Our project LT1 Formula was long overdue for some track time after TT Performance and RaceKrafters helped complete our Dart-headed, Comp-cammed 355 LT1 install by resolving our electrical and PCM issues.
In our last installment, TTP tidied up the engine bay, fixed our no-start situation (by swapping on a different Opti), and an issue with the balancer. Then Mufflex fitted the Formula with a custom dual-cat Y-pipe and 4-inch exhaust. Finally, Bob Wise at RaceKrafters cracked his knuckles and began work on a custom PCM calibration. On RK's Dynojet chassis dyno the Formula made 335 rwhp after tuning.
Bob took his time to do a thorough street tune, in addition to wide-open throttle tuning on the dyno, and I was glad he did. An SUV collided with a 16-wheeler on the NJ Turnpike ahead of me on the way to the track. In over two hours of driving the Formula didn't stall once, overheat, or anything. The tune seemed spot on (with both the trans and motor). In addition, the motor seemed much more responsive and snappier-and it sounded great! A few WOT blasts seemed to indicate that all 459 hp was there as well, making me anxious to see how this would parlay into quarter-mile times.
After arriving at Englishtown, I let the Formula cool for over an hour and bolted up a set of Hoosier 255/50/16 radial slicks (mounted on my old stock wheels) that Werner had picked up from Summit for his WS6 (April '09). Knowing how unreliable even a built 10-bolt can be with drag slicks, I elected to leave the tire pressure fairly high-around 25 psi to start. Between the 3.42 gear and 3,200-3,400 stall converter, it didn't seem to matter what the tire pressure was since I could not spin the sticky slicks (no matter how hard I stomped the gas pedal coming off the line). Later in the day, I dropped pressure to 22 psi-but the only difference I saw in 60-foot times was simply through driving style. Nevertheless, the Formula did manage a 1.71 short time-a huge improvement over the previous best of 1.90 and as good as we could expect for the LT1's current combo.
Being that the Formula packs a 4L60E, the rest of my driving strategy was simply to keep it to the floor until I passed the scoreboard. In the process of refining my launch technique, the Formula whittled its way down from high 12s to a 12.481 at 107.4 mph (7.89 at 86.0 mph at the 1/8-mile). The temperature was just over 80 degrees for the majority of the day, with humidity 37-55 percent, and the barometer was hovering around 29.72-29.76 as a thunderstorm approached. Bob [at RaceKrafters] speculated that with more gear (say a 3.90 ratio) and cooler weather, we could easily have the Formula running 11.90s. But knowing that the Formula would soon be residing in the warmest and most humid part of the country, we may have to resort to other means in order to complete our goal of having a solid 11-second daily driver. After that, the sky is the limit with this fourth-gen. Catch you next time!