I started a new thread on naisoc.com about the detonation concern that STI owners have, but the mod decided to lump it into the two larger, unless threads (too noise, not enough info).
Anyway, I have a turbo civic that use to ping on 91 octane gas. It is a bored out and fully built GSR block, running about 15psi and making about 300whp. When it started to ping, I swapped out the spark plugs for cooler plugs and the problem went away.
I am thinking that maybe some STI may have gotten the wrong spark plugs? The ECU should all be programmed the same, so the expectation is that if it pings on 91 octane gas, everyone using 91 octane gas should ping (assuming similar conditions). But that isn't the case. I am using 91 octane and my car does not ping, no matter how hard I push it. If nothing else, we should see a lot more people with problems than the handful of reported cases if the ECU is indeed the cause.
Also, the compression ratio on the STI is low (8.2:1) and even with 16.5psi of boost, and 24 degree of advance, it "should" be okay. I am running 10.2:1 compression on the civic with about 18 degree of advance on boost and I think I am running a higher flowing turbo (I haven't see compressor maps for the VF39, so I am guessing here). My turbo is a T0D5-18G on the civic.
Anyway, if you are reading this, and if you own a STI that pings, can you pull one of your plugs and see if it matches what the manal says you should have? Can you also check the gapping?
Anyway, I have a turbo civic that use to ping on 91 octane gas. It is a bored out and fully built GSR block, running about 15psi and making about 300whp. When it started to ping, I swapped out the spark plugs for cooler plugs and the problem went away.
I am thinking that maybe some STI may have gotten the wrong spark plugs? The ECU should all be programmed the same, so the expectation is that if it pings on 91 octane gas, everyone using 91 octane gas should ping (assuming similar conditions). But that isn't the case. I am using 91 octane and my car does not ping, no matter how hard I push it. If nothing else, we should see a lot more people with problems than the handful of reported cases if the ECU is indeed the cause.
Also, the compression ratio on the STI is low (8.2:1) and even with 16.5psi of boost, and 24 degree of advance, it "should" be okay. I am running 10.2:1 compression on the civic with about 18 degree of advance on boost and I think I am running a higher flowing turbo (I haven't see compressor maps for the VF39, so I am guessing here). My turbo is a T0D5-18G on the civic.
Anyway, if you are reading this, and if you own a STI that pings, can you pull one of your plugs and see if it matches what the manal says you should have? Can you also check the gapping?
