|Under the valve cover is the somewhat complicated i-VTEC cam control system. i-VTEC controls the intake cam phasing plus it has two sets of cam lobes, a high RPM cam lobe and a low RPM cam lobe.
The APD Acura was transported by Emergency Hookers to Robert Green and Ben Tran at Blueprint Racing in Walnut, Ca for installation of a set of BP Racing Stage 2 Cams and a modified Acura RSX VTEC actuator mechanism. (Blueprint modifies a stock Acura RSX-S Actuator to mechanically limit advance to 35 degrees from factory stock 50 Degrees in the K20, RSX. In the K24A2 Honda Engine with stock height pistons, 35 degrees is about the limit of advance to safely ensure valve to piston clearance in the event of an over rev condition).
|The cam advance/retard mechanism is on the intake cam. It has been modified for less control authority.
04 TSX cams/BP Stage 2 cams – The math differences, Lift/Duration/Lobe Size:
|BP Stage 2
|Max Lift 11.45mm
|Max Lift 12.6mm
|Duration 210 @ .050
|Duration 295 @ .050
|Max Lift 11.50mm
|Max Lift 11.8mm
|Duration 212 @ .050
|Duration 285 @ .050
04 TSX/BP Stage 2 Lobe Measurements:
04 TSX Lobe Measurements:
|Here you can see the high RPM lobe, the twin low RPM lobes and the screw type lash adjusters. At least it’s easy to set the valve lash on this engine!