Engine Management eCtune , Crome , AFC , FMU , Zdyne , Hondata , EMS , TE , Uberdata Anything to control your fuel, spark needs!

ECU not seeing correct boost level?

Old 05-31-2004, 10:37 AM
  #1  
1.5 BAR
Thread Starter
 
Join Date: Mar 2003
Posts: 1,190
Default ECU not seeing correct boost level?

It's tough to know exactly how much boost the ecu is seeing, because my analog boost guage always seems to give me a different reading than the pressure level on the SAFC. The SAFC is only in my car because i'm too lazy to take it out; I am using Uberdata. The SAFC settings are all on 0%. My question is, if the boost guage is displaying 10 psi, and the SAFC is only at about 0.5 bar (7.4 psi I guess), is the ecu only seeing 7.4 psi of boost, or is the SAFC just interpreting the MAP sensor voltage incorrectly?
willahlborn is offline  
Old 05-31-2004, 11:33 AM
  #2  
3.0 BAR
 
Join Date: Apr 2003
Posts: 2,260
Default Re:ECU not seeing correct boost level?

when your at ambient, is your analog gauge right on 0?

I have one of those Autometer Ultra Lites, and it sits at about 2lbs at ambient.

Maybe your gauge is off? ..I wouldn't lean towards the SAFC being too off unless you set it correctly(?).
TurboEF9 is offline  
Old 05-31-2004, 03:11 PM
  #3  
1.5 BAR
Thread Starter
 
Join Date: Mar 2003
Posts: 1,190
Default Re:ECU not seeing correct boost level?

Originally Posted by TurboEF9
when your at ambient, is your analog gauge right on 0?
Unfortunately I don't know; I am using a Banks Boost Guage, and it only shows positive pressure (can't go south of 0). I guess Banks stuff is mainly for turbo diesel stuff, I dunno.
willahlborn is offline  
Old 05-31-2004, 05:52 PM
  #4  
1.5 BAR
 
Join Date: Feb 2004
Posts: 1,039
Default Re:ECU not seeing correct boost level?

Honda MAP sensors are absolute aren't they not?
most boost gauges are relative so the boost gauge may be seeing 10psi of preasure difference from the manifold to ambient while the ecu is only seeing 7.4psi above sea level?

correct me if i'm wrong
ComputerJLT is offline  
Old 05-31-2004, 07:28 PM
  #5  
1.5 BAR
Thread Starter
 
Join Date: Mar 2003
Posts: 1,190
Default Re:ECU not seeing correct boost level?

Originally Posted by ComputerJLT
Honda MAP sensors are absolute aren't they not?
most boost gauges are relative so the boost gauge may be seeing 10psi of preasure difference from the manifold to ambient while the ecu is only seeing 7.4psi above sea level?

correct me if i'm wrong
Would this make the reading on the SAFC more accurate than the boost guage?
willahlborn is offline  
Old 06-06-2004, 02:10 AM
  #6  
0.5 BAR
 
Join Date: Feb 2004
Posts: 60
Default Re:ECU not seeing correct boost level?

are you using check valve or anything to hind the boost from the ecu?
redcrxsi is offline  
Old 06-06-2004, 02:27 AM
  #7  
3.0 BAR
 
Join Date: Dec 2002
Posts: 3,832
Default Re:ECU not seeing correct boost level?

IMHO obd0 maps read about 1-1.5psi lower than my autometer gauge.
This was referenced to my Hdata loggings.
leed is offline  
Old 06-06-2004, 03:41 AM
  #8  
1.5 BAR
 
Join Date: Feb 2004
Posts: 1,039
Default Re:ECU not seeing correct boost level?

Originally Posted by Will
Originally Posted by ComputerJLT
Honda MAP sensors are absolute aren't they not?
most boost gauges are relative so the boost gauge may be seeing 10psi of preasure difference from the manifold to ambient while the ecu is only seeing 7.4psi above sea level?

correct me if i'm wrong
Would this make the reading on the SAFC more accurate than the boost guage?

if the map sensor is absolute then yes. it will see the absolute pressure inside the manifold as it would be at sea level. makes sense to me but i really have no idea if the map sensor is relative or absolute.
but yeah; the general rule of thumb is that cheap boost gauges aren't verry accurate.
ComputerJLT is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Tom-Guy
General Discussion
26
03-05-2009 07:48 AM
rudebwoy
Forced Induction
4
08-20-2003 02:49 AM
shortyz
General Discussion
0
07-01-2003 01:46 PM
turboDXcoupe
Forced Induction
1
07-01-2003 01:46 PM


Thread Tools
Search this Thread
Quick Reply: ECU not seeing correct boost level?


Contact Us - Sitemap - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.