PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

Explain knock in my log

Thread Tools
 
Search this Thread
 
Old May 15, 2012 | 09:28 PM
  #1  
speedfreak2685's Avatar
Thread Starter
TECH Resident
20 Year Member
iTrader: (12)
 
Joined: Jul 2005
Posts: 765
Likes: 0
Default Explain knock in my log

Can someone take a peak at this WOT log and explain why I am seeing knock around 3-4000 rpm at wot? It is low timing and afr is on the rich side. I am just starting out messing with this tuning thing so please forgive my lack of knowledge. Car is a 99 ss with a D1 procharger making 10lbs max. Log was of a single WOT pull on the dyno.
Attached Files
File Type: hpl
greg miller log.hpl (6.0 KB, 109 views)
Reply
Old May 16, 2012 | 05:47 AM
  #2  
redtail2426's Avatar
TECH Fanatic
iTrader: (10)
 
Joined: Aug 2004
Posts: 1,433
Likes: 0
From: Rochester,Ny
Default

its possible that its false knock. I spent a lot of time on my tune,and if i was to log a whole bunch of wot rips,then most would be free and clear of knock,but every now and then it seems to show up slightly like that.A 1 count is pretty low,and it decayed pretty quick,which tells me it may have been false knock.What you have to do is do that a few times and see if its there everytime.There are a lot of factors that will setoff knock,and when you tune a car to run really good,you will be on the threshold of pushing it into KR,so dont worry too much if you see it every now and again,you just dont want kr everytime you go wot,and you dont want to see it across the board.If you know what to listen for you can hear it.I can do a wot run and just from listening i could tell if my car is knocking or not.
Reply
Old May 16, 2012 | 06:23 AM
  #3  
speedfreak2685's Avatar
Thread Starter
TECH Resident
20 Year Member
iTrader: (12)
 
Joined: Jul 2005
Posts: 765
Likes: 0
Default

It does it everytime around that rpm. Even at part throttle which I would believe is false knock, but scared me at wot. Its near impossible to hear my motor and listen for knock due to the blower whineing like hell and the true duals dumping right behind me. Kinda sucks.
Reply
Old May 16, 2012 | 06:58 AM
  #4  
Brad Campbell's Avatar
Launching!
iTrader: (19)
 
Joined: Jul 2010
Posts: 250
Likes: 0
From: Groton, CT.
Default

Your afr is dive bombing big time. Any reason why you are commanding 11.7 and satisfied with the off the chart result you are getting? Have you tried less timing in that area to see if you can reduce the knock? Have you read your plugs at all?
Reply
Old May 16, 2012 | 07:37 AM
  #5  
Old Geezer's Avatar
TECH Senior Member
iTrader: (3)
 
Joined: Jun 2004
Posts: 5,639
Likes: 71
From: GA, USA
Default

What Brad said^^^^^^
And, while U R at it, take a look at the fuel psi, when this is happening.

I don't have HPT, so I can't look at the log. Does the dyno show the max torque in the 3-4000 rpm range??
Reply
Old May 16, 2012 | 08:50 AM
  #6  
speedfreak2685's Avatar
Thread Starter
TECH Resident
20 Year Member
iTrader: (12)
 
Joined: Jul 2005
Posts: 765
Likes: 0
Default

This is of the tune I orrinally got when the car was orriginally tuned by a shop. I just noticed the drivability was a little off so that is when I started messing with it. Im sure it does make max tq around that rpm. As far as plug readings, im no expert at that but from what I can tell, they dont look horrible
Reply
Old May 16, 2012 | 04:54 PM
  #7  
speedfreak2685's Avatar
Thread Starter
TECH Resident
20 Year Member
iTrader: (12)
 
Joined: Jul 2005
Posts: 765
Likes: 0
Default

We did drop the timing down to 10 degrees all across the board and it still showed knock at that rpm. What else would cause knock there?
Reply




All times are GMT -5. The time now is 11:39 PM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE