Originally posted by Zu4two
The compression ratio on the Isuzu 3.5 liter engine is 9.1:1.

The manufacturer of the SC recommends 92 octane fuel, so that the timing is not prematurely retarded from knocking.

There has been some research into the effects of a cold air box/cone filter on the VX. Search on the Vmag board under cold air box.
With 9.1:1, the system should be able to handle upwards of 9 psi with 92 octane gas. 92 octane with only 4 psi is REALLY playing it safe. Nothing wrong with that. Slight overkill... but nothing wrong with do so at all...internal motor repairs are very expensive.

However, a good aftermarket rising rate FPR (fuel pressure regulator) and a higher rated fuel pump is probably more cost effective in the long run than running high octane gas.