A/F tuning Q's for weber gurus
09-05-07, 03:19 AM
#1
A/F tuning Q's for weber gurus
well today i finished installing my AEM wideband today and now i have a couple of questions for you weber guys.
first off, i am running an OER 45mm sidedraft carb (essentially a weber clone)on a stock port 12A w/ full RB exhaust. fuel pump is a holley RED and is regulated at 3.5 psi. as for jetting im currently running 65F8 idle, 180 mains, 160 air correctors, and F7 emulsion tubes, 36mm venturies/chokes (i think) and im unsure of the accelerator pump jets.
now for the A/F numbers...
at idle (1k) 12.5:1
at cruising speed (2K and 3K) or w/ throttle slightly cracked/no load 10.5:1 - 11:1
WOT from 2k to redline 12:1 - 12.5:1
partial throttle/slow acceleration/underload(ie.going up hills) 12.3:1-12.5:1
when i get off the gas/engine brake it spikes to 17:1 and then maintains 14.5:1-15:1
it seems to me that its running a bit rich...especially when cruising at a constant RPM. what do you guys think of these A/F numbers? also, i know that the stock 12a makes its peak power at 6k and my car accelerates strong up to 6k but then the power falls off pretty quick and seems to struggle to make it to redline. its fastest when i shift at or before 6.5K, and just a waste of my time (and gas) to even try to hit 7K.
i have a couple of other main, idle, and air corrector jets and a pair of F11 emulsion tubes that i can swap out if need be.
any help or suggestions will be appreciated.
thanks in advance
Dan
first off, i am running an OER 45mm sidedraft carb (essentially a weber clone)on a stock port 12A w/ full RB exhaust. fuel pump is a holley RED and is regulated at 3.5 psi. as for jetting im currently running 65F8 idle, 180 mains, 160 air correctors, and F7 emulsion tubes, 36mm venturies/chokes (i think) and im unsure of the accelerator pump jets.
now for the A/F numbers...
at idle (1k) 12.5:1
at cruising speed (2K and 3K) or w/ throttle slightly cracked/no load 10.5:1 - 11:1
WOT from 2k to redline 12:1 - 12.5:1
partial throttle/slow acceleration/underload(ie.going up hills) 12.3:1-12.5:1
when i get off the gas/engine brake it spikes to 17:1 and then maintains 14.5:1-15:1
it seems to me that its running a bit rich...especially when cruising at a constant RPM. what do you guys think of these A/F numbers? also, i know that the stock 12a makes its peak power at 6k and my car accelerates strong up to 6k but then the power falls off pretty quick and seems to struggle to make it to redline. its fastest when i shift at or before 6.5K, and just a waste of my time (and gas) to even try to hit 7K.
i have a couple of other main, idle, and air corrector jets and a pair of F11 emulsion tubes that i can swap out if need be.
any help or suggestions will be appreciated.
thanks in advance
Dan
09-05-07, 10:33 AM
#2
too rich. Go down to 175 main fuel and consider a 60 idle fuel jet.
with 36mm chokes it won't want to rev that high. if you need it to , then just install 37mm chokes (or 1mm bigger if you don't have 36's) and don't change any jetting. That'll increase airflow and lean it out without changing any jets.
with 36mm chokes it won't want to rev that high. if you need it to , then just install 37mm chokes (or 1mm bigger if you don't have 36's) and don't change any jetting. That'll increase airflow and lean it out without changing any jets.
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