timing table questions
Thread Starter
On The Tree
Joined: Oct 2002
Posts: 133
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From: Bakersfield, CA
timing table questions What are the g/cyl that our cars normally see? I know that this table covers extream ranges that are not seen but for aadding timing what would be the window for g/cyl to edit??
Re: timing table questions .1 - Idle, no load driving
.2 to .4 - Normal around town to spirited driving
.4 to .5 - Sprited driving
.6+ - Very sprited to WOT driving.
Some spots to pay attention to:
Lower Left Corner - Low RPM, High G/cyl. This should be left at the stock values.
.6+ @ 4500 rpm - This is peak torque, and timing should be added very gingerly (don't increase it as much as you would your WOT timing) to avoid KR on your WOT runs.
Good Luck,
Kevin
.2 to .4 - Normal around town to spirited driving
.4 to .5 - Sprited driving
.6+ - Very sprited to WOT driving.
Some spots to pay attention to:
Lower Left Corner - Low RPM, High G/cyl. This should be left at the stock values.
.6+ @ 4500 rpm - This is peak torque, and timing should be added very gingerly (don't increase it as much as you would your WOT timing) to avoid KR on your WOT runs.
Good Luck,
Kevin
TECH Senior Member
Joined: Nov 2001
Posts: 9,246
Likes: 3
From: Troy, AL
Re: timing table questions While we're on the subject...
I was seeing 26.5 degrees timing stock. I raised it 2 degrees above that and then another 2 degrees. Seemed to make a little difference in trap speed but not much. What is everyone's opinion on the best timing advance setting for WOT for these '01s and '02s?
I was seeing 26.5 degrees timing stock. I raised it 2 degrees above that and then another 2 degrees. Seemed to make a little difference in trap speed but not much. What is everyone's opinion on the best timing advance setting for WOT for these '01s and '02s?
Re: timing table questions I take it all the way to KR then drop it back a point or two.
Total advance is very car specific. It depends on octane, compression, cam, exhaust, squish, temperature, sparkplug, and combustion chamber condition.
FWIW, most cars I can get away with ~30 deg with good gas.
Some people claim that timing after a certain point doesn't increase peak HP. This is true, but it will level off your peak HP more and do as you observed, generate better trap speeds.
Good Luck,
Kevin
Total advance is very car specific. It depends on octane, compression, cam, exhaust, squish, temperature, sparkplug, and combustion chamber condition.
FWIW, most cars I can get away with ~30 deg with good gas.
Some people claim that timing after a certain point doesn't increase peak HP. This is true, but it will level off your peak HP more and do as you observed, generate better trap speeds.
Good Luck,
Kevin
TECH Senior Member
Joined: Nov 2001
Posts: 9,246
Likes: 3
From: Troy, AL
Re: timing table questions In my case I'm not sure you would ever run into KR at any sane timing advance even if I didn't have the KR sensors disabled (yeah, I know the risks but I've been around the LS1 game awhile and feel I don't need that most often annoying safety catch.)
The engine is internally stock.
It has TR-6 plugs which are cooler than stock.
It has headers with no cats (no cats helps these cars not to have KR more than most folks would believe.)
I run a 160 thermo with very cool fan settings.
93 octane gas
So, let's assume for a minute that detonation, and therefor KR, is not a concern. How high is too high? My opinion is that going from 26-28 degrees helps noticable. Going from 28-30 doesn't hurt and may help just a tinsy bit. Going higher than 31 may actually hurt power.
Now these observation were made through extensive track testing with my '00 Z28. I don't know if they hold true for my '02 but I don't see why they wouldn't. Initial track testing tends to point that way as well.
Thoughts?
The engine is internally stock.
It has TR-6 plugs which are cooler than stock.
It has headers with no cats (no cats helps these cars not to have KR more than most folks would believe.)
I run a 160 thermo with very cool fan settings.
93 octane gas
So, let's assume for a minute that detonation, and therefor KR, is not a concern. How high is too high? My opinion is that going from 26-28 degrees helps noticable. Going from 28-30 doesn't hurt and may help just a tinsy bit. Going higher than 31 may actually hurt power.
Now these observation were made through extensive track testing with my '00 Z28. I don't know if they hold true for my '02 but I don't see why they wouldn't. Initial track testing tends to point that way as well.
Thoughts?
Re: timing table questions On street setups where I don't encounter KR, I don't go higher than timing at 31. Any higher than that I think that the risk of pinging the motor with changes in gas / ambient conditions / outweigh what minimal gains can be made.
Unless it is a race application, then we go the extra mile to find out what the optimal timing of the engine is. Which coincidentally has to be done at the track under race conditions. <img border="0" title="" alt="[Cool]" src="gr_images/icons/cool.gif" />
I agree with you on timing for your setup. Colder plugs throw the KR limit up. For nitrous setups with a split timing system (IAT relay, MSD system, whatever) I stop timing at 30-31 since the cold plug throws things out of whack.
It is interesting to see two sides come to the same conclusion. Me on the dyno and behind a calculator, and you out at the track.
For your setup, I would have set timing at 28 (because you have no KR detection) and called it a day.
Unless it is a race application, then we go the extra mile to find out what the optimal timing of the engine is. Which coincidentally has to be done at the track under race conditions. <img border="0" title="" alt="[Cool]" src="gr_images/icons/cool.gif" />
I agree with you on timing for your setup. Colder plugs throw the KR limit up. For nitrous setups with a split timing system (IAT relay, MSD system, whatever) I stop timing at 30-31 since the cold plug throws things out of whack.
It is interesting to see two sides come to the same conclusion. Me on the dyno and behind a calculator, and you out at the track.
For your setup, I would have set timing at 28 (because you have no KR detection) and called it a day.
