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PRO Series Cheap Class - Feature

Ideas On Building A 9-Second Cheap Street Race Car

Photography by , Pro Fastest Street Car

Last year, the PRO-Edelbrock Fastest Street Car series created a new class called Cheap Street, and this year Car Craft jumped in as class sponsor. The goal of this class is to give budget-oriented hot rodders an opportunity to compete in heads-up competition. As an integral part of the overall PRO series, Cheap Street is aimed at racers who don't have a ton of money to spend but want to step up and try their hand at head-to-head drag racing.

To make it interesting, Cheap Street places limits on both the engine and drivetrain, but then also offers a single-stage nitrous system to give these cars serious performance. Currently, the class is running in the low 10s to high 9s, so these guys are already gettin' with the program. To keep a lid on cost, Cheap Street is also a claimer class in three big areas: engine, carburetor, and transmission. There's a $3,000 claim rule on the long-block, and any of the top eight qualifiers can claim either the class winner or runner-up. There is a limit of one claim per year per category, and you must have the cash at the time of the claim. For the transmission and torque converter, the claim is $2,000, and the carburetor claim is $500 with the same limitations on the number of claims per year.

That quickie overview spells out the basic rules, but we thought it would be worthwhile to go into a little more detail on some of the other class requirements to get an idea of what might work best. As any good racer knows, the first step is to get a copy of the rules and study them. The next step is to come up with some ideas on how to maximize the rules to give you the greatest advantage. Let's take a look at some of the important rules and where to go with them.

Power To WeightWe talked with noted engine builder and NHRA drag racer Kenny Duttweiler about how to take maximum advantage of these Cheap Street rules. The first places Kenny went were the weight rules and power to weight. The Cheap Street rules use a base weight example of a 365ci small-block in a car that weighs 3,250 pounds with the driver. Unfortunately, the class rules do not allow smaller engines to weigh less, so the trick is to work with a small-block of around 365 ci.

A light car with a small motor is always a good idea, but you also don't want to give up displacement. You have to assume that everyone else is going to build an engine between 360 and 370 ci. Given the restrictions, keeping the displacement right around 365 ci would be a wise choice, since each cubic inch over 365 adds 10 pounds to the weight of the car. If you build the engine right at the recommended weight and displacement, this computes to 8.904 pounds per cubic inch. But as soon as you start adding displacement above 365 inches, weight is added at 10 pounds per cubic inch. For example, building a 383ci engine (385 ci is the maximum displacement allowed) adds 18 ci and an additional 180 pounds. This is a bunch of weight, making the car now 3,430 pounds. The rules will cut 50 pounds for a pre-'75 body style like a '68 Camaro, so you could theoretically get the car down to 3,380 pounds including the driver.

Another aspect of this idea is that the class is limited to a 10.2 x 26.5-inch rear tire. Since larger engines generate more torque, you may not be able to use all that torque with such a small tire. However, the heavier car could also put more weight on the rear tires, which would be an advantage. A 355ci small-block Chevy would be relatively easy to build and not cost nearly as much, but it also gives up 10 ci. That may not sound like much, but if you use 1.5 hp per cubic inch as a factor, that's the same as giving up 15 hp. That could easily be the difference at the top end between taking the win light and going home. For the Ford guys, it might actually be an advantage to go ahead and build a 347ci stroker engine that gives up a small amount of displacement in favor of the shorter-deck-height 5L block. We will go into far more detail on engine ideas next month in Part II of this story.

Chassis SavvyWhile the long-block, transmission, and carb can all be claimed, the rest of the vehicle cannot. The smart racer will maximize his investment toward achieving as close to perfect traction as possible. Since all the rules are aimed at limiting power, the idea should be to put as much of it to the ground as possible. The rules also place limitations on the chassis, since ladder bars, four-links, and coilover shocks are prohibited. For leaf-spring cars, like early Camaros, Mustangs, Novas, or Mopars, the Cal-Trac or Competition Engineering Slide-A-Link bars are an excellent choice. For coil-spring cars like Chevelles or Fox-body Mustangs, adjustable tubular bars and airbags are the place to start to create an equal load on both rear tires.

Of course, the front suspension is another place where there is plenty of room for improvement. Taller front springs, soft adjustable shocks, and travel limiters are all pieces that should be a part of any competitive Cheap Street chassis upgrade. Don't forget that the alignment should be set with the front suspension at the height it will be when running down the track, not at normal ride height as with street-driven cars.

While a set of digital scales may not be in your budget, if you search around you should be able to locate a set that you can borrow or rent to at least check out front-to-rear weight bias as well as rear tire load left to right. Since the axle tries to pull the right rear tire off the ground under acceleration, preloading a given amount of weight on the right rear with the chassis at rest is always a good idea. It might require several adjustments to get this right for your particular car and can change as track conditions vary.

Building a car that is 100 pounds lighter than the minimum also gives you the flexibility to move the weight where it will do the most good. You must also consider that building a lightweight car will be more difficult when one of the first things you have to add is roughly 120 to 150 pounds of NHRA-legal 'cage (a little less if you use chrome-moly tubing) in order to have a car that can run safely into the 9-second bracket. There are already cars running in the high 9s in this class, so it only makes sense to build a car that is legal to run that quick.

Other safety requirements that you must have to run in the 9s include an external battery switch if the battery is relocated to the trunk, an up-to-date five-point-harness system properly attached to the rollbar, a window net, proper protective clothing (which changes as soon as you break into the 9s), a current Snell-approved helmet, an NHRA competition license, plus a slew of other details too cumbersome to outline here.

Suffice it to say, if you are interested in building a car to race in Cheap Street, there's much more to fielding a competitive effort than just bolting a hot small-block in your street car and welding in a rollbar. The best plan is to attend a few races, talk to as many Cheap Street competitors as you can, and get a feel for what it will take to field a car. Then start your planning process along with a list of everything you'll need and what it will cost.

You should also keep in mind the cost of getting to and from the track. You'll need a trailer, spares, a crew of competent friends to help, and a dependable tow rig. All of these things can add to the cost of going racing. This is where partnerships come into play, since even Cheap Street isn't really cheap racing. However, this should in no way be construed as putting a damper on the concept of building a Cheap Street car. Making it affordable enough to attract car crafters to compete is the prime directive for Cheap Street. After you've come up with a plan, then the only thing left to do is to get out in the garage and let fly with those wrenches. We'll see you at the track!

SOURCES
Pro Fastest Street Car Racing
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