AEM wideband, bosch sensor, placed after turbo, before cat.

So it is knocking killed the engine, right?

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MY08 STI 422whp at 1.5bar on E85, built by Diversion Garage, assembled and tuned by EvoR

Update from new owner: 375whp at 1.4bar on 98, at Tokyo Motorsport

Catastrophic detonation is not related to fatigue.....You said "I think fatigue is the reason why most old sti has piston failure" - You are not correct in your assumption......Most of them Die from big end bearing failures.

The STI Bug in question failed due to a leap in Volumetric efficiency that the ECU was never designed to compensate for, which probably lead to severe DET.

Detonation is a pressure spike with enough energy to crack cylinder bores, bend conrods & shatter pistons.

Engine Detonation causes a very high, very sharp pressure spike in the combustion chamber but it is of a very short duration.

The sharp spike in pressure creates a massive force in the combustion chamber. It causes the structure of the engine to ring, or resonate, much as if it were hit by a hammer. Resonance, which is characteristic of combustion detonation, occurs at about 6400 Hertz. So the pinging you hear is actually the structure of the engine reacting to the pressure spikes.

The high impact nature of the spike can cause a clean fracture of the ring land, bend conrods and fractured valves-intake or exhaust.

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[CENTER][COLOR=#ff0000]Built Ej207: Semi-closed RA Cases - Wiseco Forgies - Manley rods - BC 272 cams - GDA Heads - billet f/whl - Vi-pec - WbO2 - 800cc Yellow tops - TD05-20G - 409Hp ath @ 1.75bar on E85[/COLOR][/CENTER]

Lol, closed road.

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Air is for pussies.

Look at tve lines around 12:46:21. Thats pretty lean for full boost.

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The one perkent...

I'm sure it had speed when I looked at it 15 minutes ago..? Wise move.

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Air is for pussies.

:thumbup:

12:44:38 - That would have rattled hard!

12.6 - 13.7 on 19-20 psi would have been it's death knell.

That cat of yours must have been severely blocked if clearing it shifted your AFR's 3 points leaner than it should have been.

FYI: I run similar heads to yours (same combustion chamber design) - my safe AFR at 22-23 psi is 11.2:1 on Bp98 with 15-16 degrees of timing.

Invest in a wideband O2 dude - Techedge 2J or similar, it will save you $1000's in the future.

Time to build something stronger now!

Check out Welcome - Real Street Performance & don't forget the Perth-WRX discount code

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[CENTER][SIGPIC][/SIGPIC][/CENTER]
[CENTER][COLOR=#ff0000]Built Ej207: Semi-closed RA Cases - Wiseco Forgies - Manley rods - BC 272 cams - GDA Heads - billet f/whl - Vi-pec - WbO2 - 800cc Yellow tops - TD05-20G - 409Hp ath @ 1.75bar on E85[/COLOR][/CENTER]

I dont understand the logic of having a car tuned, then completely altering a massive part of its breathing system and flogging the crap out of it.

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Huge range of extinguisher brackets for cars!

http://kap.industries/

I bashed out the cat a couple of weeks after the tune because I noticed that the material inside had come loose and was rattling around a lot. After i did this I called the workshop that tuned my car and asked if i would need a retune due to gutting the cat. I was advised that after removing a cat a retune is generally not required. However they weren't to know that at the time of tune the cat may have been partially blocked. Maybe it was blocked then or maybe it got blocked after, who knows. But perhaps with that information I would have had a different response from them.
Anyway like I said lesson learned.

Wow! Then that is completely crap! Sorry to hear mate! We take our tuners word for gospel and if they said it wasnt needed then to me that lays fault with them. They should have at least done a dyno run to check.

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Huge range of extinguisher brackets for cars!

http://kap.industries/