Originally Posted By: gathermewool
The '02 takes incredibly well to tuning, from what I've read. How many miles? Original engine, turbo, etc.?
Is the upstream cat still installed? I've heard about these breaking up and taking out the turbo. An easy mod is to gut or remove the upstream cat. I assume you'll be doing this as a part of your turbo-back install, but if you weren't aware I'd definitely make this a part of that upgrade.
Most guys used to run Rotella T6 5W-40, not 5W-30, which is newer (myself included, in my previous STI). If I'm not mistaken, the new T6 5W-40 lost it's gas engine cert and is now only diesel-rated, now that they make a 5W-30, as well. I don't know anything about the new 5W-30.
Changing out your tranny fluid for Redline NS 75W-90 would be a good idea, though there are a billion threads on what works best. the RL NS worked better for me than the stock fluid and Motul Gear 300 in the tranny.
Motul Gear 300 has pretty much the best specs, from my previous research that is now 5 years old or so. Changing your diff fluids out for any decent synthetic will be leaps and bounds better than what most do, though. I just figure that $10/quart isn't much when the pumpkin only takes a quart. You'll likely never have to change the fluid after this.
Originally Posted By: addyguy
Any 5W-40 HDEO OR Euro 5W-40 or 0W-40 will do the trick here.
Castrol Edge 0W-40 is rapidly becoming a favourite oil here.
+1. I use Edge 0W-40 in my FA20DIT. It's my favORite oil.
I have about 197k on the chassis but only about 50k on the swapped JDM EJ205 and unknown on the tranny (previous owner claims he replaced with a 04) Thanks for the info, but it already has the factory catless up pipe that came on the JDM cars so no need to worry about it falling apart. Going full catless since we don't have emissions out here in HI.
I'm leaning towards thicker than 0w40 since I never see cold temps, but I will look into the Castrol and see if I can find any deals.
Thanks for the help, I will search for the Redline or Motul 300. I can use the same gear oil for the transmission/front and rear diff right?