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458 Can someone explain the stock 458 Valve operation, installing a Forza controller!

Discussion in '458 Italia/488/F8' started by s4play, Mar 29, 2020.

  1. s4play

    s4play Karting

    Oct 25, 2006
    161
    hey guys,

    So I bought a new Forza exhaust controller for my 458 Spider and was going to install it today. I pulled the rear diffuser and noticed the top of the solenoid tubes were not connected to anything.

    In stock form, the exhaust valves open in the "RACE" mode after a certain RPM, I wanted to keep it open all the time since I think it sounds great.

    This is the Forza controller I planned on installing since I want to keep the valves open:

    [​IMG]


    You can see in the red circle what I'm referring to, what are these supposed to be connected to? In my car both are just hanging there? can anyone tell me where those open hoses are supposed to go? If it's pulled why does my car still work properly with the valves opening at a certain RPM?

    [​IMG]



    This is both exhaust valves that looks properly hooked up to the solenoid:

    [​IMG]
     
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  3. 348ts92

    348ts92 Rookie

    Sep 27, 2002
    40
    St Louis, USA
    Full Name:
    Magnus Tannfelt
    I had a Forza controller on my 458 too and it is a great product.
    The third picture shows to me that the valves are connected as they should. I guess the open hose is for drainage or similar and have nothing to do with the exhaust valves.
    Since you have the diffuser of you can always check if the valves function when starting up the engine and rev it up to about 3500 rpm.
    Just connect the controller and you should be good to go...and enjoy the sound.


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  4. Corradosv

    Corradosv Karting

    Oct 17, 2016
    120
    Monaco MC
    Hi,
    the system is based on a couple (one per bank) of open/closed (no modulation) flap valves that deviate the exhaust flow in or out of the main silencer. The flap valves are operated by the pressure difference between atmosphere and engine intake vacuum working on the opposite sides of the actuator; such pressure gap between the actuator surfaces becomes an actuating force that moves the flap valve rod.
    The open hoses you ask about are the atmosphere pressure intakes, and the solenoids route (or don't) the intake vacuum on the other side of the actuator; the solenoids opening is controlled by the ECU, based on the throttle/rpm combination and the throttle/rpm opening threshold depends on the manettino position.
    The system is "fail open", which means that if you want the flaps to always be open, what you need to do is to disconnect the rubber hoses that connect the solenoids to the actuators on the exhaust side and plug them on the solenoids side (so-called "golf-tee hack" as a golf tee is normally used to plug the hoses): this way there will be no vacuum routed on one actuator side and the valve will stay always open. You can do that (I did it) accessing the actuators from under the car by just removing the rear diffuser, a 1hr job the first time, anybody can do it in like half an hour the second time.
    No CEL will light on, as there is no closed-loop check of the actuator position, and the system is ON/OFF and fully pneumatic, whereas in other systems (e.g. the new Mustang) the flaps are operated by electric motors (so they are not just open/closed, but they are modulated) that send a position feedback to the ECU.
    I personally like the valves to be always open so this is what I did on my car, thus saving the cost and the install pain of a control module.
    Whatever anyone says be confident you will have ZERO ISSUES in disconnecting and plugging the vacuum hoses on the actuators' ends.
    I hope it helps.
     
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  5. s4play

    s4play Karting

    Oct 25, 2006
    161
    thanks for the replies! Really appreciate it as we finished the install last night and took some fun videos of the BEFORE and AFTER, check it out here!




    Hope you guys enjoy the video!
     
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  6. Corradosv

    Corradosv Karting

    Oct 17, 2016
    120
    Monaco MC
    apologize: you will of course plug them on the actuators' side, but I realize it's too late and I hope you enjoy the controller!
     
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  8. FerrariCognoscenti

    FerrariCognoscenti Formula Junior

    Jan 19, 2021
    275
    I will try this. Thank you! Is there a photo showing the l rubber hoses that connect the solenoids to the actuators on the exhaust side that need to be plugged in on the solenoids side?


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  9. achaddy

    achaddy Karting

    Jun 13, 2005
    78
    Oxford, UK
    Full Name:
    Andy Chadwick
    I've just fitted one of these as I have also fitted a valved Titanium Exhaust with sports Cats so wanted to have the option of valves shut when in my neighborhood. I like some of them:rolleyes: but always open when out on the open road.
    Not sure I see the point in spending $400 on the device if you just want the valves always open. Just pull the vacuum tubes and be done.
     
  10. FerrariCognoscenti

    FerrariCognoscenti Formula Junior

    Jan 19, 2021
    275
    Do you have any photos of the vacuum tubes to pull?


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  11. Corradosv

    Corradosv Karting

    Oct 17, 2016
    120
    Monaco MC
    Hi, apologize for my late reply. These are the hoses to pull AND PLUG. Capping the actuators' opened nozzles would be good, but not needed to work. Note that minutes ago I posted a wrong picture and immediately tried to cancel it; I hope I did it, if not THIS is the right one! I hope it helps.
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  13. FerrariCognoscenti

    FerrariCognoscenti Formula Junior

    Jan 19, 2021
    275
    Thank you!

    When I pull those hoses, do I plug the hoses somehow? Or do I plug the receptacle the hoses were originally plugged into? What should I use to physically plug them?
    Thanks a lot


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  14. Corradosv

    Corradosv Karting

    Oct 17, 2016
    120
    Monaco MC
    What you MUST do is plugging the hoses, as they are under vacuum, and they would be sucking un-metered air if you don't do that. They call it the "golf-tee hack" because a golf-tee is what most use, I used a couple of bolts and a couple of zip-ties for extra caution.
    As for the receptacle (it's a sort-of-mushroom nozzle, or dog's d**k if you want), capping it won't hurt, just to avoid crap and moist go into it, but it won't be under vacuum, so it won't be sucking by itself. I didn't do that because it's hard to work on that with the rear bumper on, and I didn't feel to take it off.
    I hope it helps.
     
  15. FerrariCognoscenti

    FerrariCognoscenti Formula Junior

    Jan 19, 2021
    275
  16. FerrariCognoscenti

    FerrariCognoscenti Formula Junior

    Jan 19, 2021
    275
    Thank you. I am wondering if maybe just capping the receptacle with electrical tape or something would be good.


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  17. SVCalifornia

    SVCalifornia Formula 3

    Mar 28, 2011
    2,139
    Silicon Valley
    Full Name:
    Keith
    Great idea! Something that keeps dirt, dust and water out... or any contamination! A hard cap would be perfect!

    SV
     
  18. FerrariCognoscenti

    FerrariCognoscenti Formula Junior

    Jan 19, 2021
    275
    Thanks! Do you plug one hose or both?


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  19. Corradosv

    Corradosv Karting

    Oct 17, 2016
    120
    Monaco MC

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