AFR turbo vtr

  1. Established Member Joined: Jun 2009 west mids (dudley) Posts: 1201 cammed 106 flatty
    #1
    what air/fuel ratio do i need to aim for when turbo'ing ?

    ill be running 7psi so what number does my afr need to display on boost and off boost as i dont want to have it to lean and feck things up.. some help on this would be great!

    also does any1 have a sig con2 for sale?
  2. Frequent Poster Joined: Aug 2008 ESSEX Posts: 727 106 GTi Turbo
    #2
    depends on many variables.

    if you have no ignition control, standard pistons etc. id verge on the safe side, be running mid 11s. certainly back off the gas if you see it climb higher than 12.5.

    mid to low 12s would be average for a forged engine with correct ignition control. extreme high boost high power cars should be running mid to high 11s at full power and revs.

    had a mf2 fueled car int he other day, had to abandon the dyno test, soon as it hit boost it ran into the 16s!!!


    how accurate is ur lambda gauge? dont rely on it, use your ears too, if you get a fluttery misfire, or hear it det (sounds like a metallic rattle under load), back off the throttle immediately.



    - colin.
  3. Established Member Joined: Jan 2008 Posts: 1802
    #3
    Don't forget to install the correct heat plugs, and check the plug tips for the deposit pattern as this can help tell you how the mixture is burning

    Andy
  4. Established Member Joined: Jun 2009 west mids (dudley) Posts: 1201 cammed 106 flatty
    #4
    Awesome replies guys

    yea im going for a 7 heat which i believe is about right.

    its a wideband AFR so as accurate as they can get i spose rather not skimp out when it comes to fueling, even tho i am using mf2!!...

    ok so anything around 11 i should be ok, all the way through the rev range yea?