This Stock Displacement LS1 '99 T/A Is Stuffed With Enough Show-And-Go Mods To Spin Heads And Dyno Rollers With Ease
Auto Meter Ultralite fuel pressure, nitrous pressure, and air/fuel ratio gauges are set into an A-pillar pod with a Raptor shift light above it.
When Tony Samsill of Flower Mound, Texas, first saw the '98 Pontiac Trans Am, he knew he wanted one of his very own. But more than patience and perseverance were needed; Tony had to grow up a little-literally-he was 12 years old! He recalls, "My neighbor bought a brand new '98 silver WS6 and when I saw it, I was beside myself. He took me for a ride in it about a year later and, after being scared to death by how fast it was, I decided I had to have one."
After reaching the driving age and whetting his appetite on his first GM ponycar, an '87 IROC-Z, Tony quickly graduated to a '96 WS6 black T-top T/A, followed by a red '97 WS6 convertible.
Three years later, Tony found this Trans Am. "I was at a dealer auction trying to buy inventory for the dealership I work for, and I happened to see what was soon to be my Trans Am, a '99," he told HPP. "Pewter was not my first color choice, nor was an automatic, but when it came through and I saw the price and how nice it was, I couldn't say 'no,' so I bought it. After seven years of waiting, I finally had the T/A that was reminiscent of the first Fourth-Gen I ever rode in. This one is a keeper."
When Tony bought this T/A, he got a lot more than sentiment. One model year prior to Samsill's Pontiac being built, GM made major revisions to the Fourth Generation Firebirds, including body enhancements, bigger brakes and, of course, the introduction of the LS1 engine.
The all-aluminum LS1 powerplant replaced the iron block LT1. Horsepower increased from 285 to 305 standard and from 305 to 320 for Ram Air Formulas and Trans Ams. Part of the Gen III family of engines, the LS1 was a brand new design that was developed with GM's sophisticated computer-modeling software.
It is comprised of a deep-skirt aluminum block with 6-bolt, cross-bolted main caps. Cast-in-place iron cylinder liners feature a bore of 3.90 inches and employ a cast nodular iron crank with undercut and rolled fillets and a stroke of 3.62 inches. The resulting displacement is 346 ci or 5.7 liters. Attached to the crank are powdered metal 6.1-inch connecting rods. The pistons are hypereutectic-cast aluminum flat-tops.
LS1 heads feature 2.00/1.55 valves, 1.7-ratio roller rockers and 66.67 cc combustion chambers. Compression is set to a 10.5:1 ratio and the cam features 198/209-degrees duration at 0.050 and 0.500/0.500 inch lift. The intake manifold is made from plastic to dissipate heat more quickly and a set of 28 lb/hr injectors provide the fuel. A throttle body and MAF supply the metered air for the sequential-port fuel injection system. Coil-near-plug ignition adds the spark.
Knowing that GM had already provided a great foundation for performance in his '99 T/A, Tony concentrated on bolt-ons and bolt-ins to add more.