Five hundred rear-wheel horsepower may seem like a lot to some people, but not to Frank Viana. After thousands of dollars spent putting in a fortified bottom end, lumpy cam, and a Procharger kit, the Chino Hills, California, resident couldn't understand why his 2002 35th Anniversary SLP SS wasn't making more power. Thankfully, he had only a 50-mile drive to Van Nuys to consult LS1 specialist Robert Barth at Strictly Performance Motorsports. Thinking back to the February '06 issue of GMHTP, Barth is no stranger to Procharged LS1 SSs. The question was, could he command a repeat performance with Viana's six-speed SS convertible?
Step one was adding a custom fuel system using two Aeromotive A1000 fuel pumps, and an Aeromotive regulator to supply 60 psi of fuel pressure to custom fuel rails and Siemens 72 lb/hr injectors. After modifying the tune using HP Tuners, Barth managed to up horsepower from its previous best of 505 to 588. In the second phase of the build, the previously installed motor was replaced with a fresh mill from Strictly Performance. After honing the cylinders and machining the LS1 block with billet main caps, an Eagle 4.00-inch stroke forged crank was used to thrust Eagle forged rods and Ross pistons, occupying 385 inches of usable displacement.
For throttle response, the stock 10.1:1 compression was maintained with Cometic head gaskets and Strictly Performance ported heads. These hand-ported stock castings utilize 2.02 intake and 1.56 exhaust valves, as well as dual springs from REV to accept 20 psi of boost pressure from the Procharger D-1SC blower. Strictly Performance also equipped the fresh motor with a custom-grind cam to take full advantage of the boost, as well as the displacement and top end flow increase. Using .578-inch lift and 233 degrees of duration at .050, the combustion chambers gulp the charged intake air. Meanwhile, .603-inch lift and 244 degrees of duration allow efficient dispersion of the spent gases through Bassani 3/4-length headers with 1.75-inch primaries. A ported high volume oil pump supplies the engine--including the cam, Ross rings, and Clevite bearings--with lubrication.