A peppy 2 banger lol. Not much but the car only weighs a little under 2500 so every little mod helps. My mods are pec Stage II Clutch, Fidanza Flywheel, knocker mod, and adjustable cam gear on intake side set at -4*.
The knocker mod is a long story. A guy on the ZX2 forums figured this one out. The knock sensor on the zx2 is way to sensitive. It detects knock when there is no knock and pulls about 6* of timing. just unplug it and bam, problem solved. Regular PCMs can get away with running 87 octane and still get away with no nock but if you start to get knock just up the oct. since I have an S/R PCM I have to use 91 oct. I just run 93 just to be safe. The advantages are smoother power band, better mpg, and more hp. It was dynode at 3-4 hp gain. I also got my highest mpg at 38mpg all thruway. Before the mod i was getting around 35-36mpg.