Zener Diode Boost Fooler - Ford Truck Enthusiasts Forums



1999 - 2003 7.3L Power Stroke Diesel SPONSORED BY:

Zener Diode Boost Fooler

Reply
 
 
 
LinkBack Thread Tools Search this Thread
  #1  
Old 04-01-2009, 04:04 PM
MR5x5 MR5x5 is offline
Senior User
Thread Starter
 
Join Date: Mar 2007
Location: Issaquah, WA
Posts: 471
MR5x5 is gaining momentum as a positive member of FTE.MR5x5 is gaining momentum as a positive member of FTE.
Zener Diode Boost Fooler

Anybody out there using a zener diode at the MAP sensor to limit the boost signal to the PCM in order to avoid defueling.

Just curious if there is a downside to this method..?

Mike
Reply With Quote
  #2  
Old 04-01-2009, 04:06 PM
superduty4x4's Avatar
superduty4x4 superduty4x4 is offline
Post Fiend
 
Join Date: Jul 2003
Location: Newport, WA
Posts: 12,024
superduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud of
Popular opinion says it works. There are a few guys who caution against it for reasons I can't remember, but it had to do with damage to the MAP sensor. I have one some place... I wish I could find the bugger and install it.
I had a thread on this a while back, I'll try to dig it up.
Reply With Quote
  #3  
Old 04-01-2009, 04:11 PM
megawatt00's Avatar
megawatt00 megawatt00 is offline
Moderator
 
Join Date: Jan 2008
Location: Rochdale MA
Posts: 13,140
megawatt00 has a superb reputationmegawatt00 has a superb reputationmegawatt00 has a superb reputationmegawatt00 has a superb reputationmegawatt00 has a superb reputationmegawatt00 has a superb reputationmegawatt00 has a superb reputationmegawatt00 has a superb reputationmegawatt00 has a superb reputationmegawatt00 has a superb reputationmegawatt00 has a superb reputation
Why not just use an air regulator installed in the map line?
Reply With Quote
  #4  
Old 04-01-2009, 04:14 PM
superduty4x4's Avatar
superduty4x4 superduty4x4 is offline
Post Fiend
 
Join Date: Jul 2003
Location: Newport, WA
Posts: 12,024
superduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud of
Quote:
Originally Posted by megawatt00 View Post
Why not just use an air regulator installed in the map line?
The zener diode is easier to install and looks basically factory when done- no need to mount a regulator, run new lines, etc. Just an electronic way of accomplishing the same thing.

link 1
link 2
link 3
Reply With Quote
  #5  
Old 04-01-2009, 04:29 PM
megawatt00's Avatar
megawatt00 megawatt00 is offline
Moderator
 
Join Date: Jan 2008
Location: Rochdale MA
Posts: 13,140
megawatt00 has a superb reputationmegawatt00 has a superb reputationmegawatt00 has a superb reputationmegawatt00 has a superb reputationmegawatt00 has a superb reputationmegawatt00 has a superb reputationmegawatt00 has a superb reputationmegawatt00 has a superb reputationmegawatt00 has a superb reputationmegawatt00 has a superb reputationmegawatt00 has a superb reputation
Quote:
Originally Posted by superduty4x4 View Post
The zener diode is easier to install and looks basically factory when done- no need to mount a regulator, run new lines, etc. Just an electronic way of accomplishing the same thing.

link 1
link 2
link 3
That was some intresting reading Chase. Thanks for the links!
Reply With Quote
  #6  
Old 04-01-2009, 04:32 PM
smoky_diesel's Avatar
smoky_diesel smoky_diesel is offline
Elder User
 
Join Date: Sep 2007
Location: Chandler, AZ
Posts: 693
smoky_diesel is a name known to allsmoky_diesel is a name known to allsmoky_diesel is a name known to allsmoky_diesel is a name known to allsmoky_diesel is a name known to allsmoky_diesel is a name known to all
I think the closest zener is going to be 4.7 volt.

Not sure what the output impeadence/drive capability of the MAP sensor is but there may be an issue with the zener clamp current, depending on what diode you use. I believe the EEC-IV inputs are BJTs with input impeadence in the 10's of kohm range so it will only ask the sensor for 1ma or so. most zeners need way more current than that to hold there voltage rating (4.7volts or whatever)

I went with the ITP OBA because it is proven, simple and I didn't want to hack up the factory wiring.

Now, if you really wanted to over engineer a voltage clamp with nano second delay, use a mircrocontroller with a A/D & D/A converters and write some software
Reply With Quote
  #7  
Old 04-01-2009, 04:35 PM
superduty4x4's Avatar
superduty4x4 superduty4x4 is offline
Post Fiend
 
Join Date: Jul 2003
Location: Newport, WA
Posts: 12,024
superduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud of
Quote:
Originally Posted by smoky_diesel View Post
I think the closest zener is going to be 4.7 volt.

Not sure what the output impeadence/drive capability of the MAP sensor is but there may be an issue with the zener clamp current, depending on what diode you use. I believe the EEC-IV inputs are BJTs with input impeadence in the 10's of kohm range so it will only ask the sensor for 1ma or so.

I went with the ITP OBA because it is proven, simple and I didn't want to hack up the factory wiring.

Now, if you really wanted to over engineer a voltage clamp with nano second delay, use a mircrocontroller with a A/D input and write some software
No need to hack wiring, just stuff the wires of the diode into the plug.
You lost me after EEC-IV
Reply With Quote
  #8  
Old 04-01-2009, 05:01 PM
MR5x5 MR5x5 is offline
Senior User
Thread Starter
 
Join Date: Mar 2007
Location: Issaquah, WA
Posts: 471
MR5x5 is gaining momentum as a positive member of FTE.MR5x5 is gaining momentum as a positive member of FTE.
Chase, Thanks for the links. Not sure I'm seeing a definitive answer. Maybe effects the map, maybe not... Maybe need a to add a resistor, maybe not... Both the diode and a mechanical solutions have some "non-ideal" characteristics.

Being a mechanical guy who doesn't tust anything electrical, I guess I'm leaning toward the mechanical solution.

Thanks again.
Reply With Quote
  #9  
Old 04-01-2009, 07:14 PM
ron's power stroke's Avatar
ron's power stroke ron's power stroke is offline
Post Fiend
 
Join Date: Jun 2006
Location: White Mnt's,New Hampshire
Posts: 9,716
ron's power stroke has much to be proud ofron's power stroke has much to be proud ofron's power stroke has much to be proud ofron's power stroke has much to be proud ofron's power stroke has much to be proud ofron's power stroke has much to be proud ofron's power stroke has much to be proud ofron's power stroke has much to be proud ofron's power stroke has much to be proud ofron's power stroke has much to be proud of
electronic "do-dads". a number of these were replaced due to their effect on low speed, low boost drivability. don't mess with the electronics, the PCM and MAP Sensor maintain 100% normal connectivity with no electronic interference withthe OBA..the OBA lets the map see live ###''s at that moment.. the resistor is slow to re act..
Reply With Quote
  #10  
Old 04-01-2009, 07:26 PM
superduty4x4's Avatar
superduty4x4 superduty4x4 is offline
Post Fiend
 
Join Date: Jul 2003
Location: Newport, WA
Posts: 12,024
superduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud ofsuperduty4x4 has much to be proud of
Quote:
Originally Posted by ron's power stroke View Post
electronic "do-dads". a number of these were replaced due to their effect on low speed, low boost drivability. don't mess with the electronics, the PCM and MAP Sensor maintain 100% normal connectivity with no electronic interference withthe OBA..the OBA lets the map see live ###''s at that moment.. the resistor is slow to re act..
Ron- the OBA keeps the MAP from seeing boost over 23 psi (or wherever you have it set). The diode does the same thing, only by limiting voltage instead of psi. I can see where the diode could effect the sensor in other ways (I'm no electronics expert) or may be slower to react but all it does is limit the voltage the MAP sends to the PCM. Ifthe diode has no other effects on the MAP sensor I think it's a way better option than an OBA- less clutter, less cost. I really wish I could find the one I had...
Reply With Quote
  #11  
Old 04-02-2009, 05:22 PM
smoky_diesel's Avatar
smoky_diesel smoky_diesel is offline
Elder User
 
Join Date: Sep 2007
Location: Chandler, AZ
Posts: 693
smoky_diesel is a name known to allsmoky_diesel is a name known to allsmoky_diesel is a name known to allsmoky_diesel is a name known to allsmoky_diesel is a name known to allsmoky_diesel is a name known to all
Quote:
Originally Posted by ron's power stroke View Post
the resistor is slow to re act..
all electronics operate at the speed of light.

it is the non-ideal charateristics of a diode that give the precepion of a 'delay'. the plot by ernest eugene in one of the links above shows it well

adding a resistor in series to the diode circuit to protect overloading the MAP will only make it preform less ideal, or not at all. a typical zener needs to be reverse biased and fed 20-100ma to get it to drop (or hold) it's rated voltage. the MAP isn't going to support that, it would need a voltage follower current amplifer.
Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Help with 91 Bronco wiring ussue BigLarry 1978 - 1996 Big Bronco 1 04-28-2016 09:01 AM
12v to 6v zener diode help rtcabal 1967 - 1972 F-100 & Larger F-Series Trucks 16 12-29-2015 08:04 PM
Got my MAP fooler today. Total cost = $0 superduty4x4 1999 - 2003 7.3L Power Stroke Diesel 3 03-24-2008 10:16 PM
zener diode install? jadel 1999 - 2003 7.3L Power Stroke Diesel 6 02-14-2005 08:24 PM
Map Sensor Mods? oldhampete 1999 - 2003 7.3L Power Stroke Diesel 11 10-28-2003 11:24 PM


Go Back   Ford Truck Enthusiasts Forums >

Tags
03, 73, 99, boost, boosting, diode, f250, fooler, foolers, ford, hacking, map, mess, pcm, sensor, turbos

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Forum Jump


All times are GMT -5. The time now is 02:56 PM.


This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. FordŽ is a registered trademark of the Ford Motor Company.