Nitrous is the secret to getting this Poncho into the 10s. Keppler chose a component system manufactured by NOS utilizing two bottles: a 20 pound main and a 10 pound backup, both housed in the Catalina's roomy trunk. On the intake, he installed a Big Shot plate and solenoids and jets good for a 250 shot of juice. The cost of the nitrous system was $500.
Exhaust exits through Doug's 1 7/8-inch primary, 3-inch collector headers to a 3-inch X-pipe and free Walker Super Turbo mufflers. The total cost of the exhaust system was $800.
For quicker times during competition,...
For quicker times during competition, Keppler switches out his 15x7 Rally IIs for 15x3.5 and 15x8 Welds wrapped in Hoosier 28x4.5x15 tires and 29x10x15 slicks. An air bag in the right rear spring, filled to 6 psi, is also employed to improve traction. On the Wal-Mart tires (not shown), he turned 10.90 at 128.6 mph on a 1.88 60-ft time.
To handle and fully exploit the increase in engine power, a TCI flexplate and TCI 3,000 rpm stall converter were installed. A '73 Pontiac Turbo 400 transmission, upgraded with a Trans-Go shift kit and a '92 Cadillac trans cooler is controlled by a stock column shifter. The total cost of the transmission/torque converter combo was $450.
Power transfer comes from a Denny's driveshaft with 1350 U-joints connected to a GM 8.5 rear end from a '73 Grand Am. It is outfitted with a Strange spool, 33-spline axles, and an aluminum rear cover with brace and upgraded C-clips. The gear set is 3.42:1. "The Strange spool was only $150. That's cheaper than a Posi unit costs," Keppler says. "The total cost of the rear end was $1,300."
Suspension And Brakes
Keppler scavenged for junkyard parts to trick out his suspension as well. He pulled used front springs from an '85 Cutlass and added upper and lower polyurethane control arm bushings. He also removed the Catalina's front sway bar and installed Summit 90/10 (front) and 50/50 (rear) shocks. Other chassis mods include BMR rear upper control arms for a '70 A-body, owner fabricated rear spring jacks to stiffen the rear suspension for nitrous launches and slick usage, a '73 Grand Am lower control arms, and sway bar. A double hump transmission cross-member comes from a '73 Olds Cutlass, and the rear framerails were notched for tire clearance. Total cost of the chassis mods was $500. The front spindles, calipers and rotors came from a '77 Grand Prix to get the desired 5x4.75 bolt pattern, and the '73 Grand Am 9.5-inch rear drums were retained. The wheel/tire combo on the street and for most strip excursions is 15x7 Rally IIs wrapped in 235/75R15 Douglas Xtra-Trac A/W whitewalls. "The tires are the cheapest you can buy, but they hook up almost as well as slicks," Keppler laughs. "The Rally IIs were free, so the total investment was $150."
On The Strip
Keppler launches at 1,200-1,500 rpm and shifts at 5,800 rpm. Nitrous is activated via a full throttle switch. His '78 Catalina has run a best e.t. of 10.37 seconds at 125.02 mph on spray and 12.01 at 114 mph on motor. It weights 3,975 pounds with fuel and driver. His best 60-ft is 1.43 on slicks and 1.66 on street tires.
To run in the 10s, Keppler...
To run in the 10s, Keppler removed the engine accessories, the factory A/C system (notice the handmade A/C delete plate), and the inner fender wells and lightened his front bumper. Notice the two fuel lines. The upper line is for nitrous fuel and the lower line is for gasoline. A Hobbs fuel pressure safety switch is installed in-line to the nitrous fuel system.
He says, "At the track at speed, driving the Catalina is like sitting on your couch looking out a big picture window, but on the street, it's like driving an old truck."
Conclusion
Our calculator shows that this Catalina has a total investment of $9,900, according to the owner's bookkeeping, thereby entering the 10-second club under $10,000. Now, we are not going to tell you that you can go out and build the exact same car for the exact same money and get the exact same result. Obviously, Keppler is a talented mechanic and his parts were collected over the years from a number of different sources that you may not be able to match on a price point. The focus of this story is simply to show how one man reached his goal of running 10s on a low budget. Perhaps you can glean some ideas from this story that you can apply to your Pontiac. Keppler says he is proud of his Catalina. "It's a fairly versatile machine, and it's good therapy. And when I pull up to somebody, it always puts a smile on my face."