adjusting low and high octane timing tables....
Thread Starter
7 Second Club
iTrader: (11)
Joined: Jul 2002
Posts: 8,758
Likes: 9
From: Port Tobacco, MD
adjusting low and high octane timing tables.... Where should I start adding or removing timing on the table? 60gm/cyl and 2600? Anyone copy the table and paste it would be great.
Phillip
Phillip
Re: adjusting low and high octane timing tables.... You can benefit by adding timing to your entire table. You can't just add timing blindly though, you have to tune it.
The method that I prefer:
Add 2 deg to your entire timing table. Drive the car around and check for KR in all driving conditions. Be sure to log MAF, RPM, Total Advance, Knock Retard. Try to keep it to the minimum perameters when doing this.
If you don't see any KR add another 2 deg to your entire table. Drive the car around and check for KR in all driving conditions. You should start bumping into KR now. At the points you encounter KR calculate out the g/cyl for that RPM and MAF.
Convert your MAF from lb/min to g/sec first
lb/min * 0.1256 = g/sec
G/Cyl = 15 * (g/sec) / RPM
You now have the RPM and g/cyl for the points that have too much timing. Remove 1 deg of timing at these points, and try again.
You can do this all afternoon. Slowly increase your timing table, find which points are producing KR and reduce these points.
Developing a *good* timing table takes time. You can develop a good one for you car in an afternoon, but it is best to do this procedure a couple times to ensure that you have a solid reliable timing curve that produces maximum HP with as little KR as possible.
The method that I prefer:
Add 2 deg to your entire timing table. Drive the car around and check for KR in all driving conditions. Be sure to log MAF, RPM, Total Advance, Knock Retard. Try to keep it to the minimum perameters when doing this.
If you don't see any KR add another 2 deg to your entire table. Drive the car around and check for KR in all driving conditions. You should start bumping into KR now. At the points you encounter KR calculate out the g/cyl for that RPM and MAF.
Convert your MAF from lb/min to g/sec first
lb/min * 0.1256 = g/sec
G/Cyl = 15 * (g/sec) / RPM
You now have the RPM and g/cyl for the points that have too much timing. Remove 1 deg of timing at these points, and try again.
You can do this all afternoon. Slowly increase your timing table, find which points are producing KR and reduce these points.
Developing a *good* timing table takes time. You can develop a good one for you car in an afternoon, but it is best to do this procedure a couple times to ensure that you have a solid reliable timing curve that produces maximum HP with as little KR as possible.
TECH Resident
iTrader: (3)
Joined: Nov 2001
Posts: 979
Likes: 0
From: Richmond, VA Where fast cars, well......are hard to come by.
Re: adjusting low and high octane timing tables.... I think when you log flow rate, atap makes a lb/min column and a g/sec column.
Staging Lane
Joined: Feb 2002
Posts: 97
Likes: 0
From: Newport, Michigan
Re: adjusting low and high octane timing tables.... When you are out making WOT runs and logging ATAP files, how do you know if the PCM is using the low or high octane table?
To me, I thought the only way to know was low timing.
NoGo has a very good method in developing a timing map specific for your mods. Like he said, it takes a long time to get the max timing at all load/RPM cases without KR.
BTW: For NoGo, I do the same thing to get an excellent MAF calibration table for my car.
To me, I thought the only way to know was low timing.
NoGo has a very good method in developing a timing map specific for your mods. Like he said, it takes a long time to get the max timing at all load/RPM cases without KR.
BTW: For NoGo, I do the same thing to get an excellent MAF calibration table for my car.
Re: adjusting low and high octane timing tables.... </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Doc99SShome:
<strong>When you are out making WOT runs and logging ATAP files, how do you know if the PCM is using the low or high octane table?
To me, I thought the only way to know was low timing.
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">This method works well enough for me.
Find a gas station rest-stop along side the freeway.
Put 5 gallons of gas in your car. Log timing and KR
On the way out of the rest stop gun it. Watch your KR and Total Advance. You should at LEAST see see 23+ total advance. If you aren't, there is another problem holding back your timing.
If you saw KR go through the roof, do another blast down the freeway. You should see timing return to 23+. If it doesn't, and only hangs at 19, then you just got kicked back to the Low Octane Table, and you have some KR issues to address.
Good Luck,
Kevin
<strong>When you are out making WOT runs and logging ATAP files, how do you know if the PCM is using the low or high octane table?
To me, I thought the only way to know was low timing.
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">This method works well enough for me.
Find a gas station rest-stop along side the freeway.
Put 5 gallons of gas in your car. Log timing and KR
On the way out of the rest stop gun it. Watch your KR and Total Advance. You should at LEAST see see 23+ total advance. If you aren't, there is another problem holding back your timing.
If you saw KR go through the roof, do another blast down the freeway. You should see timing return to 23+. If it doesn't, and only hangs at 19, then you just got kicked back to the Low Octane Table, and you have some KR issues to address.
Good Luck,
Kevin
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
