic materials, direct injection and high boost pressures are no longer just someone with a tuned vehicle has to deal with, but are now in the hands of consumers who just want worry free motoring out of their new Tacoma or Volvo XC90. Every part of a daily driven engine is being pushed to new limits to eke out more power with greater efficiency. Doing all that with the knowledge of long oil change intervals and short trips filled with stop and go traffic is a daunting challenge.
Luckily, IndyCar unlike any other racing is guiding engine manufacturers to their next generation powertrains. NASCAR has barely come out of the carburetor era, and Formula 1 is completely devoid of any connection to consumer cars in general. Racing should be connected to the consumer. More engine manufacturers should be building engines for this series because it is obvious that the best lessons in engine manufacturing come from IndyCar.