How Do I Increase Performance on a F22B1 VTEC Engine?

The F22B1 is a 2.2-liter, American-spec variant of Honda's F-series four cylinder, and was commonly found under the hoods of a number of 1990's Accords and Acura CLs. While not as popular in the aftermarket as the company's B-series and H-series engines, this largest of F-series motors is still a potent performer when combined with the right parts. A quick browser search will return results for dozens of different turbo kits for this engine, but you'll have a hard time matching the return-on-dollar investment of a quality nitrous system.

  • Remove the stock camshafts and replace them with aftermarket units. The B1's VTEC system doesn't use the "real" standard cam and race cam combo of older systems; it uses a small cam for standard running and an even smaller cam for emissions and fuel economy. To extract the most from your F-series, you'll need a cam capable of putting it in the 7,000 rpm range.

  • Unbolt the head and install a set of chrome-moly studs in place of the factory bolts. The factory bolts aren't rated to withstand the huge cylinder pressures you'll experience with nitrous. They might hold up for a little while, but eventually the head will lift and you'll blow a gasket. This can be disastrous indeed given the F22's open-deck configuration.

  • Remove the factory intake manifold, drill it and modify it to accept bungs for a direct-port nitrous system. If you don't have the fabrication skills or equipment necessary to weld bungs to the intake, send your manifold out to someone who does. The ideal location is about two inches ahead of the fuel injectors in the intake runners.

  • Reinstall the manifold and screw a set of wet-flow nitrous injectors into the bungs. You could go with a dry-flow system that relies on the engine's stock fuel-management system and injectors to modulate fuel delivery, but even a small hit of nitrous will put you close to maxing out the injectors. That aside, the stock fuel management system will cut fuel when you reach the rev limiter, which will cause your engine to run lean under nitrous and go boom.

  • Connect your nitrous lines and solenoids as directed by your nitrous kit's instructions, but connect the fuel supply line to a supplemental propane tank instead of the stock fuel system. Propane has an octane of about 110, and will help to absorb heat during the combustion event. This makes propane injection a far safer choice for an open-deck block like the F22 than even the highest-octane gasoline.

  • Screw in a 25-percent larger fuel supply jet for the propane. Propane contains less energy than gasoline per gallon -- about 91,600 British Thermal Units compared to gasoline's 125,000 BTU. Attempting to run gas jets with propane will lean out your nitrous system, causing the stock computer to inject extra gasoline to compensate. On the plus side, this extra fuel combined with the propane's inherent cooling ability means that you'll see a roughly 25 percent gain in power using the same-sized nitrous jets.