308 gt4 carb jetting | FerrariChat

308 gt4 carb jetting

Discussion in 'Technical Q&A' started by GavC, Jul 29, 2004.

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  1. GavC

    GavC Formula Junior

    May 9, 2004
    492
    Lincolnshire, Englan
    Full Name:
    Gavin Culshaw
    I am looking for any advice on jetting for my uk spec 1977 308gt4. I have read most of the posts on the forum and would like some help on what would the best be. I have a K&N filter with modified airbox and sports exhaust run platinum plugs etc. Just had a top end rebuilt and now its time for the dyno.
    Most 308's on this site seem to say .60 idle, 140 main,200 air correction. is this US spec.anybody got any better ideas. Sorry I don't have the stock settings to hand they are in the car at the garage. Help would be appreciated.
    Thanks Gav.
     
  2. thecarreaper

    thecarreaper F1 World Champ
    Silver Subscribed

    Sep 30, 2003
    18,128
    Savannah

    the book i have list the following, perhaps use it as a base setting?
    main : 130 , idle .50 , f36 e tube, 200 air corrector from page " A1-4, Haynes Weber carb manual. been fighting with my 308's carbs . going to order new linkage tomorrow.
     
  3. pma1010

    pma1010 F1 Rookie

    Jul 21, 2002
    2,559
    Chicago
    Full Name:
    Philip
    Gav
    This subject has been covered comprehensively in the archives of the new and the old site. If you are running the stock cams, stay with the stock jetting on your GT4.

    My guess is you should run 55/135/f36/220, but please check.

    The emissions stuff hadn't really impacted euro cars back then and if Enzo thought he could get more juice from a 140 main, he'd have put them in. Just put the stock jets in and drive it hard!
    Philip
     
  4. GavC

    GavC Formula Junior

    May 9, 2004
    492
    Lincolnshire, Englan
    Full Name:
    Gavin Culshaw
    Thanks Guy's will try these out.Did try to search the old site it wouldn't work.
    The car's been off the road for nearly a year. Used a 911 carrera to help me get my fix it didn't work so sold it' however the motorbike does give me the thrill but its a bit more dangerous still not a Ferrari So I will give it a bit when its finished
    Thank
    Gav
     
  5. Peter

    Peter F1 Veteran
    Owner

    Dec 21, 2000
    6,441
    B.C., Canada
    I have played with a similar combination of 60/140/210 and found that it was too rich and made my car (US 308 GT4 with no emissions and Borla exhaust) quite sluggish. I have since gone back to the stock sizes (55/135/220).
     

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