Yikes, bad wordage I hope?

I'd go with forced induction such as a turbo due to the low compression pistons. If you wanted better engine efficiency and more power without boosting (turbo or supercharger) you could have your stock pistons replaced with higher compression pistons. Having a low compression motor and not boosting is very backwards to me. The V6 Xterra has a 8.9:1 compression ratio. It's the reason why I can put the crappiest grade of unleaded and still run fine. It's also one reason why the engine is slightly low on power and slightly high on fuel consumption.

Also, the KA24DE 16 valve head flows very well. A set of cams will certainly help the engine breathe. Cold air intake, free flowing exhaust manifold and less-restrictive muffler piping...

Don Nimi runs a shop that caters to the KA24 motor. Check out PDM Racing . Some or most of the engine mods should be compatible. You could also save up for a Pathfinder engine swap. Its aluminum block VQ is powerful yet efficient. Its 10:1 compression ratio does require super unleaded, but that's a small tradeoff. There's also the VH engine from the Q45.

Addendum - the KA24DE head has a mechanical valvetrain unless Nissan changed it. It can certainly take an additional 1500 rpms before rev limit. I've seen KA24DEs tuned to 200hp and beyond without a turbo, so it's certainly not a terrible idea to make a 4-banger Xterra more powerful.

[ 10-05-2001: Message edited by: primerAL ]