Once broken in on the street, the rearend didn't make a peep-indicating a good gear install. The tranny proved a little rough even after a few miles and the softer calibration, breaking loose the tires on virtually every 1-2 shift (even at part throttle); however, I am waiting to pass judgment until we test out a looser converter and the fluid is changed (as recommended), after a few thousand miles. For the track, the TCI 4L60E proved lightning-quick and ideal, but the tight 2000-2200-stall converter would not allow proper weight transfer before locking up. Though this converter was great on the street and an autocross course, it wasn't cutting it even on E-town's well-prepped track. Additionally, the worn stock front brakes were causing the Formula to break the beams prematurely when stalling. While doing my best to stall the Formula, it didn't seem capable of besting a 13.39 at 102.88 mph or a 1.910 short time (on separate runs). This improvement over the Formula's previous best of 13.77 (with 2.15 60-foots) was deemed totally unacceptable by both Editor "Hammering" Rick Jensen and myself, given the long list of mods done in between. You better believe we're going to rectify this problem ASAP. [Photo by Frank Cicerale]
Though it was not my intention to install a Panhard bar at this time, the factory's off-center rearend orientation (as evidenced by the unequal gaps in the rear wheelwells) necessitated an adjustable version for floorpan clearance with the torque arm. Thankfully, BMR was able to overnight this single-adjustable chrome-moly unit (PN MPHR002) with polyurethane bushings, and we were back in business. Jason measured the distance from the inner wheelwell to the outside of the tire on both sides, and kept adjusting the nut until dead center was found. After tightening down the locking nuts and using a little red Loctite, all the bushings were greased, and we were done. |  |  |
Ed Wright at Fastchip was happy to e-mail a recalibrated tune for the Formula's new rearend ratio, to keep the speedometer and odometer reading accurately and to set the shift firmness back to stock (for the built tranny), which was uploaded using the Moates.net USB-to-ALDL Converter. | 
A set of Nitto 555R 245/50R16 drag radials were to be the rubber of choice, which would easily have mounted to the stock 16s-but we still had a set of SLP ZR1-style rims lying around the office from our former LS1 project car, allowing for a simple track-side swap. The Nittos have proven to be quite sticky once properly heated with a long smoky burnout, yet pretty streetable in dry conditions. We had every confidence that the 25.67x9.80-inch DOT-legal radials would provide all the traction the Formula needed, without killing the modest 3.42 ratio gear. | |