EM TuningSky Insurance
Results 1 to 36 of 36
Like Tree5Likes
  • 1 Post By Sam_
  • 1 Post By badger5
  • 1 Post By Sam_
  • 1 Post By Sam_
  • 1 Post By <tuffty/>

Thread: N75? Strange Boost

  1. #1
    Sam_'s Avatar
    Down under

    Status
    Offline
    Join Date
    Mar 2011
    Location
    Sydney, Australia
    Posts
    2,750

    N75? Strange Boost

    I don't have a boost gauge fitted (other than the liquid gauge) but recently I've been noticing some strange behaviour. I'll be driving at part throttle pulling away slowly and the turbo will spool up really early as if there's much more load than there actually is. You can hear it dump boost sometimes too. It's very strange. I also think I'm getting overboost which is causing the knocking (which is now almost permanently if I give it some).

    Could the strange spool behaviour be the N75? It drives fine otherwise.

    I'm fitting a brand new OEM pump at the weekend in the hope that it might be the cause of the knock (lack of fuel).
    Handling mods++. GTX30 soon-ish. Hiding parts from the mrs since 2011. Build thread

  2. # ADS
    ADS
    Join Date
    Always
    Location
    Global
    Posts
    Many
     
  3. #2
    [Dave B]'s Avatar
    Rrrrrrrr-tech

    Status
    Offline
    Join Date
    Jan 2003
    Location
    Manchester
    Posts
    1,987
    Does it suddenly drop power when this happens, and is it happening in 1st and 2nd gear?
    > S3 225 (03) - OEM+
    > 205 GTI (90) - Limited Edition Miami Blue with full leather - 1 of only 300 made
    > Clio v6 255 (05) - Lethal Weapon

    View: My S3 diary

  4. #3
    Sam_'s Avatar
    Down under

    Status
    Offline
    Join Date
    Mar 2011
    Location
    Sydney, Australia
    Posts
    2,750
    It usually happens as I come up the ramp out of the work car park, so first gear. It's hard to explain but basically you can hear what sounds like the turbo spooling up and making boost yet I am going really slowly, and then it dumps by itself and returns to normal behaviour. It's very odd. Only happens occasionally and it's me being OCD that wants to sort it out.
    Handling mods++. GTX30 soon-ish. Hiding parts from the mrs since 2011. Build thread

  5. #4
    Westy's Avatar
    Double Dark Side! Diesel & 8P

    Status
    Offline
    Join Date
    Dec 2008
    Location
    Cambridgeshire sometimes Hertfordshire
    Posts
    17,264
    I had this exact same issue when my car was cold. I investigated the DV (007p) and realised that a blue spring had been put in there when it was mapped and that half the metal piston had been rubbing where it was sticking. anyway I fitted an OEM valve and it's been fine ever since. Go check your DV for signs of wear or sticking.
    8P A3 TDI - 220bhp - 335lbft
    A3 Maintenance Thread
    Bye bye S3 you will be missed.
    S3 Build Thread







  6. #5
    Sam_'s Avatar
    Down under

    Status
    Offline
    Join Date
    Mar 2011
    Location
    Sydney, Australia
    Posts
    2,750
    Good call. It could be that the spring in the Tial is too strong. I do get the odd bit of flutter. Hmm.
    Handling mods++. GTX30 soon-ish. Hiding parts from the mrs since 2011. Build thread

  7. #6
    Westy's Avatar
    Double Dark Side! Diesel & 8P

    Status
    Offline
    Join Date
    Dec 2008
    Location
    Cambridgeshire sometimes Hertfordshire
    Posts
    17,264
    Quote Originally Posted by Sam_ View Post
    Good call. It could be that the spring in the Tial is too strong. I do get the odd bit of flutter. Hmm.
    It was driving me mad and then I noticed the car was jerky on part throttle in 5th/6th on the motorway. A new valve stopped all this weirdness.
    8P A3 TDI - 220bhp - 335lbft
    A3 Maintenance Thread
    Bye bye S3 you will be missed.
    S3 Build Thread







  8. #7
    Sam_'s Avatar
    Down under

    Status
    Offline
    Join Date
    Mar 2011
    Location
    Sydney, Australia
    Posts
    2,750
    Cool. Might chuck an OEM on there for now. it's not like I "need" the Tial on there yet.
    Handling mods++. GTX30 soon-ish. Hiding parts from the mrs since 2011. Build thread

  9. #8
    Westy's Avatar
    Double Dark Side! Diesel & 8P

    Status
    Offline
    Join Date
    Dec 2008
    Location
    Cambridgeshire sometimes Hertfordshire
    Posts
    17,264
    Quote Originally Posted by Sam_ View Post
    Cool. Might chuck an OEM on there for now. it's not like I "need" the Tial on there yet.
    An OEM valve will prove if your DV is the issue as its a sealed unit that can't be played about with. Hope it sorts your issues. I found part throttle was sooooo much smoother with the OEM valve. Love it.
    8P A3 TDI - 220bhp - 335lbft
    A3 Maintenance Thread
    Bye bye S3 you will be missed.
    S3 Build Thread







  10. #9
    Sam_'s Avatar
    Down under

    Status
    Offline
    Join Date
    Mar 2011
    Location
    Sydney, Australia
    Posts
    2,750
    Awesome. Sounds like it's the same thing perhaps. I'll grab a 710N and go from there then.
    Westy likes this.
    Handling mods++. GTX30 soon-ish. Hiding parts from the mrs since 2011. Build thread

  11. #10
    Westy's Avatar
    Double Dark Side! Diesel & 8P

    Status
    Offline
    Join Date
    Dec 2008
    Location
    Cambridgeshire sometimes Hertfordshire
    Posts
    17,264
    Any luck with this Sam? My car has started to do it again even with the OE DV but my mrs keeps filling the car with 95ron fuel so I think it's that. Only when cold though
    8P A3 TDI - 220bhp - 335lbft
    A3 Maintenance Thread
    Bye bye S3 you will be missed.
    S3 Build Thread







  12. #11
    Sam_'s Avatar
    Down under

    Status
    Offline
    Join Date
    Mar 2011
    Location
    Sydney, Australia
    Posts
    2,750
    I've not had a chance really. The weather last weekend was insane, pure rain and storms. I should venture out this weekend and grab a 710N and some new plugs (unrelated) but there's some good swell coming in so I might go grab some surf shots if the weather is good.

    I'm going to order a 8-9psi spring for the Tial QR in the meantime anyway as I have the 11psi one which is clearly too stiff. A bit of reading on Vortex etc shows that the 8-9 psi one is the way to go. I told the guy when I bought it that the 1.8T was lower vacuum but he was all 'it'll be fine'.
    Handling mods++. GTX30 soon-ish. Hiding parts from the mrs since 2011. Build thread

  13. #12
    RIP S3dave

    Status
    Offline
    Join Date
    May 2004
    Location
    nr Glos
    Posts
    7,141
    Quote Originally Posted by Westy View Post
    Any luck with this Sam? My car has started to do it again even with the OE DV but my mrs keeps filling the car with 95ron fuel so I think it's that. Only when cold though
    95UL?

    owch!
    when max'd out on the map on 99?
    **http://www.facebook.com/Badger5Ltd**

    Check out the ever Growing eBay Shop>
    http://stores.ebay.co.uk/Badger-5-LTD?_trksid=p4340.l2563

    Badger 5 Ltd, Queen Annes Gate, Oldends Lane, Stonehouse, Glos, GL10 2DG


    http://www.badger5.co.uk, Tel:01453822880
    bill@badger5.co.uk
    **NEW** Badger5 Section CLICK here>> http://www.audi-sport.net/vb/213-badger-5/

  14. #13
    Prawn's Avatar
    My other car is a MINI!!!!

    Status
    Offline
    Join Date
    Dec 2006
    Location
    Basingstoke
    Posts
    9,326
    95 ron in that is some scary **** Westy. you need to educate her!
    -------------------------------------------------------------------------------------------------

    Prawns TFSI Turbo'd 1.8T Track Car

    But I know nothing so ignore me.

  15. #14
    "Stick a V8 in it!"

    Status
    Offline
    Join Date
    Jan 2008
    Location
    Glenrothes, Fife, Scotland
    Posts
    15,324
    Take the keys off her and tell her to walk.

    Putting the right fuel in isnt ****ing hard, if she cant do it right she shouldnt be driving.

    2000 A4 1.8T Sport Quattro Avant, Berry Pearl
    2000 A4 1.8T Sport Quattro Saloon, Black-ish
    1997 S4 - PPC £999 Challenge Track Car Build
    TD5 Land Rover Defender build


  16. #15
    superkarl's Avatar
    MAN OF STEEL

    Status
    Offline
    Join Date
    Mar 2010
    Location
    Liverpool/Southport. N west
    Posts
    7,520
    What sort of timing would it be pulling from 99map on 95? That bad?

  17. #16
    Sam_'s Avatar
    Down under

    Status
    Offline
    Join Date
    Mar 2011
    Location
    Sydney, Australia
    Posts
    2,750
    I'm sure it was an honest mistake
    Handling mods++. GTX30 soon-ish. Hiding parts from the mrs since 2011. Build thread

  18. #17
    Westy's Avatar
    Double Dark Side! Diesel & 8P

    Status
    Offline
    Join Date
    Dec 2008
    Location
    Cambridgeshire sometimes Hertfordshire
    Posts
    17,264
    I've educated her but she don't give a crap and just puts the cheapest stuff in

    Obviously she doesn't drive it like its meant to so hopefully it'll be ok. The map should just pull all the timing. I'm sure it was mapped on 97ron anyway as the closest garage to RTech is a BP that does Ultimate (which isn't reall Ultimate).

    I need to get the keys off her!
    8P A3 TDI - 220bhp - 335lbft
    A3 Maintenance Thread
    Bye bye S3 you will be missed.
    S3 Build Thread







  19. #18
    RIP S3dave

    Status
    Offline
    Join Date
    May 2004
    Location
    nr Glos
    Posts
    7,141
    Quote Originally Posted by aragorn View Post
    Take the keys off her and tell her to walk.

    Putting the right fuel in isnt ****ing hard, if she cant do it right she shouldnt be driving.
    could have been worse and diesel'd it by mystake
    Westy likes this.
    **http://www.facebook.com/Badger5Ltd**

    Check out the ever Growing eBay Shop>
    http://stores.ebay.co.uk/Badger-5-LTD?_trksid=p4340.l2563

    Badger 5 Ltd, Queen Annes Gate, Oldends Lane, Stonehouse, Glos, GL10 2DG


    http://www.badger5.co.uk, Tel:01453822880
    bill@badger5.co.uk
    **NEW** Badger5 Section CLICK here>> http://www.audi-sport.net/vb/213-badger-5/

  20. #19
    RIP S3dave

    Status
    Offline
    Join Date
    May 2004
    Location
    nr Glos
    Posts
    7,141
    Quote Originally Posted by superkarl View Post
    What sort of timing would it be pulling from 99map on 95? That bad?
    I have seen CF or 6 easily on 99 to 95, and if tuned to see up to 6cf on 99, then you can do the maths.... It would consume the std 12CF it can pull max
    **http://www.facebook.com/Badger5Ltd**

    Check out the ever Growing eBay Shop>
    http://stores.ebay.co.uk/Badger-5-LTD?_trksid=p4340.l2563

    Badger 5 Ltd, Queen Annes Gate, Oldends Lane, Stonehouse, Glos, GL10 2DG


    http://www.badger5.co.uk, Tel:01453822880
    bill@badger5.co.uk
    **NEW** Badger5 Section CLICK here>> http://www.audi-sport.net/vb/213-badger-5/

  21. #20
    Sam_'s Avatar
    Down under

    Status
    Offline
    Join Date
    Mar 2011
    Location
    Sydney, Australia
    Posts
    2,750
    I finally got around to replacing the 10 psi spring in the Tial today with an 8 psi one. Seems it no longer flutters at low rpm/throttle and it already seems smoother. Time will tell tomorrow when I pull out of work. I was going to buy an OEM 710 but they were like $50-60 here and a new spring for the QR was only $35.
    Westy likes this.
    Handling mods++. GTX30 soon-ish. Hiding parts from the mrs since 2011. Build thread

  22. #21
    Sam_'s Avatar
    Down under

    Status
    Offline
    Join Date
    Mar 2011
    Location
    Sydney, Australia
    Posts
    2,750
    Way way way better with the 8 psi spring. It no longer seems to do the weird boost at low rpm thing. It must be getting bled off or something. It doesn't seem to be surging either which has mean the knocking I had has stopped. More testing required to confirm but I think that solved it.
    s3dave likes this.
    Handling mods++. GTX30 soon-ish. Hiding parts from the mrs since 2011. Build thread

  23. #22
    Westy's Avatar
    Double Dark Side! Diesel & 8P

    Status
    Offline
    Join Date
    Dec 2008
    Location
    Cambridgeshire sometimes Hertfordshire
    Posts
    17,264
    I hope my Xmas pressie is in the post for helping you with this issue
    8P A3 TDI - 220bhp - 335lbft
    A3 Maintenance Thread
    Bye bye S3 you will be missed.
    S3 Build Thread







  24. #23
    Sam_'s Avatar
    Down under

    Status
    Offline
    Join Date
    Mar 2011
    Location
    Sydney, Australia
    Posts
    2,750
    haha of course mate
    Handling mods++. GTX30 soon-ish. Hiding parts from the mrs since 2011. Build thread

  25. #24
    Sam_'s Avatar
    Down under

    Status
    Offline
    Join Date
    Mar 2011
    Location
    Sydney, Australia
    Posts
    2,750
    Spoke too soon. It still does it. Bloody thing. It is still smoother though. I'll have to order an N75 valve and fit this new OEM fuel pump I have (might be the cause of the pinking but doubtful?).
    Handling mods++. GTX30 soon-ish. Hiding parts from the mrs since 2011. Build thread

  26. #25
    Sam_'s Avatar
    Down under

    Status
    Offline
    Join Date
    Mar 2011
    Location
    Sydney, Australia
    Posts
    2,750
    I just cleaned the MAF with isopropyl alcohol and no noticeable change.

    The pinking issue is the most worrying. It's been on and off for a while now and mainly seems to do it under one kind of scenario, when I build up slowly or hold RPMs on the edge of boost and then nail it. It's like there's a massive requirement for fuel which perhaps the pump can't meet. All the major "usual suspect" parts have been replace 12-18 months ago, only the pump hasn't. The thing is, if it was the pump the ECU would cut timing correct? Perhaps I'm hitting the maximum it can pull and it can do no more.

    I really need to get the SPA fuel/boost pressure gauge setup as I don't really 100% know what's happening with boost. The liquid gauge measures 1550 which I think is the max it can read. Realistically though, fitting the new OEM pump I have is probably easier as getting the big sensor connectors from the cabin through to the engine bay won't be easy. I have the pump without the level sensor and top part attached so it's a bit of extra work to change the pipes over. I've just been waiting for a low tank to do it. I'll stick in a new fuel filter at the same time and see if that helps. Bloody thing.
    Handling mods++. GTX30 soon-ish. Hiding parts from the mrs since 2011. Build thread

  27. #26
    Sam_'s Avatar
    Down under

    Status
    Offline
    Join Date
    Mar 2011
    Location
    Sydney, Australia
    Posts
    2,750
    Just worked out I got ~30 mpg on the last tank. Seems high? It gets a bit of stick most days but rarely pinks.
    Last edited by Sam_; 15th December 2013 at 09:55.
    Handling mods++. GTX30 soon-ish. Hiding parts from the mrs since 2011. Build thread

  28. #27
    Sam_'s Avatar
    Down under

    Status
    Offline
    Join Date
    Mar 2011
    Location
    Sydney, Australia
    Posts
    2,750
    Does anyone know a decent forum I can get some help with issues like this? Would be good to hear if other people have had the same issue.

    I'll replace the fuel pump tomorrow and go from there I guess.
    Handling mods++. GTX30 soon-ish. Hiding parts from the mrs since 2011. Build thread

  29. #28
    RIP S3dave

    Status
    Offline
    Join Date
    May 2004
    Location
    nr Glos
    Posts
    7,141
    what % load does it think its running on.. block 002... 003 for timing actual, 020 for CF corrections,
    **http://www.facebook.com/Badger5Ltd**

    Check out the ever Growing eBay Shop>
    http://stores.ebay.co.uk/Badger-5-LTD?_trksid=p4340.l2563

    Badger 5 Ltd, Queen Annes Gate, Oldends Lane, Stonehouse, Glos, GL10 2DG


    http://www.badger5.co.uk, Tel:01453822880
    bill@badger5.co.uk
    **NEW** Badger5 Section CLICK here>> http://www.audi-sport.net/vb/213-badger-5/

  30. #29
    Sam_'s Avatar
    Down under

    Status
    Offline
    Join Date
    Mar 2011
    Location
    Sydney, Australia
    Posts
    2,750
    Cool cheers Bill, I'll do some logging later tonight.
    Handling mods++. GTX30 soon-ish. Hiding parts from the mrs since 2011. Build thread

  31. #30
    Sam_'s Avatar
    Down under

    Status
    Offline
    Join Date
    Mar 2011
    Location
    Sydney, Australia
    Posts
    2,750
    Here's the logs. It was a bit hard to actually do a proper full run in 3rd so some were in 2nd and I rarely took it to redline purely because of where I was. It's a tiny bit cooler tonight and I didn't hear any knock at all and it felt pretty strong (saw ~222g/s on one run without taking it too high rpm wise). I wonder if it's purely IAT related and WMI might have to be considered?



    I also managed to log 001, 002, 031 by accident on my first run, not sure if that's of any use.

    Handling mods++. GTX30 soon-ish. Hiding parts from the mrs since 2011. Build thread

  32. #31
    Sam_'s Avatar
    Down under

    Status
    Offline
    Join Date
    Mar 2011
    Location
    Sydney, Australia
    Posts
    2,750
    Here's links to full size if you can't read those:

    Screen Shot 2013-12-19 at 9.14.00 pm.png
    and
    Screen Shot 2013-12-19 at 9.09.25 pm.png
    Handling mods++. GTX30 soon-ish. Hiding parts from the mrs since 2011. Build thread

  33. #32
    Sam_'s Avatar
    Down under

    Status
    Offline
    Join Date
    Mar 2011
    Location
    Sydney, Australia
    Posts
    2,750
    Guess I'll just have to leave it be for now and wait until I fit the new engine. I haven't got a clue what's up and taking it to an "expert" here would be a dead end.
    Handling mods++. GTX30 soon-ish. Hiding parts from the mrs since 2011. Build thread

  34. #33
    <tuffty/>'s Avatar
    Badger 5 Edition

    Status
    Offline
    Join Date
    Sep 2008
    Location
    Gloucestershire
    Posts
    15,476
    Sorry dude been a bit busy at work and a little wasted now... will make the effort to review your logs and comment in the morning...

    <tuffty/>
    Sam_ likes this.
    Silver 2001 AMK S3. Silver alcantara interior... now with added powarrrrrrrr, torques. VAGCOM + KII-USB. >> My build thread...

  35. #34
    Sam_'s Avatar
    Down under

    Status
    Offline
    Join Date
    Mar 2011
    Location
    Sydney, Australia
    Posts
    2,750
    Thanks mate - it's quite a weird one. Any help is appreciated!
    Handling mods++. GTX30 soon-ish. Hiding parts from the mrs since 2011. Build thread

  36. #35
    Sam_'s Avatar
    Down under

    Status
    Offline
    Join Date
    Mar 2011
    Location
    Sydney, Australia
    Posts
    2,750
    Replaced the fuel pump today and some new BKR7E's gaped to .032". Took it for a quick spin and couldn't get any knock, although it's not done it for a few days anyhow. Time will tell.
    Handling mods++. GTX30 soon-ish. Hiding parts from the mrs since 2011. Build thread

  37. #36
    Sam_'s Avatar
    Down under

    Status
    Offline
    Join Date
    Mar 2011
    Location
    Sydney, Australia
    Posts
    2,750
    Not sure if it was the fuel pump or the other little bits I've done recently but drove to a mates today for a Christmas BBQ and it felt epic driving back through the national park. Some nice sweeping open roads and even got to try a launch (been a while) and it feels very strong. Logged the most it ever has...

    Handling mods++. GTX30 soon-ish. Hiding parts from the mrs since 2011. Build thread

 

 

Similar Threads

  1. AGU - Disconnected pipe from actuator to N75. Full boost?
    By Stanley in forum A3/S3 Forum (8L Chassis)
    Replies: 24
    Last Post: 9th December 2012, 15:54
  2. A Strange Boost Issue Noticed While On A Spirited Drive Yesterday...
    By S3 Paul in forum A3/S3 Forum (8L Chassis)
    Replies: 6
    Last Post: 31st May 2011, 12:45
  3. Strange Boost problem :(
    By IOM-S3 in forum A3/S3 Forum (8L Chassis)
    Replies: 5
    Last Post: 10th February 2011, 09:45
  4. n75 valve boost solenoid?
    By Bellic in forum A3/S3 Forum (8L Chassis)
    Replies: 3
    Last Post: 25th April 2007, 19:54
  5. Strange Boost Beaviour
    By madiba in forum A3/S3 Forum (8L Chassis)
    Replies: 8
    Last Post: 2nd March 2005, 09:54

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Single Sign On provided by vBSSO

Garage Plus, Vendor Tools vBulletin Plugins by Drive Thru Online, Inc.

Content Relevant URLs by vBSEO