Iron Man

Whipping LS1 Ass in a Stock-Block Trans Am

Greg Jarem Mar 21, 2005 0 Comment(s)

When all of his friends were trading their LT1s for the fresh new LS1s in the late 1990s, Joe Overton stood his ground. The Virginia native clung to his 1994 Trans Am like Anna Nicole to a Tasteykake, determined to prove that comparable power could be made with his faithful iron-block (without forced induction). Much to his surprise, Joe surpassed his dreams to become the fastest naturally aspirated LT1, even overtaking Gen III competitors with a straight track run of 9.36 seconds.

When asked how he accomplished such a task where many others have failed Joe answered in one word, "perseverance." A quality he learned no doubt from his hardworking father, a Class A machinist who showed him the ropes building a 1969 big-block Camaro from the ground up. Several years later he would come to own a low mileage TA and his own business, Lethal EFI Performance. After graduating from bolt-ons to a 381 cubic-inch stroker kit with the original LT1, Joe decided to ditch the stock PCM and convert to ACCEL DFI with Gen 6 software. He then spent countless hours tuning the LT1 and getting to know the capabilities of the new aftermarket software, which later became a large part of his business. He even participated in ACCEL's own research and development, and was one of the first on board for the new Gen 7 software, which subsequently found its way onto his TA.

With the updated and expanded capabilities of Gen 7, Joe was able to take his "hopped up street car" to the next level making it a full-blown racecar. The first stop was back to The Shop in Charles City, Virginia, which was the only place willing to work on the relatively new engine the first go round in 1995. This time displacement would reach 388, with a 0.060 over bore matched with Ross custom forged pistons and Sealed Power moly rings. The 3.75-inch stroke was maintained, reusing the Cola 4340 steel crank and Carrillo 6-inch Winston Cup issue forged-steel connecting rods. While this is a relatively small stroke for a drag race intended LT1, Joe rebutted, "the smaller stroke keeps me from taking too much material out of the block, which would weaken it, and the factory block can really only handle so much. With the extra quarter-inch of stroke I have all the torque I need yet I can spin the motor to eight grand."

Of course achieving such high rpm with a pushrod motor requires quite a bit of trickery and top quality parts. The most obvious trickery being a carb style ACCEL Pro Ram intake manifold with a Force Fuel 2,000 cfm, 4 blade throttle-body, which increases plenum volume and air speed required for high rpm capability. Air Flow Research 227cc LT4 heads were slightly modified to accommodate the unique setup, and then meticulously ported by Eric Bradby of E.B. Porting. After many hours of flow testing to ensure the increase in airflow wouldn't sacrifice torque, they would then have to be paired with a stout valvetrain and the perfect cam. Cam selection is another forte of Joe's, as he is often the man behind the scenes of several renowned cylinder-head porting shops. As you can imagine he plans to keep the specs on his carefully selected, custom-ground cam a secret. T&D 1.7 ratio rocker arms and CV Products 7.875- and 7.850-inch hardened one-piece pushrods keep valve actuation precise and reliable. A prototype set of Crane valve springs combined with Pro Series lifters are also responsible for keeping Joe from having to replace even one part on the heads in over two years and three hundred passes.

On the fuel side Joe relies on Siemens 55-pound injectors, an Aeromotive fuel pressure regulator to maintain 50 psi and a Weldon 2,000hp fuel pump. Surprisingly the stock '94 Opti-spark remains intact, accompanied by an ACCEL coil and an MSD 6AL ignition box. When mated to Autolite plugs and ACCEL Extreme wires, optimum combustion is achieved and monitored through temperature sensors located within the Hedman 1.875-inch long tube headers with 3.5-inch collectors.

The drivetrain is about as bulletproof as it gets thanks to an ATI TH400 and a Strange 12-bolt rear. Joe divides his torque among 4.33 gears, 33-spline solid axles with a spool, a Mark Williams 3-inch aluminum driveshaft and an ATI 4800-stall converter. A Hurst Quarter Stick helps him negotiate the reverse manual style transmission as he blasts down the track at speeds over 140 mph.The only problem with running the quarter mile in 9.36 seconds with a stock suspension and no power adders is that it becomes difficult to find someone that will actually run against you. Joe spent this past year traveling across the country competing in the LS1Tech Racing Series, but for almost all of the races he was the only one in the Prostock/Super Modified class. His only real competition has come in a few grudge matches against LS1s, so next year, with help of a few sponsors, Joe will be running in the Edelbrock PRO Series Prostock class. With two new motors on the way, he intends to be the first LT1 in the eights. Not bad for a production small-block and stock suspension.

Of course just because they call it stock suspension doesn't mean it is really stock. Joe worked with Brian Jeffries of JBZ Race Cars as well as Wolfe Race Craft to achieve the TA's 1.24 short times. Beginning with a Wolfe 6-point roll cage that was converted to a full cage; then adding subframe connectors, a rear sway bar, double adjustable (rear) lower control arms and panhard bar. A Spohn torque arm with integrated driveshaft loop also aid traction, while a PA Racing tubular K-member and (front) lower control arms help equal the weight distribution in conjunction with a Madman manual steering rack and removed front sway bar. Enabling the transfer of weight are Afco front shocks and QA1 springs while QA1 shocks and V-6 Firebird springs reside out back. This combination, along with a set of Hoosier 29x10 drag slicks, easily enables him to lift the Moroso skinnies on launch; luckily a Billingsley Racing wheelie bar keeps the rear bumper off the asphalt.

Popping wheelies and putting on a show, though, are not what Joe Overton and his LT1 Trans Am are about. The two represent perseverance, hard work and good old fashion values "on which we used to rely," but with a cutting edge, Gen 7 twist. The end result is an LT1 TA so bad it's literally in a class by itself.

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Photo Courtesy Randy Allen

The 388 is fed with a carb-style ACCEL Pro Ram, which increases intake air velocity and plenum volume, enabling huge rpm. Notice the oil feed line in the passenger valve cover, which is connected to a Moroso 3-quart Accusump located in the passenger cabin. The Accusump oil accumulator is used to pre-oil the engine on cold starts, keep the oil pressure from dropping under hard braking, and to remove oil from the oil pan decreasing windage and freeing up horsepower.

An ACCEL coil is used to help boost the performance of the stock Opti-Spark while a Meziere electric water pump reduces parasitic loss.

A VFN fiberglass Ram Air hood helps reduce front end weight while also providing the Pro Ram with fresh air. The use of fiberglass and other lightweight materials reduces the iron block TA to a slim 3,000 pounds with driver.

Joe tries to keep the interior as civil as possible, but light too. The fiberglass dashboard is made by VFN and is lined with Autometer gauges. A Grant GT steering wheel, Kirkey racing seats and Wolfe aluminum covered door panels are also used to save weight and offset the necessary Wolfe 10-point roll cage.

The Bogart 15x10 and 15x3.5 Aluma Lites are complements of SJM Manufacturing and are shod with Hoosier 29x10 drag slicks and Moroso 26x4 skinnies.

A Moroso switch panel is used for the essentials while a Compuech exhaust temperature meter helps monitor combustion.

The Optima Red Top battery is relocated to the trunk next to a three-gallon fuel cell for better weight distribution.

Hey LS1 guys...look familiar?

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