We take a closer look at the Whipple High Output Supercharger System for the 2005+ Mustang GT
There are a variety of ways to increase the horsepower of your Mustang, but one of the most simple and efficient ways of getting a lot of power is with a supercharger. There are several different systems available for the 2005+ Mustang GT (See "Supercharger Buyer's Guide for the S197 Mustang GT"), including twin-screw, roots, and centrifugal applications. We took a closer look at the Whipple twin-screw system, which was co-developed with Ford Racing.
Whipple offers two flavors of supercharger kits, including a non-intercooled base system and a high output intercooled system. The base kit includes Whipple's latest twin-screw supercharger, the W140ax, and comes with 34 lb/hr fuel injectors, Ford Racing spark plugs and PCM flash tool, a 95mm MAF, cold air induction with a larger S&B air filter, and a new aluminum intake manifold. In base trim, the Whipple system produces a claimed 415 rwhp with 6 psi of boost. For those wanting even more power, the high output system can be ordered which includes everything in the base kit plus an aluminum air-to-water intercooler, an oversized Fluidyne heat exchanger, a Shelby GT500 high-flow fuel pump, and a reconfigured PCM using the Ford Racing flash tool. These upgrades increase power to 475 rwhp and 450 lb-ft of torque at the wheels. The base system can be easily upgraded to the HO system, and both run on 91 octane.
The particular kit on our test car is the Whipple HO Supercharger System with the optional polished finish. The supercharger was installed and tuned at ST Motorsports in San Bernardino, CA, who has dealt with just about every type of supercharger made for the Mustang. It is important to note that the custom was tuning was done with a DiabloSport Predator Flash Tuner instead of the PCM calibration that comes from Whipple. The installation process is relatively simple and straightforward; the most complicated portions include the wiring and replacing the stock fuel pump with the GT500 unit. We would recommend having a professional installation done unless you are completely confident in your abilities in working with all aspects of a vehicle.
Whipple claims nearly 80% power increase across the entire rpm range, and ST Motorsports did a base run before the installation of the supercharger so we could compare the numbers before and after. Our test car made 231.5 rwhp, which is on the lower side of what a stock GT usually makes. According to ST Motorsports, they generally see 5-speed cars dyno between 230 and 260 horsepower at the wheels. After final tuning with the supercharger in place, our test car made a best run of 465 rwhp and 432 rwtq, although the final tuning put the car at a safe and conservative 454 rwhp and 431 rwtq. This is slightly less than Whipple's claimed numbers, but this particular car's base numbers were low and a relatively conservative tune was used. With a more aggressive tune, 475 rwhp can be easily achieved.
The supercharger made a consistent difference from 3000-4000 rpm, producing approximately 100-120 more horsepower and 145-155 more lb-ft torque. The gap starts to grow around around 4500 rpm, and while the stock power curve flattens out and even loses power at 4800 rpm, the Whipple keeps gaining more and more power all the way to redline. The torque curve is much flatter, having a longer peak and dropping off less at the higher rpm's. With the Whipple supercharger installed, more horsepower and torque is consistently produced at all rpm's, with a flatter torque curve and a power band that increases steadily through the entire rpm range.
Overall the Whipple supercharger system is very impressive. Out of all the supercharger kits available, it produces some of the highest horsepower numbers yet remains competitively priced compared to other systems. It benefits from modern twin-screw technology that allows horsepower and torque to be produced consistently throughout the entire rpm range, improving drivability and overall performance. Best of all, the kit requires no drilling or welding, and is emissions legal in all fifty states.
For more information on Whipple supercharger systems, go to www.whipplesuperchargers.com.
 The Whipple supercharger was installed and tuned at ST Motorsports in San Bernardino, CA |  The final tune for the whipple supercharger yielded 453.9 rwhp and 431.6 rwtq |  A DiabloSport Predator flash tuner was used to optimize the power from the supercharger |
 A fuel pump from a Shelby GT500 is used to deliver the extra fuel required from the supercharger |  This supercharger came with the optional polished finish |  A massive cold air intake system helps deliver cool air to the supercharger |
