5.3 L heads.....11:1 CR.....What timing is everyone running?
04-11-2003, 09:31 PM
#2
Re: 5.3 L heads.....11:1 CR.....What timing is everyone running? I'm running 28 degree's flat curve on LS6 Heads at 11.2-1 compression with no knock.Might try 30-32 degrees next <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
04-11-2003, 10:50 PM
#3
Re: 5.3 L heads.....11:1 CR.....What timing is everyone running? 28-32 degrees.
I honestly haven't seen any significant gains from stepping timing on an LS1. Once past peak toque, you can take timing strait to its maximum.
Stepping timing after peak torque will level out your peak HP more, but just barely. Usually, the small gains that can be made by walking your timing up with rpm are offset by the increased in possibility of KR (in which you will loose ~5hp).
When you tune your timing curve you are doing for it for only one temperature. The amount of timing that you can get away with is slightly dependant on the ambient temperature, pressure, humidity. You need a little leeway on your timing curve to avoid running into KR.
Good Luck,
Kevin
I honestly haven't seen any significant gains from stepping timing on an LS1. Once past peak toque, you can take timing strait to its maximum.
Stepping timing after peak torque will level out your peak HP more, but just barely. Usually, the small gains that can be made by walking your timing up with rpm are offset by the increased in possibility of KR (in which you will loose ~5hp).
When you tune your timing curve you are doing for it for only one temperature. The amount of timing that you can get away with is slightly dependant on the ambient temperature, pressure, humidity. You need a little leeway on your timing curve to avoid running into KR.
Good Luck,
Kevin
04-12-2003, 02:03 PM
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Re: 5.3 L heads.....11:1 CR.....What timing is everyone running? Hey Kevin, thanks for the input..as always. What do you think of running timing around 28 prior to peak torque then step down to 25 at peak torque and staying there till red line?
04-12-2003, 02:25 PM
#5
Re: 5.3 L heads.....11:1 CR.....What timing is everyone running? By leaving your timing low after peak torque, I think you may be leaving a little bit of power on the table. Most modified vehicles can easily run 28 degrees of timing without any KR (this is what they used to come from the factory 98-00).
Usually, the best gains with timing are made by making a healthy reduction at peak torque then taking timing right to its maximum. Here is a good example of the kind of timing trend that I have seen the best gains with.
28 29 30 30 30 26 24 31 31 31 31 31 31
or a safe timing table
28 29 30 30 28 26 24 28 28 28 28 28 28
The 26 would be at 4400 rpm, and the 24 would be at 4800 rpm.
The kind of timing reduction depends on the duration of the cam, naturally, but you get the idea.
Increasing your timing left of peak torque is going to put more area under the curve (until you run into KR), and increasing your timing to the right of peak torque is going to put more area under the curve (to a point ~32 degrees)
Good Luck,
Kevin
Usually, the best gains with timing are made by making a healthy reduction at peak torque then taking timing right to its maximum. Here is a good example of the kind of timing trend that I have seen the best gains with.
28 29 30 30 30 26 24 31 31 31 31 31 31
or a safe timing table
28 29 30 30 28 26 24 28 28 28 28 28 28
The 26 would be at 4400 rpm, and the 24 would be at 4800 rpm.
The kind of timing reduction depends on the duration of the cam, naturally, but you get the idea.
Increasing your timing left of peak torque is going to put more area under the curve (until you run into KR), and increasing your timing to the right of peak torque is going to put more area under the curve (to a point ~32 degrees)
Good Luck,
Kevin
04-12-2003, 06:48 PM
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Re: 5.3 L heads.....11:1 CR.....What timing is everyone running? I am running 11:1 C/R I am getting KR around 4500rpm. Right now I am still on the stock timing curve. Should I reduce timing more at the torque peak? I believe it's 24 right now.
At what are rpm after the torque peak do you set the timing to max?
Also might O2 are 846 and 907 when KR is induced.
The car showed 14:1 A/F at this point also. I already added 5% to the PE table.
At what are rpm after the torque peak do you set the timing to max?
Also might O2 are 846 and 907 when KR is induced.
The car showed 14:1 A/F at this point also. I already added 5% to the PE table.
04-12-2003, 08:52 PM
#7
Re: 5.3 L heads.....11:1 CR.....What timing is everyone running? Timing and A/F go hand and hand.If you do not have enough fuel you can get knock retard,just like to much timing.You can also run tons of timing and fight knock with more fuel to a point.
I have 2 H/C cars running 30 degrees of timing from 2200rpm to 7000rpm with no knock and A/F at 13-1.But my car picks up knock at around 5k rpm ussing the same table.
So each car is different <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
I have 2 H/C cars running 30 degrees of timing from 2200rpm to 7000rpm with no knock and A/F at 13-1.But my car picks up knock at around 5k rpm ussing the same table.
So each car is different <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
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04-14-2003, 12:37 AM
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Re: 5.3 L heads.....11:1 CR.....What timing is everyone running? NoGo and Slowhawk...thanks as always. I will try baselining the timing curve as I indicated then start increasing straight across like you indicated after peak torque. I will post results this week.
