I have a Kenne Bell 2.8 liquid cooled supercharger with a 3.5 inch pulley, long-term long tube headers and 60 pound fuel injectors ,Kenne Bell boost a pump and I am getting 600 rear wheel horsepower. But Kenne Bell formula for that pulley and supercharger says I should be getting 660 rear wheel horsepower I also have an AEM methanol injection kit which gave me an additional 20 rear wheel horsepower. Does this sound right to those in the know?