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Thread: LS3 with Terminator system tune help.

  1. #1

    Default LS3 with Terminator system tune help.

    I have a LS376/515 crate engine in a '78 TA with T56 and the Holley Terminator EFI system. I'm new to tuning EFI systems and have been reading and watching as many "how to's" as I can find online. I have this system very driveable now but, it still goes very rich when accelerating. In carb terms, the "tip-in" seems too much and the AFR will drop to the 9-10 range for 1 sec or so and then start to clean up.
    I'm using a tune that comes with the system named 480HP LS2 as the base tune and have been "Learning" from there after I input the correct displacement. I haven't changed that timing table at all, but the base fuel and Target AFR table have been changed slightly in the idle and cruise area. In high load and WOT areas the AFR is 12.7. I have also reduced the ramp in the fuel modifier AE vs TPS%, so that it's not adding anything until 70% and that seemed to help.

    Cam specs for this engine: 226°/236°, .525"/.525", 2.165 in /1.590 ex. Engine is rated at 533 HP/477 TQ and I figure I'm getting around 300 HP/320 TQ. It runs slightly behind my 2002 Firehawk in 4th from 70 - 110 MPH and my Firehawk put down 310 RWHP a couple years ago on a chassis dyno.

    So long background. Any tips to finding why it goes rich when rolling into the throttle? I'm planning on getting the car to a chassis dyno to have it tuned. In the meantime, are there any tips from people here? Where to go look?

  2. #2
    Join Date
    Dec 2009
    Location
    Connecticut
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    23,769

    Default

    The AE vs TPS RoC Blanking value is for light tip-in throttle, and the AE vs TPS Rate of Change is for regular Acceleration Enrichment.
    http://forums.holley.com/showthread....9444#post29444 (EFI Acceleration Enrichment In Carburetion Terms)

    Acceleration Enrichment can't be tuned until the Base Fuel Table is well tuned.
    If you have a momentary lean spike, on light throttle acceleration, check
    your AE vs TPS/MAP RoC Blanking values (in Fuel Modifiers/Fuel Control):
    If they're 15 & 7, those are the old values from the V1 ECU firmware.
    Change the AE vs TPS RoC Blanking value to 4-6.
    Change the AE vs MAP RoC Blanking value to 5-7.
    Some users reported the need for an even lower TPS RoC Blanking value.
    Ensure there's no TPS/MAP RoC signal activity at idle, due to noise/kPa fluctuation.
    http://forums.holley.com/showthread....1379#post61379 (AE Tuning Information)
    http://forums.holley.com/showthread....7925#post47925 (Additional AE Tuning Information For Stubborn Engines)
    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, 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, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/3000 RPM converter, 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 MT tires.

  3. #3

    Default

    Thank you Danny. I did set the AE vs TPS RoC Blanking value from 15 to 7, based upon the below I could go down even further. Also, I'm using V4. To tune the Base Fuel Table better, should all AE variables be super limited?

  4. #4
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    23,769

    Default

    Tuning the Base Fuel Table and blending the Fuel Graph smooth: Read the 4th & 5th paragraphs: http://forums.holley.com/showthread....2523#post62523 (Holley EFI Tuning Tips & Information)
    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, 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, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/3000 RPM converter, 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 MT tires.

  5. #5

    Default

    You might want to check your timing. All of my research showed that the LS3 likes significantly less WOT timing than other LS engines due to the rectangular port heads. I have a good tune on my LS3 (BTR Stage 2 cam) that I came up with after some fine-tuning from a well known remoter tuner. I'd be happy to share it with you. MSG me if you want it.

  6. #6

    Default

    PM sent, I have a similar setup I’m trying to get going.

  7. #7

    Default

    I went over several setup related items, one of the checks was to see if the my TBI body was progressive or synchronized. Holley says this system is synchronized, but the linkage from the main barrels to the secondaries has a slot allowing an estimated 30% movement on the primary side before the secondary side starts to open. I check the "progressive" box in the engine Config File and then input 35% and that cleared a lot of issue up. Now when I hit the throttle the engine just revs up, in 1st gear it starts spinning the tires at 3K RPM from a roll and the power just keeps coming hard through 6K. My tune is a basic tune from Holley with a little touch up from me and what I have read and learned.

  8. #8

    Default

    Quote Originally Posted by SS8UUP View Post
    PM sent, I have a similar setup I’m trying to get going.
    I didn't see any PMs. Try my stuff from my last post and see if that helps. Also, I'm using the "LS2 480HP" tune from the GM/Custom Cals/Folder as the base for my tune.

  9. #9

    Default

    Maybe this is something I'll have to test on my own. Is it better to bend the linkage so that there's less than 5% primary movement before the secondaries move and un-check the progressive check box again? Would that yield better performance?

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