Couple questions about the 08 WRX

[MsclTnr0208]

First question is simple. I'm in need of new tires and i'm not happy with the factory size, will 225/45/17 fit on my car or is the factory rim to thin? Second I have a custom 3 inch cat back and a custom CAI on my car. I hooked up a boost gauge and around 4k rpms my PSI starts dropping. It goes from around 13 or 14 down to about 7 at 6k rpms, but it will hold the 13 PSI if i don't go over 4k. Someone told me that a smaller turbo will lose PSI at higher rpms but i can't see it losing that much. Also a little while ago a oil line that went to my turbo broke and was spewin oil everywhere and I had to drive it a little bit before i got it fixed. Does the PSI drop sound like a boost leak? Or could my turbo possibly have been damaged from my oil problems?

[mosc]

the 225s will fit without issue as long as they are fairly stiff sidewall (anything high performance).

The 7psi at 6k RPM is about right. It's a 2.5L motor and a tiny ass turbo. It can't supply enough air at the higher RPMs to hold max boost. Max boost is at about 3500rpm, like you've been seeing.

Doesn't sound like your oil spewing caused any harm?

[dumdum]

Get some engine management and the boost levels will go up with a new tune.
PERRIN Stage 1 2008 WRX Test and Tune - NASIOC
TurboXS 2008 WRX Stage 1 & Stage 2 Results! - NASIOC