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Thread: TCC Apply Speed Ratio

  1. #1
    Advanced Tuner metroplex's Avatar
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    TCC Apply Speed Ratio

    I've noticed some oddities in how Ford sets these at the factory.
    It's my understanding that this table has the Speed Ratio (Engine RPM to Input Shaft Ratio), but doesn't explain how this ratio is used.

    I noticed my Explorer XLT (6F55) has it set to all 0's, as does the Police Interceptor Utility 3.7L

    But on the Explorer Sport, SHO, F-150 6R80, and Mustang 6R80s, there are values here ranging from 0.60 at the low torque up to 0.80 at the high torque rows.

    Does it mean that if you exceed this speed ratio, then the TCC will lock up? I'm just a bit confused as to how this table is used. My goal is to set it up so the torque converter locks up as early/often as possible to reduce overheating of the ATF and to improve fuel economy and power transfer.

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    Examples:

    .90 = Input shaft has to be at 90%+ of the engine rpm for a lock to occur. If engine rpm is at 3000, then lock would occur when input shaft is at or > 2700 rpm. This would only be a small rpm drop upon lock (300rpm). This definitely creates heat by delaying lockup but makes it easy on the converter clutch.

    .50 = Input shaft has to be a 50%+ of the engine rpm for a lock to occur. If engine rpm is at 3000, then lock would occur when input shaft is at or > 1500rpm. This would be a large rpm drop upon lock (1500rpm). This is probably what you want but harder on the clutch especially at higher torque. This is why stock is .8 for higher torque rows.

    You could find a happy medium and keep it progressive like stock...

    Get it?

    EDIT: Keep in mind that an apply has to be commanded in the first place for these values to even be active. I have mine go from .75 to .90 because I have a 4C and just hated how it rode the converter clutch at low rpms due to the high rpm difference. I may change it though and simply command a FASTER lockup rate to compensate....

    If you do some testing on the faster lockup rate please let me know the changes you make for it to be faster. I tried doubling the values and didn't notice a difference (might be because I have high speed ratio (numerically) - so it was already fast). Murfie said that lower values were faster but that doesn't make sense to me.. Speed ratio got rid of the converter slip during lockup but think I want to reduce heat and lock up earlier but faster as well now too.. Overall I am very pleased with my trans settings but there is always more room to tweak
    Last edited by blackbolt22; 06-05-2019 at 11:10 PM.
    2014 Mustang GT Premium. 4C & Borla Exhaust
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  3. #3
    Advanced Tuner metroplex's Avatar
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    So what happens with the speed ratio rows set to 0.00? That's the factory setting on my Explorer XLT and the Police Interceptors. Does this mean lockup whenever it is commanded?

  4. #4
    Quote Originally Posted by blackbolt22 View Post
    Examples:

    .90 = Input shaft has to be at 90%+ of the engine rpm for a lock to occur. If engine rpm is at 3000, then lock would occur when input shaft is at or > 2700 rpm. This would only be a small rpm drop upon lock (300rpm). This definitely creates heat by delaying lockup but makes it easy on the converter clutch.

    .50 = Input shaft has to be a 50%+ of the engine rpm for a lock to occur. If engine rpm is at 3000, then lock would occur when input shaft is at or > 1500rpm. This would be a large rpm drop upon lock (1500rpm). This is probably what you want but harder on the clutch especially at higher torque. This is why stock is .8 for higher torque rows.

    You could find a happy medium and keep it progressive like stock...

    Get it?

    EDIT: Keep in mind that an apply has to be commanded in the first place for these values to even be active. I have mine go from .75 to .90 because I have a 4C and just hated how it rode the converter clutch at low rpms due to the high rpm difference. I may change it though and simply command a FASTER lockup rate to compensate....

    If you do some testing on the faster lockup rate please let me know the changes you make for it to be faster. I tried doubling the values and didn't notice a difference (might be because I have high speed ratio (numerically) - so it was already fast). Murfie said that lower values were faster but that doesn't make sense to me.. Speed ratio got rid of the converter slip during lockup but think I want to reduce heat and lock up earlier but faster as well now too.. Overall I am very pleased with my trans settings but there is always more room to tweak
    On my 6R140 I cut the lockup rate tables by about half and lockup was much more aggressive. Another way i increased the lockup speed was increasing the TCC gain from 0.12 to 0.15. Now it locks up very quick, probably too aggressive for most peoples taste.

  5. #5
    Advanced Tuner metroplex's Avatar
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    What did you use for speed ratio values?

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    Quote Originally Posted by metroplex View Post
    So what happens with the speed ratio rows set to 0.00? That's the factory setting on my Explorer XLT and the Police Interceptors. Does this mean lockup whenever it is commanded?
    Right I would think as soon as it's commanded it locks so it's not even considered in the equation.
    2014 Mustang GT Premium. 4C & Borla Exhaust
    "Don't fix it if it ain't broken"

  7. #7
    Advanced Tuner metroplex's Avatar
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    Quote Originally Posted by blackbolt22 View Post
    Right I would think as soon as it's commanded it locks so it's not even considered in the equation.
    I looked at my stock Fusion Sport tune and the speed ratio cells are all 0, same as the stock Explorer XLT, and Police Interceptor Utility.
    The Explorer Sport and SHO both had various values, and I ran all 0.60 for the SHO.

    Stock TCC Gains were around 0.240-0.247

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    Quote Originally Posted by CKrueg View Post
    On my 6R140 I cut the lockup rate tables by about half and lockup was much more aggressive. Another way i increased the lockup speed was increasing the TCC gain from 0.12 to 0.15. Now it locks up very quick, probably too aggressive for most peoples taste.
    OK so Murfie was right. What threw me off was someone posted in here they got their converter to lockup quicker by raising the values way higher... (you also posted in that thread) and higher values always makes more sense for faster/harder lol.

    Thanks for clearing it up and the other tip!! If weather permits I will tweak mine this weekend.

    Quote Originally Posted by metroplex View Post
    I looked at my stock Fusion Sport tune and the speed ratio cells are all 0, same as the stock Explorer XLT, and Police Interceptor Utility.
    The Explorer Sport and SHO both had various values, and I ran all 0.60 for the SHO.

    Stock TCC Gains were around 0.240-0.247
    Stock gain for me is .196 lol.
    2014 Mustang GT Premium. 4C & Borla Exhaust
    "Don't fix it if it ain't broken"

  9. #9
    Advanced Tuner metroplex's Avatar
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    I kept the stock 0.00 speed ratio cells, and adjusted the TCC Unlock/Lock tables so the TCC is commanded to lock as soon as it is shifted into a higher gear.