The Pickett Foltz/Pacific Diesel #6
by Greg Pickett
Greenwood's first real tubeframe car had been conceived at a point when SCCA and IMSA rules were changing to allow a wider variation in the cars that could race. Up to that point, the rules had basically been in favor of cars with some semblance of the factory chassis and suspension. When the tubeframes were permitted. John was right in there.
The #77 car which he introduced at Brainerd, MN began to have its successes very early, nearly out of the box. For whatever reason, later that year, he sold the car to Jerry Hansen. I bought it from Hansen at the end of that season still in its two-tone silver paint.
The second tubeframe car was purchased by John Paul, Sr. Near as I recall, John Paul, Sr. had seen the car running and had been in talks with John Greenwood about how to get the most effect out of his own racing program. John Paul went to Charlie Selix, Bob Urban and Gary Pratt to get a car built. They told me that they had to go to Greenwood to ask for permission to build it. They needed the work and I think that John was beginning to see the end of his ability to keep financing his racing with the Corvettes, so he agreed.
When I got the #77 car I did quite a bit of rebuilding. Right away, I called Bob Riley to see if he was available. Bob had just penned a new kind of suspension retrofit for street Corvettes. The first one involved putting coil-overs on the rear of Corvettes, and then they built a more refined kit with a more detailed suspension geometry. This is where I think the company (or alliance) was tied up with George Foltz and Charlie Selix. I think the name was something like Protofab-RFP. Anyway, they sold this new suspension kit to Corvette America, Ecklers, and so on. The gymkhana racers ate it up.
So it was very natural to ask Bob Riley how to do more work on the tubeframe car. Well, he told me I had to let George Foltz work on it and try out a couple of new ideas.
One of the most obvious features of those cars was the all-aluminum, fuel injected CanAm engine, that George built at Foltz Engineering. This wasn't much different from the Greenwood/Kinsler engines that (I think) were built by McLaren Racing in Detroit. But each builder has his own tricks, you know.
Anyway, we had originally started the year with 490 cu. in. But the engines were so powerful that, at 750 HP and 750 ft lb of torque, we just kept breaking things further back in the driveline. So, every time we sent the engine back for a rebuild we would de-stroke it a little. We finally ended up with nice little 430 cu. in. package that still made 700 HP/650 ft-lb of torque, still driving through an M-22 transmission and a standard Corvette differential. So, obviously, you still put your foot down very carefully. You had to tiptoe around with that car.
Anyway, George Foltz was doing some really good work and Chevrolet Engineering was starting to notice us. So I went to Vince Piggins and bought out everything I could for the M-22s. I bought four full transmissions and enough parts to build another three or four more. George would put all of this together but he was so nervous about putting 650 ft. lb. of torque through parts designed to handle about 400 ft. lb. that he wouldn't watch the race. He would walk back and forth in the pits, bolting together another transmission.
But George's contribution wasn't limited to the engine and driveline. He had a couple of other ideas, including some new control arms that allowed a bigger wheel and tire on the front. He also designed a new rear hub that let us put bigger tires on the rear. We ran the biggest CanAm tires on the back and Indy 500 rear tires on the front. They were 16" diameter, 14" wide tires on the front and 16" diameter by 21" wide tires on the rear. That was really unbelievable. With the rear body off the car there was only about two feet between the inside edges of the tires.
Now, the stock Corvette stub axles were also a problem. Chevy Engineering would magnaflux those pieces for us. They would do about three dozen axles to get a dozen really ace pieces for us. But we still had to change them out every time out - every practice, every run. We would replace the outside piece with the inside piece and throw away the outside piece. They were just spider-webbed with cracks. The power going through those parts was just unbelievable. But, by doing this we never had a failure in a race.
It was over the winter of 1978 that I also commissioned a redesign of the front and rear body work into a more attractive sculpted effect. You can see a little bit of Monza in it because that's really where they came from. The widebody Monzas were pretty aerodynamic so copying them a little was just logical. And for the wing, that's the Riley-penned A.J. Foyt Coyote Indy car design, cut down. The wing is a dihedral wing with a separate flapper. The original Greenwood /Hansen car had only a single plane wing. Bob, of course, is a genius and is finally becoming recognized as such.
The side door NACA duct for the oil coolers was removed and the coolers were moved up front. There was still a small duct for brake cooling. The final bodywork was also wider than the Greenwood body. John had designed his purposely more narrow because he was targeting higher speeds. I think his car had topped 216 MPH at Daytona. But we wanted downforce.
Now there were a couple of funny stories about getting this car ready. But you kind of have to know Bob Riley to appreciate the humor. Bob is this big Texan and I don't think anyone has ever seen him run. He just kind of moseys along and talks pretty slow. Anyway, we took the car out to Road Atlanta for some tests. We had the rear bodywork ready and we had the big Foltz Engineering engine in it. But this was our first time out and the front bodywork wasn't ready yet; so we just cut out the wheel wells on the original bodywork. This was the first time I had ever sat in the car. Bob told me to be real careful because there is a big dip at Road Atlanta coming onto the last turn and it takes some tuning to get the suspension right. If I wasn't careful it would compress the springs to the point where we would loose more bodywork. So I went out and did a couple of laps to warm it up. Then, once the car was warmed up, I took it through the dip pretty hard and I could see Bob Riley running back to the pits. We had come within one or two tenths of the all time lap record set by David Hobbs. By the end of the day we were over a second faster. So we had gone fast and Bob Riley had gone fast.
But we had also gone through every gear and differential that we had. Putting that kind of power through the stock production Corvette pieces was just murder.
The next year we were able to put a quick change center section in the car and this let us get some stronger pieces in the differential. We also used the A/P Racing calipers front and back and drilled rotors.
But even with all the upgrades we could get, the car still needed to be treated gently. I shifted slowly. You would pause in neutral and let the revs come down a bit. Even with the final 430 cu. in. engine, 650 ft. lb. of torque was a lot of force to put through stock Corvette pieces and you couldn't just let it out.
My overall impression was brute power. Unbelievable straight-line speed. No normally aspirated car has ever performed this way to this day.