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Old 01-13-2016, 01:09 PM   #33
nplack
Scooby Newbie
 
Member#: 257150
Join Date: Sep 2010
Chapter/Region: MWSOC
Location: FDL WI
Vehicle:
2002 2.5RS
Silver

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Well, its been at least 6mths and the thread has reset (again), best time for lurker Plack to check in!

Also, this just happened last week:

Guess that is what was making a racket in the 'rock crusher' trans for some time. Never knew it was an issue, but the center diff on some 5MT have a tendency for the giant spring clip to come loose and get all wound up in the transfer case. Bits of that spring got wound up in the output gears and split off a few teeths. Trashed now, but main trans unit seems fine. Probably just sell it for parts and get a different spare used OEM unit.

Transmission went to popping real bad on the way home from work last monday night. Limped it home and started tearing it down the next day. In the time before work each day, I managed to swap in my spare trans by last Friday and had her up and going again. New (used) trans is super smooth and very quiet. At least on the order of my 2010. Well worth the $250 I paid for it.

Picked up a knocking motor and intake tract from a '05 9-2x (2.0 wrx) to steal parts for Brandon - he needs stock cams and this motor was cheap enough to warrant purchase of entire unit just to strip the cams.


Got as far as this on tearing the motor down. As time allows, I will find out how bad the bearing damage is.


So now I am contemplating options to freshen/build this block to swap into my car for a cheap reliability/HP upgrade. Current motor has 175k on the clock and questionable history.

Current plan is to do a 2.1 stroker (some call it 2.2, but it is actually more like 2.125L).
Slightly bore/hone block 0.5mm over. Clean up oil galleys.
11+ STi Hardened crank - spin balanced with new flywheel
08+ STi OEM rods - hand polish and weight balance
Mahle 92.5mm forged 2.1 stroker pistons
ACL race bearings, widened clearance, 1.5 thou on crank, 2.0 on rods
11mm pump, hand modified and cleaned. Will make sure I can keep up oiling with wider clearances.
Early 2.0 waterpump (best high RPM flow)

Should be able to keep costs comparable to a OEM shortblock doing it myself, but end up with much better build and clearances.

Why not a 2.5? Already had one, don't want another. Simple as that.

Why a stroker? Counterintuitively, it will have better RPM potential than 2.0 or 2.5, short of maybe a EJ207 and even that is debatable. Stock 2.5 STi already gets to an easy 7.5k. Using 2.0 (92mm) pistons makes for much lighter piston set for less inertial rod stress as well as less swept volume for less suction load. Should mean a fairly safe 8.5k redline without spending a fortune. Either way it is better than the 2.0 I have right now.

Will I make any power up there? No. But goal is reliability at high RPM. Always build in headroom.

Still researching cams and valvetrain options. Seems Supertech Iconel for $350 is good insurance against a dropped valve and value added to the heads so long as I don't wipe them out. Buying new buckets to shim it out will suck, but I want to do it right. Single valve spring only, perhaps a slight bump in seat pressure to be safe.

Would like to find some OEM cams that can outperform current ones, but there is so much disinformation out there. Perhaps a set of used BC 272 or similar, but I don't want to go crazy and have a tuning nightmare.

Considering a slight bump in turbo as well. -19t or VF39 would be an option on the cheap if I can find a good one. Decent bump in high end flow. Not shooting for 400-ft lbs and 35psi at 3500rpm. Just nice smooth powerband all over. Might even go for a bloush modified or similar. But turbo is easy mod in future, does not have to be part of initial build.

Well that was a bunch of typing. Thoughts?

Hows AUG?!
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