The Xtreme Marine XM284HR camshaft with a .547 lift, 230/236 duration, and 112 LSA is an excellent camshaft for a ZZ-454 in a marine application, but how well would the cam do with boost? Richard Holdener with Speed Secrets teamed up with Comp Cams to put the combination to the test. This test was out of the norm in that there was no back to back dyno testing involved. In fact the camshaft on the ZZ-454 crate motor had already been upgraded with an Extreme Marine Comp camshaft with a .547 lift, 230/236 duration, and 112 LSA, for a more than 40 HP gain.
Naturally aspirated the 454 with the Xtreme Marine Comp cam made 537 HP @ 5,800 RPM with a broad torque curve topping out at 516 Lb-Ft of torque @ 4,400 RPM. The story doesn’t stop there with this Big Block destined for a boat though, as the owner was concerned with the need to replace the upgraded camshaft with one intended for boost applications if he decided to add a blower at a later date.
To find out how well the Xtreme Marine camshaft responds to boost, an F1A-94 Procharger was installed along with an ATW intercooler, and just to keep it simple, the combo was ran as a blow through carburetor application. With 10.6 PSI of boost the combo made 944 HP @ 6,000 RPM and 827 Lb-Ft of torque @ 6,000. Increasing the output by over 400 HP, which isn’t surprising considering as the F1A-94 Procharger is capable of supporting over 1,200 HP.
Because the point of this test was to see how well the XM284HR camshaft from Comp Cams responds to boost, it was ran at a couple of different boost levels. The combination was pushed all the way up to 1000 HP to illustrate that the Xtreme Marine camshaft has no problem with boost. Inspiring confidence, the camshaft supplied the engine with plenty of naturally aspirated power for the mean time without any worry that it will do well with boost if a supercharger is added later.