This thread is in response to the lack of centralized info... I have just compiled info about what I know (or more accurately, have learned from others) If you are reading this then you are probably overwhelmed with the info out there for our cars :huh:. You probably want to get some ideas about what to do and want to make your car better... Modding can be addictive and costly , but it can also be exceedingly rewarding :banana:. Let me start by presenting some thoughts on modding: (this is kinda tailored for STis, but has carry over to WRXs) Suspension first then power... speed is nothing without control The bushing upgrade route is great for its effectiveness and low cost. But there is allot of chassis stiffening that can be done as well as more suspension mods that will allow for even better handling. If this isn't your race car and it is your daily driver (only car) then dependability and drivability are important. The stock STi turbo is really good and fits the car well. It provides great spool speed and low lag with lots of versatility. Due to the low lag, people at the drag strip have recorded times as fast as guys with bigger turbos and more HP because the stock turbo is more responsive. Don't underestimate the VF39 turbo, HP isn't everything... if it was then you should have gotten a Corvette. STis are about handling and FUN driving. Putting money into other areas will enhance the fun drivability of the car and make you more satisfied with the same HP level. The engine modding is the tough one, because as you start changing stuff there you will be making trades (one benefit for another side affect) Do you homework about what is out there and see if you can find something that fits your style and what you want to accomplish. For example: if you want a drag car then you will not put much more work into the chassis or suspension and will focus on the max power that you can get out of the car... or if you want a car that is a good daily driver then you will have to set limitations to what you are going to change. For example, if you get really stiff bushings, motor and tranny mounts then you car will be louder on the inside and you will feel more vibrations making the car less comfortable as a daily commute car... but if you are like me then you don't mind some extra noise in the car and would rather have a car that is fun to drive. The only area that I would caution you (meaning an area where you can spend money and basically ruin you car) is the engine modifications... make sure you know what you are getting into. There is no free lunch, you have to make sacrifices to get more power. Sacrifices like drivability as a daily driver, engine life, throttle response, more likely to break things, speeding tickets less reliability, etc. You can get more out of the engine, so don't think that I am trying to discourage you from doing that. I just don't want you to fall into any of the traps I did or almost did fall into. On the forums you will always be able to find people who claim XYZ about this and that, take all of it with a grain of salt and use it when you are trying to get more info... just don't make your decisions solely based on what they say. Weigh the pros and cons of each engine mod with care, keep in mind what you want to accomplish not just "more power." After you drive the car for a few thousand miles you will have a good feel for what you think is lacking and what you do and don't like... just remember that suspension and handling mods make the car faster just like adding horse power but without the loss in dependability and the often high costs associated with getting more HP. A good place to start looking for mods is at what other have done to their cars (just to get ideas for what is out there and what other like). I recommend getting tools and a jack so you can do most if not all the mods yourself... it will be more satisfying when you finish each mod and you will gain better understanding of your car as well as knowing that it was done right. I cant tell you how many times I have watched others work on my car and seen them screw up something, happens almost every time... this is why I do all my own work now or always watch the mechanic when they are around my car. The forums and the service manual tell you almost all you all you need to know about any basic or intermediate work you would do to your car. Did I mention that working on your own car saves you more $$$ so you can buy more parts Welcome to the club, :banana: Now for the beginner INDEX of info, both everyday need to know, and modding. Unabomber's...Index of EVERYTHING: Maintenance ... cuz you have to... if you want to take care of your car http://forums.nasioc.com/forums/showthread.php?t=995498 http://forums.nasioc.com/forums/showthread.php?t=206764 CEL codes: 2004 WRX STi Service Manual Suspension & Driveline FAQ: The rules... for effective (suspension) modding: My favorite and most concise thread on suspension: Suspension & Driveline info: OFFICIAL Brakes/Steering/Suspension Installation/Walkthrough Thread: Suspension, Handling, & Stiffening Threads of Interest STi Suspension Buyers Guide Transmission (AT/MT) & Driveline: DCCD - DRIVER CONTROLLED CENTER DIFFERENTIAL Drivetrain Threads of Interest Wheel and Tire info: Wheels & Tires Threads of Interest Braking Engine info: Engine info thread: and more http://www.iwsti.com/forums/engine-...opular-engine-power-performance-stickies.html Popular Engine, Power & Performance Stickies Engine, Power, & Performance Threads of Interest Engine Management FAQ: ECU Tuning & Performance Electronics Threads of Interest Meth info: Car Audio, Video & Security FAQ/How-TO I.C.E./Security Threads of Interest Exterior/Styling Threads of Interest Interior/Dressup Threads of Interest How-To Catalog for after you get your parts How-to's with pics HSPN HOW TO'S / INSTALLS Just some info to digest not definitive, but a good start to what's out there.