The stock S-trim comes equipped with a 3.6-inch pulley. Since Johnson felt comfortable adding a few pounds of boost, he had Snelgrove swap it for a 3.33-inch pulley. "This should get us to right around 12 pounds of boost," said Johnson. Sure enough, after re-adjusting the tune, he spun the rollers on the dyno and saw a maximum boost output of 12 psi at 8,000 rpm. Power output was up to 696, a gain of 15 rwhp.
At this point, the S-trim is maxed out, according to Johnson. "The blower was out of its ability to move more air," he said. "If we want to make more power, we could go with the T-trim." But then they would have to dial it way back or add octane, according to Johnson. And Bleich wanted to maintain the ability to run on 93-octane fuel.
We haven't pushed it to the limit, but Mr. Bleich will have a long relationship on the street and track with his much-improved Boss. Horsepower output is up by almost 100 percent, and he doesn't have to baby it or run any fancy, expensive fuels--the perfect balance.