News

Rejetting for LA > SLC elevation

Discussion in '308/328' started by miahshodan, Dec 6, 2018.

  1. miahshodan

    miahshodan Rookie

    Feb 25, 2016
    17
    West Jordan, UT
    I recently bought a 1975 308 GT4 from Los Angelos and brought it to Salt Lake City, Utah. I tried adjusting the carbs for the eleveation (4500 ft) But I think I only made it worse. I suspect they need more than an adjustment, they probably need different jets. My question is how much different. The car has a K&N filter, no sound deadening in the airbox (doesn't look like it ever did), no airpump, no cats and a aftermarket exhaust.

    Car runs so rich now that my eyes water when I am by the engine and it is running.

    Current jets are:
    Main: 135
    Idle: 50
    Air bypass 220

    Also anyone else in the area and/or know a good independent in the area?
     
  2. jmaienza

    jmaienza Formula Junior

    Jan 8, 2009
    418
    Massachusetts
    Full Name:
    Joe
    A good place to start is to contact www.piercemanifolds.com and speak to a technician. They are very knowledgeable and have all the jets you may need.
     
  3. miketuason

    miketuason F1 World Champ
    Silver Subscribed Owner

    Feb 24, 2006
    12,754
    Cerritos, CA.
    Full Name:
    Mike
    Use smaller mains and larger air correctors, that should lean out the mixture.
     
  4. miahshodan

    miahshodan Rookie

    Feb 25, 2016
    17
    West Jordan, UT
    thanks, are you thinking like a 130 main and a 225 air bypass, or something more drastic?
     
  5. miahshodan

    miahshodan Rookie

    Feb 25, 2016
    17
    West Jordan, UT
    Thanks, I'll give them a call when they are back, evidently they are off on Friday....wish I was ;)
     
  6. miahshodan

    miahshodan Rookie

    Feb 25, 2016
    17
    West Jordan, UT
    ok, I got new main and idle jets and replaced the idle jets no problem. The main jets however, have me flummoxed. I was under the impression that the main jet was at the end of the emulsion tube and the two pieces could be taken apart somehow. When I took my current emulsion tube/jets out they appear to be all one piece. There is no visible seam and I could not pull them apart. Is it possible a previous owner bought some kind of combination?
     
  7. jmaienza

    jmaienza Formula Junior

    Jan 8, 2009
    418
    Massachusetts
    Full Name:
    Joe
    Here is a picture. Air corrector-top; emulsion tube-middle; main jet-bottom.

    You may have to hold the assembly in a vise with rubber lined jaws, then use a pair of pliers with rubber layer and gently twist off the main jet and then the air corrector. Go easy and be gentle. Don't let any metal contact the parts. You don't want scratches on the components.

    Image Unavailable, Please Login
     
  8. miahshodan

    miahshodan Rookie

    Feb 25, 2016
    17
    West Jordan, UT
    thanks, that was what I thought, but I hadn't dared put enough force into it to get them apart. Tried a little harder tonight and they came apart no problem.
     
  9. 4redude

    4redude Formula Junior

    Jan 13, 2005
    633
    Someplace new
    Full Name:
    Brian Keegan
    Ferrari put out a Service Bulletin giving the recommended adjustments for cars at higher elevations.
    See attached bulletin.
     

    Attached Files:

Share This Page