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

NEW PARTIAL Rat's nest removal mod...

Thread Tools
 
Search this Thread
 
Old 07-17-12, 09:44 AM
  #1  
Full Member
Thread Starter
iTrader: (1)
 
Xamnglc's Avatar
 
Join Date: Nov 2010
Location: Anchorage,AK
Posts: 84
Likes: 0
Received 1 Like on 1 Post
NEW PARTIAL Rat's nest removal mod...

Things to keep in mind:

1. I'm far away from my car right now so all of this info has been sources and constructed from forum info/ Mazda FSM's...(Being deployied in Afganistan leaves me lots of time to think about what I'm gonna to do my 85 12A R-x7)
2. This setup assumes the user will install a header or bypass the catilytic convertors some other how...
3. This setup also assume an aftermarket air cleaner is installed.(Hance the need for breathers)
4. Please provide feedback so I can perfect it and in 2 months when I get back to AK I will do it...
Purpose: To delete uneeded emissions items and keep those the promte MPG. This is intended to be a hybrid setup between full rats net and full without.
-------------------------------------------------------------------------------------
THis first Image is a diagram of the current no emissions config(Carl and Matts idea):
-------------------------------------------------------------------------------------
The second image is the proposed idea:
1. Allow the computer to control timing which will boost MPG
2. Allow the stutter valve to remain since mazda claims it increases MPG by 20%
3. I'm not sure if the stutter valve will work corretly without #2 AAB so it stays also(More Research Pending)
4. All other emissions items removed(CATS, ACV, Airpump, RELIEF Valve, Switching Valve... )
-------------------------------------------------------------------------------------
The Third image is the proposed idea: if the shutter valve will work without AAB #2 the just plug the stutter valve in to manifold air of any kind. Since I'm not in front of my car to find out if the removed items are manifold air(RELIEF Valve/Switching Valve) I'll need someone to do the research form me.
Attached Thumbnails NEW PARTIAL Rat's nest removal mod...-ratsnest.jpg   NEW PARTIAL Rat's nest removal mod...-ratsnestlight.jpg   NEW PARTIAL Rat's nest removal mod...-ratsnestlightnoaab2.jpg  
Old 07-17-12, 05:22 PM
  #2  
Work in Progress

iTrader: (9)
 
82FanTC's Avatar
 
Join Date: Aug 2006
Location: Minneapolis
Posts: 569
Likes: 0
Received 1 Like on 1 Post
There is no "computer" that runs timing on an FB. It is done within the distributor via vacuum and weights. Keeping the timing stock with the vacuum advance hooked up to the stock position will provide the best fuel economy.

Can't really comment on the shutter valve hypothesis.
The following users liked this post:
tyler tolbert (04-26-24)
Old 07-17-12, 05:25 PM
  #3  
Full Member
Thread Starter
iTrader: (1)
 
Xamnglc's Avatar
 
Join Date: Nov 2010
Location: Anchorage,AK
Posts: 84
Likes: 0
Received 1 Like on 1 Post
Originally Posted by 82FanTC
There is no "computer" that runs timing on an FB. It is done within the distributor via vacuum and weights. Keeping the timing stock with the vacuum advance hooked up to the stock position will provide the best fuel economy.

Can't really comment on the shutter valve hypothesis.
Not in the sense of a modern fuel injected car would, but in the sense that it can cut advance during deceleration

Last edited by Xamnglc; 07-17-12 at 05:34 PM.
Old 07-18-12, 12:14 PM
  #4  
Full Member
Thread Starter
iTrader: (1)
 
Xamnglc's Avatar
 
Join Date: Nov 2010
Location: Anchorage,AK
Posts: 84
Likes: 0
Received 1 Like on 1 Post
In another thread I read that with the soliniods
"At idle, there is no vacuum present.
At 1000-1200 RPM, the leading vacuum solenoid opens applying leading vacuum advance.
At 2900-3100 RPM, the trailing vacuum solenoid opens applying trailing vacuum advance.
If throttle is released past 4000 RPM, both trailing and leading vacuum advance is cut.
"

UPDATE: I have attached 1981 tech data which explains mazda's original intent

So basically, Vacuum advance could be hooked up to port air, as mazda does for CA emssions models.
But the computer control part is that Vacuum advance is cut when cold or with the choke on in any tempature. Base timming without advance would be better when cold...
Attached Thumbnails NEW PARTIAL Rat's nest removal mod...-1.jpg  

Last edited by Xamnglc; 07-18-12 at 12:33 PM.
Old 07-19-12, 05:10 AM
  #5  
Lives on the Forum

 
Kentetsu's Avatar
 
Join Date: Jun 2004
Location: Grand Rapids Michigan
Posts: 11,359
Received 14 Likes on 11 Posts
Interesting project. I can attest to the fact that with a stripped rat's nest, best performance is with ported vacuum to the advance (although I run leading/trailing advance together).

Keep up the good work man.


.
Old 07-19-12, 12:52 PM
  #6  
Lapping = Fapping

iTrader: (13)
 
Jeff20B's Avatar
 
Join Date: Aug 2001
Location: Near Seattle
Posts: 15,725
Received 70 Likes on 64 Posts
The diagram on the far right looks correct.
Old 07-19-12, 03:53 PM
  #7  
Full Member
Thread Starter
iTrader: (1)
 
Xamnglc's Avatar
 
Join Date: Nov 2010
Location: Anchorage,AK
Posts: 84
Likes: 0
Received 1 Like on 1 Post
Update

update: I have determined that #2 Anti Afterburn valve is not require for shutter valve operation... THe coast and shutter valve work with each other and #2 AAB has to be closed to allow the shutter valve to work with the original config...
Old 07-20-12, 03:30 AM
  #8  
Junior Member
 
CharlieBrownRacing's Avatar
 
Join Date: Jan 2012
Location: washington
Posts: 20
Likes: 0
Received 0 Likes on 0 Posts
WA ok i want in on this

so very interesting this would seem to be the best for fuel economy and performance if u need any help just ask man if u need pics or anything i have a 83 gsl and am very tempted to remove the the rats nest but wanted the shutter valve function
Old 07-20-12, 11:49 AM
  #9  
Full Member
Thread Starter
iTrader: (1)
 
Xamnglc's Avatar
 
Join Date: Nov 2010
Location: Anchorage,AK
Posts: 84
Likes: 0
Received 1 Like on 1 Post
Originally Posted by CharlieBrownRacing
so very interesting this would seem to be the best for fuel economy and performance if u need any help just ask man if u need pics or anything i have a 83 gsl and am very tempted to remove the the rats nest but wanted the shutter valve function
can you follow the rats nest and tell me which port the yellow and soliniod connects to so I can be sure I have the diagam is correct...

Last edited by Xamnglc; 07-20-12 at 11:53 AM.
Old 07-20-12, 03:22 PM
  #10  
Full Member
Thread Starter
iTrader: (1)
 
Xamnglc's Avatar
 
Join Date: Nov 2010
Location: Anchorage,AK
Posts: 84
Likes: 0
Received 1 Like on 1 Post
ok, Ive figured it out... Here is a new diagram
Attached Thumbnails NEW PARTIAL Rat's nest removal mod...-ratsnestlightnoaab2.jpg  
Old 07-20-12, 05:04 PM
  #11  
Always Wanting to Learn

iTrader: (49)
 
DreamInRotary's Avatar
 
Join Date: Aug 2011
Location: Cambridge, Minnesota
Posts: 3,078
Received 42 Likes on 40 Posts
Cool idea, looks awesome. I will keep tabs on the thread until I see it has come to fruition. I actually just bought the silicon hose to redo my rats nest in all blue - I like the custom look under the air cleaner with the blue hose, and I want it back on the car. Not trying to start the debate, there are plenty of other threads for that.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
jdayau
Build Threads
8
11-29-19 12:11 AM
Steelwheelz
2nd Generation Specific (1986-1992)
6
09-15-15 03:22 PM



Quick Reply: NEW PARTIAL Rat's nest removal mod...



All times are GMT -5. The time now is 07:36 AM.