MERCURY RACING 850/1025/1075/1200SCI STAGE 4

The Whipple Stage 4 system boast the latest twin screw supercharger design, dual 2.9 Liter superchargers that are over 26% larger than the stock 2.3L superchargers. The larger compressors turn at a lower rpm, generating less heat and lower power consumption, while giving far more power capacity to the package.

The Stage 4 also includes a new billet spring loaded tensioner, billet tensioner idler plate and all new supercharger pulleys to make a much more reliable and adjustable belt system. Combine this setup with the supplied camshaft, valve springs and keepers and you make another 150-175hp (1075) over stock while another 100 ft/trq helps accelration considerably. 850SCI and 1025SCI packages pickup significantly more, making it an incredible upgrade during rebuilds. The factory rpm limiter is also increased, giving customers the ability to greatly increase top speed MPH while running original props. The stock RPM limit of 6200 is modified to 6800rpm where peak power ends. 

Key features:

• Hi-performance PCM calibration with MPH gains of 7-15mph**
• Higher lift and more aggressive duration camshaft
• Isky tool room valve springs
• HD 12-rib belt
• Billet spring loaded belt tensioner
• Larger diameter SC pulleys for better belt contact surface
• Billet front tensioner plate for excellent user adjustment
• Increased horsepower for increased top speed MPH
• Increased low-speed torque for decreased plane time
• Increased low, mid and high speed torque for better acceleration and throttle response
• Increased spark at low and mid speeds for increased engine efficiency
• 6800 RPM limit vs. stock 6200 RPM limit giving increased propping range and increased horsepower
• 91 octane safe (RON+MON)/2
• Stock idle, starting and drive-ability is maintained

*NOTE: PCM'S MUST BE SENT TO WHIPPLE SUPERCHARGERS FOR CALIBRATION SERVICE ALONG WITH RECEIPT, NEW PCM'S ARE AVAILABLE UPON REQUEST. TURN AROUND IS NORMALLY 7-10 DAYS.