Simply Silver said:
This is for a "fun" daily driver. I am unaware of any auto-cross events in my area. I do not mind giving up a little comfort for performance.
First off, a lot of information is available from the
Protege FAQ and the
spring buyer's guide.
Here are the options I would consider for springs/struts:
10% stiffer than stock - MP3 springs (0000-88-C03-KT) and struts (0000-88-C04-KT). Drop 1/2." People commonly run MSP springs on P5s but the MP3 springs more closely match the P5's weight distribution.
15-20% stiffer than stock - Tein H-Tech, iON sport, Racing Beat springs and Tokico HP/Illumina struts.
More stiff - Tein S, Espelir, Eibach, Tanabe GF, etc. with HP/Illumina.
Then there are high-dollar coilovers which offer lots of adjustment but probably overkill for a street car.
Sway bars (most people just switch out the rear to reduce understeer):
MSP rear sway bar (BP7H-28-151A) with AXR clunk fix bracket - no adjustability but also no clunk. If you mount the MSP bar on stock mounting points it will clunk eventually.
AWR rear sway bars offer adjustability but may make noise.
Linear rate springs are better for performance driving; progressive rate springs attempt to improve comfort while increasing stiffness (this
sorta works). A lot of guys use lowering springs with stock struts. This is ok for mild springs (since stock P5 struts are pretty sporty), but the struts will wear faster. With more aggressive springs, this will actually hurt suspension performance.
Hope this helps.