fter the conclusion of the NHRA Mello Yello Drag Racing Series at the Auto Club NHRA Finals in mid-November, the Pro Stock community has been working at a frantic pace in response to the 2016 rules that call for replacement of the traditional carburetors with new EFI induction systems and implementation of a 10,500-rpm engine rev limiter.
These changes, which will require a new engine research and development program and major changes to the car body, including the creation of an air-duct system, the removal of the iconic hood scoops, and the introduction of a new cowl-style hood, have created a level of activity that hasn’t been seen in the factory hot rod ranks since the category switched from the weight-break format to the 500-cid, heads-up configuration for the 1982 season. This is a brief preview of the new components that will be utilized in Pro Stock next year as the factory hot rods boldly step into the electronic-fuel-injection era.
Among the major challenges for the Pro Stock teams are fitting the new components to their engines and chassis frames, many hours of engine dyno time, adapting to the new laptops and software that will take the places of wrenches and screwdrivers for tuning, and ultimately making corresponding changes to the clutches, transmissions and rear-end gears, and suspension systems to adapt to the new power curves.
NHRA specifications call for an inlet opening with a maximum size of 80 square inches, and Haas fashioned two openings of 40 square inches each, with the middle section of the grille left intact for added strength. This is Alex Laughlin’s Gas Monkey Garage Camaro. Note also the flattened hood as scoops are no longer permitted in the class.
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NHRA, along with Holley, which will be providing the spec EFI systems, has been extremely active in helping teams expedite this changeover in the most efficient manner possible.
Timothy White, NHRA director of engineering, said, “When the decision was made for the EFI requirement, we looked at what was offered by the various manufacturers for an off-the-shelf product in order to limit time for implementation and to keep the costs down. Holley’s HP ECU system was selected because we felt it best met our desired needs. Since then, we have met with the Pro Stock teams to discuss air-induction issues on a weekly basis, and we are in contact with Holley every day.
“In terms of adapting to new technology and the amount of work required, this is a major project, and NHRA is making every effort possible to get through this transitional period.
“Holley has really gone the extra mile by not only offering tuning seminars, but also by sending Robin Lawrence, their EFI technical sales and motorsports manager, to visit each of the teams’ shops to help them with any particular issues that they are dealing with. We feel that this one-on-one approach is much more productive for the learning process than just phone calls or texting.”
K&N, which is manufacturing the air-induction systems per the NHRA specifications, is also similarly involved, and White said, “Both Holley and K&N have been more supportive and productive than I could have imagined. From a hardware perspective, things have been going great.”
Speaking in a radio interview with WFO’s Joe Castello, Lawrence said, “The Holley HP ECU system has proven itself with GM’s COPO Camaro, the Circle Track ARCA/Ilmor 396 engine, and many other high-performance applications. The three main components, the HP ECU, the throttle body, and the fuel injectors, are spec’d and serialized and are not open to modification. But the intake manifold, other than the height restrictions, is pretty wide open for development, and I think that you will see a lot of ingenuity and creativity in this area.”
Lawrence stated that the EFI units will provide expanded tuning latitude for the teams, which ultimately will result in significant performance gains. “While the carburetors have been refined to a very high degree over the years, compromises still had to be made to keep all the cylinders happy,” said Lawrence. “Sometimes a cylinder might be too lean on the launch, and then another cylinder would be too rich at the finish line. Many times, you were Band-Aiding the cylinders to keep them from hurting themselves.
“The EFI will be much more programmable. The tuners can not only tune each cylinder individually, but also for each gear. For the first time in Pro Stock, they will be able to tune the fuel curve as well as the timing curve, and this will produce significant dividends as each team learns how to optimize this more advanced technology.”
