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is this true?? and is it worth it?

Discussion in 'A4/S4 forum(B5 Chassis)' started by ALPINE, Jun 16, 2008.

  1. ALPINE
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    ALPINE Yes its diesel, now cry u lost

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    i was reading around the interweb for possable suggestions to my STILL ever looming boost gremlin. i came across this. makes sense what there saying but what do you lot recon?


    CRANKED WASTEGATE:

    The nice thing about this mod is that it’s free power. However, there are atleast two things you SHOULD have done to not worry about anything bad happening…this write-up IS to get you lots of power efficiently right? Anywho, the wastegate is a small flapper valve inside the exhaust side of the turbo that opens to allow exhaust gases to go around the turbine, and thus keeps the turbo from spooling up anymore. The way it works is you have an actuator with a vac nipple and an actuator rod. As you build boost, the charged air goes through the line into the actuator, and pushes on a piston inside, that then pushes the rod. The rod is attached to the flapper, so when the rod moves, the flapper opens. To “crank the wg,” you move the 2 nuts downward to pull the rod away from the actuator. This way, the flapper stays closed longer, thus giving you quicker spool, a higher boost spike, and more boost at redline. You’ll need a 10mm open end wrench for this. Get around to the passenger side of the engine bay, and look down behind the head. You’ll see the rod. First, turn the bottom nut down (clockwise) say 5 full turns. Next, tighten the top nut the same way. Once both are tight, you’re ready to go. Go drive the car and watch your boost levels, and if you feel safe, don’t tighten anymore. If you feel like doing as much as possible, turn the bottom nut until you have about 1.5-2 full turns LEFT and stop there. If you go too far, you’ll completely shut the flapper and not have any boost control.
    #1
  2. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator

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    what exactly is your boost problem?

    sounds like they're suggesting increasing the preload on the actuator, and that can produce boost spiking and ecu faults if not done carefully. I certainly wouldnt be doing that to an engine thats already got problems
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  3. ALPINE
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    ALPINE Yes its diesel, now cry u lost

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    my boost problem being... inconsistency. (hope thats the spelling)
    i have owned many turboed cars and this 1 is the most female of them all!! (no offence ladys) 1 day it will run at 5psi all day long. next day it will run at 7psi (as it should) most days its running 10ish (which is a bonus) the past few days its been there when it want to be at about5-6 psi.

    i have checked the following...

    hoses :- all good
    turbo:- its been taken off and had a visual check, all seems well and not oily
    n75f valve. has been binned and replaced with a J valve. (this did sort the problem for a week or two)
    wireing, all been checked, all is well.
    car has been serviced, new oil, new filters, even new water!! lol (coil packs are quite new)
    dump valve has been taken off... cleaned.. re-lubed and put back on.

    im lost now dont know what else to look at??
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  4. Lee Goodall
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    Lee Goodall ..got my head together!

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    You tried using VAG-COM or a similar VAG checker? You still on the standard map? Shouldn't be reaching 10 PSI with a standard map?!
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  5. ALPINE
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    ALPINE Yes its diesel, now cry u lost

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    yep im all standerd appart from the forge re-circ, air filter, n75j, and a few slicone hoses.

    i have had it plugged into vag-com for a dianostics and it told me it had a intermitent fault on the n75. appart from that (as far as i know) its standerd. it does beat my mates 05 audi a3 1.8t and sits on scoobis bumpers. (on a private road of corse) im thinking my DV is **** tbh. i would love a re-map too! just a little expensive for our budget tho. :sadlike:
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  6. Lee Goodall
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    Lee Goodall ..got my head together!

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    How are you sitting on Imprezza bumpers at 10 PSI?.. do you drive Kamikazestyle to keep up? lol

    Suppose you might see 10 PSI with the N75J then.. just a shame it's not all the time!

    Have you checked your turbo actuator?
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  7. Lee Goodall
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    Lee Goodall ..got my head together!

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    Have you plugged VAG-COM in since the new N75J?
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  8. ALPINE
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    ALPINE Yes its diesel, now cry u lost

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    no mate i have not. i havent got a lead unfortunatly. the person that did plug me in is no longer about this area.
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  9. Oranoco
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    Oranoco Well-Known Member

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    It sounds like they are advising adjusting the actuators preload. Once the preload has been set it really should be left alone.

    Is your actuator actualy operating as it should as they do go soggy after a while. Reploacement is a better option than trying to adjust the preload to compensate
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  10. Lee Goodall
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    Lee Goodall ..got my head together!

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    Maybe the fault is still there? I'd try getting/borrowing a lead and testing it again if possible.. sounds like actuator or boost control valve (N75J) to me but I'm no expert.
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  11. jcb
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    jcb Active Member

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    cranking your wastegate is not a good idea, any more than buying a manual boost controller and upping the boost is.
    you will spike and run lean if you are lucky, if you are not you will burn or drop a valve and smoke the engine.

    your car will think it is running at 9psi and you will be running at whatever you decide to crank it up to, no extra fuel, no map to deal with the extra boost.

    you need to get your car on VAGCom and check requested vs actual boost and any other associated pressures.
    if your n75 has faults change it
    are you running a dump or a recirc valve?
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  12. AUDI TURBO
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    AUDI TURBO Member

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    completely agree with jcb. you cant just adjust one type of the engine boost in this case without the air and fuel to make it work. i learnt that with my mbc when i made my entire turbo and exhaust manifold glow orange!!!!!!!!!! lack of oil, fuel, air!!!!!!!
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  13. ALPINE
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    ALPINE Yes its diesel, now cry u lost

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    im running a re-circ, and i have changed my n75 valve due to the fault showing up. i went for the n75J insted of a F. just come back in from mates house and the car is boosting to 10psi spiking to 12. yesterday it was running 5 psi!!! i have not touched a thing!! lol

    as for the cranked waistegate thing, i didnt think it was good as i have heard none of you talk about it.

    when servicing my DV i could compress the spring with my fingers. should it have more tention than that? and could that be my prob??
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  14. jcb
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    jcb Active Member

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    J valves can cause boosting issues, try a standard one and elimnate that as the cause
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  15. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator

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    yup was about to say exactly that the J valves can be funny.

    Defo dont go near the wastegate now that you've explained the problem, vagcom leads are pennies on ebay so get yourself one ordered.

    Not sure on the dumpvalve spring, but an S3 dump valve is about 20quid new from audi so its probably worth changing it anyway just to eliminate it.
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  16. ALPINE
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    ALPINE Yes its diesel, now cry u lost

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    i been playing today.... i have orderd a vag-com lead... i have also tryed my m8s F valve and it makes no difference so it aint the n75. orderd a new spring from FORGE so we will see what happens there.

    at least there is 2 things eliminated, lead and j valve is ok :)
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  17. hiltoa
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    hiltoa VAG erfahren

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    Have you checked the wiring to the N75, and the hoses going to and from it - could be issues with these, especially given the intermittent nature of the fault, and the fact you have been moving stuff around in this area...
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  18. AUDI TURBO
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    AUDI TURBO Member

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    I tryed the new audi dump valve and thought it was poo!!!!!!!! i got the forge one and what a difference. much better but £100.00...............
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  19. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator

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    how exactly can it be poo?

    its sole purpose is to stop the compressor stalling by allowing boosted charge somewhere to go when the throttle closes

    as long as its working and not leaking then i cant see what the issue is.

    the only possible reason i can see for changing the stock one for something else is a) you want a chavvy atmospheric valve that munts the engines fuel mix and afm readings or b) your running a lot of boost and the stock valve cant cope, but the 710N replacements are perfect here

    there are a lot of companies out there that will happily take your money for products with little or no benefit to you other than lightening your wallet, and unless you've a seriously mental engine with a lot of power the dump valve is a perfect example of this
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  20. AUDI TURBO
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    AUDI TURBO Member

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    Just saying that i didnt like it but i was running a remapped ecu. all i can say is satndard dump valve for whatever reason car felt sluggish. got a forge 007 and woohoo more boost and picks up alot better. and belive it or not had a quiter woosh noise!!!!!!!!
    #20

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