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Old 08-19-2012, 05:44 AM   #426
aamir1632
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Hey guys, im not too sure what to expect with my car anymore. I have a 2012 sti with a little over 13k miles. Never beat on the car, but drove it aggressively at points, before bringing the car into the dealer i was running COBB stage 2, and a tbe. I have a cracked 4th ringland and subaru is giving me a "good-will" one time repair. Not a new short block, just a repair. I was thinking about replacing the current pistons with forged ones since they already have the motor broken down, and will void the warranty on the pistons after this repair anyway. Does anyone have any suggestions one whether i should replace the pistons with forged ones or just leave the oem spec ones on there?
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Old 08-19-2012, 09:23 AM   #427
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Originally Posted by aamir1632 View Post

Hey guys, im not too sure what to expect with my car anymore. I have a 2012 sti with a little over 13k miles. Never beat on the car, but drove it aggressively at points, before bringing the car into the dealer i was running COBB stage 2, and a tbe. I have a cracked 4th ringland and subaru is giving me a "good-will" one time repair. Not a new short block, just a repair. I was thinking about replacing the current pistons with forged ones since they already have the motor broken down, and will void the warranty on the pistons after this repair anyway. Does anyone have any suggestions one whether i should replace the pistons with forged ones or just leave the oem spec ones on there?
IMO, if you plan on selling the car in a year or two, go with the free repair and stock piston replacement.

If you plan on keeping the car for longer...and maybe even tracking it...go with the forged pistons.
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Old 08-19-2012, 02:38 PM   #428
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I dont know guys Im on my second motor 2011 WRX 15K miles. Yes I modded (heavily), yes I am at 350WHP etc. But damn these engines are not doing well even in stock form! I was just on the Dyno yesterday and had a problem, waiting to see what it is!
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Old 08-19-2012, 02:44 PM   #429
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Originally Posted by 2011boostdwrx View Post
I dont know guys Im on my second motor 2011 WRX 15K miles. Yes I modded (heavily), yes I am at 350WHP etc. But damn these engines are not doing well even in stock form! I was just on the Dyno yesterday and had a problem, waiting to see what it is!
Second motor? Both replaced from Subaru or you purchased a built block? What kinda driving do you do? Hard launches? Shifting at 7k? What mods do you have? What kind of dyno were you dynoed on? How often do you change your oil?
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Old 08-19-2012, 02:52 PM   #430
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Originally Posted by 2011boostdwrx View Post
I dont know guys Im on my second motor 2011 WRX 15K miles. Yes I modded (heavily), yes I am at 350WHP etc. But damn these engines are not doing well even in stock form! I was just on the Dyno yesterday and had a problem, waiting to see what it is!
350 hp should not be blowing motors left and right, if it is tuned correctly.

I know you guys who blow multiple motors don't like to hear it, but the problem is likely on your end .. not the car. The real issue is either your tune (most likely), you beating the crap outta the car, bad gas, lack of maintenance, cheap ebay parts, or any combination of those issues.
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Old 08-19-2012, 04:58 PM   #431
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Originally Posted by GrumpyPitbull View Post
350 hp should not be blowing motors left and right, if it is tuned correctly.

I know you guys who blow multiple motors don't like to hear it, but the problem is likely on your end .. not the car. The real issue is either your tune (most likely), you beating the crap outta the car, bad gas, lack of maintenance, cheap ebay parts, or any combination of those issues.
I blew up 3 stocks motors on a stock tune and a cobb stage2 tune within 10,000 miles. Running a fully built engine now with absolutely 0 problems and a aggressive tune on the stock turbo.

Subaru pistons just suck, every single failure was ring lands.
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Old 08-19-2012, 09:10 PM   #432
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Sure its been said 800 times in this thread(just like 8000 times on this damn forum)............................................ FACTORY-TUNE-SUCKS. GOOD TUNERS ROCK.
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Old 08-21-2012, 11:52 AM   #433
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Get the cosworth piston set and install it. Then enjoy your car for years to come.

C
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Old 11-14-2012, 01:14 PM   #434
Ferris1977
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Default Wrx 265 2010

I just got my car back after a month in the shop!

it cost Subaru japan/Canada 23 000$ to fix it. I don't beat my car... I like the acceleration but I won't take it to the extreme...

they had to chage the following:

- 2 pistons with all gaskets, rings and seals..... yes 2 ringlands...
- tranny, came straight from Japan
- intercooler
- head gaskets
- turbo
- clutch
- flywheel

They told me I got a lemon so they changed the entire powertrain... Sucks for a 45-46K Car....

I don't enjoy it anymore... You look at it and it breaks!
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Old 01-16-2014, 10:24 PM   #435
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I bought my 2013 STI last April. Tuned it with Cobb stage 1 for 4ish months then went with an e-tune from Clark Turner. I reset it back to stock in September in anticipation of an oil change and move to Colorado. 2 days before my oil change my motor blew on the stock tune at 6000 rpms shifting into 4th. I only had 5700 miles on the car.

My nearest dealer is very small and they did not ask questions, but it was Avery stressful few weeks. I've left my car stock all winter and I'm really on the fence about whether or not to retune it in the spring. I've wanted an STI ever since I got my drivers license (30 now) it's such a bummer to have zero confidence in my engine.
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Old 01-17-2014, 07:39 AM   #436
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Quote:
Originally Posted by moogatwo View Post
I bought my 2013 STI last April. Tuned it with Cobb stage 1 for 4ish months then went with an e-tune from Clark Turner. I reset it back to stock in September in anticipation of an oil change and move to Colorado. 2 days before my oil change my motor blew on the stock tune at 6000 rpms shifting into 4th. I only had 5700 miles on the car.

My nearest dealer is very small and they did not ask questions, but it was Avery stressful few weeks. I've left my car stock all winter and I'm really on the fence about whether or not to retune it in the spring. I've wanted an STI ever since I got my drivers license (30 now) it's such a bummer to have zero confidence in my engine.
From an engineering perspective, Subaru's decision to put cast hypereutectic pistons in a 300HP 2.5L turbo engine and then saddling said engine with a marginal tune borders on "criminal" negligence and engineering malpractice. Of course, a piston breaking due to a whiff of detonation doesn't result in a bridge collapsing so this sort of engineering failure goes largely unnoticed outside the fan base...

I cannot believe that Subaru engineers did not see elevated numbers of piston failures, deep within the bowels of FHI engine dyno cells, during development of this engine and its calibration yet still had the temerity to ship them like this anyway.

Having opined that, the engine is strong in most other regards and can produce quite a bit more power than stock but the key is to ditch that OE tune. Cast pistons can live with a lot of cylinder pressure but they can't tolerate the hammering of detonation. The OE tune runs too close to the edge in this regard.

It seems counter-intuitive but the car can make way more torque & power and can still be safer with even an OTS Cobb Stage 1 in favor of the stock tune. Honestly, I would (and did) risk the factory engine warranty in favor of ditching that OE tune. I think the engine -- properly fueled and maintained -- can live a long time as long as the duties of fuel and spark delivery are wrenched out of the seemingly incompetent hands of Subaru engineers, programmers and beancounters...
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Old 01-17-2014, 08:14 AM   #437
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Quote:
Originally Posted by Blackfin View Post
From an engineering perspective, Subaru's decision to put cast hypereutectic pistons in a 300HP 2.5L turbo engine and then saddling said engine with a marginal tune borders on "criminal" negligence and engineering malpractice. Of course, a piston breaking due to a whiff of detonation doesn't result in a bridge collapsing so this sort of engineering failure goes largely unnoticed outside the fan base...

I cannot believe that Subaru engineers did not see elevated numbers of piston failures, deep within the bowels of FHI engine dyno cells, during development of this engine and its calibration yet still had the temerity to ship them like this anyway.

Having opined that, the engine is strong in most other regards and can produce quite a bit more power than stock but the key is to ditch that OE tune. Cast pistons can live with a lot of cylinder pressure but they can't tolerate the hammering of detonation. The OE tune runs too close to the edge in this regard.

It seems counter-intuitive but the car can make way more torque & power and can still be safer with even an OTS Cobb Stage 1 in favor of the stock tune. Honestly, I would (and did) risk the factory engine warranty in favor of ditching that OE tune. I think the engine -- properly fueled and maintained -- can live a long time as long as the duties of fuel and spark delivery are wrenched out of the seemingly incompetent hands of Subaru engineers, programmers and beancounters...
emissions.....its ALL emissions

if it wasnt for emissions.....this wouldnt be a problem

ya cant pass emissions with a tune that isnt dangerous
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Old 01-17-2014, 08:48 AM   #438
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emissions.....its ALL emissions

if it wasnt for emissions.....this wouldnt be a problem

ya cant pass emissions with a tune that isnt dangerous
First, I'm pretty sure that cast pistons were used in part because they allow a tighter cold fit which reduces HC-inducing crevice volumes. The fact that they are quieter than forged when cold (for the same reason) may have played a part in that decision. But I also believe that cost was the major driving factor here.

But second, I don't know that I buy that a safer tune could be done and not pass emissions. Subaru themselves issued a new tune to at least partly address the issue of the crappy OE tune hurting engines and causing driveability issues.

And then there's the fact that Subaru is not the only player putting turbos on small engines and dealing with federalization issues. A good number of other makers are making hi-po turbo motors without the sort of reliability issues Subaru owners are facing and are meeting all necessary emissions regulations to boot.

So sad that the new STi (2015) still has this engine and, presumably its glass jaw...
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Old 01-17-2014, 10:04 AM   #439
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So sad that the new STi (2015) still has this engine and, presumably its glass jaw...
Uh wut?
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Old 01-17-2014, 10:47 AM   #440
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Originally Posted by mmetalmilitiaa View Post
Uh wut?
Car & Driver leaked that the new STI that was announced has the EJ257 and not the direct injection FA series as the 2015 WRX.

Since it has the EJ most people assume it will still have the cast pistons and crap tune, thus still having ringland issues.
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Old 01-17-2014, 12:02 PM   #441
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Its true. The new 2015 STI has the same drivetrain that the 08 to 2014 STI had. It was a real sad day when they released the car. It might be even less of a engine as the manifold is no longer coated red.

Moogatwo, Sorry for loss. That stock map you ran has a very large jump in timing at 6K and that might have got ya...
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Old 01-17-2014, 12:25 PM   #442
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Its true. The new 2015 STI has the same drivetrain that the 08 to 2014 STI had. It was a real sad day when they released the car. It might be even less of a engine as the manifold is no longer coated red.
It still is!!!

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Old 01-17-2014, 12:27 PM   #443
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That's cool. The car Subaru released had a silver manifold like a older WRX.

http://bit.ly/1dNpHrq
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Old 01-17-2014, 12:55 PM   #444
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I saw that too...
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Old 01-17-2014, 12:58 PM   #445
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Interesting that they've got a "sound tube" bringing intake noise into the cabin.


Hokey++;
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Old 01-17-2014, 01:07 PM   #446
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Yeah. I saw that also. Just like the BRZ. First mod, unhook that, Cap it off and throw out.
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Old 01-17-2014, 01:35 PM   #447
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Quote:
Originally Posted by Blackfin View Post
...
It seems counter-intuitive but the car can make way more torque & power and can still be safer with even an OTS Cobb Stage 1 in favor of the stock tune. Honestly, I would (and did) risk the factory engine warranty in favor of ditching that OE tune. I think the engine -- properly fueled and maintained -- can live a long time as long as the duties of fuel and spark delivery are wrenched out of the seemingly incompetent hands of Subaru engineers, programmers and beancounters...
Completely agreed. I picked up a 2011 STI with 9700 miles on it last week. Before the purchase I took it to have a compression and leak down test performed to ensure the motor was 100% healthy. When those numbers all came back great I bought the car and drove like a granny for the 3 mile drive home. I pulled into the garage and immediately installed the COBB intake & Stage 1+SF tune with the V3 Accessport.

This graph is all the convincing I needed. If COBB's data is to be believed, the stock tune stays very lean under boost till over 3500RPM.



I know the warranty is now void but I wasn't about to take any chances with that stock tune. She's been running like a dream and all data logs are completely clean so I can sleep easy, for now...

Last edited by sc00ter; 01-17-2014 at 01:46 PM.
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Old 01-17-2014, 01:44 PM   #448
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My first motor on my '11 sti cracked a ringland at 10k miles on an OTS cobb stg 2 map. Was on the cobb map for about 1k before it blew. Did I say cracked. I meant completely shattered into a million pieces. Also, it almost spun a bearing.

Learned real quick about OTS maps, theyre terrible. Especially if you dont live at sea level.

I then built the motor, and have a tune by Cory at Mayhem tuning pushing about 390 wheel on 91 oct fairly conservative. No troubles at all.
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Old 01-17-2014, 01:50 PM   #449
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...
Learned real quick about OTS maps, theyre terrible. Especially if you dont live at sea level.
...
Very blanketed and incorrect statement. The COBB OTS maps run on the safe side and I know plenty of people up at 5200ft-8000ft elevation who have run the OTS Stage 1 and Stage 2 tunes for 60k+ miles with absolutely no issues. In fact, at higher elevations the air is less dense so if anything the tunes are quite possibly safer due to a more rich mixture than at sea level. On my WRX I had the OTS Stage 1 tune installed for almost 30k miles and never had a hiccup.
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Old 01-17-2014, 01:59 PM   #450
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The biggest problem with OTS maps is not the maps themselves, But the owners of the cars swapping them around like playing cards are poker night.

In the map notes you will find the boost pressure that the map is supposed to run. If its over that level, You need to install the LOW wastegate map. If its way under, You can install the HiGH wastegate map.

HWG map is NOT FOR MAKING MORE POWER. Its there in case the car is under boosting a lot. Everyone just installs the HWG map and then the car is over boosting badly. I just had a Stage 1 STI come in, boosting 21 psi on the HWG map on 91. The car should make 17 or so so on the stage 1 map. This car needed the LWG map.

The owner was lucky but I am sure it would have blown. The injectors are beyond maxed and he had no fuel pump.
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