Header bolt removal can be a pain with aftermarket headers, especially considering that you can't usually get a socket on the end of the bolts. Just grab a pair of wrenches, loop the larger one over the smaller one, and let leverage do its thing. You can also use two small wrenches, hooking the box end of one on the open end of the other.
Once the heads were bolted on the car, there was an immediate seat-of-the-pants difference in performance. Our slugomatic AOD Mustang now finally feels like the quarter horse that it is, and HP Performance's Dynojet dynamometer showed we had picked up 24 hp and 22 lb-ft of torque at the rear wheels. This put our coupe at a total of 265 hp and 303 lb-ft of torque on muscle alone. HP's Tony Gonyon noted that the same combination with a manual transmission would produce about 30-40 hp more. We were happy with the results, and even happier once we cracked open the nitrous bottle and let the happy gas loose. With the Nitrous Express system delivering 150 hp worth of nitrous, power output jumped to 378 hp and 486 lb-ft of torque at the wheels. All of that torque was available by 3,500 rpm, too.
Having used HP Performance for previous Fox-body tuning, we knew we'd be logging each dyno run using the Race Systems SnEEC-IV real-time datalogger. We're glad we did too, because the SnEEC-IV revealed that our stock 19-lb/hr fuel injectors were seeing a 98 percent duty cycle, which isn't exactly safe since fuel injectors can lock up when run wide open. Since our nitrous system is a wet system, the added fuel comes in through a fuel solenoid, and it turned out that the tune-up is actually safer on the jug.
The power numbers from the dyno looked great, but what we really wanted to do was get it to the track. Heading to Bradenton Motorsports Park in Florida, we arrived with the nitrous bottle full, intent on slaying our previous best elapsed times of 14.55/97 mph on motor and 13.04 at 112 mph on the sauce. With the extra horsepower from our last few rounds of bolt-ons, we ran a 14.13 at 100 mph.
The front dress, including alternator, A/C compressor, power-steering pump, and accompanying brackets must be removed before you can take off the heads. Follow these with the removal of the distributor, upper and lower intake manifold, and valve covers.
Our available track time was coming to an end, so we cracked open the Nitrous Express bottle and heated up the hides. Our black notchback responded with a 12.89 at 114 mph--better than our 13.04, but we heard the rev limiter at the 1-2 shift and knew it killed some e.t. The AOD was taking so long to shift that moving the shifter at 4,000 rpm still allowed the engine to tag the limiter at 6,000.
For the next run, we shifted a tad earlier, and the car quickened to a 12.69 at 115 mph. For our final run, we left the shifter in Drive and let it do its thing. The transmission shifted at 3,500 each time, and the Pony charged to a 12.68 at 115 mph. It would've been a faster run had the tires not spun at the nitrous hit.
Next month, we'll install a fully built AOD from the folks at TCI, along with one of their higher stall-speed torque converters. Quicker shifts will help elapsed times as will the high stall speed, which should get us into the nitrous sooner. We'll also take care of the maxed-out injector issue and step up to a slightly stickier tire package, so stay tuned.