Results 1 to 8 of 8

Thread: Big change in elevation.

  1. #1

    Default Big change in elevation.

    Hi. I've had the Sniper running for a couple of months now and it has been Learning & running well. The Sniper is controlling timing with a Holley dual sync and a MSD 6AL. I'm at 1750 meters (5750 feet) elevation above sea level and all the Learning has been done at this elevation. I'm going to be going to the coast for the holidays, so elevation will obviously drop to basically sea level. Before I drive down, what should I set the Closed Loop Compensation Limits & the Learned Compensation Limits to?

  2. #2
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    23,053

    Default

    http://forums.holley.com/showthread....5941#post15941 (Effect Of Elevation Changes On Fuel & Timing)
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS TW 11R 205 heads, 11.8:1 comp, TFS R-Series intake, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 160A 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, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/2800 RPM converter, M4602G aluminum driveshaft, FRPP 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 tires.

  3. #3

    Default

    Thanks for the link Danny, useful info on there. But I know that the Target Air/Fuel Ratio would stay the same and that timing would have to be retarded a bit at lower altitude. But I still kinda would like to know at what I should set the Closed Loop Compensation & Learned Compensation Limits? Must I set it to 100 or would 50 be fine?

  4. #4
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    23,053

    Default

    Quote Originally Posted by JMZ328 View Post
    But I still kinda would like to know at what I should set the Closed Loop Compensation & Learned Compensation Limits?
    (The 2nd & 3rd sentence of that LINK answers your question.)
    Anytime the ECU has to Learn (self-tune) the Compensation Limits can remain high.

    Must I set it to 100 or would 50 be fine?
    If the Base Fuel Table has already been tuned, then 50% will be fine.
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS TW 11R 205 heads, 11.8:1 comp, TFS R-Series intake, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 160A 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, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/2800 RPM converter, M4602G aluminum driveshaft, FRPP 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 tires.

  5. #5

    Default

    Thanks Danny.

  6. #6
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    23,053

    Default

    You're welcome.
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS TW 11R 205 heads, 11.8:1 comp, TFS R-Series intake, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 160A 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, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/2800 RPM converter, M4602G aluminum driveshaft, FRPP 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 tires.

  7. #7

    Default

    You can actually answer your own question with math. Figure out the difference in air density between 6000 ft & sea level, and I think you'll find out that your Sniper will be correcting around 25%. Take some notes while you drive and see what happens. Or run a datalog at home and then at the beach and compare them.

  8. #8

    Default

    Before you go on your trip, make sure you save a good copy of your "At Home" tune somewhere. That way when you get back home all you have to do is reload that tune back in and you'll be all set.

    As for what to do for your "Going on a trip" tune. If it were me. I'd put the CL Comp table at 50% and the Learn Comp table at 20% as a starting point.

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