LS4 Performance Grand Prix GXP | Monte Carlo SS | Impala SS | LaCrosse Super

Timing?

Thread Tools
 
Search this Thread
 
Old May 23, 2010 | 11:49 AM
  #1  
Gorske's Avatar
Thread Starter
Staging Lane
 
Joined: Jul 2008
Posts: 74
Likes: 0
From: St. Joseph,MI
Default Timing?

Just curious but wondering how much timing people are running at WOT. I know mine stock was 32 degrees and my tuner just bumped it to 33 after wide band tuning it. Just seeing how much you guys are running before you start getting knock.
Reply
Old May 23, 2010 | 11:56 AM
  #2  
TiredGXP's Avatar
TECH Enthusiast
iTrader: (2)
 
Joined: Dec 2007
Posts: 677
Likes: 0
From: Sherwood Park, AB
Default

FWIW, here's my high octane timing table. May see 34* over 5500 RPM

Timing?-timing.gif

I'm at about 2200 ft, so rarely get more than .68g/cyl unless it's real cold.
Reply
Old May 23, 2010 | 12:10 PM
  #3  
AlabamaGuy's Avatar
TECH Addict
iTrader: (5)
 
Joined: Jun 2009
Posts: 2,802
Likes: 0
Default

OK so I'm guessing both of you are in high elevations...I'm at 28* and that's HIGH for around here.
Reply
Old May 23, 2010 | 12:23 PM
  #4  
Gorske's Avatar
Thread Starter
Staging Lane
 
Joined: Jul 2008
Posts: 74
Likes: 0
From: St. Joseph,MI
Default

St. Joseph, MI 637ft. above sea level. The track I run is in Martin, MI and that is at 837'.
Reply
Old May 23, 2010 | 12:31 PM
  #5  
TiredGXP's Avatar
TECH Enthusiast
iTrader: (2)
 
Joined: Dec 2007
Posts: 677
Likes: 0
From: Sherwood Park, AB
Default

Temperature might have something to do with it too. I lose maybe 8* from the IAT modifier table when the intake tract heat soaks in town during rush hour. Normally doesn't get warm enough for that table to come into play on the freeway...
Reply
Old May 24, 2010 | 12:52 AM
  #6  
JDMC5's Avatar
TECH Fanatic
iTrader: (3)
 
Joined: Feb 2009
Posts: 1,366
Likes: 0
From: Highland, MI
Default

More timing isn't everything. I think the stock tables are too aggressive in the first place. I'm not sure why GM did it but the LS4 runs more WOT timing than any other LS engine I've seen. Most LS engines only need between 25-29* total. I can't imagine them needing much different timing requirements. I have not confirmed what an LS4 likes on a dyno so take it for what it's worth.
Reply
Old May 24, 2010 | 12:58 AM
  #7  
AlabamaGuy's Avatar
TECH Addict
iTrader: (5)
 
Joined: Jun 2009
Posts: 2,802
Likes: 0
Default

Originally Posted by JDMC5
More timing isn't everything. I think the stock tables are too aggressive in the first place. I'm not sure why GM did it but the LS4 runs more WOT timing than any other LS engine I've seen. Most LS engines only need between 25-29* total. I can't imagine them needing much different timing requirements. I have not confirmed what an LS4 likes on a dyno so take it for what it's worth.
I think mine was holding 18* before headers, then bumped to 27*, spiking at 28* from time to time.
Reply
Old May 24, 2010 | 01:08 AM
  #8  
JDMC5's Avatar
TECH Fanatic
iTrader: (3)
 
Joined: Feb 2009
Posts: 1,366
Likes: 0
From: Highland, MI
Default

damn, only 18? I've never seen that. I guess it all depends on where you live. BTW, LS engines like a a/f mixture about 12.5-13.0, again not sure what they run so damn lean from the factory.
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

 Brett Foote
story-1

Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

 Pouria Savadkouei
story-2

Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

 Verdad Gallardo
story-3

7 Most Reliable High-Performance Engines GM Has Ever Built

 Verdad Gallardo
story-4

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

 Verdad Gallardo
story-5

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-6

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-7

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-8

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-9

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
Old May 24, 2010 | 01:39 AM
  #9  
AlabamaGuy's Avatar
TECH Addict
iTrader: (5)
 
Joined: Jun 2009
Posts: 2,802
Likes: 0
Default

Originally Posted by JDMC5
damn, only 18? I've never seen that. I guess it all depends on where you live. BTW, LS engines like a a/f mixture about 12.5-13.0, again not sure what they run so damn lean from the factory.
My tune was extremely lean from the factory. Not sure what it was, the car just wouldn't take any timing before the headers but afterward it took a ton more.
Reply
Old May 24, 2010 | 07:26 AM
  #10  
TiredGXP's Avatar
TECH Enthusiast
iTrader: (2)
 
Joined: Dec 2007
Posts: 677
Likes: 0
From: Sherwood Park, AB
Default

Originally Posted by AlabamaGuy
My tune was extremely lean from the factory. Not sure what it was, the car just wouldn't take any timing before the headers but afterward it took a ton more.
Odd. Mine was very rich >5,000 rpm. ECM was commanding something like 10.9 in PE mode. Now ~12.8 +/- at WOT. it would be leaner at lower RPM because of the goofy stock PE enable settings - wouldn't go into PE until after 3,500.
Reply
Old May 24, 2010 | 07:53 AM
  #11  
TiredGXP's Avatar
TECH Enthusiast
iTrader: (2)
 
Joined: Dec 2007
Posts: 677
Likes: 0
From: Sherwood Park, AB
Default

Originally Posted by JDMC5
More timing isn't everything. I think the stock tables are too aggressive in the first place. I'm not sure why GM did it but the LS4 runs more WOT timing than any other LS engine I've seen. Most LS engines only need between 25-29* total. I can't imagine them needing much different timing requirements. I have not confirmed what an LS4 likes on a dyno so take it for what it's worth.
For the most part, I agree with this. In the absence of a dyno, I set timing on the basis of several 3k to 6k WOT runs - whatever timing appeared to minimize the time for the run. Much of my timing table -ares that you can't actually hit while driving - are just "plugged" to make it smother. YMMV.

While I do have more timing than stock at high rpm, In some areas of my timing map, primarily between 1200 and 2000 I had to pull up to 5* because of KR. It was most evident when climbing a hill on the highway.
Reply
Old May 24, 2010 | 05:05 PM
  #12  
Gorske's Avatar
Thread Starter
Staging Lane
 
Joined: Jul 2008
Posts: 74
Likes: 0
From: St. Joseph,MI
Default

Thanks for the input guys. They are supose to have a dyno setup near where I live and Ill have to get some numbers and post it for you guys.
Reply
Old May 25, 2010 | 12:23 AM
  #13  
JDMC5's Avatar
TECH Fanatic
iTrader: (3)
 
Joined: Feb 2009
Posts: 1,366
Likes: 0
From: Highland, MI
Default

Originally Posted by TiredGXP
For the most part, I agree with this. In the absence of a dyno, I set timing on the basis of several 3k to 6k WOT runs - whatever timing appeared to minimize the time for the run. Much of my timing table -ares that you can't actually hit while driving - are just "plugged" to make it smother. YMMV.

While I do have more timing than stock at high rpm, In some areas of my timing map, primarily between 1200 and 2000 I had to pull up to 5* because of KR. It was most evident when climbing a hill on the highway.
yeah I'd really like to tune a couple on the dyno to get some hard data on these cars. But, like I said I can't imagine them being too much different than all the other LS engines.
Reply
Old May 25, 2010 | 12:39 AM
  #14  
AlabamaGuy's Avatar
TECH Addict
iTrader: (5)
 
Joined: Jun 2009
Posts: 2,802
Likes: 0
Default

Originally Posted by JDMC5
yeah I'd really like to tune a couple on the dyno to get some hard data on these cars. But, like I said I can't imagine them being too much different than all the other LS engines.
Only thing I can see a major difference will be the smaller bore shrouding the valves, and the super restrictive intake.
Reply
Old May 25, 2010 | 02:22 AM
  #15  
JDMC5's Avatar
TECH Fanatic
iTrader: (3)
 
Joined: Feb 2009
Posts: 1,366
Likes: 0
From: Highland, MI
Default

yeah but the smaller valves help shrouding, in any effect it's not a factor since it will be the same case in all the other 5.3's.

The biggest factors that are going to make a difference aren't much different at all. Chamber design, rod length, stroke, compression are all the same/ similar.
Reply




All times are GMT -5. The time now is 02:19 PM.

story-0
6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

Don't get dad new socks or a grill brush this year.

By Brett Foote | 2026-06-04 05:00:17


VIEW MORE
story-1
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-2
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-3
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-4
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-5
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-6
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-7
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-8
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-9
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