Results 1 to 7 of 7

Thread: S50 VF Engineering a/f ratio questions

  1. #1
    Join Date
    Mar 2009
    Location
    Beaver tails and Maple syrup
    Posts
    86
    My Cars
    The Dirty 30

    S50 VF Engineering a/f ratio questions

    Hello


    I have an e30 with an s50 with vfe kit. I've had this car for many years but don't drive it much and feel the car used to perform better at WOT.

    Currently the car makes about 5psi and at wot AF is 13.2. (I swear it used to be in the 12s but don't truly remember)

    Crusing and idling AF is fine.

    Is the WOT AF rich enough? It will just stay at 13.2 no matter the rpm at WOT.


    Thanks


    Sent from my Pixel 4 XL using Tapatalk

  2. #2
    Join Date
    Aug 2011
    Location
    Los Angeles
    Posts
    511
    My Cars
    my brother's ti
    In my limited experience, I think 13.2 is fine. I'm no expert, maybe someone with more experience will chime in.

    It's always a good idea to boost leak test these motors though. They were not designed for boost and it is much harder than you think to have a boost leak-free set up. a small boost leak would cause power loss most noticeable at WOT

  3. #3
    Join Date
    Mar 2009
    Location
    Beaver tails and Maple syrup
    Posts
    86
    My Cars
    The Dirty 30
    Quote Originally Posted by E36M3LX View Post
    In my limited experience, I think 13.2 is fine. I'm no expert, maybe someone with more experience will chime in.

    It's always a good idea to boost leak test these motors though. They were not designed for boost and it is much harder than you think to have a boost leak-free set up. a small boost leak would cause power loss most noticeable at WOT
    Thanks. I'll try doing another leak down test.

    Sent from my Pixel 4 XL using Tapatalk

  4. #4
    Join Date
    Sep 2002
    Location
    USA
    Posts
    45,770
    My Cars
    BMWs
    Quote Originally Posted by Rex Manning View Post
    Hello


    I have an e30 with an s50 with vfe kit. I've had this car for many years but don't drive it much and feel the car used to perform better at WOT.

    Currently the car makes about 5psi and at wot AF is 13.2. (I swear it used to be in the 12s but don't truly remember)

    Crusing and idling AF is fine.

    Is the WOT AF rich enough? It will just stay at 13.2 no matter the rpm at WOT.


    Thanks


    Sent from my Pixel 4 XL using Tapatalk
    5 psi sounds like the belt is slipping and 13.2:1 AFR on gasoline at the pressure on an S50 is safe.

    - - - Updated - - -

    Quote Originally Posted by Rex Manning View Post
    Thanks. I'll try doing another leak down test.

    Sent from my Pixel 4 XL using Tapatalk
    Leak down is not boost leak.

  5. #5
    Join Date
    Jan 2002
    Location
    York, PA / NYC Manhattan
    Posts
    2,376
    My Cars
    72 2002tii, 87 300 SDL, 91 M5, 95 M3 LTW
    I would want to be low low 12s for longevity especially on a non intercooled kit.

  6. #6
    Join Date
    Mar 2009
    Location
    Beaver tails and Maple syrup
    Posts
    86
    My Cars
    The Dirty 30
    I contacted VFE and they stated should be 12.0.

    I have a feeling I have an exhaust leak at the flange between the exhaust manifold and the exhaust pipe.

    Unfortunately I cannot access one of the nuts (probably accessible on lift) and the remainder are all seized so the one I cannot access is most likely seized as well.

    Sent from my Pixel 4 XL using Tapatalk

  7. #7
    Join Date
    Mar 2011
    Location
    Seoul, phoenix, missoula
    Posts
    179
    My Cars
    galant vr4 S13
    Glad you confirmed with VF because afr at WOT for that setup should absolutely be within .2 off 12afr under full load.

    Exhaust leak can be an issue leading to faulty o2 readings BUT you will normally see false readings at low exhaust flow not so much at WOT where the exhaust is at a relatively high pressure compared to the atmosphere. (Meaning exhaust leaks out of any cracks)
    A more likely list of culprits could be within the fuel system.
    -fuel pump not able to keep up as it ages. I’d recommend running a pump with a good bit of head room (extra flow capabilities). I personally use an AEM 340lph fuel pump in my turbo e36.
    -dirty fuel filter and or injectors (again restricting fuel delivery)

    Change out the fuel filter/s and consider a new pump getting power from a 30amp relay -10ga power/ground (oem pump wiring will not support high flow pumps higher amperage draw.)

Similar Threads

  1. Couple Vf engineering S/C install questions.
    By tlamm in forum Forced Induction
    Replies: 11
    Last Post: 01-29-2015, 10:06 PM
  2. Questions about VF-Engineering S/C
    By LiveStrong///M3 in forum Forced Induction
    Replies: 2
    Last Post: 03-11-2007, 07:45 PM
  3. vf-engineering questions.
    By m^ke in forum Forced Induction
    Replies: 1
    Last Post: 02-28-2007, 12:40 PM
  4. VF-engineering SC Install questions
    By JL@autotechnic in forum Forced Induction
    Replies: 1
    Last Post: 07-14-2006, 09:59 PM
  5. Question about the VF-Engineering supercharger
    By Sephiroth619 in forum Forced Induction
    Replies: 11
    Last Post: 04-12-2006, 08:59 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •