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Old 06-21-2003, 06:28 PM   #51
dsmperformance
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Quote:
Originally posted by Vishnu Performance

Should be a pretty easy fix though...
Keep up the good R&D, thats what we all like to hear!
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Old 06-21-2003, 07:20 PM   #52
hatchy
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Holy *****. That should explain a lot!

Quote:
Originally posted by Vishnu Performance


It would almost appear that the Rate of Retard (degree/RPM) and the Rate of Advance values (upon knock detection) are reversed. Should be a pretty easy fix though...

my 2c,
shiv
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Old 06-22-2003, 12:37 AM   #53
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Quote:
are more likely to detonate on the road during transient load conditions than they are at a steady-state, full load, ramp-up dyno pull.
Now that I'm over 1000 miles I'd agree with this. WOT high RPM runs sound pretty clean, whereas at lower RPM as you put your foot down (heading to WOT) is where it pings most.

I heard a few "big clunks" today.

I have a Fluke DMM with RS232 port. If I could log the output of the factory knock sensor in parallel with logging RPM and advance from the OBDII port, it would provide pretty conclusive proof of the issue. Unfortunately I'm still dealing with my house move so don't have any time to pursue this week.

Glenn
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Old 06-22-2003, 08:48 AM   #54
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Quote:
Originally posted by Vishnu Performance
[b]
Cam timing is also a potential culprit but one that is going to take some time to dig into. The knock correction system is also behaving quite different from that of the standard WRX. It would almost appear that the Rate of Retard (degree/RPM) and the Rate of Advance values (upon knock detection) are reversed. Should be a pretty easy fix though...
Shiv, so, do you mean the fix is still easy, even if it turns out to be a cam timing issue, since you are still "digging into" it? Also, what would a "potentially easy" fix be? Sorry, I am not trying to criticize you, just trying to understand...

Last edited by wolverine; 06-22-2003 at 08:59 AM.
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Old 06-23-2003, 04:28 PM   #55
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Shiv,

Can you explain more on what you mean about the reversed values with the wrx vs sti? The sti ecu does not seem to do much correction with knock and rarely picks up the knock.
Thanks....
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Old 06-23-2003, 08:49 PM   #56
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They filled my Sti up with 91 octane and I got detonation like a bag of popcorn going off all at once at 4000 to 4500 rpms.

I ran that tank out and filled up with 93 octane and added a can of NOS octane booster.

I have only heard it detonate once at about 5500 rpms on this tank of gas.
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Old 06-23-2003, 08:54 PM   #57
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Default our gas sucks!

we need better gas
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Old 06-23-2003, 09:57 PM   #58
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Ok, went back to adam at Z1 perfomance to take him for a ride in the nice hot 86 degree weather we had today and he didn't notice any detting at all with A/C on full boil and WOT. I'm running on 94 octane gas. Was good news for my ears that's for sure! Going to vote on the poll.

Tom
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Old 06-24-2003, 07:31 AM   #59
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Quote:
Originally posted by Vishnu Performance
It's looking more likely that the factory fuel enrichment strategy is also playing a big role in this problem.
Have you logged the fuel pump voltage during this DET? The STi uses 3 fuel pump voltage levels, controlled by the ECU, so it's worth logging this to see if its down to a problem with fuel supply due to slow pump response.
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Old 06-25-2003, 09:24 AM   #60
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Okay i did some quick 3-4 rpm testing yesterday. Condition 93 degrees with crazy humidity.

Gas used: Shell 93 octane
Mileage 700 miles

I did some 3rd gear and 4th gear pull from 2 to 3k rpm, 2-4k rpm and some gradual pull from 3 to 4.5k rpm.

I didn't hear anything except for the common boxer sound and the whine of the turbo.. It seems pretty clean from all rpm range.

I did this test in an open vacant new village, with my head sticking out lol..
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Old 06-25-2003, 10:36 AM   #61
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No mention of being uphill....

If you want to really push the envelope, put the engine under more load (uphill).
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Old 06-25-2003, 12:50 PM   #62
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Not sure why anyone would want to try to induce pinging by driving in a non-realistic fashion ???

If you're going uphill in high gear (5th, 6th?) and really low revs and labouring the engine, then you probably can induce pinging by stomping on the gas; the manual clearly states that this may happen.......but really that's no way to be driving any manual transmission car.

Now if pinging occurs under "normal" load conditions when accelerating briskly through the 4k rev range that's something to be more concerned about.
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Old 06-25-2003, 01:56 PM   #63
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I agree completely, but I wouldn't consider 4k going uphill under decent acceleration an 'extreme' situation. Just mentioning that most ping cases seem to occur during incline acceleration. I'd hope, regardless of the gear, that 4k RPMs isn't 'laboring' for this engine.
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Old 06-25-2003, 02:01 PM   #64
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Hey CloNeGTS!

Quote:
I wouldn't consider 4k going uphill under decent acceleration
I didn't know they had hills in Kansas.

Mike McBride
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Old 06-25-2003, 05:54 PM   #65
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Hey CloNeGTS,

Sorry, my earlier post wasn't meant to be facetious or smart-ass. I think what I meant to say was that if someone seeks out hilly terrain, and intentionally shifts the car into 6th at an unreasonably low speed going uphill (e.g. 20-30 mph) and then gets on the gas (keeping the car in 6th gear, for example), these extreme loading conditions will probably induce pinging.....but we shouldn't be driving the car this way.

If it pings frequently and long-term under normal driving conditions, even "aggressive" driving conditions, then that's just not right.
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Old 06-25-2003, 10:46 PM   #66
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Oh yeah...naw, I understand what you were saying. I didn't clarify either.....

Kansas...yeah.....we have mounds....not really hills!
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Old 06-26-2003, 02:11 PM   #67
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say youre going into a turn and you leave it in 3rd because you dont think youre going to lose that much speed...then say you decel to about 15, and then hit the gas on the way out of the turn. is that sound (diesel truck like sound) the sound of pinging? still having a little trouble figuring out what it sounds like...
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Old 06-26-2003, 05:09 PM   #68
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No, that's not pinging.........that's probably just the engine labouring because you're in too high a gear for that speed/RPM.....not good, especially if you're still running it in.

Pinging sounds like pebbles bouncing around in a metal can (one description I've heard).
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Old 06-26-2003, 10:26 PM   #69
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Old 06-27-2003, 07:32 PM   #70
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Its seems nobody has made the distinction (unless I missed it) between pinging and detonation. There is a BIG difference between the two. Detonation is harmful. If you experience true detonation you'll either sustain immediate engine damage and/or the CEL will come on.

Pinging is not detonation. The knock sensor does not detect pinging. It detects knock. I'm no car genius but I thought this was common knowledge?
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Old 06-28-2003, 01:07 PM   #71
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A lot of terms are used loosely around here but as I understand it you have pre-ignition and detonation. Pre-ignition is when carbon deposits in the combustion chamber retain enough heat (a hot spot) that it will ignite the fuel mixture prior to spark ignition. Detonation is caused by low octane fuel. The higher the octane rating the more resistant the fuel is to ignite at lower temperatures and pressures. In either case the point is that the mixture is ignited before the spark fires when the piston is still compressing the intake charge. Whether pre-ignition or detonation a "ping" is generated/heard because of the blunt force of the explosion in the combustion chamber happening too early when the piston is still on the compression up-stroke. Either one can cause engine damage and both will make the "ping" sound people are talking about in this thread.

Punk
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Old 07-03-2003, 08:33 AM   #72
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FYI - SOA is reading this post. (I can't tell ya so don't ask)

SOA wants to see the plots, maps and graphs to determine "IF" there's a problem.
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Old 07-03-2003, 08:43 AM   #73
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There's the TurboXS graph I've already linked on the first page. See that hump @ 4Krpm? There's your problem - the jump in timing at or near the motor's peak VE.
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Old 07-03-2003, 08:44 AM   #74
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Quote:
Originally posted by Sparks
FYI - SOA is reading this post. (I can't tell ya so don't ask)

SOA wants to see the plots, maps and graphs to determine "IF" there's a problem.
One would think that SOA would have the resources to do this themselves.

Of course they didn't do it before the car came out...
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Old 07-03-2003, 09:03 AM   #75
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With all due respect, SOA does NOT consider this to be a problem. They have stated that some ping/knock is expected due to their aggressive tuning and poor fuel standards in the US. Unless some very well documented proof is provided they will take NO action.
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