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Old 10-26-2012, 05:13 PM   #26
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Quote:
Originally Posted by 2011boostdwrx View Post
Also remember Cosworth has the pick of the crop from Suby when it comes to the blocks. Could mine have had some Metallurgy issues, yes possibly just the luck of the draw I guess.
There is no way that

1) Subaru lets someone from Cosworth pick through the blocks as they come out of the factory
2) Cosworth is going to magnaflux or x-ray every block for defects looking for the perfect specimen.

This isn't like picking pumpkins.
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Old 10-26-2012, 05:15 PM   #27
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Originally Posted by kapp_badbloodz View Post
Lol no Cosworth, to my knowledge, has failed yet. It is the built OEM blocks that are 704 castings that are failing. I didn't say Cosworth :P
Full cosworth longblock have failed in the past on <704 casting. If cosworth builds a block with a new block I dont see how it wont be a 704.

Quote:
Originally Posted by 04ImprezaWRX View Post
Cosworth is still going to use a 704 block. So your saying it was the person who built the block then and not the block. Cosworth makes good products and follow strict tolerances but if there using a 704 block which you are saying is weak. Than aren't you starting at square one? All you are doing than is changing builders and not the block problem you speak of per say.
agreed.
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Originally Posted by kapp_badbloodz View Post
I am ordering my cosworth short block next week ^____^ the shop told me that cosworth stands being its products so if anything does happen I'll be good in that retrospect.
Stands behind their products doesnt mean much. Cossy had a bad batch of cams that split in half. Some customer's blocks were compeltly trashes afterwards. Do you think cosworth paid for the longblock?..of course not. The best they would do is replace your cams and say sorry.
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Old 10-26-2012, 08:35 PM   #28
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If these 704 blocks are such a cause for concern then shouldnt we see more failures. If a car fails on the dyno at 20ish psi with only a few thousand miles then it was clealy quite weak. Should there not be a fair amount of cases of cracked blocks on stock cars after even say 20,000 miles? That should be enough heat cycles and see enough boost enough times that even not at the elevated levels of stress of higher psi it should show a casting flaw if there is one.
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Old 10-26-2012, 10:55 PM   #29
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Originally Posted by kellygnsd View Post
This is a rather new problem also. If it is legit in time you will see more instances of it but being that is is a relatively new problem you shouldn't expect all of the block to fail at once and everyone to instantly post their failures on Nasioc. Give it time.
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Originally Posted by Ilovecugars View Post
If these 704 blocks are such a cause for concern then shouldnt we see more failures. If a car fails on the dyno at 20ish psi with only a few thousand miles then it was clealy quite weak. Should there not be a fair amount of cases of cracked blocks on stock cars after even say 20,000 miles? That should be enough heat cycles and see enough boost enough times that even not at the elevated levels of stress of higher psi it should show a casting flaw if there is one.
Kellygnsd already covered this one...although it would be interesting to hear from someone inside SOA, or more likely a dealership mechanic, if this is a legit issue.
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Old 10-27-2012, 01:42 PM   #30
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It's a tough situation because Subaru won't let anyone know what has or hasn't changed and when. We have 704 blocks built over 700 whp and we've had 3 failures at 550-600 whp. We reinforced a block and the problem magically goes away?

You will never know if your older 704 block is good or not until it's too late. If Subaru fixes what I believe is a problem, we'll never know because we won't take that chance with our customer motors

I can tell you with the number of calls I'm getting about these block failures, some in their 3rd block, it's far more widespread and issue than is being posted about. Now the fact they are breaking under 400whp has to do with using the oem ecu and letting too much detonation through which massively spikes cylinder pressure so it might as well be 600 hp.
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Old 10-27-2012, 02:24 PM   #31
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Quote:
Originally Posted by Element Tuning
Now the fact they are breaking under 400whp has to do with using the oem ecu and letting too much detonation through which massively spikes cylinder pressure so it might as well be 600 hp.
When u talk about the ECU being a problem, would you say that tuning elevates this or do u go stand alone to combat part of this issue.?

Mario
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Old 10-27-2012, 03:33 PM   #32
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It's just that the oem ecu advances timing until it knocks if timing allowance is high enough. The driver isn't aware it's detonating and it blows up eventually. I'm not going to tell Everton they need a hydra or a standalone ems but knock control s better/more tunable while allowing limits to automatically "LIMP" and CEL to alert the driver.

I have plenty of new 704 blocks we built being ragged at 450 whp using Hydra EMS I've tuned. I'm not worried about them I'm worried about motors I've shipped or am selling for use with oem ecu. For all them we reinforce the block but also the Hydra guys because they are primarily 600+Hp customers.

It's a real issue for everyone regardless of engine management. For our customers building motors with us, $650 upgrade to reinforce is a no brainer.
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Old 10-27-2012, 08:52 PM   #33
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Quote:
Originally Posted by Element Tuning
It's just that the oem ecu advances timing until it knocks if timing allowance is high enough. The driver isn't aware it's detonating and it blows up eventually. I'm not going to tell Everton they need a hydra or a standalone ems but knock control s better/more tunable while allowing limits to automatically "LIMP" and CEL to alert the driver.

I have plenty of new 704 blocks we built being ragged at 450 whp using Hydra EMS I've tuned. I'm not worried about them I'm worried about motors I've shipped or am selling for use with oem ecu. For all them we reinforce the block but also the Hydra guys because they are primarily 600+Hp customers.

It's a real issue for everyone regardless of engine management. For our customers building motors with us, $650 upgrade to reinforce is a no brainer.
Very well put, thank you.

Mario
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Old 10-28-2012, 12:48 AM   #34
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Sounds like more of an issue with knock control strategies when using the OEM ECU than an actual issue WITH the OEM ECU...
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Old 10-28-2012, 03:05 AM   #35
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Quote:
Originally Posted by Element Tuning View Post
It's a tough situation because Subaru won't let anyone know what has or hasn't changed and when. We have 704 blocks built over 700 whp and we've had 3 failures at 550-600 whp. We reinforced a block and the problem magically goes away?

You will never know if your older 704 block is good or not until it's too late. If Subaru fixes what I believe is a problem, we'll never know because we won't take that chance with our customer motors

I can tell you with the number of calls I'm getting about these block failures, some in their 3rd block, it's far more widespread and issue than is being posted about. Now the fact they are breaking under 400whp has to do with using the oem ecu and letting too much detonation through which massively spikes cylinder pressure so it might as well be 600 hp.
How long have you tested this block reinforcement? With only 3 failures that you have seen, its not like they are failing daily or even weekly. I guess so far the blocks you have reinforced haven't failed, how many have this done and what kind of mileage so far on them?

Im just really curious into your block reinforcement, care to show pics or what has been done to block?

Quote:
Originally Posted by aboothman View Post
Kellygnsd already covered this one...although it would be interesting to hear from someone inside SOA, or more likely a dealership mechanic, if this is a legit issue.
I have worked for 2 different dealers in NC. I talk to quite a few dealer techs and talk to subaru at training centers and on occasion with reps. I havent heard or seen any failures in OEM builds. I did see one block with cracked cylinder wall that was build by another shop, but I was told that car was running untuned with larger turbo and boost control would vary from 15lbs to 30lbs. So I think reason for that failure was high cylinder pressures, not a problem with block manufacturing.

Now I have seen some cracked ringlands but thats not this issue.

Last edited by bswilmington; 10-28-2012 at 03:11 AM.
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Old 10-28-2012, 04:29 PM   #36
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Quote:
Originally Posted by Element Tuning
It's a tough situation because Subaru won't let anyone know what has or hasn't changed and when. We have 704 blocks built over 700 whp and we've had 3 failures at 550-600 whp. We reinforced a block and the problem magically goes away?

You will never know if your older 704 block is good or not until it's too late. If Subaru fixes what I believe is a problem, we'll never know because we won't take that chance with our customer motors

I can tell you with the number of calls I'm getting about these block failures, some in their 3rd block, it's far more widespread and issue than is being posted about. Now the fact they are breaking under 400whp has to do with using the oem ecu and letting too much detonation through which massively spikes cylinder pressure so it might as well be 600 hp.
Interesting. What are you doing/recommending concerning ecu problems? Are you suggesting that even regular engine management will not fix this particular issue?

Its commonly known that late 07-current impreza OEM tunes are shoddy as hell and is one of the things to first look into... but from what I got is that even the ECU should be replaced? Are you running a ROM or another piggyback unit? I would like to hear more of this hypothesis as it is interesting.

I personally think its a conspiracy with SOA and keeping their cars from being tuned. I'll write book on it just you wait
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Old 10-29-2012, 02:43 AM   #37
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Quote:
Originally Posted by Element Tuning View Post
It's just that the oem ecu advances timing until it knocks if timing allowance is high enough. The driver isn't aware it's detonating and it blows up eventually. I'm not going to tell Everton they need a hydra or a standalone ems but knock control s better/more tunable while allowing limits to automatically "LIMP" and CEL to alert the driver.
I'd blame that sort of thing on the tuner, not the ECU. If the tuner gives the car a tune that can run 100% ignition advance without knocking, then there will be no problem.

And if the tuner gives the car a tune that advances timing past the point of detonation, then the tuner just plain screwed up. The OEM knock control behavior has been documented well enough for long enough that there's just no excuse for a tuner to be surprised when the ECU turns the ignition advance multiplier up to 100%.

Plus you can set up the stock ECU to switch to wastegate boost if it sees non-trivial knock. It's not quite as blatant as a CEL, but it's still a pretty clear sign that it's time to stop playing and start troubleshooting.
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Old 11-20-2012, 05:15 PM   #38
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Old 11-20-2012, 08:27 PM   #39
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This isn't a metallurgy or manufacturing issue IMO.
It's in the tune, mostly.

That said, north of 550whp on our DD, we recommend our sleeve job with Dartons.
Our record on that:
Zero dropped sleeves with a main housing bore straighter than a homophobe.

Splitting isn't the only repercussion of big cylinder pressure, as ovalling can lead to a decently short life. Some folks swear by stock sleeve blocks; ask some of them that really track these cars north of 550whp how often they go through cases.
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Old 11-20-2012, 11:49 PM   #40
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Originally Posted by NSFW View Post
I'd blame that sort of thing on the tuner, not the ECU. If the tuner gives the car a tune that can run 100% ignition advance without knocking, then there will be no problem.

And if the tuner gives the car a tune that advances timing past the point of detonation, then the tuner just plain screwed up. The OEM knock control behavior has been documented well enough for long enough that there's just no excuse for a tuner to be surprised when the ECU turns the ignition advance multiplier up to 100%.

Plus you can set up the stock ECU to switch to wastegate boost if it sees non-trivial knock. It's not quite as blatant as a CEL, but it's still a pretty clear sign that it's time to stop playing and start troubleshooting.


Quote:
Originally Posted by ASF Machine View Post
This isn't a metallurgy or manufacturing issue IMO.
It's in the tune, mostly.

+1

Stock ecu/cobb is more than capable of controlling these cars. The knock system works great.

ECU doesn't crack the liner, user error cracks the liner
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Old 11-21-2012, 02:12 AM   #41
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Originally Posted by ASF Machine View Post
Zero dropped sleeves with a main housing bore straighter than a homophobe.


Could you PM me pricing/more info on your sleeving services?
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Old 11-21-2012, 03:40 AM   #42
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Ok good luck keeping a new 704 block together at 550+. What once was 850 whp capable on stock blocks no longer is. Busting below 400 HP it's detonation no doubt.

I honestly wasn't ultra concerned at first since I knew I was running at 500 whp without failure. It wasn't until I was contacted by random people with cracked cylinder liners under 400 whp that I became alarmed. It was a large number of motors, from stock, random shop, to Cosworth.

I really don't care if people don't want to listen, if they want to run stock blocks, or if they want to sleeve. I'm taking care of Element Tuning motors and my customers with a solution I've confident works better than other solutions I've tested.

Last edited by Element Tuning; 11-21-2012 at 03:50 AM.
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Old 11-29-2012, 08:46 PM   #43
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Originally Posted by Junior2JZ View Post

Stock ecu/cobb is more than capable of controlling these cars. The knock system works great.

ECU doesn't crack the liner, user error cracks the liner
Where is the like button?

If anyone thinks the stock ECU's knock control strategy is that bad they haven't tuned many stock ECU cars...

Nate
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Old 09-28-2013, 11:52 AM   #44
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Just to update this thread.

I had a 704 block from a 2011 STi that blew a ringland. We bored it to 100mm for the pistons/rods we got for a rebuild, and running stock turbo on e85 and most bolt ons.

cracked cyl 3 cylinder wall... THe plugs pulled showed no knock activity, and my tune is relatively conservative even for a e85 tune....

Take it for what it's worth, but I do think the newer blocks are weaker.
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Old 09-28-2013, 12:50 PM   #45
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So you boring an already thin liner to 100mm didn't have anything to do with it?
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Old 09-28-2013, 02:12 PM   #46
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^^^^exactly^^^
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