Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums - Camaro5.com
 
autoguy
Go Back   Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums - Camaro5.com > Engine | Drivetrain | Powertrain Technical Discussions > Tuning / Diagnostics -- engine and transmission

Tuning / Diagnostics -- engine and transmission Tune and diagnostics for engines and auto transmission.

Reply
 
Thread Tools
Old 02-22-2010, 08:44 AM   #1
ProudLS
 
ProudLS's Avatar
 
Drives: Camaro SS
Join Date: Dec 2009
Location: TX
Posts: 193
Nock Sensor on LS3..!! Need help Please.!!

Yesterday I was trying to tune my car with HP Tuner but the weird thing is that with stock tune I have knock 3 to 6 from 4100to 6000 RPM..!! and the timing was 21 degree.

We have changed the knock sensitivity to 260 and I still have the same thing. Can I go lower than 260? I think it was false knock coz I did not hear any knock from the engine neither see any smoke coming from the exhaust.

We also could not change the cutoff limit from 6200 to 6600..!!

Mods that I have: ARH LTs 1 7/8, Borla axel back, Airaid CAI and Eibach lowering spring.

Thanks.
ProudLS is offline   Reply With Quote
Old 02-22-2010, 09:21 AM   #2
kelley@vectormotorsports
 
Drives: 2009 Pontiac G8 GT
Join Date: Jun 2009
Location: Clinton Twp., MI
Posts: 241
First. What fuel are your using? 91 or 93?

LS3's can knock on 91 from the factory. We never touch the knock retard settings in any tune. They are there for good reason.

Also, the LS3 RPM limiter is 6600 from the factory.

Be careful, programming software that gives full access is powerful and causing engine damage is easily done if you are not careful.
kelley@vectormotorsports is offline   Reply With Quote
Old 02-22-2010, 10:02 AM   #3
ProudLS
 
ProudLS's Avatar
 
Drives: Camaro SS
Join Date: Dec 2009
Location: TX
Posts: 193
I have been told that we can go up to 260..!! I will try to do another run with 93 and see the result.

P.S. would the headers cause this knock? it could be touching underneath the car and that is causing the knock?
ProudLS is offline   Reply With Quote
Old 02-22-2010, 11:22 AM   #4
Russell James


 
Russell James's Avatar
 
Drives: '12 SS/RS LS3 IBM
Join Date: Dec 2009
Location: SE Michigan
Posts: 3,399
Quote:
Originally Posted by ProudLS View Post
I have been told that we can go up to 260..!! I will try to do another run with 93 and see the result.

P.S. would the headers cause this knock? it could be touching underneath the car and that is causing the knock?
Yes an exhaust contact can easily cause a false knock. Should be no reason to mess with knock sensing or the rev limit. Anything less than 93 can also cause real knock. You won't be able to hear it. The computer senses it way faster than a human ear can pick it up.

It use to be a few years back, you could hear a burst of detonation - then the computer would pull the timing and eliminate it. These latest gen of computers though are so fast, they pick up knock in a split second and dump the timing to eliminate it before you even here the slightest bit.

I'd tinker with 93 from a different station, and some octane booster, and eliminate all exhaust contacts....leave the knock sensing alone, and then see if it is still pulling the timing. I bet it won't be.

May also help to put some miles on the CAI and headers so it self adjusts as much as possible. I've seen where putting a CAI in, during those first couple of drives, the car was showing quite a bit of knock activity. Then after some miles of driving all was back to normal.
Russell James is offline   Reply With Quote
Old 02-23-2010, 12:18 PM   #5
ProudLS
 
ProudLS's Avatar
 
Drives: Camaro SS
Join Date: Dec 2009
Location: TX
Posts: 193
Yesterday I added some octane booster and did a test, there was not any knock above 1 which is good but the timing was 25 all the way up to 6200 rpm

So, is 25 degree ok for my setup? or can I go higher 28-30?

Thanks,
ProudLS is offline   Reply With Quote
Old 02-23-2010, 03:11 PM   #6
DSteck
Account Suspended
 
Drives: 2006 Corvette Z06
Join Date: Feb 2010
Location: St. Louis, MO
Posts: 590
Timing should not be a set number across the board.

I find the best power running 22-24º around peak torque, and ramping up to 25-27º at peak horsepower on Gen IV engines. After peak torque, it's good practice to drop off a degree or so by redline. Your cylinder air mass and operating conditions change at different RPM... you shouldn't just run the same timing across the board and call it good enough.
DSteck is offline   Reply With Quote
Old 02-23-2010, 08:00 PM   #7
ProudLS
 
ProudLS's Avatar
 
Drives: Camaro SS
Join Date: Dec 2009
Location: TX
Posts: 193
Quote:
Originally Posted by DSteck View Post
Timing should not be a set number across the board.

I find the best power running 22-24º around peak torque, and ramping up to 25-27º at peak horsepower on Gen IV engines. After peak torque, it's good practice to drop off a degree or so by redline. Your cylinder air mass and operating conditions change at different RPM... you shouldn't just run the same timing across the board and call it good enough.
Thanks for the info, I will try to play around and see how it goes.
ProudLS is offline   Reply With Quote
Old 02-24-2010, 08:15 PM   #8
bumblebeecamaro
Car Lover By Nature
 
Drives: Mini Cooper S
Join Date: Dec 2009
Location: Central FL
Posts: 2,307
Quote:
Originally Posted by ProudLS View Post
Thanks for the info, I will try to play around and see how it goes.
unless you are a well seasoned tuner, I would highly suggest that you don't "play" with any settings. listen to Kirk on this one, you can damage your engine quite easily...
__________________
bumblebeecamaro is offline   Reply With Quote
Old 02-25-2010, 10:02 AM   #9
DSteck
Account Suspended
 
Drives: 2006 Corvette Z06
Join Date: Feb 2010
Location: St. Louis, MO
Posts: 590
Quote:
Originally Posted by bumblebeecamaro View Post
unless you are a well seasoned tuner, I would highly suggest that you don't "play" with any settings. listen to Kirk on this one, you can damage your engine quite easily...
If you leave knock settings alone, it's actually pretty hard to blow up an engine.
DSteck is offline   Reply With Quote
Old 02-25-2010, 11:25 AM   #10
brtaus
 
brtaus's Avatar
 
Drives: None
Join Date: Oct 2009
Location: Phoenix, AZ
Posts: 577
Quote:
Originally Posted by Russell James View Post
Yes an exhaust contact can easily cause a false knock. Should be no reason to mess with knock sensing or the rev limit. Anything less than 93 can also cause real knock. You won't be able to hear it. The computer senses it way faster than a human ear can pick it up.

It use to be a few years back, you could hear a burst of detonation - then the computer would pull the timing and eliminate it. These latest gen of computers though are so fast, they pick up knock in a split second and dump the timing to eliminate it before you even here the slightest bit.

I'd tinker with 93 from a different station, and some octane booster, and eliminate all exhaust contacts....leave the knock sensing alone, and then see if it is still pulling the timing. I bet it won't be.

May also help to put some miles on the CAI and headers so it self adjusts as much as possible. I've seen where putting a CAI in, during those first couple of drives, the car was showing quite a bit of knock activity. Then after some miles of driving all was back to normal.
I notice a difference with this. I usually fill up at Chevron but the last tank I had to fill up a a Circle K, and about a 1/4 tank into it, I noticed it seemed to run a bit rougher than it does with Chevron gas.
brtaus is offline   Reply With Quote
Old 02-25-2010, 05:46 PM   #11
RogueSS
 
RogueSS's Avatar
 
Drives: Black 2SS/RS M6 #100296
Join Date: Feb 2010
Location: Salt Lake City, UT
Posts: 542
Quote:
Originally Posted by Russell James View Post
Yes an exhaust contact can easily cause a false knock. Should be no reason to mess with knock sensing or the rev limit. Anything less than 93 can also cause real knock. You won't be able to hear it. The computer senses it way faster than a human ear can pick it up.

It use to be a few years back, you could hear a burst of detonation - then the computer would pull the timing and eliminate it. These latest gen of computers though are so fast, they pick up knock in a split second and dump the timing to eliminate it before you even here the slightest bit.

I'd tinker with 93 from a different station, and some octane booster, and eliminate all exhaust contacts....leave the knock sensing alone, and then see if it is still pulling the timing. I bet it won't be.

May also help to put some miles on the CAI and headers so it self adjusts as much as possible. I've seen where putting a CAI in, during those first couple of drives, the car was showing quite a bit of knock activity. Then after some miles of driving all was back to normal.

That's all well and good, unless you live somewhere where there is no 93...such as Utah. Highest octane gas you can buy is 91.

Now, the engineers claim it's due to our altitude, the 91 is equivalent to 93....is it? Who knows, but there is no such thing as 93 octane gas in Utah.
__________________
AirRaid CAI, GM Performance Parts Axle Back Exhaust, Pfadt Rear Balance Bar, Pfadt 1.25" Drop Sorings, Elite Engineering PCV Catch Can, Hurst Shifter

All work by JDP Motorsports

04/14/12: 381 RWHP 383 RWTQ at JDP Motorsports
RogueSS is offline   Reply With Quote
Old 02-25-2010, 06:20 PM   #12
E85LSX
 
E85LSX's Avatar
 
Drives: 2010 Camaro
Join Date: Jul 2009
Location: Long Island
Posts: 244
I wouldn't decrease the sensitivity of the knock sensors but you can make them less intrusive by increasing the decay rate and reducing the attack.

Another thing I wouldn't do is try to tune the spark on the street with the knock sensors. . .

Also keep in mind that from the factory these cars are over-sparked around .2g/cyl and below in the high octane table.
__________________
Mods: TVS2300, 3.2 pulley, American Racing Headers, Custom Cam, Coil Overs, Tuned for E85, 610RWHP* 570RWTQ
Follow me on Twitter
www.e85lsx.com

E85LSX is offline   Reply With Quote
Old 02-25-2010, 06:29 PM   #13
CaliEMT
Decepticons. . . MOBILIZE
 
CaliEMT's Avatar
 
Drives: 2010 2SS/RS Black
Join Date: Jan 2010
Location: Santa Maria, Ca
Posts: 314
Wow, I wish I knew what you guys were talking about :(

Wouls anyone mind giving me quick lesson?
CaliEMT is offline   Reply With Quote
Old 02-26-2010, 08:22 AM   #14
ProudLS
 
ProudLS's Avatar
 
Drives: Camaro SS
Join Date: Dec 2009
Location: TX
Posts: 193
Quote:
Originally Posted by E85LSX View Post
I wouldn't decrease the sensitivity of the knock sensors but you can make them less intrusive by increasing the decay rate and reducing the attack.

Another thing I wouldn't do is try to tune the spark on the street with the knock sensors. . .

Also keep in mind that from the factory these cars are over-sparked around .2g/cyl and below in the high octane table.
You are absolutely right, now I have 22-24 from 3500to 5200 and 25-27 from 5200 to 6300. Zero knock on 93 octane. My AFR is 14.4 to 14.6 at the high end. I hope this tune is the best of what I can get from my car.
ProudLS is offline   Reply With Quote
Old 02-26-2010, 08:34 AM   #15
full of days
 
full of days's Avatar
 
Drives: Camaro GT
Join Date: Dec 2009
Location: Charlotte
Posts: 725
so is hp/tq performance and mpg variance the only loss with a lower octane? I would imagine the PCM would take over and adjust the engine performance when a lower octane gas is run. Am I mistaken?
__________________

Post Tenebras Lux


full of days is offline   Reply With Quote
Old 02-26-2010, 09:29 AM   #16
ProudLS
 
ProudLS's Avatar
 
Drives: Camaro SS
Join Date: Dec 2009
Location: TX
Posts: 193
Quote:
Originally Posted by full of days View Post
so is hp/tq performance and mpg variance the only loss with a lower octane? I would imagine the PCM would take over and adjust the engine performance when a lower octane gas is run. Am I mistaken?
No you are right. The PCM will switch to low octane map with lower timing.
ProudLS is offline   Reply With Quote
Old 02-26-2010, 11:04 AM   #17
E85LSX
 
E85LSX's Avatar
 
Drives: 2010 Camaro
Join Date: Jul 2009
Location: Long Island
Posts: 244
Quote:
Originally Posted by ProudLS View Post
You are absolutely right, now I have 22-24 from 3500to 5200 and 25-27 from 5200 to 6300. Zero knock on 93 octane. My AFR is 14.4 to 14.6 at the high end. I hope this tune is the best of what I can get from my car.
If your A/F ratio is 14.4-14.6 at WOT you are running very lean. I would shoot for around a 12.5 A/F during WOT throughout the RPM range.

Are you using a wideband to monitor the A/F ratio?
__________________
Mods: TVS2300, 3.2 pulley, American Racing Headers, Custom Cam, Coil Overs, Tuned for E85, 610RWHP* 570RWTQ
Follow me on Twitter
www.e85lsx.com

E85LSX is offline   Reply With Quote
Old 02-26-2010, 11:18 AM   #18
ProudLS
 
ProudLS's Avatar
 
Drives: Camaro SS
Join Date: Dec 2009
Location: TX
Posts: 193
Quote:
Originally Posted by E85LSX View Post
If your A/F ratio is 14.4-14.6 at WOT you are running very lean. I would shoot for around a 12.5 A/F during WOT throughout the RPM range.

Are you using a wideband to monitor the A/F ratio?
Sorry its 12.40 - 12.6 and yes I have innovate lc-1
ProudLS is offline   Reply With Quote
Old 02-28-2010, 08:56 AM   #19
DSteck
Account Suspended
 
Drives: 2006 Corvette Z06
Join Date: Feb 2010
Location: St. Louis, MO
Posts: 590
Glad to hear it's running well for you. Definitely leave your low octane map alone so that you have a fall-back if you ever do get knock. It doesn't completely switch over, but uses it as a reference to learn.
DSteck is offline   Reply With Quote
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Official 1/4 Mile (V8) 2010+ Camaro Fast List Merc Dragstrip and Launch Techniques Discussion 2651 Today 08:42 PM
Unofficial 1/4 Mile (V8) 2010+ Camaro Fast List Merc Dragstrip and Launch Techniques Discussion 250 04-01-2014 10:40 AM
LS3 engine specifications Tran Wiki 3 10-06-2010 10:56 PM
LS3 Specs revealed: GM's 436hp Sick 6.2L LS3 TAG UR IT Camaro V8 LS3 / L99 Engine, Exhaust, and Bolt-Ons 28 07-30-2009 06:02 PM
Check your Order here bvonscott Camaro Price | Ordering | Tracking | Dealers Discussions 665 06-29-2009 01:00 PM


All times are GMT -5. The time now is 08:56 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.