Bolt and Go, Part II

Bolting on parts and feeling the added performance is one of the things that make high-performance cars such a blast, especially when the parts are available in a dyno-proven package like Holley’s new Street Avenger System. Each of the three systems (Pure Street, Hot, and Wild Street) is offered in three stages for any performance budget. If you read our first Bolt and Go story (see link below) you know that we improved our stock 350 Nova’s e.t. from a dismal 17.27 at 79 mph to a snappy 15.44 at 90.18 mph by bolting on Stage 1 of Holley’s Pure Street System. The Stage 1 kit includes a Holley Street Avenger 670-cfm carburetor, Weiand Action-Plus intake manifold, Annihilator ignition system, and Hooker headers and exhaust. The kits also offer plenty of cool-looking accessories to give your engine compartment a really hot look.

In our quest for better quarter-mile times, this time we installed Stage 2 of the Pure Street package, which includes a Lunati hydraulic camshaft and lifter kit, plus a new Lunati timing chain. Next, we added an Art Carr high-stall converter to enhance our newfound power on the track. So hang on while we raise the performance bar again and improve the Nova’s hustle time.

Stage 2 and Counting

After a day under the hood of our Nova, we had the Lunati camshaft and timing chain installation completed. The cam gave the 350 a distinctive idle and made the Hooker exhaust system sound totally cool at stoplights. With the added duration, the camshaft now exhibited a definite increase in midrange power. But because more duration moves the engine’s torque level up the rpm scale we knew the stock converter might be the limiting factor. To take full advantage of the power increase of this camshaft, we decided to first track test the car with the stock converter and then revisit the track with a high-stall converter. So on a Friday night we headed to the dragstrip to make a few passes.

On our first test with the new camshaft and stock converter the e.t. improved from our previous month’s 15.44 to 15.21. This two-tenths e.t. reduction demonstrated that although the engine had more midrange power, the longer-duration camshaft matched to a stock converter didn’t allow enough engine rpm to launch the car hard enough for an optimal e.t.

To improve that, we contacted Art Carr Transmission in Huntington Beach, California. Proper torque converter selection depends on several variables including vehicle weight, engine size, camshaft duration, gear ratio, braking ability, tire diameter, >> and the intended use of the vehicle. To launch our Nova harder, Art Carr suggested replacing the Nova’s stock 13-inch converter with an Art Carr Super Torque 10-inch that is rated at 2,400 to 2,600 stall speed. With any high-stall converter it’s also imperative to add a transmission cooler because this added slippage creates additional heat that can shorten the life of your automatic transmission. To protect our transmission from excessive heat, Art Carr installed an aluminum stack-plate transmission cooler.

Following an afternoon with the Nova up in the air, we had the car back on the street and immediately noticed the difference. The engine idled easily in gear with its >> hot-car sound and demonstrated immediate power from a standing start. Breaking the rear tires loose became habit-forming, and we soon realized we needed to add a posi-traction unit to our to-do list. We could hardly wait to see how the Lunati camshaft and Art Carr converter helped the e.t.

Back on Track

On a Wednesday night we headed back to the track. Our best pass that night stopped the clocks at a 14.81 at 93.33 mph. With the new Lunati camshaft and the Art Carr 10-inch converter we had cut the e.t 0.63 second from our Stage 1 results. The Nova now runs 2.48 seconds quicker and 14.17 mph faster than it did when we began. All of this with an 8.5:1-compression 350, stock 1.94-inch valve heads, and a 3.08 open rearend. Now that we are solidly in the 14s, we look forward to pushing the Nova into the 13s.

Bolt and Go, Part I

Bolt and Go, Part III