KJ Jones
July 25, 2007

Horse Sense: GTR High Performance experienced an unfortunate setback on July 4, 2006, one day before our scheduled clutch installation. One or several lowlifes broke into GTR's showroom and made off with computers that contained the company's critical business records. We believe someone in the SoCal 'Stang community might know something about this caper, so we hope somebody will provide information that might help the Topete brothers recover their PCs or the valuable data that was stored on them. Call Rick or Gonzalo at (909) 987-4386 if you can help solve the mystery.

If we asked 'Stangbangers to name their favorite transmission, we bet the unanimous response would be manual because most people believe those types of 'Stangs are more fun to drive.

We've provided information covering manual-transmission upgrades for 5.0 and 4.6 Mustangs (see "Rock the Gearbox," Dec. '05, p. 134, and "Top Gear," Sept. '06, p. 124), it's been awhile since we've filled you in on clutch technology for stick shift gearboxes.

Advanced Clutch Technology of Lancaster, California, has been in the high-performance arena for more than 10 years, so we can't say the company is new to the game. In that decade, ACT's focus has been on the sport-compact market, so we were surprised to see its display at the NMRA's season opener in Bradenton, Florida. Sales Manager Daryl Sampson told Editor Turner about ACT's initial foray into the Mustang world-and what a foray it is.

ACT's opening act is the introduction of nine different 10.5- and 11-inch clutch kits for street applications. The 10.5-inch street clutch is rated at 483 lb-ft a with heavy-duty pressure plate and 573 lb-ft of torque with the Xtreme pressure plate. For full-on race-Mustang applications, ACT offers a 10.5-inch spring- or solid-hub race clutch rated at 619 lb-ft with a heavy-duty pressure plate and 733 lb-ft of torque with the Xtreme pressure plate. Eleven-inch clutch kits for '03-'04 Cobras and S197 GTs are also offered, but the torque rate is not available.

After hearing about ACT's clutch kits for late-model 'Stangs, installing one immediately became an agenda item. We went to see Ricardo and Gonzalo Topete of GTR High Performance, a 'Stang facility in Rancho Cucamonga, California, to ask for their help in locating a car and performing the clutch swap.

We followed Rick and GTR tech Chris Balster as they removed a worn-out stock-style clutch and replaced it with ACT's Heavy-Duty Street Kit for '86-'92 Mustangs (PN FM1-HDSS; $418.83) on a '91 GT owned by Caesar Diaz.

We performed the clutch job on Caesar Diaz's clean '91 GT. Once the car is safely racked, Chris Balster gets things started by removing the exhaust system. Of course, the negative battery cable was disconnected prior to lifting the car. Wiring for both O2 sensors must be disconnected before the H-pipe can be taken down. Do-it-yourselfers should keep that in mind because the H-pipe or catalytic converters sometimes need to be wrestled out. Forgetting to unplug the sensors can possibly lead to wiring damage that will be difficult to repair.

The old clutch/pressure plate assembly is removed and discarded.

When you're doing this type of project, making a reference index on the driveshaft and the diff flange is like leaving a trail to find your way home. When it's time to reassemble the drivetrain, simply align the two marks and bolt down the shaft. This ensures that the driveshaft is reinstalled in its original position and lessens the potential of throwing off the drivetrain's overall balance.