Help with false knock
01-01-2017, 02:40 PM
#1
Help with false knock Hope this is in the right section. Figured people with tuning experience may have came across this issue.
I recently had my 2003 Z06 tuned. The graph below shows 2 different sessions on the dyno. It's on a dyno dynamics. I'll try and do my best to explain the issue below.
At my first session (Orange graph) the car wasn't making the power we thought it should be. The mods are Callaway Honker, NW102, Fast 102 and pfadt tri y 1 7/8 headers with stock cam and heads. We tried adding timing but it would get pulled out by knock. We even disabled the sensors and no changes. My car has 24,000 miles on it from the previous owner so my tuner suggested I change the fuel filter, add a can of sea foam and also install a catch can. He also said to ditch the valve cover breather and hook the pcv line up on the passenger side valve cover as normal. I had to install a AN fitting on the TB coupler to do so.
Session 2 (Blue graph)
I made all the changes recommended by the tuner and we made significant gains but still wasn't able to add timing. Won't take anymore than 21. I'm running the Hinson polyurethane mounts so they don't have much give. I also noticed my fast 102 is touching the firewall. Could that be the issue? You can hear the dash vibrate when the car starts cold. It's not loud or anything but noticeable. Seems like with more timing we can get more out of it. The gains here we strictly from AFR tweaks.
Any ideas on false knock?
I recently had my 2003 Z06 tuned. The graph below shows 2 different sessions on the dyno. It's on a dyno dynamics. I'll try and do my best to explain the issue below.
At my first session (Orange graph) the car wasn't making the power we thought it should be. The mods are Callaway Honker, NW102, Fast 102 and pfadt tri y 1 7/8 headers with stock cam and heads. We tried adding timing but it would get pulled out by knock. We even disabled the sensors and no changes. My car has 24,000 miles on it from the previous owner so my tuner suggested I change the fuel filter, add a can of sea foam and also install a catch can. He also said to ditch the valve cover breather and hook the pcv line up on the passenger side valve cover as normal. I had to install a AN fitting on the TB coupler to do so.
Session 2 (Blue graph)
I made all the changes recommended by the tuner and we made significant gains but still wasn't able to add timing. Won't take anymore than 21. I'm running the Hinson polyurethane mounts so they don't have much give. I also noticed my fast 102 is touching the firewall. Could that be the issue? You can hear the dash vibrate when the car starts cold. It's not loud or anything but noticeable. Seems like with more timing we can get more out of it. The gains here we strictly from AFR tweaks.
Any ideas on false knock?
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02-25-2017, 12:56 PM
#9
Got rid of the false knock.
The tune needed to be cleaned up. PE settings were still at stock settings. Turned off TQ management and some other knock settings. None of those things were helping me. In the end lowering the settings on the global knock sensor got completely rid of it.
One thing I discovered was switching to a BREF6 plug I hit .92 in cyl air mass from 4800 - 5800. Car pulls amazing. When I had the TR55's in I only hit .88. I was told due to the ported fast 102 on a stock cam/head car, the non projected tip plugs work really well. Figured I try it for $25 and it was well worth it.
The tune needed to be cleaned up. PE settings were still at stock settings. Turned off TQ management and some other knock settings. None of those things were helping me. In the end lowering the settings on the global knock sensor got completely rid of it.
One thing I discovered was switching to a BREF6 plug I hit .92 in cyl air mass from 4800 - 5800. Car pulls amazing. When I had the TR55's in I only hit .88. I was told due to the ported fast 102 on a stock cam/head car, the non projected tip plugs work really well. Figured I try it for $25 and it was well worth it.