Q jet Q

Thread Tools
 
Search this Thread
 
Old Nov 11, 2009 | 05:05 AM
  #1  
Jamesbo's Avatar
Thread Starter
Moderator
 
Joined: Jun 2008
Posts: 18,073
From: Atlanta, Georgia
Q jet Q

69 442 400 ci, auto, air, q-jet w/ Divorce choke

Is the [I think it's called] "pull off vacuum" [ or vacuum brake] on the passanger side of the front of a Q-jet purppose to prevent the secondaries from fulley opening up at WOT so the engine can "catch up" and won't bog down? Or a smoother "kick in?
Old Nov 11, 2009 | 04:41 PM
  #2  
442Harv's Avatar
Registered User
 
Joined: Mar 2007
Posts: 1,738
From: Tracy Ca
I always thought it was made so you cannot open the secondaries, if the choke is still on? Motor need to warm up first, before you floor it.
Old Nov 11, 2009 | 07:54 PM
  #3  
sethj78's Avatar
Registered User
 
Joined: Jul 2008
Posts: 142
From: Edmond OK.
Choke pull off is what its called I think. What r u trying to do?? Adjust the secondaries?? They only open when the motor sucks them open if adjusted right.
Old Nov 11, 2009 | 09:56 PM
  #4  
J-(Chicago)'s Avatar
Seasoned beater pilot.
 
Joined: Jan 2007
Posts: 5,468
From: Chicago
The vacuum pod attached to the secondaries by that rod prevents the secondary air dams from flapping or bouncing during throttling.

I removed mine and haven't had a problem with flapping, but rumor has it, you pick up a better 60' time if you keep it on, and have the vacuum inlet/outlet size calibrated to your motor.

Last edited by J-(Chicago); Nov 11, 2009 at 09:58 PM.
Old Nov 11, 2009 | 09:57 PM
  #5  
J-(Chicago)'s Avatar
Seasoned beater pilot.
 
Joined: Jan 2007
Posts: 5,468
From: Chicago
Originally Posted by sethj78
They only open when the motor sucks them open if adjusted right.
Correct.



At wide open throttle they are open, but if you immediately let off the gas, the return spring snaps them shut right away.
The vacuum pod helps gradually let the flaps down.

Last edited by J-(Chicago); Nov 11, 2009 at 10:02 PM.
Old Nov 12, 2009 | 05:36 AM
  #6  
Jamesbo's Avatar
Thread Starter
Moderator
 
Joined: Jun 2008
Posts: 18,073
From: Atlanta, Georgia
Gotcha

Thanks
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Skitch72
Small Blocks
5
Oct 27, 2013 09:00 AM
oldzy
Small Blocks
2
Aug 29, 2010 09:18 PM
DAN76
General Discussion
0
Jul 24, 2009 09:01 AM
mpothuizen
Small Blocks
2
Dec 3, 2006 01:40 AM




All times are GMT -7. The time now is 04:49 PM.