I have a completely stock JDM v4 wrx auto wagon that I picked up cheap for DD duties. From what i've read it's got a piddly td04, 390cc injectors and of course the 4 speed slush box.
I'm wondering if a 2.5 or 3" decat downpipe mated to the rest of the stock exhaust, or possibly an aftermarket centre section would be a worthwhile upgrade ? Or is that opening up a can of worms with boost creep and hitting boost cut on cold nights under high load ?
Thanks.