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Boost pressure?

Discussion in 'VCDS (formerly VAG-COM) forum' started by Defratos, Apr 3, 2005.

  1. Defratos
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    Defratos You’re Dethpicable!!

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    Hi fellas, I've got VAG com, and me and my bro were workin around on it the other day, but I was just wondering, is there a way of finding out how much boost pressure I am running? Currently everytime I plug my bro's car in (VW V6 4motion) a "Turbo" button appears, but when I plug my car in there is no "Turbo" button, any ideas? even a web site to help understand VAG com better?
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  2. PaulRS3
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    PaulRS3 Active Member

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    turbo button has nothing to do with "turbo" at all.

    its a faster logging speed for certain complient ecus.

    if you wanna log boost you need to be logging measuring block 115
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  3. Defratos
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    Defratos You’re Dethpicable!!

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    ah I c, Ok cool I'll try it out, thanks mate
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  4. Stevieuk2003
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    Stevieuk2003 New Member

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    Should the 409.1 software and ebay lead allow me to log boost pressure on my S4?
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  5. Uwe@Ross-Tech
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    Uwe@Ross-Tech Member

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    No. Boost is up in measuring block 115. The shareware limits you to the first 25.

    -Uwe-
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  6. Stevieuk2003
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    Stevieuk2003 New Member

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    Apologies if you're not the person to ask on this Uwe but I've got the cheap ebay lead and 409.1 software at the moment, but want to buy the full USB interface and latest legal version. The main thing i want to do is check load boost pressure on my 2000MY S4 as i suspect the wastegate actuator valve (N75?) is suspect and the car is still under 12 months Audi dealer warranty as i bought it last month from them. I am also concerned that my oil temp rises to over 150 deg C quite often :ohmy: and dealer has checked all is well but i would like to log it for myself (although i can't find a measurement block that shows this at present)

    I have seen reports of cost being around £100 but the Ilexa website asks for £219. Also if i use VAG-COM does it leave a trace that the dealer can tell someone has been connected and will this invalidate my Audi warranty?

    Cheers in advance
    Steve
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  7. Uwe@Ross-Tech
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    Uwe@Ross-Tech Member

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    If you don't change any settings, the dealer will never know you've used VAG-COM. Furthermore, there's a reason why all cars (regardless of manufacturer) have the same kind of diagnostic socket -- because the USA and EU have mandated that independent shops should be able to do some level of diagnostics without having to buy the car manufacturer's specialized tools. Therefore I don't think a manufacturer can void your warranty for plugging a tool into the completely standardized socket in the car.

    You can definitely log boost with VAG-COM. I don't know off the top of my head whether oil temperature is available via a scan tool on that car. If it is, it will most likely be found in the instrument cluster as opposed to the engine. Tip: Take a picture of your oil temperature display when it's at a temperature above 150C and give that to the dealer.

    As far as pricing: A VAG-COM license with KEY-USB interface sells for $249 US. That's ~£125 at the moment. This does not include shipping (under £20) or taxes charged by your Queen..;-)

    -Uwe-
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  8. Stevieuk2003
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    Stevieuk2003 New Member

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    Thanks Uwe. But who should i buy VAG-COM from in the UK?

    Thanks for the advice. Great minds think alike! I have already taken several pictures showing the high oil temp and have drafted up an an email ready to send them to Audi
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  9. bearthebruce
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    bearthebruce Ross-Tech, LLC

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    We have several distributors in the UK. Please see this web page:
    Distibutors
    Most of them have stock of all interface cables.
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  10. Stevieuk2003
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    Stevieuk2003 New Member

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    Hi again,
    I've got official VagCom now (direct from US) and have done an initial run and looged the results. I have some questions as to what sensible readings and general behaviour should be for:-

    a) Boost pressure (generally peaking at 1700 mB but seen occasional higher reading of 2000 Bar)

    b) N75 valve (How often and when should it operate (boost high / throttle closing?),how quickly, by how much)

    c) Engine load (I have logged well over 100% many times (165% peak seen)

    Also whats the best way to check performance? I thought if i logged vehicle speed only i would get a faster time stamp so more accurate 0-60?

    Also any other pointers as to which key paramaters and behaviour i should examine in particular?

    Many thanks in advance

    PS I guess someone is going to,quite rightly, to tell me to buy the factory repair manual. Dare i ask how much and who from? OR should i buy specific sections for electronics from Erwin or whatever it is called?
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  11. Uwe@Ross-Tech
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    Uwe@Ross-Tech Member

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    Boost Pressure: Is this engine stock or chipped/remapped?

    N75 Valve is driven by a "Duty Cycle" signal which can be monitored.

    I believe engine load is based on a calucluation of how much air is going into your cylinders vs their displacement. On a turbocharged engine, it is normal for this to be over 100% when you're on boost.

    -Uwe-
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  12. Stevieuk2003
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    Stevieuk2003 New Member

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    Uwe,
    Its completely stock S4, but behaving stange sometimes when under moderate load at low speed. This seems to me to upset it even if i try to 'clear it a little' by accelerating hard. Seems to have loads of lag some days and none on others. Looking for the reason why really.

    I have already monitored N75 valve and logged its behaviour but looking for some input as to what is normal, what isn't.
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  13. Uwe@Ross-Tech
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    Uwe@Ross-Tech Member

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