knock issues

speedjunkie · 08-04-2009, 04:46 PM

A bit of backstory first...I rebuilt the engine (streetported btw) Mar 08, at that time I installed FJO injector driver, Innovate wideband, GReddy Ti exhaust (which was EXTREMELY loud with no resonator), HKS Twin Power, Power FC, Noltec engine mounts, SARD FPR, MOCAL dual oil coolers, SS braided OMP lines, HKS Circle Earth grounding kit, Odyssey PC680 battery, brand new engine wiring harness, APEX'i AVC-R, deleted all emissions...I think alot of those things probably don't matter, but for the sake of explaining my problem...

I noticed that my knock was pretty high. Last summer I did a single turbo swap and had the car tuned. My knock sensor was pretty worn out and the tuner told me to get a new one so I did. The new one gave me low numbers at idle, but under throttle they were still shooting up (I don't remember how high specifically or under exact conditions, I'll look later), so we decided to tune using AFR and EGT. After we tuned, I had a resonator welded in because it was just too damn loud without it. It cut the noise A LOT.

I just swapped in a 500R from A-Spec, and I've been talking to Ari Yallon about tuning it. I'm adding water (with a bit of methanol) injection to help with reliability also. I explained my problem with knock and how we previously tuned using AFR and EGT, and he said we could do that but it wouldn't give us the wiggle room to feel comfortable pushing it to the limits, and if I want to tune with water injection I really need to have my knock under control anyway.

Last year during tuning, my thoughts were that since our sensors are so sensitive, maybe the exhaust vibrations were causing the high knock, but I'm not so sure. I still have to get exact numbers and conditions and I'll post them up, and I'm also going to have someone tap lightly on the engine at idle and see how high the knock goes. Oh, the car has been running pretty much pig rich the whole time, so I highly doubt I'm getting detonation, or even close. I mean seriously, since Mar 08 my AFRs have been hovering around high 9s to low/mid 11s.

As far as I can tell there isn't anything rattling though. Any ideas?

08-04-2009, 04:46 PM	#1
speedjunkie RCC Loves Me Not You Join Date: Mar 2008 Location: Colorado Springs, CO Posts: 2,089 Rep Power: 20	knock issues A bit of backstory first...I rebuilt the engine (streetported btw) Mar 08, at that time I installed FJO injector driver, Innovate wideband, GReddy Ti exhaust (which was EXTREMELY loud with no resonator), HKS Twin Power, Power FC, Noltec engine mounts, SARD FPR, MOCAL dual oil coolers, SS braided OMP lines, HKS Circle Earth grounding kit, Odyssey PC680 battery, brand new engine wiring harness, APEX'i AVC-R, deleted all emissions...I think alot of those things probably don't matter, but for the sake of explaining my problem... I noticed that my knock was pretty high. Last summer I did a single turbo swap and had the car tuned. My knock sensor was pretty worn out and the tuner told me to get a new one so I did. The new one gave me low numbers at idle, but under throttle they were still shooting up (I don't remember how high specifically or under exact conditions, I'll look later), so we decided to tune using AFR and EGT. After we tuned, I had a resonator welded in because it was just too damn loud without it. It cut the noise A LOT. I just swapped in a 500R from A-Spec, and I've been talking to Ari Yallon about tuning it. I'm adding water (with a bit of methanol) injection to help with reliability also. I explained my problem with knock and how we previously tuned using AFR and EGT, and he said we could do that but it wouldn't give us the wiggle room to feel comfortable pushing it to the limits, and if I want to tune with water injection I really need to have my knock under control anyway. Last year during tuning, my thoughts were that since our sensors are so sensitive, maybe the exhaust vibrations were causing the high knock, but I'm not so sure. I still have to get exact numbers and conditions and I'll post them up, and I'm also going to have someone tap lightly on the engine at idle and see how high the knock goes. Oh, the car has been running pretty much pig rich the whole time, so I highly doubt I'm getting detonation, or even close. I mean seriously, since Mar 08 my AFRs have been hovering around high 9s to low/mid 11s. As far as I can tell there isn't anything rattling though. Any ideas?

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