This ROUSH Performance P-51A™ Mustang is #26 of 151 built and is the highest horsepower Mustang that the company has produced at the time of its release, and represents the first time that internal engine components have been upgraded by ROUSH technicians in their Livonia, Mich., facility. The ROUSHcharged™ P-51 4.6L powertrain system includes TVS Technology ROUSHcharger™, intake manifolds, intercooler & radiator, cold air induction system, carbon fiber cold air tube, Forged Aluminum Pistons, Forged Steel H-Beam Connecting Rods, Forged Steel Crankshaft, Unique high flow fuel injectors (~52lb/hr), Unique fueld rail, Dual 60mm eletronic throttle body, Upgraded fueld system, aluminum Flywheel, Upgraded Clutch, and ROUSH calibrated ECM--producing 510hp / 510lb-ft.
Under hard acceleration the rear felt as if it was swaying in an oval pattern from right-down-left-up-right-down… to the point where above 120 MPH it became violent and walked the car around its lane. This turned out to be (at least in part) due to deflection in the rubber panhard bar bushings, so I replaced them with Polyurethane units (Prothane Suspension Parts) as shown here. Interestingly enough, the bar is hollow and filled with sand for vibration dampening.
The Panhard bushings certainly reduced the effect but after several runs I was able to reproduce the problem while accelerating hard on a country road where the surface was slightly wavy. Next up were new lower control arms (LCA) made from mild tube steel and sporting poly bushings with grease Zerk fittings. While at it I also replaced the brake lines with stainless steel braded units from Russel and replaced the factory brake fluid with Motul RBF 600 Racing fluid.
After two track days the rear discs were shot so on went a new set of British EBC Rotors and Brembo Pads!
Here's a look at the shifters this car has known. From left to right, the factory Ford unit, Roush aftermarket unit and MGW aftermarket unit which we installed today.
One of the many shift problems this car has under severe load is it locks you out of second to third and oftentimes third to second shifts. I believe some of this is a result of the remotely mounted shifter; i.e. attached to the body vice the transmission. Roush replaced the Ford unit with a billet main body and shorter stick thereby shortening the throw but the problems persisted so I'm replacing their unit with what's said to be the best on the market right now, the MGW. Notice I'm using the rear bushing designed for track use.
Here she is all buttoned up and ready to test!