Relatively Simple & Less Expensive (but often with smaller gains):
* Cold Air Intake (CAI): Improves airflow to the engine. This is a popular and relatively inexpensive modification, but gains can vary.
* Performance Exhaust System: Reduces backpressure, allowing for better exhaust flow. Again, gains vary depending on the system and the rest of your engine setup. Consider cat-back systems (after the catalytic converter) to avoid potential legal issues.
* Tune (if applicable): A custom tune (often requires a handheld tuner or professional tuning) can optimize the engine's computer settings to take advantage of other modifications you've made (CAI, exhaust). A poorly done tune can actually damage your engine.
* Improved Ignition System: Upgrading to higher-performance spark plugs and wires can lead to slightly better combustion efficiency.
More Involved & Expensive (potentially significant gains but higher risk):
* Forced Induction (Turbocharger or Supercharger): This adds significant horsepower but is a very involved and costly modification. It usually requires extensive engine upgrades to handle the increased power.
* Engine Modifications: Head porting and polishing, camshaft upgrades, higher compression pistons, etc., all significantly increase horsepower but are usually best left to experienced mechanics. These are also expensive and require extensive knowledge to do correctly.
* Nitrous Oxide System: Adds temporary horsepower by injecting nitrous oxide into the intake. This is relatively easy to install compared to forced induction but requires careful management to avoid engine damage.
Before you do anything:
* Identify your engine: Knowing the exact engine (e.g., 3.9L V6, 5.2L V8, 2.0L I4) is crucial. Modifications are engine-specific.
* Research your specific model: Look for forums and online communities dedicated to your specific 1999 Dodge model. This is where you'll find the most relevant information about successful modifications and potential pitfalls.
* Consider your budget: Modifications can range from a few hundred dollars to many thousands.
* Understand the risks: Improper modifications can damage your engine. If you're not mechanically inclined, it's best to leave the more complex modifications to professionals.
In short: Start with simple bolt-on modifications like a CAI and exhaust. Then, if you want more, consider a tune to optimize performance. Only move to more drastic engine modifications if you have the budget, experience, or are willing to pay a professional to do the work. Always research thoroughly and prioritize safety.
