Steve Baur
Former Editor, Modified Mustangs & Fords
July 1, 2008
Our Little black coupe has been running fairly well, but increased horsepower shows the weak link to be the stock AOD transmission. Slow shifts and a tight torque converter prevent us from achieving maximum performance.

Over The last several issues, you may recall numerous articles featuring the buildup of a '92 black Mustang notchback unofficially called the Little Juice Coupe. This month, we'll give you a brief recap of the modifications and progress the car has made during its 1,320-foot test sessions. We'll also show you the first part of the Mustang's high-performance transmission install.

The AOD has always been a hindrance in early Fox cars, and this one is no exception. Our Mustang's AOD transmission has seen better days, and its slow shifts indicate it's having a hard time coping with the added horsepower and torque from our engine mods.

The funny thing about this project is that it started out as a last minute fi ll-in. Originally, we had planned to install the Nitrous Express nitrous-oxide system on our '93 Cobra project, Stolen Goods, but we came across this LX and decided a low-buck 5.0 buildup would better suit those readers without fat pockets. It worked out for the best, as this lethargic AOD-equipped coupe needed some motivation.

Our subject vehicle had received some mods prior to us getting our mitts on it, and in addition to the 70,000 miles on the odometer, the coupe had accumulated a 3.55 rear axle ratio, Ford Racing Performance Parts underdrive pulleys, Flowmaster two-chamber mufflers, a K&N panel filter, and MM&FF's 10-minute tune-up. Even with a decent amount of mods, the coupe eased through the quartermile at a leisurely 15.05 seconds and tripped the mph clocks at 92-not bad, but barely enough to keep ahead of your average Honda Accord these days.

We took our time installing the Nitrous Express Stage One EFI system, and the cleanlooking installation shows it. We hid the NX window switch and TPS full throttle unit in the glove compartment, and the nitrous solenoids inside the fender. We also upgraded the fuel system with a fuel pump from Brothers Performance. The BBK 255-lph (PN BBK1607) in-tank pump assured us that the engine and fuel solenoid were getting the proper amount of fuel. Using a set of 245/50/16 Nitto drag radials and NX jetting for 100 hp, the black coupe sped to a 13.62 at 104 mph in the quarter-mile. We backed that up with a 13.75 at 104 mph--an awesome result with a 1.5-second improvement in elapsed time, as well as a 12-mph increase in trap speed.

Our next round of mods began with an offroad x pipe system and 15.8-inch equal-length shorty-style headers from DynoMax. We complemented the improved exhaust flow with an FRPP Cobra intake manifold. By the time we completed these mods, ambient temperature at the track dropped some 30 degrees, so there was a little better air in which to run. On motor alone, we improved our elapsed time from 15.05 to 14.55, and our speed went from 92 to 97 mph. Adding our 100-shot of nitrous allowed us to drop our elapsed time further, going from a 13.62 to a 13.06. Our mph went up from 104 to 110. We were really cooking now.

Since we were so close to the 12s, we stepped up to the 150hp jets. Before doing so, however, we thought it was pertinent to address the stock ignition system. Calling upon the folks at MSD Ignition, we ordered a Digital 6 ignition box, MSD plug wires, and an MSD Blaster Coil. The Digital 6 provided us with a timing retard feature where we could run our advanced timing during normal operation, and then once it received our 12-volt signal from the nitrous arming switch, it would pull 4 degrees of timing.