Functional Pro Street: by Steve Chryssos
VOLUME 1, ISSUE 3
I will never forget my first live Pro Street encounter. I was a snot-nosed punk roaming the Car Craft Street Machine Nationals East. The car was an electric blue metal-flake ‘64 or ‘65 Malibu. The wheels were intended for a Mercedes-Benz, but were seriously modified to suit the “big ‘n’ little” Pro Street look and the car’s menacing appearance blew me away. I thought for sure that this hot rod could conquer all challengers.
After the event, I passed a number of Pro Street cars on the highway. They were all doing 45 mph in the right lane with the engines “wound out.” A 3-speed transmission and 5.14 gears will do that. The worst part about all this was that the cars weren’t driving flat. They were bouncing and looked as uncontrollable as a cockroach.
Sometime later, I helped my boss build a ‘67 Chevelle Pro Streeter. While expectations ran high, he sold the car shortly after it was completed. Simply put, it was boring. After two dozen burnouts, three cruise nights, and one high-10-second pass down the quarter-mile, that mean looking Chevelle had already outlived its usefulness. My boss never wanted to drive it anywhere. The 15-inch wheels would not accept bigger, better brakes. Furthermore, good brakes were not readily available at the time. The “pizza cutter” front tires could not negotiate basic low-speed turns. The 604-inch big-block/TH400/4.56 gear drivetrain hobbled street and highway driving. And those big, bouncy rear tires made the car go down the road like a farmer’s tractor.
No doubt these sad circumstances above have been repeated throughout the history of Pro Street. Some say that Pro Street is dead. On its tombstone: “Here lies Pro Street-RIP. Performance at the drags was less than expected. Street manners were dismal.” But I’m not so quick to close the book on Pro Street. New parts and systems--overdrive transmissions, radial tires that accept large diameter wheels, front suspension parts, and good brakes--can return the build style to its former glory and beyond.
The recipe for a functional Pro Street car borrows the front suspension, wheel diameter and brakes from Pro-Touring. Front tires should be wider. A 235mm on the front certainly looks narrow enough, but is capable of negotiating street and highway maneuvers. Other than anti-sway bars, I don’t see how these parts will significantly hinder E.T. Certainly the rear suspension could maintain current back-half technology with a converging four link, wheel tubs, and a narrowed rear axle.
To make those 4.88s livable on the street, an overdrive transmission is mandatory. The 4L80E is essentially a TH400 with overdrive and built accordingly can easily handle 1000hp. Fully programmable, the 4L80E can be calibrated to match those 33-inch tall tires. A Gear Vendors over/underdrive is another alternative. Overdrive manual transmissions used to be weak links, but equipment from D&D, Rockland Standard Gear, and Liberty offer high-strength five- and six-speed solutions.
Engine block and cylinder head technology has progressed to the point where monster cubes are readily available at a reasonable price. Extra displacement makes big power without the need for boost or a radical camshaft. If you do want boost, centrifugal blowers and turbos provide all the power you need without sacrificing low rpm function and idle quality. In addition, these power adders fit under the hood so you can actually see where you’re going.
Perhaps the single most important change in Pro Street product development is tire technology. Mickey Thompson recently introduced the Sportsman S/R radial. While these tires are available for 15-inch rims, the big news is that they are offered for 18- and 20-inch diameter wheels as well, enabling big brakes and choice from a wide range of current wheel designs that utilize a full rim flange and a directional tread pattern. If you are savvy about your brake diameter selection, you can swap over to slicks and “front runners” for the track.
The term Pro Street evolved from a popular class in drag racing known as Pro Stock, where stock appearing, full-body drag cars run heads up. So the term connotes Pro Stock for the street. Unfortunately, Pro Street evolved into a caricature. Can current technology save the genre? I say yes. Can Pro Street be resurrected? I say absolutely. A Pro Street car should click off a sub-10 second E.T. and be fully drivable on the road. It’s good to know that the necessary parts and systems exist. Let’s go build some cars.
/Steevo
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