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Thread: Tuning VVT cams for a lopey idle

  1. #21
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    P/V clearance is not an issue in the pentastar.
    If you look hard at the tables, you will see that factory std they are at times swingin the cams as far as they will go.
    They do this for emissions, certainly not for performance. Using cam timing to get EGR etc.
    When tuning for performance, I reduce how far the cams move and get em back to where they perform best.
    Makes quite a difference, the engine note even sounds much better.
    There is not much overlap at idle, so increasing this, should maybe get you some lope.

  2. #22
    I wish someone would just post what they did for a "Ghost Cam". I'm not going to do the fuel/ignition mod to recreate it. I want to do the actual cam mod. My cam's are setup pretty good already where they are pretty potent on the street, I'm just looking to see what they did to create the lope. I understand about the lobe separation, I just don't want to create a tune with a lobe separation that will not throw the valves through the pistons...lol

  3. #23
    Senior Tuner Higgs Boson's Avatar
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    not many people do ghost cams because ghost cams are for posers.

    besides, a lopey stinky overlappy idle is an UNfortunate byproduct of a fixed grind OHV cam. yes, it lets people know you have a big cam that is useful at 6000 RPMs but in the case of a 3.6 PS it will be just as slow as before at 6000......same duration and lift, just a polluting idle.

    it's not that people aren't posting ghost cam settings, it's that hardly anyone cares. and it's not like you are going to just be able to move the cams into place for idle lope. you are going to have to retune spark, VE, idle torque/base airflow, idle corrections, etc etc.

  4. #24
    Senior Tuner mbray01's Avatar
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    X2^^^^^^^^^^

    When it comes to making these ghost cam tunes work, and work good, there is so much more than just advancing and retarding cams. Getting idle trims, airflow modeling and timing is paramount to the car being happy.

    so two things
    1 very few people do this, or want it, and

    2 those who spend tons of time making it all work, are not really going to share this knowledge for free. There are a few people who share "free write ups" about doing this, but tend to be very vague, and lack a lot of the pertinent info to make it work properly. Most of the free knowledge given is things that are already assumed, like cam advance and retard. These are the easy things. The hard parts, the parts that take hours upon hours to make the car happy, are the parts that are not shared freely. Time is money!

    Professional tuners charge for their services because of the massive amounts of time and effort we have invested in learning our trade. If we give this info out for free, we would be out of a job.

    yes it is that simple.

    If you insist on doing it yourself, and not pay someone to tune it for you, then YOU are going to have to go down the road all of us have been down. READ READ READ, RESEARCH RESEARCH RESEARCH. LOTS AND LOTS OF TRIAL AND ERROR!!!!!!!!!!!!!!!!!!!
    Michael Bray
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  5. #25
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    I have never tried to do this, but to be honest in theory it doesn't seem possible to do. Lope comes from overlap/LSA, with a single cam you cannot effect or change this, the intake and exhaust move together, its mechanically fixed. whereas in the mustang you can control intake and exhaust cams separately and change the overlap.

  6. #26
    Senior Tuner Higgs Boson's Avatar
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    Quote Originally Posted by 06300CSRT8 View Post
    I have never tried to do this, but to be honest in theory it doesn't seem possible to do. Lope comes from overlap/LSA, with a single cam you cannot effect or change this, the intake and exhaust move together, its mechanically fixed. whereas in the mustang you can control intake and exhaust cams separately and change the overlap.
    There are DOHC dodge motors, like the 3.6 pentastar. In post 4 OP clarifies that is what he is tuning.

  7. #27
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    Quote Originally Posted by Higgs Boson View Post
    There are DOHC dodge motors, like the 3.6 pentastar. In post 4 OP clarifies that is what he is tuning.
    Thanks missed that.

  8. #28
    Thanks for the information posted here.
    This may also help others that are curious on the "Ghost Cams" for there vehicles.
    And as mentioned before, yes this is the 3.6 Pentastar motor with DOHC VVT engine.

  9. #29
    But in hemi witch table controls cam?....ex or in?

  10. #30
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    Quote Originally Posted by Hemituna View Post
    P/V clearance is not an issue in the pentastar.
    If you look hard at the tables, you will see that factory std they are at times swingin the cams as far as they will go.
    They do this for emissions, certainly not for performance. Using cam timing to get EGR etc.
    When tuning for performance, I reduce how far the cams move and get em back to where they perform best.
    Makes quite a difference, the engine note even sounds much better.
    There is not much overlap at idle, so increasing this, should maybe get you some lope.
    Would you be interested in sharing with me a rough idea of what these engines like regarding valve timing? I'm going in tomorrow to dyno tune and would like to build a file in advance.

  11. #31
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    Yes, it can be done, and is easy to do.

    Lope is not caused by LSA, it is more due to overlap. Set your cams at idle, to what they are at redline. This is maximum overlap, and may be too much, so be ready to back it off some

    Expect low vaccuum and lots of unburnt fuel. Sounds cool, but serves no other purpose. Id post a vid of one I did if I could.

  12. #32
    Senior Tuner Higgs Boson's Avatar
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    Quote Originally Posted by Trguy79 View Post
    Yes, it can be done, and is easy to do.

    Lope is not caused by LSA, it is more due to overlap. Set your cams at idle, to what they are at redline. This is maximum overlap, and may be too much, so be ready to back it off some

    Expect low vaccuum and lots of unburnt fuel. Sounds cool, but serves no other purpose. Id post a vid of one I did if I could.
    It's not as easy as that, at least not on my Wrangler. The cams go back to base positions at idle and VVT doesn't do anything unless you are moving. Just something I noticed, I am not trying to ghost cam my Wrangler. The Fords and GMs have idle criteria to enable VVT, do the Chryslers? I haven't really looked.

  13. #33
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    The GPEC does (Caliber SRT4)...

    Eng->Airflow-> VVT-> (Intake Idle & Exhaust Idle)

  14. #34

  15. #35
    Senior Tuner Higgs Boson's Avatar
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    Quote Originally Posted by Trguy79 View Post
    The GPEC does (Caliber SRT4)...

    Eng->Airflow-> VVT-> (Intake Idle & Exhaust Idle)
    see post #6. unless the SRT4 comes with the 3.6 pentastar.

    but I did ask about Chrysler in general in #32 so fair enough.

  16. #36
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    The Hemi's and Pentastar are same, I have had HPt support look to see if we can change idle vvt but no luck so far.

    Sucks cos when loading it up and launching, you are stuck at base settings till it senses some speed.

    At idle, the pentastar at least has the intake cam fully retarded, but the Hemis have the cam fully advanced.

    Not so good when holding on the converter and building boost with full cam advance...they want to knock a LOT!!


    Quote Originally Posted by Higgs Boson View Post
    It's not as easy as that, at least not on my Wrangler. The cams go back to base positions at idle and VVT doesn't do anything unless you are moving. Just something I noticed, I am not trying to ghost cam my Wrangler. The Fords and GMs have idle criteria to enable VVT, do the Chryslers? I haven't really looked.
    Last edited by Hemituna; 01-05-2017 at 09:12 PM.

  17. #37
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    I know you are dealing Pentastar. Just putting the info out there in case it helped....

  18. #38
    We are kind of discussing the VVT in general as now since the HEMI and 3.6 use VVT......

  19. #39
    Quote Originally Posted by Hemituna View Post
    The Hemi's and Pentastar are same, I have had HPt support look to see if we can change idle vvt but no luck so far.

    Sucks cos when loading it up and launching, you are stuck at base settings till it senses some speed.

    At idle, the pentastar at least has the intake cam fully retarded, but the Hemis have the cam fully advanced.

    Not so good when holding on the converter and building boost with full cam advance...they want to knock a LOT!!
    I havent changed yet, but i think high baro table is the one to make changes at idle...at least the numbers i get on the scanner matches those tables.

  20. #40
    Senior Tuner Higgs Boson's Avatar
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    Quote Originally Posted by Javier Wilde View Post
    I havent changed yet, but i think high baro table is the one to make changes at idle...at least the numbers i get on the scanner matches those tables.
    Well, that would depend on Baro wouldn't it..... if you live in Colorado it should be following Low Baro.