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  1. #31
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    whats the afr at wot. Controller may be killing the solenoid as safety. Have you calibrated the o2? Are you logging it at all?

  2. #32
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    Quote Originally Posted by DBL.DWN View Post
    whats the afr at wot. Controller may be killing the solenoid as safety. Have you calibrated the o2? Are you logging it at all?
    Afr is at 11.2-11.7 it’s all logged. Solenoid safety kicks in when boost is present and afr is over 12. That is evident on gauge when boost is being or attempting to be cut.


    Sent from my iPhone using Tapatalk
    2005 Silver Magnum R/T-
    Forged 5.7 based 392 built by Arrington
    Rear Mount t76 turbo
    3.06 Getrag, Tranzformer (I love that box)
    1st run on new build
    11.8@117 with only 4.5 psi and a 1.8 60'

  3. #33
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    However my 1st time to track with build I ran an 11.8 @ 117 with 4 psi.
    Running 275/45/20 stock pzeros and a 1.9 60’
    I thought it is a nice base. Not to get a better driveshaft then turn it up a bit.


    Sent from my iPhone using Tapatalk
    2005 Silver Magnum R/T-
    Forged 5.7 based 392 built by Arrington
    Rear Mount t76 turbo
    3.06 Getrag, Tranzformer (I love that box)
    1st run on new build
    11.8@117 with only 4.5 psi and a 1.8 60'

  4. #34
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    Wichita, Ks.
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    Does the controller show/log the pressure that is being applied to the WG? The first thing would be to make sure the controller is applying the correct pressure to WG. If the controller is applying the correct pressure, then you can move on to other diagnosis.

    That is really good time btw, with 4psi and a pedestrian 60'.

    10.33 @ 134 4150# on MH275/17's
    11.55 @ 126 on 275/20 Nittos

  5. #35
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    All of my o2 sensors are upstream turbo.
    Any issue with this?


    Sent from my iPhone using Tapatalk
    2005 Silver Magnum R/T-
    Forged 5.7 based 392 built by Arrington
    Rear Mount t76 turbo
    3.06 Getrag, Tranzformer (I love that box)
    1st run on new build
    11.8@117 with only 4.5 psi and a 1.8 60'

  6. #36
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    Quote Originally Posted by adamwe4 View Post
    All of my o2 sensors are upstream turbo.
    Any issue with this?


    Sent from my iPhone using Tapatalk
    Upstream of the turbos?

    Are they pressure compensated o2s (extremely expensive)?

  7. #37
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    Nov 2014
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    What is considered upstream? Between the header and the turbo? Or after the turbo?


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  8. #38
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    Quote Originally Posted by BradJo9 View Post
    What is considered upstream? Between the header and the turbo? Or after the turbo?


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    Upstream of turbos would be before them....between the header and the turbo.

    I can't imagine the back pressure created by the turbos would be enough the need pressure adjusted sensors, unless a turbo seized up. I might be wrong though, it's happened once or twice before lol

    Sent from my XT1650 using Tapatalk

  9. #39
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    Oct 2006
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    So tuning is going well and all sensors seem to be operating fine. Just heard there might be an issue. Certainly don’t want to create one . Car put down 550hp and 630 tq on a mustang dyno. At 7 psi.


    Sent from my iPhone using Tapatalk
    2005 Silver Magnum R/T-
    Forged 5.7 based 392 built by Arrington
    Rear Mount t76 turbo
    3.06 Getrag, Tranzformer (I love that box)
    1st run on new build
    11.8@117 with only 4.5 psi and a 1.8 60'

  10. #40
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    Aug 2008
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    Wichita, Ks.
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    narrow bands for factory setup can be before turbos, but it might burn them out after a while. I went 3 years before mine went tits up. You shouldn't be in PT much under boost and at WOT the narrow bands are not used. For a wide band, definitely after the turbo.

    10.33 @ 134 4150# on MH275/17's
    11.55 @ 126 on 275/20 Nittos

  11. #41
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    Quote Originally Posted by punisher69 View Post

    I can't imagine the back pressure created by the turbos would be enough the need pressure adjusted sensors, unless a turbo seized up. I might be wrong though, it's happened once or twice before lol

    Sent from my XT1650 using Tapatalk
    On an efficient system, you will have 1:1 backpressure. Most will probably see 2:1. That means in a 1:1 setup, if you have 7psi intake manifold pressure, you will have 7psi in the exhaust between the heads and the turbos. 2:1, will see 7psi intake, 14psi exhaust.

  12. #42
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    Quote Originally Posted by DBL.DWN View Post
    On an efficient system, you will have 1:1 backpressure. Most will probably see 2:1. That means in a 1:1 setup, if you have 7psi intake manifold pressure, you will have 7psi in the exhaust between the heads and the turbos. 2:1, will see 7psi intake, 14psi exhaust.
    So, if I'm reading that correctly, to make 7psi of boost, the exhaust will be at 14psi?

    I have ZERO experience building a turbo engine and find this to be extremely interesting.

    Sent from my XT1650 using Tapatalk
    Last edited by punisher69; 05-13-2018 at 10:55 PM.

  13. #43
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    Quote Originally Posted by punisher69 View Post
    So, if I'm reading that correctly, to make 7psi of boost, the exhaust will be at 14psi?

    I have ZERO experience building a turbo engine and find this to be extremely interesting.

    Sent from my XT1650 using Tapatalk
    Yes, the exhaust between the heads and turbo (upstream exhaust) will be at or more the intake pressure. Ideally you'll have 1 backpressure: 1 manifold pressure. But most will be up to 2 backpresure : 1 manifold pressure.
    This is why you should put your widebands post turbo (downstream exhaust).
    Thanks punisher69 thanked for this post

  14. #44
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    2:1 means you are pressing the limits of the turbo. If you are turbo limited by class, then yes this is probably where you will be. But if your not power adder limited by class, then a well designed setup shouldn't be over 1.5:1 IMO. However, it doesn't change the fact that that the reading is effected by pressure, but with wide band you really want it to read correctly everywhere.

    10.33 @ 134 4150# on MH275/17's
    11.55 @ 126 on 275/20 Nittos

  15. #45
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    Sep 2009
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    I had run on throttle giving the waste gate a strong vacume will help. I ran a line directly from the intake manifold. As well if you put the waste gate between the throttle body and the intercooler. these fixed my "run on throttle"



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