STi7 engine failures
#31
Deep sorry, don't have info to that kind of detail.
I do know that it was in Oz, which obviously means that it wasn't on pump 100RON gas.
It was a decat, high speed blasting - which probably means that one shouldn't be encouraging 1.7bar spiking BEFORE the car is run in!
I do know that it was in Oz, which obviously means that it wasn't on pump 100RON gas.
It was a decat, high speed blasting - which probably means that one shouldn't be encouraging 1.7bar spiking BEFORE the car is run in!
#32
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Thread Starter
RT
Exactly. Ours was spiking to 1.7 bar from just 60 miles on the clock - decat fitted the day it was delivered. After 1 week old it went on a 1500 mile trip to Austria and back like this.
And if the engine *had* let go, who would have picked up the tab?
Just don't need that kind of aggro.....
Exactly. Ours was spiking to 1.7 bar from just 60 miles on the clock - decat fitted the day it was delivered. After 1 week old it went on a 1500 mile trip to Austria and back like this.
And if the engine *had* let go, who would have picked up the tab?
Just don't need that kind of aggro.....
#35
Hi DAVE TS,
Yes, this was a different garage to Tony + Trout.Without naming the garage, it was near the England/Scotland border. But i do know that the running in procedure would not have been adhered too. Regards, SIMON.
Yes, this was a different garage to Tony + Trout.Without naming the garage, it was near the England/Scotland border. But i do know that the running in procedure would not have been adhered too. Regards, SIMON.
#36
Pete, do you know if the 2 cars you mentioned were run in properly?
Also, under what circumstances did they blow? Even with a standard engine and exhaust, the STI7 *can* peak as high as 1.4bar with WOT on 4th gear.
Surely this can't be too good for a new engine!
The Oz failure I know of was supposedly at about 2500 miles, decat exhaust, repeated high speed blasting (I assume gears 3, 4 and 5).
Also, under what circumstances did they blow? Even with a standard engine and exhaust, the STI7 *can* peak as high as 1.4bar with WOT on 4th gear.
Surely this can't be too good for a new engine!
The Oz failure I know of was supposedly at about 2500 miles, decat exhaust, repeated high speed blasting (I assume gears 3, 4 and 5).
#37
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Both cars had been run in, although I am not sure how well.
As boost does not peak below 4k on an STi, the running in period is effectively doen off boost and this puts considerably less strain on the internals.
Despite the advertising hype (80% improved parts), the STi uses the same crank, rods and bearings as the WRX.
As boost does not peak below 4k on an STi, the running in period is effectively doen off boost and this puts considerably less strain on the internals.
Despite the advertising hype (80% improved parts), the STi uses the same crank, rods and bearings as the WRX.
#38
OK, let me try and sum it up.
Other than the 6th to 3rd incident, all the other failures sound like they're due to some form of "piston seizure".
As most of the cars are new-ish, this "seizure" is likely caused by overly tight tolerences between the piston and cylinder bore.
Of course, 1.7bar doesn't help. But this is not THE cause of the failures, just a contributing factor. (From previous GC STI experience, overly high boost results in melted pistons, not seized pistons.)
Is my take on this accurate?
Other than the 6th to 3rd incident, all the other failures sound like they're due to some form of "piston seizure".
As most of the cars are new-ish, this "seizure" is likely caused by overly tight tolerences between the piston and cylinder bore.
Of course, 1.7bar doesn't help. But this is not THE cause of the failures, just a contributing factor. (From previous GC STI experience, overly high boost results in melted pistons, not seized pistons.)
Is my take on this accurate?
#39
Hrmph! Same Crank, ConRods and Bearings!!
No wonder they're selling stronger Cranks and ConRods as aftermarket parts. See www.subaru-sti.co.jp or www.japanparts.com.
Pistons are different. I know they Molebdenum (spell??) coated, but are they cast or forged?
No wonder they're selling stronger Cranks and ConRods as aftermarket parts. See www.subaru-sti.co.jp or www.japanparts.com.
Pistons are different. I know they Molebdenum (spell??) coated, but are they cast or forged?
#40
Ok you guyys are starting to scare me.....
Is the new JPN spec STI a lemon....I only got 800 kms on mine and have been keeping under 4000 rpms. So when it does 1k miles I should not take it above 6rpms ?? When can I take it to red line safely or will it never be safe as the new JPN spec STI is a lemon ????
Cheers,
Ray
Is the new JPN spec STI a lemon....I only got 800 kms on mine and have been keeping under 4000 rpms. So when it does 1k miles I should not take it above 6rpms ?? When can I take it to red line safely or will it never be safe as the new JPN spec STI is a lemon ????
Cheers,
Ray
#41
Ray, to be fair, the failures are few and far between. Seizure is a "non-linear" thing, if it happens, its a 100% blow. If it doesn't happen, then there's 0% damage. This is unlike excessive heat/boost which has a cumulative effect of weakening/fatiguing the aluminium.
I know of two local cars (MY01 JDM STI's) who have decat'ted and EBC'ed to 1.5bar. And that's 1.5bar in all gears. They're used as daily drivers and have had their fair share of WOT weekend track days.
To call the JDM MY01 a lemon is unfair. Any high perf car tuned to its limits of power can bite back if used without respect. For example, the surest way to det is to give it WOT in first gear after a 10 minute idle and heat soak. We know the car's weaknesses and simply drive around them.
The rest of the world's sub 100RON pump gas doesn't help the matter either, so I'd watch very carefully what I put in and whether the car dets.
Just make sure to run her in properly. As I said before, if I could do it again, I'd definitely take the run-in beyong 1000 miles.
I know of two local cars (MY01 JDM STI's) who have decat'ted and EBC'ed to 1.5bar. And that's 1.5bar in all gears. They're used as daily drivers and have had their fair share of WOT weekend track days.
To call the JDM MY01 a lemon is unfair. Any high perf car tuned to its limits of power can bite back if used without respect. For example, the surest way to det is to give it WOT in first gear after a 10 minute idle and heat soak. We know the car's weaknesses and simply drive around them.
The rest of the world's sub 100RON pump gas doesn't help the matter either, so I'd watch very carefully what I put in and whether the car dets.
Just make sure to run her in properly. As I said before, if I could do it again, I'd definitely take the run-in beyong 1000 miles.
#42
All cars have a running in period and the engine will age prematurely if not observed.However should it really die within a few thousand miles? You d'ont seem to hear about Evos/Skylines doing this.
#44
You know, if you wanna be "conservative" yet use some performace, why don't you take her to 6500rpm or so, but NOT use WOT.
The car is already mighty fast (relative to everything else) on 2/3 throttle. Yet, you'll keep boost to a lowly 0.7 - 0.8bar.
Frankly in my daily drive, thats about all I get to use. If I wanna floor her, I'd have to actively look for an opportunity or a big-enough break in traffic!
The car is already mighty fast (relative to everything else) on 2/3 throttle. Yet, you'll keep boost to a lowly 0.7 - 0.8bar.
Frankly in my daily drive, thats about all I get to use. If I wanna floor her, I'd have to actively look for an opportunity or a big-enough break in traffic!
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