ce genre de poulies :http://store.roushperformance.com/detail.aspx?ID=599
Gain more horsepower, gas mileage, and accessory life with the ROUSH® 25% reduction Mustang Underdrive Pulley. This pulley fits 2005-2010 Ford Mustang GTs with the 4.6L engine only, and does not work with ROUSHcharged™ vehicles.
The ROUSH Underdrive Pulley dampens damaging engine harmonic vibration, meets SFI Spec. 18.1 and has a diameter that is 25% less than stock. The benefit is that 25% less power is diverted to running accessories, such as the alternator. As a result, more power is freed for performance. This part has been found to increase power by 8-10 hp. Due to the increased efficiency, fuel economy is also increased. In addition, because the accessories run by this belt are being run at reduced rate, their longevity is improved.
Since being established in 1976 as Jack Roush Performance Engineering, ROUSH has become the winningest name in racing, with numerous championships in professional drag racing, road racing, and NASCAR. The ROUSH company is also recognized internationally as a premier provider of automotive product development and systems integration solutions, with more than 2,000 employees in facilities across the globe. The company's success remains deeply rooted in the core values that are unique to ROUSH: reliance upon the talent of the individual, a disciplined work ethic, scrupulous attention to detail, and an acutely intense desire to be the best. As a result, every ROUSH product shares in this rich tradition of racing performance and the highest level of OEM quality and design.