Here we are again, looking for ways to make more power from the '96 4.6-liter Two Valve residing in the engine bay of Project Redheaded Step Child. Though we jumped the gun a bit in Part 1 by immediately testing minor bolt-on components, we stepped back in Part 2 and treated the 200k mod motor to some much needed TLC.

The list of high-maintance components included new plugs, wires, and coil packs along with fresh Lucas synthetic oil, a new fuel filter, and an Accufab adjustable fuel-pressure regulator. We even replaced the well-worn accessory belt, something we noticed when performing the installation of the BBK underdrive pulleys. With the V-8 now ready for more power upgrades, we went to Magnaflow for a few exhaust modifications after all, what goes in must also come out.

Exhaust modification rank right up there with mass air, throttle body, and pulleys in terms of popularity, and for good reason. They cannot only unearth additional power, but they also can alter the very character of the Mustang by replacing the mellow stock system with something more menacing.

Givin the relatively modest power output offered by the near stock,pre-PI mod motor, we were actually somewhat appreciative of the quiet demeanor. The last thing we wanted to do was draw unwanted attention from a near by LS1, 350Z, or WRX. Don't get us wrong-if we pulled up next to them, it was most certainly go time. It just sucks to hope for wheel spin or a missed shift from your opponent in order to be competitive. Though the minor mods performed in Part 1 were worth a few extra ponies, we weren't even up to the power output of a stock PI engine, let alone on of the other modern muscle cars.

As luck would have it, the gang at Magnaflow offered us not only a stainless steel performance after-cat exhaust for '96 GT, but also a trick Tru-X-X-pipe system. The Tru-X was designed to replace the factory H-pipe. In 1996, Ford relied on no less then six catalytic converters, the factory H-pipe also suffered from excessive tight-radius bends. The combination of the tight-radius bends and triple converters (per side) made us look forward to replacing the stock system with the much-improved Tru-X system offered by Magnaflow.

Though not technically an emission-legal part, the car will pass the sniffer portion of the stringent California test (we know this for a fact) if not the actual visual portion. Only a performance savvy inspector will likely catch the X-pipe, sine the Magnaflow system did not feature (obviously effective) catalytic converters. We like the idea of having cats in place since enthusiasts should continue to do their part to keep air clean. Performance and reduced emissions are not mutually exclusive. Given the power gains offered by the replacement of the factory cats, we'd say there are probly little power left to be had by removal of the two remaining cats--that is, until we step up the power level with cams, potted heads, and a new intake. We'll be taking a look at long-tube headers and a cat-less Xpipe in the near future, but for now we like the idea of being clean and mean.

The Magnaflow Tru-X system was a direct bolt-on replacement for the factory cat pipe. In addition to the stainless steel construction, the Tru-X featured provisions for the four oxygen sensors (before and after the cats). The system bolted to the factory exhaust manifolds and even relied on the factory mounting brackets (on the tranny mount).

After the installation of the new Tru-X system, we were instructed to take the car out for a quick drive to burn off the coating applied for shipping and storage. The power gain was immediately evident from behind the wheel. We were impressed that the power seemed to be better everywhere, not just at high rpm. The Dynojet verified what our backsides where telling us, with the peak power up by 11 hp, from 199 to 210 hp. Elsewhere along the curve, the power gain was up by as much as 12-13 hp. The torque gains were equally impressive, with a peak up to 281 lb-ft from a maximum of 268 with stock cat pipe.

All totaled, the trip to Magnaflow upped the peak power output of our project car by 15 hp and 18-ft lb of torque. Though 300 rwhp was still a ways off, we where that much closer to our goal. Next month we hope to step up yo PI power levels with the installation of a set of Xtreme Energy cam.