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Hondafan 02-12-2011 03:30 PM

STi #4 ringlands blown! Time to build it!
I'm now officially another person on the list to have blown the ringlands on my STi. SOA won't cover anything because the car had a DP on it. I get that I SHOULD HAVE reverted it to stock, but the nearby dealership is pretty lenient on mods, and I didn't think it was going to be something major.

The car was having erratic boost and a misfire between 2500-3000 rpm. I thought it was spark (ignition) related, and that a warranty repair wouldn't be that big of a deal. It was intermittent and I figured something mechanical would be consistent. I could clear the ECU learning and it would run smoothly for the first few miles, only to go back to running weirdly. I replaced the A/F Sensor, and got no result out of it. I pulled the spark plugs, as the dealer didn't compression test it while they had it for the first 3 trips, nor the 2 weeks they had it when they were "working on it." They kept reverting back to assume that the ECM was bad because of the AP. I kept on the assumption that the ECM wasn't bad and continued the diagnosis beyond what Subaru figured I had screwed up. Now on to the good part.

I know that the stock motor isn't very well designed for even stock boost levels, let alone 18-19 PSI for stage 2. I've been trying to read up on pistons and I'm looking into Wiseco, CP, and Crawford forged pistons. I know from BoostAddict's experience not to go with Mahle's. The other thing I've been reading is that many built motors don't last as long as stock??? Here's my objective and I'm asking for advice from the people who really know.

I use this car as a regular DD, but I might want to increase the power to somewhere north of the 350 whp range once the car is paid off. I will resist the desire to push the motor to higher power than stage 2 if that means I get something that will last me 100K or more. I'm looking for power but with am emphasis on reliability. I would appreciate quieter forged pistons, and I read that the CPs are quieter, but I haven't heard the difference anyway.

My last option is to repair the car to completely stock, only working on the side that's bad, replacing the piston and rings, and trading it in for a new one that's not modified at all so the warranty won't be denied. I'll also be looking at an EVO X if I explore trading in the car. The car made no additional sounds with the ringlands blown, and we're not expecting to see any scarring in the cylinder, but can't know until it's torn down.

I'm weighing my options to build the motor to handle 20-ish PSI if I can keep it reliable, or I guess I'll be going completely back to stock with this vehicle or moving on to another car.

The bore will remain 99.5mm, 1.208 height, with the stock compression ratio as well. Which pistons would be best for my intentions with the motor? Wiseco, CP, or Crawford? Also, I've found a built block by Outfront Motorsports that's preassembled for 1800 [COLOR="Red"]EDIT: 2600 shipped. The 1800 is for a stock short block.[/COLOR]shipped for the short block. That one doesn't say what brand of pistons are in it though. What would you guys do?

It sucks to have a car with 19K on it and have a toasted motor, huh?

black beast2 02-12-2011 04:01 PM

Sorry to hear that man I know it sucks bad.I was happy to get 80,000 miles out of mine before it blew and ive been running a stage 3 set up with over 350whp for the majority of thoes miles,I couldnt even imagine only getting 19,000! Anyway I went with the 100mm wiesco's and they are pretty quite for the most part,except of course in the morning they are loud as hell till she gets warm..why do you say a built block wont last as long as stock? It seems to me that a motor built with better parts would be able to take more power and last longer then one built weaker,is that not tru?

Hondafan 02-12-2011 04:11 PM

I thought it was true, but as I've been reading around, I guess most people don't get a huge amount of mileage on built blocks. Maybe that's because they're pushing way over stock boost? I just keep on reading on iwsti, nasioc, and 3grwrx that they don't last as long as stock internals. I guess it's ridiculous to think a motor wouldn't last as long as my stock motor, huh?

Also, thanks for the info on the Wiseco's. I'm leaning more toward the Wiseco or CP's.

RcrsWetDream 02-12-2011 04:16 PM

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Built blocks don't last as long when they're build with 2618 pistons. They require more PTW clearance than typical pistons ( I think 4032?) so they tend to wear out your cylinder walls and pistons skirts quicker, thus losing compression quicker and requiring a refresh more often.

You could get away with buying an aftermarket set of pistons and call it good to be honest. Stock STI rods have been proven north of 400whp, the only thing really holding the stock short block back are the pistons. If you're having the dealer do it just have them install the new pistons and get the block machined. Depending how bad the ring land was you may not even need to bore the block over.

Now if you want to have some fun and do it yourself...... Well you can do alot of damage to your short block for <3k.... Just ask me I'm in process.

Bore, hone, crank polish, hot tank and degreasing of block: $250
Piston Skirt and Dome Coating (Wiseco's come with skirt coating but swaintech is better): $200
Wiseco Pistons (come with wrist pins and rings), Manley Rods: $780
Master engine gasket kit(every gasket under the sun incl. head gaskets): $214
Permatex Ultra Grey (seals block halves, same as FujiBond): $5
ACL Race Bearings: $150
Reuse Stock Case Bolts and Head Studs: Freesville
I bought new case bolts and ARP head studs: $219

Building your own engine and either spending the same amount of money for a 100% built short block, or saving over a grand, priceless.

Honestly any aftermarket forged 2618 pistons will hold 500+whp. It's more a brand preference as 99% are simply copies of the stock piston with a slightly different dish for different compression ratios. If I show you a stock STI piston vs my Wiseco's the dish will be a bit shorter on the Wiseco. It'll also push my build to around 9.1-9.2:1 CR, but I'm running corn.

Hondafan 02-12-2011 04:32 PM

There's no way I'm going to pay Subaru to do the work, as I don't trust them when they had the car for 2 weeks and couldn't diagnose it down to a common problem. Then when I showed them the smoke coming from the oil filler neck, they said it was completely normal. I've got a close friend who owns a shop and I've had do multiple motors on my Hondas and I absolutely trust him. Plus, he does it on the side for $25 an hour. I'm not quite sure I'm prepared to tackle an engine transplant on my Subie just yet.

I'll be doing a summer project on my Z28, just because I can take months to do the fix. Too bad I hadn't already done the Camaro, as at least that would give me something to drive right now! I can't believe how much LS1 parts cost for that car. It's not even great technology! I feel so much more at ease spending this much on the Subaru than the Chevy. Thanks again, Chris!

pzr2874 02-14-2011 11:37 AM

Did you purchase an extended warranty from your dealer ? If so... get your cash back. It's worthless now. That sucks.

turmic 02-14-2011 12:13 PM

CPs are not really quiet at all when they're cold. I had mine coated to reduce the noise...whatever ron used to do to them. I think it was skirt coating. But, once my engine is warmed up you can't really hear that much of a difference over stock. I never heard Wiseco pistons, so I can't comment. Mahle's are quiet as stock I've been told by my tuner. But, I don't trust them. I know matt runs Aria pistons and he has a freak engine. So, there is another option.

Its your car, but i'd just have the pistons replaced with rings (of course) and keep it. I don't know why you heard over 20 PSI is bad for the engine. I was over 20 PSI with the stock block (30+k miles) and am still over with the built block with no problems. (With a RAW performance Stage 3 block and I'm knocking on wood that it seems that Ron did a great job on my build)

Hondafan 02-14-2011 03:45 PM

[quote=pzr2874;256663]Did you purchase an extended warranty from your dealer ? If so... get your cash back. It's worthless now. That sucks.[/quote]

Nope. I planned on changing things anyway so I figured that any claim would be denied anyway.

I'm hoping that I can have my car back up and running within a month. How long does it usually take to get the pistons coated? What is the coating that they're coated with? Is it some type of electroplating? I'm starting my parts shopping this weekend or next week. Should I have the pistons shipped directly somewhere to be coated instead of having them shipped to me first? I don't mean to complain, but it sure sucks to spend ~3K to not really get any additional power out of the block.

2 more questions:

1- Do I need to get a tune specific for the new motor while keeping everything within stock parameters?

2- Can a tuner increase the boost above the 18-19 PSI I was pushing before while at 65% IDC with this new motor? Or will I need additional parts (like a 3-port EBC?)

RcrsWetDream 02-15-2011 12:30 AM

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I would get tuned to be safe. Your current tune blew a ringland after all.

I'm running 19-20 psi on my 91 tune and I have been for a while with no issues, so yeah on the built engine you can probably run more boost than the stock map sensor can read. 3-port always helps but isn't 100% necessary.

As for the coating on pistons I think turn around is about 2 weeks once they get them. I believe it's like a powder coat, that it's baked on.

turmic 02-15-2011 09:00 PM

I'm not familar with exactly how my coating was done. Because I didn't question it, but I knew that I wanted it from reading the difference it makes.

Not to be a d!ck, but I agree with Chris. A protune over the OTS map your using would be a lot better...considering what happened to your stock engine. I don't know what tuners you have in your area. But, a limp or break-in map with lowered boost for breaking in the new engine for a few hundred miles couldn't hurt. I ran a limp map to break in my engine and clutch. But for stage 2, it wouldn't be necessary. My car was running the upgraded turbo while I was breaking everything in.

Hondafan 02-24-2011 10:41 AM

Update time.

My mechanic scoped the motor with his little camera in cylinder number 4 to see if the cylinder walls were scarred so I could order the pistons and get the parts on their way. He was just checking it that way because he's doing all the work on the side for a deep discount. I'll be waiting a lot longer on my work to be completed, but for labor at $25-$30 an hour, it's worth the wait.

Anyway, this morning he called and said the cylinder wall was fine but there was a chunk out of the piston. I had to have gone ridiculously lean for that to happen. On your guys' advice, I'm going to get the Wiseco's and have them coated. I'll order those today, as they're the part that I anticipate the longest delay for. I'm just hoping that chunks of the piston didn't do damage to the head or even the turbo on the way out. There's going to be a good amount of inspection necessary when it comes time to pull parts and reuse stock stuff.

Is there a reason to order a new oil pump with better flow, timing belt kit (car has 19,700 miles now), water pump, injectors (will injectors automatically decrease fuel efficiency? Or can I replace them and tune the flow down?), etc? I just ask because I'll have it all torn apart right now and I might as well save the labor.

My plan is this. I plan to get tuned as I'll be installing my ELH that's just been wrapped and waiting for the car, but I want to find a tuner who can do so with the AP. I like the simplicity of it, and the only local tuner I've been recommended uses opensource. Thoughts? You guys are absolutely right on the tune thing. I thought Cobb's OTS maps ran pig rich, but apparently they don't run rich enough for my car.

Next question:
With Swain Tech, they have the Gold coating and TBC coating. The gold coating is more, but say it's for turbo applications. Is that what I need to get done? Or the TBC?

RcrsWetDream 02-24-2011 12:38 PM

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From: Me

I am looking to get the domes of my pistons coated and would like to know if I should go with the TBC or Gold Coat for my application. The pistons in question are Wiseco 8.9:1 2618 forged pistons going into a 2009 WRX's EJ255 (running closer to 9.2:1 CR). The car will be running E85 and pushing around 22psi of boost. Thanks, Chris Weeks

From SwainTech:

Thanks for writing. You wold be fine with TBC.

Swain Tech Coatings, Inc.

Obvioulsy it's a bit different for you but the gold is for the high high boost and high nitrous engines. Think 30+psi.

Injectors won't hurt fuel economy. You only flow as much fuel as you need, the rest gets sent back to the tank. Yes, you have to scale back the injectors so you're not flooding the cylinder with extra fuel. Say your current injectors (for ease: 500cc) get a 1ms pulse, you'll get double the fuel if you use 1000cc injectors. So to get the right fuel you have to scale the injector back to dump the right amount of fuel. Look into the injector dynamics. They're boss, Jason has them on his STI and it idles like butter.

The newer STI oil pump is adequate. 08+ all have the 11mm pump in them.

Timing kit will be fine, but make sure the tensioner is good. Pulling that off the wrong way can ruin it (you have to slowly compress the cylinder).

Hondafan 02-24-2011 02:47 PM

Officially ordered the following:
Wiseco Forged Pistons - 99.5 bore, 8.9:1 CR
Manley H Beam Connecting Rods
ACL Race Bearings (Thanks for the recommendation, Chris!)
ARP Headstuds (Still wondering if I need/want main studs?)

[COLOR="Red"]TOTAL: $1082 shipped[/COLOR]
Real Street Performance is running a sale for tax season so I saved a whopping $33, otherwise it would have been $1115.

I'll be getting the master gasket set, Killer B Windage Tray (is that worth the $70? I figured it couldn't hurt), and a 6 pack of OEM oil filters from totaling $354. The cheapest I have found the master gasket set is $250 and that's at FBP. Anyone know of a cheaper place? I have a couple days I can wait on that stuff, so going for thoughts/opinions, if you have any.

Oh, and Jason is Medamullet, right? His inbox is full on SLCSubaru and Nasioc.

RcrsWetDream 02-24-2011 04:20 PM

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Yeah he's medamullet. If you want his number I can pm it to you.

I paid 214 for the gasket kit shipped from Fred Beans. Let me search for the site, but they matched a competitor price for me.

Found it, STI gasket kit is a bit more, but it's only $235 shipped. Fred beans will match it, you just have to call:


same part # as:


Hondafan 02-24-2011 06:01 PM

He has joined True Tune in Bountiful, and it looks like one of the tuners that joined them with Jason does tuning with the AP, but it'd be great if you PM'ed me his number anyway. I'm going to meet with them next week to discuss power goals and parts and I'm going to have them make me a map to break in the motor and then bring it in to them to get the protune done. I'm highly stoked now. The biggest delay will be related to the pistons. The first AutoX event in Utah is March 18th or 19th and I really hope to have the car done for that!

[COLOR="Red"]Update:[/COLOR] I ordered in the master gasket set, which FBP matched prices so I saved $15, 2 gallons of super blue coolant, oil filter 6 pack with crush washers for the drain plug, and the Killer B windage tray. Total cost so far is just under $1500 shipped including the pistons, rods, bearings, studs, and everything I ordered today. Add in the SwainTech coating for about $200, and then $600 in labor, and I don't think $23-2400 is bad at all for a built STi block.

I'm just crossing my fingers that the hole in the piston didn't grenade anything like BoostAddict's did to his turbo. Or the head/valves. Please be a tiny chunk that was able to pass by stuff without shredding stuff!

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