Knock Sensor Sensitivity
Burning Brakes
Joined: Mar 2003
Posts: 966
Likes: 43
From: Lansing MI
Originally Posted by INTHERED
Can the knock sensors be programmed to be less sensitive so that
false knock can be eliminated ?
Thanks >>>>> Mike
false knock can be eliminated ?
Thanks >>>>> Mike
Former Vendor
Joined: Mar 2006
Posts: 153
Likes: 0
Yes. I know that LS1 Edit, HPTuners, EFILive, and TunerCats all have this capability. There are essentially 7 tables: Low, Med, High for both Per Cylinder Mode and Per Revolution Mode, and one table for idle. The tables contain values that represent the amount of time between 'events' that will be deemed as a misfire. People with modified engines typically have to modify the Idle, Low, and Mid tables to avoid setting a P0300 DTC.
Instructor
Joined: Jul 2004
Posts: 110
Likes: 0
From: Newport News VA
You can also raise the decay rate after a knock event is registered so normal spark timing will return quicker after knock. I've also had alot of success by updating to the 2002 global tables.
Instructor
Joined: Jul 2004
Posts: 110
Likes: 0
From: Newport News VA
Here's what I've changed in relation to my knock tables:
Raised fast recovery rate by .02 in the 1200, 1600, 2000rpm cells to help eliminate the false knock I was getting in 6th gear.
Lowered fast attack rate by 4 from 4800rpm on up.
Copied Knock Sensor level vs rpm vs cyl from stock 2002 fbody bin:
Keep in mind, I have a 99 Firehawk so my tables may be a little different (or even not available) in C5s depending on the year. Also note that I'm running an Open Loop Speed Density tune using an LC-1 for AFR. I also have LT headers, an ls6 intake (with the ls6 valley cover and pcv set up), air lid with the maf replaced with smooth bellows and straight pipe, and 4.10 gears. With these changes I no longer see knock during everyday driving (like I used to). In the rare instance I do see some knock, it is always 1.0 or less and decays away within 1 second. I bought this car in Cali and shipped it to Hawaii about a year and a half ago. When I bought it, the car was pulling timing and pinging like crazy (on the stock tune with 4.10s as the only mod). Most of the kr was eliminated by installing the ls6 pcv stuff and adding a catch can. The rest was eliminated through tuning. Hope this helps.
Raised fast recovery rate by .02 in the 1200, 1600, 2000rpm cells to help eliminate the false knock I was getting in 6th gear.
Lowered fast attack rate by 4 from 4800rpm on up.
Copied Knock Sensor level vs rpm vs cyl from stock 2002 fbody bin:
Keep in mind, I have a 99 Firehawk so my tables may be a little different (or even not available) in C5s depending on the year. Also note that I'm running an Open Loop Speed Density tune using an LC-1 for AFR. I also have LT headers, an ls6 intake (with the ls6 valley cover and pcv set up), air lid with the maf replaced with smooth bellows and straight pipe, and 4.10 gears. With these changes I no longer see knock during everyday driving (like I used to). In the rare instance I do see some knock, it is always 1.0 or less and decays away within 1 second. I bought this car in Cali and shipped it to Hawaii about a year and a half ago. When I bought it, the car was pulling timing and pinging like crazy (on the stock tune with 4.10s as the only mod). Most of the kr was eliminated by installing the ls6 pcv stuff and adding a catch can. The rest was eliminated through tuning. Hope this helps.
Last edited by bshell; Mar 23, 2006 at 12:50 PM.
