1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

A/F tuning Q's for weber gurus

Thread Tools
 
Search this Thread
 
Old Sep 5, 2007 | 03:19 AM
  #1  
Sgt.Stinkfist's Avatar
Thread Starter
premix, for f's sake
Tenured Member: 20 Years
iTrader: (6)
 
Joined: Jun 2004
Posts: 1,438
Likes: 5
From: madison, WI
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
Reply
Old Sep 5, 2007 | 10:33 AM
  #2  
DriveFast7's Avatar
Blood, Sweat and Rotors
Tenured Member 20 Years
iTrader: (1)
 
Joined: Aug 2001
Posts: 3,742
Likes: 1
From: California
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.
Reply
Old Sep 5, 2007 | 11:22 AM
  #3  
Jeezus's Avatar
Stu-Tron Get Yo Groove On
Tenured Member: 15 Years
iTrader: (5)
 
Joined: Nov 2006
Posts: 8,482
Likes: 31
From: Huntsville AL
I have the same setup, and run 40mm chokes. Its horrible down low, but she really likes it when you go past 5000. Pulls to 7300, but gas mileage is not the best. What is ideal A/F?
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Coochas
1st Generation Specific (1979-1985)
44
Nov 5, 2019 11:08 PM
Logan Reinisch
General Rotary Tech Support
44
Sep 17, 2018 12:20 PM
NLPerformance
1st Generation Specific (1979-1985)
10
Oct 2, 2015 07:11 AM




All times are GMT -5. The time now is 12:19 PM.