The intake and exhaust will get you ~15hp but that's about all I've heard. There is another option that totally slipped my mind...headers from SLR www.spencerlowracing.com or you could find a local GOOD muffler shop that does custom work like that. There's another thread in this forum that is asking about another option for headers (other than SLR) and the company is based in Denver. I'm getting my pickup's exhaust done by them tomorrow so I'll help the other Tyler light a fire under their arses laugh

You did get a good deal on your X, congrats. Also, the first gen X is pathetic when it comes to HP and torque numbers, so you're right it doesn't have any get up and go...sad fact of the Xterra life.

Another option is to find a reputable custom horsepower shop in your area and have them give you a quote on developing a one off (or possibly a kit for sale) supercharger/turbo kit for the Xterra. I will say this, you might get some flak for suggesting a turbo option as most of the vocal folks here are into off-roading and turbos aren't a good setup for off roading unless you're desert running or have a really low crawl ratio (lower than either the Calmini or AC gears will give you) to get the RPMs up high enough to spin the turbines and give you boost, yet be moving really slow.

And after that rambling, I'm done for now laugh