In last month's issue, High Performance Pontiac introduced you to John Heinricy, retired director of High Performance Vehicle Operations for GM's Performance Division. He discussed his early career at General Motors, the role he had in the development of the Pontiac 6000 and Sunbird, and the birth of GM's ILE showroom-stock–racing Trans Ams and Firebirds. He also revealed how Chevrolet's pullback from showroom-stock–racing gave Pontiac and the Fourth-Generation Firebird an opportunity to compete on road-course circuits in IMSA, IROC, and SCCA contests.
This month, we pick up where we left off with John, and hear him discuss Firebirds, Trans Ams, and the WS6 package; the new-age GTO, the Solstice, and the G8; and how the adage "win on Sunday, sell on Monday" held true for Pontiac until its death in 2009.
High Performance Pontiac: In Part 1, we discussed your involvement in the development and racing of various GM products, including Firebirds. In your opinion, what are the racing strengths and weakness of showroom-stock Firebirds?
John Heinricy: [In road-course racing], the Firebird's negative is its size and mass. It is relativity big compared to the competition. They are not the greatest under braking, so [GM Performance] kept experimenting with various brake pads until we found some that worked.
Joe Kent, owner of Kent Motorsports, is shown getting ready to qualify the #97 Firebird fo
We used to race in an IMSA series that held two 24-hour races. Changing brake pads quickly was very important, so the team developed a quick disconnect and reconnect brake-change system. The calipers were pre-bled and the brake lines had quick-connect fittings. During a pit stop, the brake-line hose was disconnected at the framerail, the caliper was unbolted, and the new caliper with pads was installed. A rotor change could also be done during this process.
The crew completed this task quickly and we never lost time during a race making this change. We won the 24 Hours at Mosport in 1996 driving a '95 Firebird but were disqualified. (Stu Hayner, Marty Miller, and Don Knowles were my co-drivers and we made a great team.)
HPP: When did you take over as chief engineer of the F-body?
JH:… In 1997, and I was involved in the redesign of the '98 models. I held that position until 2000 after we finished development on the '02 model. I spent a lot of time getting the WS6 package into production. We shipped the Firebirds to American Sunroof Corporation (ASC) to have their hoods and front fascias installed. Street Legal Performance (SLP) added the Hurst shifters and any other remaining equipment before they were shipped to dealers.
We spent a lot of time developing the performance exhaust for those cars. We had to meet the noise regulations while still making the correct power. We built a two-into-one-and-back-into-two [exhaust] system that met our power target because in '98 we were unable to accomplish this with the dual-exhaust outlets. So in '98 we had a single outlet in the back that made the power, but Pontiac was not very happy about that change. We redeveloped it for '99 and returned to dual outlets. It didn't make any more power, but it sounded good and looked better.
HPP:When you left the F-body group, what was your next assignment?
After retiring from GM, John started consulting with various manufacturers on product impr
JH: In 2000, I was named GM's director of Vehicle Dynamics at the Milford Proving Grounds. A little less than one year later, I became GM's director of High Performance Vehicle Operations.
HPP: You recently won the SCCA 2013 A/Sedan National Championship driving an '02 Firebird Formula. Was that vehicle equipped any differently than the IMSA Firebirds you used to race?
JH: The A/Sedan SCCA regulations allow quite a bit more modifications to the car. Springs and shocks are open, and you can make suspension-bushing upgrades front and back. This helps you run a lot of negative camber to improve turn in to the corners. The engines are equipped with a carburetor, not fuel injection.
The base engine is the old 305ci that was in the Firebirds from '87 to '92. The rules include an engine formula that allows you to vary the engine size from 302 to 358 ci depending on the weight you want to run the car. We have to use a 600-cfm Holley carburetor, and transmission ratios need to match the stock offerings. The rearend is free; a lot of people use the 9-inch Ford differentials, and you can add a Watt's Link rear suspension for better handling. A version of the LS1 Firebird has been recently approved for competition.
The '02 Firebird I won the championship with had a 311ci engine. It produces around 450 hp. The rules require 16x8-inch wheels; you are allowed to use any brake that will fit inside that wheel. My winning Firebird weighed 3,320 pounds with driver at the end of the race with minimal fuel.