Very happy with my 2003 Baja...with 7500 miles now I am looking for a few simple engine modifications. Any suggestions? Air fileter? Searching I-Club I couldn't find exact information on automatic transmission adaptive shift logic. If I drive harder will the logic change? As a new member I appreciate any advice...thanks!

 

Any idea how much HP a filter change may add?

 

If you have the N/A Baja check out the "Non-Turbo" section in the forums you may get better results. The basic bolt ons should help out a lil though...

 

For simple mods, there's a few which you can do yourself. I have done all of mine and it is very rewarding. I always add one at a time to see the effects. Things to consider:

Air filter - go with Amsoil. Better filtration and comparable performance. I saw an increase of at least 5hp on my 02 Impreza and the engine has more power on the top.

Motor oil - again, Amsoil Synthetic is awesome. The engine runs cooler and revs better.

Cold air intake - Cobb is the holy grail but it is lots of $$$. Injen and AEM make some too which is respectable.

Iridium spark plugs - they work great. Better spark and increased fuel economy.

Lighten pulleys - reduced rotational speed at the crank gives you extra hp. Don't go with underdriven as they require different belts and they produce a lot more stress on the system.

These are just a few. You can then move to a chip and exhaust. Plenty of things to do.