4 Wheel Drive/SUVs: more power?, throttle body spacer, flow muffler

Question
hey I just purchased a 2001 tj 2.5 with 40, 000kms.  I was wondering what recommendations you have as far as getting a little more power out of her??  any mods out there??  and what do u recommend as far as shifting on the fly for max rpms?  that little arrow comes on and tells me to shift at 2000 all of the time but do i hafta shift there?  and I guess i'm just wondering how durable these little engines are??  i don't plan on doing a ton of offroad and if i was going to it would be pretty amature.  

thx sir  

Answer
Josh,

You can only get so much out of the 4-cyl, but a start would be to install a free flowing air system, such as the K&N.  Next I would get rid of the stock exhaust system, and put on a good brand header, such as the Borla, and along with that a free flow muffler.  A Flo-Master is a good choice.  Replacing the stock fan with an electric one can add a little horsepower.  Another item that helps a some, is a throttle body spacer.  From there, you can install a high output ignition system, possibly a Jacob's.  These are the least expensive upgrades.  
If you can afford it, there are some superchargers on the market that will give you, around a 40% increase in horsepower.  These work great, but are quite expensive.
I never go by the shift arrow.  That is supposed to be an economy thing, and not used for max power.  I, generally shift around 4,000 rpm, sometimes more when I need to.  The 4 cyl engine generates it's maximum torque at 4,000 to 4,200 rpm.

I hope this will give you some ideas that will work for you.

Carl