C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Knock Counts

Thread Tools
 
Search this Thread
 
Old Sep 24, 2024 | 08:52 AM
  #1  
TheKodiak's Avatar
TheKodiak
Thread Starter
Instructor
 
Joined: Apr 2022
Posts: 187
Likes: 31
From: South Texas
Default Knock Counts

When data logging, Is it normal to get 3600+ knock counts with zero degree knock retard? Thanks
Reply
Old Sep 24, 2024 | 10:09 AM
  #2  
ULTM8Z's Avatar
ULTM8Z
Melting Slicks
20 Year Member
Active Streak: 30 Days
Active Streak: 60 Days
Top Answer: 1
 
Joined: Jul 2005
Posts: 2,200
Likes: 302
Default

Is your car stock? What year?

Sometimes with aftermarket modifications like roller rockers, headers, more aggressive cams, etc... things can get a little noisier and the knock sensor will pick that up and start recording knock counts (even if it doesn't get to the point of retarding timing)

Also an incorrect sensor can cause it. Knock sensors are tuned for particular engines (i.e.. 305 vs 350 for example).

Reply
Old Sep 24, 2024 | 10:44 AM
  #3  
69427's Avatar
69427
Tech Contributor
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Jun 2004
Posts: 20,847
Likes: 959
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Default

Originally Posted by TheKodiak
When data logging, Is it normal to get 3600+ knock counts with zero degree knock retard? Thanks
It's feasible. What's the MAP reading during all the zero degree retard operation?
Reply
Old Sep 24, 2024 | 03:46 PM
  #4  
TheKodiak's Avatar
TheKodiak
Thread Starter
Instructor
 
Joined: Apr 2022
Posts: 187
Likes: 31
From: South Texas
Default

It's a '96 LT1. Roller rockers and 52mmTB, are the only major mods done by the PO. During idle, I get 2.4K knocks, 0 knock retard. Should I only be concerned if I get knock retard?


Originally Posted by ULTM8Z
Is your car stock? What year?

Sometimes with aftermarket modifications like roller rockers, headers, more aggressive cams, etc... things can get a little noisier and the knock sensor will pick that up and start recording knock counts (even if it doesn't get to the point of retarding timing)

Also an incorrect sensor can cause it. Knock sensors are tuned for particular engines (i.e.. 305 vs 350 for example).
Reply
Old Sep 24, 2024 | 03:56 PM
  #5  
TheKodiak's Avatar
TheKodiak
Thread Starter
Instructor
 
Joined: Apr 2022
Posts: 187
Likes: 31
From: South Texas
Default

During idle and cruising, 47.97 Kpa, but at WOT it's 52.4 Kpa.



Originally Posted by 69427
It's feasible. What's the MAP reading during all the zero degree retard operation?
Reply
Old Sep 24, 2024 | 04:08 PM
  #6  
ULTM8Z's Avatar
ULTM8Z
Melting Slicks
20 Year Member
Active Streak: 30 Days
Active Streak: 60 Days
Top Answer: 1
 
Joined: Jul 2005
Posts: 2,200
Likes: 302
Default

Originally Posted by TheKodiak
It's a '96 LT1. Roller rockers and 52mmTB, are the only major mods done by the PO. During idle, I get 2.4K knocks, 0 knock retard. Should I only be concerned if I get knock retard?
Assuming your knock sensor is not malfunctioning and is correct for the car, then I would likely chalk it up to false knock due to the roller rocker noise.

Questions about real/false knock are common on thirdgen.org. Couple of sample threads below... the first one is mine, where I was troubleshooting what I determined to be mostly false knock. But if you search you'll find tons of threads. Granted they're all about Gen1 small blocks, but the logic and diagnostics are largely going to be the same.

https://www.thirdgen.org/forums/diy-...tard-real.html

https://www.thirdgen.org/forums/tpi/...retarding.html



Reply
Old Sep 24, 2024 | 04:48 PM
  #7  
lt1-xjs's Avatar
lt1-xjs
Advanced
Liked
 
Joined: Mar 2024
Posts: 76
Likes: 20
From: Dayton
Default

I ran across this awhile back. I read don't worry about the counts only the knock retard. The counts start at 0 and go up to 60k or so on a loop. Looking at a few of my logs I noticed my counts went from 79 to 12k before I turned the key to start the engine. It stays at the 12k through the log unless you get spark retard at which it may go up 50 points. It also depends on where the log starts in the loop. Another started at 700 counts and remained there until I shut the car off and it climbed to 60k. I did notice couple times the count increased 40 or so and there was no knock retard. Must be the norm, 1993 lt1.
Reply
Old Sep 24, 2024 | 06:27 PM
  #8  
TheKodiak's Avatar
TheKodiak
Thread Starter
Instructor
 
Joined: Apr 2022
Posts: 187
Likes: 31
From: South Texas
Default

I wonder if I could use knock sensors from a '96 LT4. I would probably need a new ecu, or am I off? Thanks a millions Gents
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-1

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
story-2

Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

 Joe Kucinski
story-3

Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

 Verdad Gallardo
story-4

Top 10 Corvettes Coming to Mecum Indy 2026!

 Brett Foote
story-5

Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

 Michael S. Palmer
story-6

10 Revolutionary 'Corvette Firsts' Most People Don't Know

 Joe Kucinski
story-7

5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

 Michael S. Palmer
story-8

2027 Corvette vs The World: Every C8 vs Its Closest Competitor

 Joe Kucinski
story-9

10 Most Common Corvette Problems of the Last 20 Years!

 Joe Kucinski
Old Sep 24, 2024 | 06:32 PM
  #9  
ULTM8Z's Avatar
ULTM8Z
Melting Slicks
20 Year Member
Active Streak: 30 Days
Active Streak: 60 Days
Top Answer: 1
 
Joined: Jul 2005
Posts: 2,200
Likes: 302
Default

I wouldn't introduce more variables into the mix. I'd ensure you have a genuine GM knock sensor for your vehicle. In that thread I linked to, I had to do that in order to solve my issue.
Reply
Old Sep 24, 2024 | 07:21 PM
  #10  
lt1-xjs's Avatar
lt1-xjs
Advanced
Liked
 
Joined: Mar 2024
Posts: 76
Likes: 20
From: Dayton
Default

Originally Posted by TheKodiak
I wonder if I could use knock sensors from a '96 LT4. I would probably need a new ecu, or am I off? Thanks a millions Gents
I believe the knock sensors are the same lt1/lt4. It was the lt4 knock module everyone used.
Reply
Old Sep 24, 2024 | 09:42 PM
  #11  
drcook's Avatar
drcook
Safety Car
Photogenic
Photoriffic
Liked
Top Answer: 1
 
Joined: Apr 2016
Posts: 4,648
Likes: 1,059
From: N.E. Ohio OH
Finalist 2020 C4 of the Year - Modified
Default

Originally Posted by TheKodiak
I wonder if I could use knock sensors from a '96 LT4. I would probably need a new ecu, or am I off? Thanks a millions Gents
Using an LT4 knock module was standard practice when putting rollers into a 1996 LT1, either that, or tuning the LT1 one to be less sensitive.

use this as a search term
how to tune a 1996 lt1 knock module to be less sensitive
This is a LT4 knock module. I searched for months before I found one at a reasonable cost.

https://www.garretttuning.com/produc...DbEV_RgBNDIw3w

Last edited by drcook; Sep 24, 2024 at 10:34 PM. Reason: corrected terminology
Reply
Old Sep 25, 2024 | 07:33 AM
  #12  
TheKodiak's Avatar
TheKodiak
Thread Starter
Instructor
 
Joined: Apr 2022
Posts: 187
Likes: 31
From: South Texas
Default

In a nutshell, it could be a false reading is what I gathered. My MAP readings look good, plus I have no knock retard, but my egr has been deleted. Shouldn't the LT4 module help "quite" things down? (I got confused between the module vs knock senor). As far a stock knock sensors, I'm more than 100% sure they're the originals, but I'll check anyways. The car was badly neglected, when I got it.

Originally Posted by ULTM8Z
I wouldn't introduce more variables into the mix. I'd ensure you have a genuine GM knock sensor for your vehicle. In that thread I linked to, I had to do that in order to solve my issue.

Last edited by TheKodiak; Sep 25, 2024 at 07:41 AM.
Reply

Get notified of new replies

To Knock Counts





All times are GMT -4. The time now is 08:05 AM.

story-0
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-1
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE
story-2
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-3
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-4
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-5
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE
story-6
10 Revolutionary 'Corvette Firsts' Most People Don't Know

Slideshow: 10 Important Corvette 'firsts' that every fan should know.

By Joe Kucinski | 2026-04-29 17:02:16


VIEW MORE
story-7
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE
story-8
2027 Corvette vs The World: Every C8 vs Its Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-24 16:12:42


VIEW MORE
story-9
10 Most Common Corvette Problems of the Last 20 Years!

Slideshow: 10 major Corvette problems from the last 20 years.

By Joe Kucinski | 2026-04-14 16:37:05


VIEW MORE