Five NASCAR Sprint Cup Series engine builders collectively tested the new fuel injection system for the first time at Kentucky Speedway.
Hendrick Motorsports, Earnhardt Childress Racing Engines, Roush-Yates Racing Engines, Toyota Racing Development and Penske Engines had all cars running on Thursday at Kentucky with nominated test drivers, sharing the track with Cup regulars in an unusual test day ahead of the race weekend, as NASCAR's top series races at the 1.5-mile oval for the first time.
Although teams have been working with the systems for some time already, the test allowed NASCAR to collect some data from all four manufacturers as both the sanctioning body and the competitors worked on honing the implementation of the McLaren Electronics units to their engines.
"You have to remember, as far as the fuel injection goes, many of the teams have been testing a form of fuel injection over the past two years, two and a half years anyway," said NASCAR vice president for competition Robin Pemberton. "A lot of our engine builders out in the field, they do build engines for other forms, other leagues. They do have experience with that. All the input that we're getting, all the feedback is things are seamless right now."
NASCAR veteran Mike Skinner drove Toyota's fuel injected car, also taking some laps in a carbureted car. He said behind the wheel he could hardly tell any differences between the two, although while attempting different mapping settings on the unit he saw variations in performance.
"I drove both today, as you know, and on the race track at first you could tell a lot of difference, but we didn't have this thing worked out," said Skinner. "Each map change that they've made - they went backwards, they went forwards, they went backwards and they went forward - the last three runs have all been forward. On the racetrack now, I'm not so sure you can tell a big difference at all."
Nationwide Series regular Ricky Stenhouse drove the Roush fuel-injected car, setting the 16th fastest time in the final practice session of the day, close to three tenths of a second off the fastest carbureted Ford in the session.
Toyota Racing Development's president and general manager Lee White said engine builders are still trying to catch up with the carburetors in terms of horsepower and believes it will be tough to match the outputs for now given how much development has gone into the carburetors through the years.
"The carburetors are so highly evolved and do certain things so well, I'm not sure at this point I think we're still a few horsepower behind the carburetors are," said White. "Given what happens with the phenomenon of charge cooling with the carburetor sucking the air through at very high velocity, which actually cools the air to a great degree and then mixes it with fuel in that process, you don't do that with the fuel injection.
"You don't have that charge cooling effect which helps multiple horsepower, so we'll see. I think everyone here would agree that it will be very hard to make more power with the fuel injected engine than where we're at with the carburetor."
Hendrick Motorsports' R&D Jeff Andrews believes fans will hardly notice any difference between the carburetor and fuel injected cars, while engineers have obviously seen improved fuel economy. His outfit ran a car for Nationwide Series regular Aric Almirola during Thursday's sessions.
"There will be some good efficiency gains that are being made there with this fuel system in terms of fuel economy," said Andrews. "But in terms of performance, the power levels between a carbureted and a fuel-injected engine are very close; so you won't see a dramatic increase in lap times. The car is still going to sound the same. It's still a Chevrolet R07 fuel-injected racing engine and they'll be no difference there for the fan."
Ford Racing's Dave Simon said one of the challenges the new system poses has to do with all the new parts fuel injection brings in and the durability associated with each of them. However he expects a seamless transition from the carburetors at the start of the 2012 season.
"There is something like 50 new components under the hood and all of them are going to have a different life span," Simon said. "We have to figure out what that is. From here forward that is one of the biggest challenges that we have. I think again that if all the cars run well as they are supposed to, you won't see much change in competition."
He added: "From here forward we have a number of track tests and a lot of dyno testing. We have a full durability program planned. There will always be things that maybe you didn't account for or just unexpected failures. We have that now... I think that the season will start without too much drama."
Cup teams will have a further collective fuel injection test later this year at Phoenix, although they will carry on with their own development programs ahead of the 2012 season opener.