Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - quadrajet cfm
Thread: quadrajet cfm
View Single Post
  #2 (permalink)  
Old 07-27-2013, 03:49 PM
F-BIRD'88's Avatar
F-BIRD'88 F-BIRD'88 is offline
Yada Yada Yada
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,153
Wiki Edits: 0

Thanks: 5
Thanked 380 Times in 374 Posts
All the Qjets only come in 3 cfm sizes 750 795 and 850. all rated @ 1.5"
But there are a few than had the secondary air door opening limited, that did restrict the air flow further.
(these Odd ball Qjets were only used on a few motors and you don;t need to look for one)

There are a few others that have a different WOT secondary throttle WOT position when wide open.
This does not really effect the air flow. it was done on some stock GM motors to get the fuel distribution right
for that motor. You don;t need to look for these either.

You do not need to resize your Qjet. When the air door is set up correctly it automatically sizes itself to your engines WOT air flow needs. The air door opening rate and opening start point delay point is fully adjustable.
The secondary metering rod and the sec metering rod hanger choise is highly dependant on how agressive
or tame you set up teh secondary air door opening rate.

Get them both right and it is a very smooth carb. a Smaller carb is not better.

Buy a book about the Qjet carb and learn how it works and how to tune it.

Last edited by F-BIRD'88; 07-27-2013 at 03:55 PM.
Reply With Quote