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Boo's 5 year plan. Let's talk internals! (get in here Keith, Kirt, John...exct)

17K views 61 replies 14 participants last post by  boo-key 
#1 · (Edited)
The intent of this thread is to gain insight on internal modifications. Specifically what the most cost effective route for my goals will be. I consider myself pretty knowledgeable when it comes to bolt-ons (choosing and installing) but, not so much on internals. I would love to gain knowledge through your experience and suggestions in this thread. I have always been most interested in increasing power output of my wrx but, at the same time am timid because of the fear of catastrophic failure. I would rather have overkill in the area of combating this type of failure than go on any farther than my current stage 2+ set-up. Currently my car has 68xxx miles on it and everything discussed in this thread will be assuming when it hits 100k the engine is still in good working order. I estimate that at the rate I'm going it will take me about 5 more years before I hit 100k. My goals are 350awhp on e85. anything north of that would be great but, not required. Rather than just do the timing belt service then I would like to pull the engine and rebuild it to handle more power. I will be removing the engine myself but, am not comfortable with the rebuild unless I really learn a TON between now and then about it. Rather than modify my car any farther now, I will be hoarding parts as finances allow for this build. This is where you guys come in! This may seem like a large list but, keep in mind the amount of time I have allowed to acquire my goals. without further ado here's my list.

Forged pistons
connecting rods?
Bearings?
Machine work
AOS
ID 1000cc injectors (I plan on going e85)
parallel fuel mod
aftermarket fuel rails
20g turbo?
gs tmic, splitter, i/c hoses
sti 6speed trans
r180 rear diff
dccd controller
new clutch (oem) and possibly lightweight flywheel
oem water pump
oem timing belt and tensionersis
Studs?
gs thermostat
killer b oil pickup and windage tray
Head work?
stiffer engine and trans mounts
gaskets?
cobb ss with kartboy bushings

This list is not set in stone and I am open to suggestions. I only want what I will need for this build and not a bunch of extras. Remember this is a budget minded build. Now for the questions. What brand, size of pistons? Do they usually come with all hardware (rings, pins, exct...) If not what will I need? What kind of machine work will I need done? Will I have to increase bore? Should I get coated pistons? Connecting rod suggestions? What if anything will have to be done about/with the crank? What about bearings? Will I need any head work done? What kind of gaskets should I plan on buying? Do i need aftermarket head studs? Will my current walbro 255 support my fueling needs or will I need to step up? I would like to keep my 5x100 wheels, hubs, brakes so, what is the most cost effective way of doing this with the r180 and 6 speed swap? Axles?

Now Drop the knowledge on me so I can get to pricing my build and sloooowly buying parts!
 
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#14 ·
Second question; Do you have a spare motor to build or are you trying to buy parts and build the current motor? I recommend buy a used motor and tearing it down and going that route so you have less down time.
I'd highly recommend having a machine shop check the piston bores and if they are with in spec you'll need at least a hone.
I'm a huge fan of Wossner pistons, but that is just me. Lots of people go with CP or another brand. I chose Wossner because they seem to not have that cold "knock" that a lot of forged pistons do. Although a bit heavier than most I have always had good results with them.

Personally at that power level doing a STi swap isn't worth it, but running a stock trans isn't either. I run the 08 LGT gear set, which is suppose to be pretty stout, but then again I had a good bit of luck with my old set of gears and it was a bend shift fork that was my issue. So I just upgraded the gears while the trans was out.
 
#15 ·
All you need is a stout bottom end like Keith has said. My engine is overbuilt for what I make hp wise. If you get CP pistons get the side and top coated by SwainTech. The piston slap isn't bad at all if they're coated. I had a short block without coated CPs. It was way different on cold start up with piston slap. Very noisy until warmed up. It has to be freezing out to get even the slightest slap on my setup right now. Bottom end/shortblock is everything below the heads. I have a nitrided 2009 crank (Keith knows a little more than me on cranks), but the stock STI rods are fine for your power goals. Probably could get away with stock bearings. Again, I have ACL bearings and it's overkill. Keith likes a certain brand bearings...he'll comment about it. ;) I'd suggest APR headstuds. Lock that biotch down. Replace all your gaskets with a master gasket set while your in there. Umm...the 07 6 spd has a slightly different ratio. I wouldn't call either them less short then previous years by much. I think the 08+ STI is slightly longer. Can't quite find the old link on transmission ratios while on my honeymoon. But, you could probably run John's Albin gear set on your oh goals. But, a 6 spd would mean you can stop sweating bullets if plan on beating it some. It's a big matter of opinions though. You could easily get 350 whp on E85 with a 20G. Shoot...you get that with 93 oct if you have it in Tennessee. I can help with links to more info when I'm at home.
 
#16 ·
Yes piston coatings do help with cold starts. It is usually one of those topics that gets beat to death from people with different views, but hey I have seen it work and I have it done on mine. Crank wise, just about any 2.5L STi crank will work. The new ones have a revised treatment on them, but I have seen people build motors making 500+whp using the older cranks without issues. Just make sure you get a phase 2 crank.
To be honest I am not one to buy into the, "You need this, this, this and this." to make a motor build more power. Truth be told other than pistons and a couple other odds and ends my current motor runs mostly stock Subaru parts.
Bearings are another debated topic, many people run ACL, I run Clevite in mine and haven't seen any issues. Just be careful on which bearings you buy. ACL offers a few different "styles" of bearings and I'd have to dig them up, but stick with the basic rebuild bearings and you'll be fine.

p.s. Oh and for the love of all that is holy, do not get a crank turned or reground, just buy a new one.
 
#17 ·
So to answer you first post;
Forged pistons yes
connecting rods? stock Sti
Bearings? ACL, Clevite
Machine work required if you bore or hone the block
AOS Meh I dont run one, but probably should
ID 1000cc injectors (I plan on going e85) probably but not really need for your power level
parallel fuel mod no
aftermarket fuel rails no
20g turbo? minimum
gs tmic, splitter, i/c hoses yes
sti 6speed trans not so much
r180 rear diff no
dccd controller no unless you go 6 speed
new clutch (oem) and possibly lightweight flywheel upgraded clutch and yes
oem water pump yes
oem timing belt and tensionersis yes
Studs? meh go either way. I don't
gs thermostat no
killer b oil pickup and windage tray GOD no
Head work? no
stiffer engine and trans mounts recommended
gaskets? stock
cobb ss with kartboy bushings
Hope this has been of some help to you.
 
#20 ·
There is a long standing reason for me using green...:D

boo-key bear said:
I'm pretty set in doing the 6 speed swap as opposed to a gearset in my wrx trans. So Keith, are you saying that a upgraded clutch is okay in a 6 speed? I wasn't sure if it was a no no like in a stock 5 speed. I like the idea of buying another shortblock to build while mine is still in the car. I think I will do that. Why do you say GOD NO to the killer b oil pickup and windage tray? I have heard nothing but good things about them. I have also heard a lot about the possibility of the stock pickup breaking. Would I use Oem head gaskets also? When is it nessecary to use a thicker head gasket if it ever really is nessecary? I am also curious what the benefits of a destroked 2.5 and why you prefer to run yours that way Keith. I'm not thinking of going that route just curious cause I've never really heard of it.
I upgraded my clutch on the stock 5 speed...6 speed is just built a little different and designed to handle more power so I don't see why not. A lot of what you hear of people blowing up their trans is lack of driving ability or just being stupid. The reason for saying what I did with the Killer B stuff is your not going to be making enough power to require much of anything over stock. Hell I run the stock stuff and I can run a 9k redline. If your worried about the pickup tube, again more fluff, then have it tack welded. Pretty simple, but again what has worked for me over the years is just that. I am looking at trying to save you money in the long run and trust me you'll thank me in the end. I run OEM gaskets, no need for a thicker head gasket unless you have the heads shaved or want to run a lower compression, but that doesn't really lower it much. The 2.34 is simply a rev happy motor. On a GT35 you can make 450whp on pump gas and rev to 9k easy. You can do it with a 2.5L, but it was the route I took from the parts I had on hand.
 
#19 ·
I'm pretty set in doing the 6 speed swap as opposed to a gearset in my wrx trans. So Keith, are you saying that a upgraded clutch is okay in a 6 speed? I wasn't sure if it was a no no like in a stock 5 speed. I like the idea of buying another shortblock to build while mine is still in the car. I think I will do that. Why do you say GOD NO to the killer b oil pickup and windage tray? I have heard nothing but good things about them. I have also heard a lot about the possibility of the stock pickup breaking. Would I use Oem head gaskets also? When is it nessecary to use a thicker head gasket if it ever really is nessecary? I am also curious what the benefits of a destroked 2.5 and why you prefer to run yours that way Keith. I'm not thinking of going that route just curious cause I've never really heard of it.

Kirt...I looked up the swaintech coatings. Man, that sounds like some good stuff! I would definantly want it! Damnit, enjoy your honeymoon and get off the forums! We can talk about this stuff anytime but, you only get one honeymoon!
 
#21 ·
Crawford Perfomance runs 500 whp STIs with a stage three clutch on a stock STI 6 spd...the 6 spd is built by a German company that builds transmissions for tanks. Is the entire drivetrain and gears bullet proof on a STI? No...but, it's a lot tougher than the 5 spd in the 2nd gens.
 
#22 ·
When you get your block bored, ask to have the least amount of material removed as possible to maintain strength. I didn't compare and contrast every single part that went inside my engine, so I probably can't help you very much in that department. I can give you a detailed list of what I have and I know the rationale behind some of my parts, but the majority was just a package put together for me by IAG when they did my build. It's a fairly common setup and it's been reliable so far (26k miles and counting).
 
#24 ·
Coating the skirts on pistons is more to benefit break in than anything else. By 10k miles the coating is mostly worn off.

If 350 whp is your goal then you won't need E85 to hit that on a 20G. 93 should work fine. I also don't think you should need to go right off the bat building the motor. You stock internals aren't guaranteed to fail. And if you do I wouldn't use 2618 pistons. You don't need them and if this is your DD it would be more of a hassle and more expensive down the line because you will have to rebuild again later.
 
#26 ·
I copied and pasted most of this from a previous PM to another member:

$553.40 = Manley Platinum Series pistons (4, 99.75 mm)
$393.80 = Manley H-Beam connecting rod set (I-Beams would have been complete overkill)
$381.56 = 2.5L OEM Nitrided crankshaft
$52.10 = ACL Race rod bearing set (52 mm journal w/ extra oil clearance)
$102.00 = ACL Race main bearing set
$35.86 = engine case bolts (10)
$39.40 = engine case sealant
$313.72 = engine gasket set
$32.94 = oil feed lines w/ filter, raised head (2)
$194.00 = ARP head stud kit
$20.80 = PDP motor oil 5W-30 (5)
$44.95 = Royal Purple break-in oil (5)
$93.84 = Purolator PureONE oil filters (6)
$35.90 = coolant
$49.99 = IAG air pump block off plates (did the TGV deletes as a "while you're there" mod)
$299.99 = IAG TGV deletes
$1,050.00 = Kelford 264 Cams (not at all necessary)
$193.00 = Killer B ultimate oil pickup (stock parts known to fail)
$169.95 = STi 11 mm oil pump (probably overkill)
$2,370.00 = build labor (30 hours)
$300.00 = bore and hone block
$4.50 = oil plate gaskets (2)
$119.47 = OEM oil pan (replaced as a safety precaution because I wanted to be absolutely sure there was no metal in the oiling system since I cracked a piston and lost compression in half the engine which was the reason for the rebuild in the first place)
$286.15 = OEM oil cooler w/ gasket
$12.23 = pilot bearing
$15.00 = GT Spec up pipe to turbo gasket
$19.00 = GT Spec turbo to downpipe gasket
$15.00 = GT Spec manifold to up pipe gasket
$7.99 = Vibrant 3" 2 bolt exhaust gasket
$157.50 = Invidia up pipe, polished stainless w/ EGT bung (another "while you're there" mod)
$59.83 = GrimmSpeed 3 mm phenolic spacer (another "while you're there" mod - I went with the thinner one to minimize clearance issues which sometimes occur with the thicker ones)
$10.80 = lower intake manifold gaskets (2 - one between the block and the phenolic spacer and another one between the phenolic spacer and the intake manifold)
$316.00 = set valve lash for new cams (4 hours)
$33.92 = NGK one step colder spark plugs (4)
$145.90 = SPT engine mounts (2) (yet another "while you're there" mod)
$40.00 = IAG billet half moon set (If I recall, the stock pieces are plastic - they're basically plugs to fill the gaps created when the factory originally machined the older engines)
$134.85 = Royal Purple break-in oil (15)
$45.99 = Motul 5W-40 X-Cess (5L container, used after break-in, found much cheaper on Amazon.com in bulk)

I left the prices I paid in there as a benchmark so you can hopefully find things cheaper !Thumbs Up

Like it was already mentioned, there will be other costs associated with your particular build (supporting mods for whatever turbo you decide to run, turbo, tune, and possibly other miscellaneous tidbits).

The break-in period is the most painful part, besides paying for everything, of course. The odometer seems to tick by sooo slowly, but you'll have to keep a close eye on it anyway and change your oil at the recommended intervals. You'll also have to use the engine to decelerate the car as much as you possibly can and refrain from driving the same speed for more than 30 seconds to a minute at a time. This can be very annoying for cars behind you, but it's for a good cause :cool:

Also, if you plan on doing everything yourself, make sure you talk to your tuner ahead of time about getting a base map to use during your break-in period.
 
#36 ·
I can't agree more with adair!! depending on what you make off your wrx its still going to be pricy, almost or over 40K for a new sti to start off new and clean with, even a used for high 20s low 30s.
Also if your planning on doing this, your better off just parking your wrx, paying for something you don't drive, keep the value up on it, then once your done paying for the peace of metal in your garage the go get an sti.
Sorry guys rant over
 
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