Results 1 to 10 of 10

Thread: Changing Base Timing Table on existing tune.

  1. #1

    Default Changing Base Timing Table on existing tune.

    If the Base Timing Table is the only parameter I want to modify on an existing tune, would it serve me better to start over with the fuel Learning process on a Wizard fresh tune as well; or will in not matter to the fueling if I chop 4°-5° off the whole timing table? I'll save my existing tune either way as a backup of course.

  2. #2

    Default

    If that's all you want to change, then change it. I wouldn't start over, that would be a lot of work. Just highlight the area on the Base Timing Table you want to change and down arrow away a few degrees of timing. Changing timing will change the AFR a small amount, but I wouldn't worry about it. Closed Loop Comp will take care of the changes very quickly.

  3. #3
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    25,089

    Default

    Yes, just tune the Base Timing Table. Leave the Base Fuel Table alone.
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS T/W 11R 205 heads, 232°-244° duration/.623" lift/114° LSA camshaft, 12:1 C/R, TFS R-Series FTI ported intake, BBK 80mm T/B, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 200A 3G alternator, Optima Red battery, A/C, 100HP progressive dry direct-port NOS, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, -6AN fuel system plumbing, Walbro 255 LPH pump, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/3000 RPM converter, B&M Hammer shifter, FPP aluminum driveshaft, FPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 M/T Street Comp tires.

  4. #4

    Default

    Thanks Guys! Quick question for the more engine intelligent guys. If I started with a close to factory timing table on my specific engine, then added much more free flowing headers/exhaust and intake, would I retard the timing from stock spec? My thinking (which may be way off base) is that the more efficient movement of air would increase the speed of the flame front, therefore requiring less advance than a stock restricted engine. Thoughts?

  5. #5
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    25,089

    Default

    Scroll down to end of post #1, "Ignition Advance Curve Factors": http://forums.holley.com/showthread....ing-Holley-EFI (Ignition Timing Synchronization)
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS T/W 11R 205 heads, 232°-244° duration/.623" lift/114° LSA camshaft, 12:1 C/R, TFS R-Series FTI ported intake, BBK 80mm T/B, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 200A 3G alternator, Optima Red battery, A/C, 100HP progressive dry direct-port NOS, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, -6AN fuel system plumbing, Walbro 255 LPH pump, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/3000 RPM converter, B&M Hammer shifter, FPP aluminum driveshaft, FPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 M/T Street Comp tires.

  6. #6

    Default

    That’s a good read, thanks! I guess I should retard my timing a bit.

  7. #7
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    25,089

    Default

    Quote Originally Posted by HeavyChevy View Post
    That's a good read, thanks!
    You're welcome.

    I guess I should retard my timing a bit.
    Or pay for some time on a dynamometer.
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS T/W 11R 205 heads, 232°-244° duration/.623" lift/114° LSA camshaft, 12:1 C/R, TFS R-Series FTI ported intake, BBK 80mm T/B, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 200A 3G alternator, Optima Red battery, A/C, 100HP progressive dry direct-port NOS, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, -6AN fuel system plumbing, Walbro 255 LPH pump, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/3000 RPM converter, B&M Hammer shifter, FPP aluminum driveshaft, FPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 M/T Street Comp tires.

  8. #8

    Default

    I would be stunned if a mere header and intake change led to a need to adjust timing much if any. Based on your user name I assume this is a Chevy and in general small and big block Chevy's love timing. Is this a first gen? The LS and Vortec stuff like less timing.

    Can you define "close to factory timing curve" as that could mean a lot of things? What is your timing today? What are the rest of your engine specifications? Particularly important are static compression ratio, cam specs and which heads you are running.
    69 Camaro
    400 SBC, ProCharger D1SC
    1.302 60', 5.95@116.4 on pump gas

  9. #9

    Default

    Quote Originally Posted by Danny Cabral View Post
    Or pay for some time on a dynamometer.
    That would be the smart thing to do. I plan on it as soon as the holidays are over.

  10. #10

    Default

    Quote Originally Posted by gregs69rs View Post
    I would be stunned if a mere header and intake change led to a need to adjust timing much if any. Based on your user name I assume this is a Chevy and in general small and big block Chevy's love timing. Is this a first gen? The LS and Vortec stuff like less timing.
    Can you define "close to factory timing curve" as that could mean a lot of things? What is your timing today? What are the rest of your engine specifications? Particularly important are static compression ratio, cam specs and which heads you are running.
    It's a Vortec. By factory timing curve, I'm referring to the factory curve for a '96-'98 Vortec in a truck. From there, the article says to reduce timing for higher loads. My truck has taller tires than a stock Vortec pickup, a taller first gear than the 4L60E that came in those trucks and a tighter convertor than came in those trucks. It also has heavier running gear than came in those trucks and worse aerodynamics. That all added up to more load in my head. The article also says that with higher efficiency exhaust and intake to reduce timing. The factory logs that came on those engines aren't really high flow and they've been replaced by 1-5/8" primary long tube headers with 3" collectors and 2-1/2" pipes with nearly no bends. I'm assuming that exhaust flows significantly more than the factory logs, small pipes, cats, mufflers, etc.

    The amount of timing in the factory Vortec table has pretty low timing numbers to begin with and I've only slightly tweaked them downward from there. Here's the factory table and my new table.
    Click image for larger version. 

Name:	timingtable111719.jpg 
Views:	13 
Size:	104.0 KB 
ID:	8919 Click image for larger version. 

Name:	factory vortec timing table.jpg 
Views:	10 
Size:	73.8 KB 
ID:	8920

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
About us
Holley has been the undisputed leader in fuel systems for over 100 years. Holley carburetors have powered every NASCAR® Sprint® Cup team and nearly every NHRA® Pro–Stock champion for four decades. Now, Holley EFI is dominating the performance world as well as our products for GM's LS engine. Holley's products also include performance fuel pumps, intake manifolds & engine dress–up products for street performance, race and marine applications. As a single solution, or partnered with products from other Holley companies - Hooker Headers, Flowtech Headers, NOS Nitrous, Weiand, Earl's Performance Plumbing, or Diablosport - Holley products can give you the edge you need over the competition.
Join us