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T-Vis Activator Wire?

Discussion in 'Electronics' started by rye, Jul 10, 2007.

  1. rye

    rye Well-Known Member Donated!

  2. Youds

    Youds Well-Known Member

    o god why/how did u find that site..... cool idea though
     
  3. underscore

    underscore Well-Known Member

    "but takes some work to get it to look right"

    "Installation time: 30 minutes to 8 hours"

    "At this point, I recommend testing the light out before continuing with the install"

    I laugh at these people. Cool idea though Rye. You'll nedd to install V-TAKKKKKKKKKKKK first ;)
     
  4. rye

    rye Well-Known Member Donated!

    hah well our tvis works on the same principle...I already have the LED mounted and grounded it works as soon as 12v's is applied...I figured there had to be 12v' going to somewhere on the tvis to get it to open it's 2nd flaps....
     
  5. rye

    rye Well-Known Member Donated!

    that is pretty funny hahah
     
  6. CrazyAchmed

    CrazyAchmed Well-Known Member Donated!

    Isn't the T-VIS vaccum controlled?
     
  7. rye

    rye Well-Known Member Donated!

    I didn't think so....
     
  8. rye

    rye Well-Known Member Donated!

    but even if it is...there's gotta be some wire telling the computer somewhere that it's open....
     
  9. underscore

    underscore Well-Known Member

    I think it's just vacuum...no electronics at all.

    *waits for Mafix*
     
  10. MITT4G

    MITT4G Well-Known Member

    It is a vaccum system-
    But rye is right there has to be something that tells the ECU whats going on....
     
  11. underscore

    underscore Well-Known Member

    couldn't you tap into the line with a vacuum guage as a TVIS meter?
     
  12. Mafix

    Mafix Owner Staff Member Administrator Donated!

    eh hem...
    tvis uses an electronically controlled vacuum actuator.
     
  13. rye

    rye Well-Known Member Donated!

    and where's the wire that get's the voltage for it? :D
     
  14. XR Pilot

    XR Pilot Well-Known Member

    The TVIS actuator is switched by ground, not 12v. It has a constant 12v supply from the EFI relay, and the computer switches the ground to it. Easiest way to do it would be to give the LED a switched 12v source, then ground it to the TVIS wire at the ECU. I can't see this causing any problems. I believe there is a wiring diagram for the ECU pinouts somewhere on this site, otherwise if you need me to I can give you the wire location and colour :) I know where it is and how it works because we played with it on the dyno. It does work, and toyota got it pretty spot on too :D
     
  15. rye

    rye Well-Known Member Donated!

    So you think I can just splice the ground of the LED into the wire that comes out of the ECU marked "T-Vis"?
     
  16. XR Pilot

    XR Pilot Well-Known Member

    Well, they way I would do it is as follows:

    12v+-----/\/\/\/\/\------LED-------TVIS-ON-ECU

    Hope that makes sense, with /\/\/\/\ representing a resistor to drop the current to the led. Don't know if that article mentioned anything about needing a resistor (didn't read the whole thing) but unless you have a led specifically for 12v, they need a resistor to limit the current otherwise they become a SED (smoke emitting diode :lol:).

    I can't see any problem with this, but I claim no responsibility :p Shouldn't be an issue though because the computer switches 12v to earth on that channel anyway, and your only adding an extra <20ma draw to it.
     
  17. XR Pilot

    XR Pilot Well-Known Member

    Oh and just to clear up a bit of confusion in this thread, the TVIS is an electronically controlled vacuum actuator. Going from memory (from about 12 months ago ;)) it stores the vacuum from the engine in a little black canister (that has a one way valve inline, to hold the vacuum even under wide open throttle or with the engine off). The 2 wire solenoid that controls the system is turned off until 4300rpm, and whilst off it allows the vacuum to pass through to the vacuum actuator keeping the butterflies shut. Over 4300rpm, the computer energises the solenoid and bleeds off all vacuum to the actuator, at which point the spring-loaded butterfly valves in the manifold spring open, giving that happy feeling those of us without boost love :)

    So, if for instance you wanted to leave the butterflies permanently open you must cut the wire to the ECU and earth the non-ecu side of the wire to the car body or a ground wire, or alternatively disconnect the vacuum actuator from the manifold. Waste of time though, you loose power down low and gain nothing up high, trust me. Just thought I would add it before anyone asks :)

    EDIT: The butterfly valve and solenoid is located under the inlet plenum (shiny thing with TVIS written on it :p) in between cylinders 2 and 3.
     
  18. underscore

    underscore Well-Known Member

    LED's don't usually smoke when they burn out....just what kind are you using ;)

    I love how there are people out there though who would tihnk that by disabling a system Toyota spent a lot of time designing they will get more power out of a stock engine. It wouldn't be there if it lost you power ;).

    quick TVIS question though: my friend with the 1991 MR2 thinks that he has to disable his TVIS to run more boost. which I tihnk would be bad because that would just kill your low end ever more with boost lag and all.
     
  19. rye

    rye Well-Known Member Donated!

    I think he was just stating that so anyone that wanted to do it wouldn't....

    And yes, I realize that I need to use a resistor for an LED on a 12v system....I'm not that slow....hah
     
  20. CrazyAchmed

    CrazyAchmed Well-Known Member Donated!

    If I'm thinking right, the TVIS always opened, or just straight removed on a boosted car is going to let more air into the cylinders which wouldn't really create more boost or create turbo lag. But it would remove some restriction from the intake. I would think that it would actually decrease turbo lag just because the air has free roam of all the intake runners instead of half of them being closed.

    And Turbo motors have no low end(unless the turbo spools low). Its either boost or nuthin.
     

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