Hey everyone. It's been a while since I've been on the forum but I have a question that I'm sure some of the suspension gurus here can help me diagnose a tire issue.
First off, the specs on my car:
2009 WRX with 31,xxx on the odometer
Suspension: Racecomp Bilsteins with yellow springs installed ~7k miles, Perrin sways & end links, a number of bushings, braces, etc. installed
Wheels: Aftermarket 18x8 et45 (I think)
Tires: Dunlop Direzza Star Specs 235/40/18 with about ~19k miles
Alignment: A "street performance" alignment was done at a reputable shop when the Bilsteins were installed and checked when the tires were put on. Looking at the paperwork it had about -1.0 and -2.0 camber front & rear, respectively and 0 toe. It could be well out of specs since it hasn't been checked in 19k miles and the car has been beat up driving on PDX roads.
Problem: The basic issue is I have serious inside tire wear front and rear (5/32 outside and middle of tread, inside is toast) and as of recent, cupping. I actually thought I had a wheel bearing going out until I started doing everything for a 30k mile service and noticed the odd wear on the tires. I noticed minor inside tire wear a few thousand miles ago but I'm fairly certain the cupping is new, especially given the noise.
Other info: The car was mainly driven in the city until recently--I put on about 5,000 highway miles within a couple months. That is when I noticed the cupping. Also, all tires are uniformly worn...and cupped. I've scoured the internet and from what I can tell some STI owners had this issues with the stock Dunlops and a lot of highway miles. Everything else seems to point to a suspension or alignment issue.
Given the setup, does anyone have any thoughts of what the cause is and what I should do to remedy it? I originally had the car setup to do occasional track days so my first course of action is to put the alignment back to factory specs but aside from that, I'm not sure what else I should do. Thanks in advance.