Welcome to the North American Subaru Impreza Owners Club Sunday May 3, 2015
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Normally Aspirated with bolt-on Forced Induction Powertrain

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 04-20-2004, 11:48 PM   #1
Aus_RS
Scooby Newbie
 
Member#: 35441
Join Date: Apr 2003
Location: Melbourne, Australia
Vehicle:
02 RST
GT2540R

Default Experience with stock MAP sensor?

I got the part number off the stock MAP sensor, and found the datasheet for the part (www.datasheetarchive.com is a very handy site). I've posted the relavent bits here

What I'm wondering is, does the sensor really do what it shows in the datasheet, i.e. the output flattens after about 4.7 volts (~17.7PSI). If that were really true, then people wouldn't be needing 4.7V zeners or other clamps to prevent high MAP pressure CELs, right? Maybe the datasheet just shows the guaranteed linear section or something like that?

Has anyone seen what the stock sensor does in real life at higher pressure?

Cheers,
Mark.
* Registered users of the site do not see these ads.
Aus_RS is offline   Reply With Quote
Old 04-21-2004, 12:34 AM   #2
8Complex

Moderator
 
Member#: 922
Join Date: Feb 2000
Chapter/Region: MWSOC
Location: Schaumburg, IL
Vehicle:
04 FXT
Red

Default

From what I've heard, the output above 4.7-4.8v is very erratic as it's the very end of the ability of the sensor. I don't think it just flattens out as pretty much everyone has proven that it does go above that certain voltage (by needing to use voltage clamps).
8Complex is offline   Reply With Quote
Old 04-22-2004, 07:06 AM   #3
wac
Scooby Specialist
 
Member#: 689
Join Date: Dec 1999
Chapter/Region: NESIC
Location: Lebanon, NH, USA
Vehicle:
2005 Outback 2.5 XT
Champagne Gold Opal

Default Re: Experience with stock MAP sensor?

Quote:
Originally posted by Aus_RS
What I'm wondering is, does the sensor really do what it shows in the datasheet, i.e. the output flattens after about 4.7 volts (~17.7PSI). If that were really true, then people wouldn't be needing 4.7V zeners or other clamps to prevent high MAP pressure CELs, right? Maybe the datasheet just shows the guaranteed linear section or something like that?
You have to realize that P2 is most likely absolute pressure, which corresponds to only about 2 psi of boost.

Also, the graph is a generalization of the MAP sensor response curve. Although actual sensors have guaranteed response for linearity and accuracy in the P1-P2 range, nothing is guaranteed beyond those specified limits of operation. Subaru took care of this by implementing a voltage limit interlock (there's probably a CEL if the voltage went below ~0.3V too).

-WaC
Wayne
wac is offline   Reply With Quote
Reply

Thread Tools
Display Modes

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
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Anyone have experience with P0325 Knock Sensor? kaoz Vancouver Impreza Club Forum -- VIC 11 05-31-2008 03:19 PM
STI UTEC with TXS map sensor and map switch bgod Engine/Power/Exhaust 3 09-06-2007 10:22 PM
Anybody have any experience with DEI motion sensors? hector Car Audio, Video & Security 8 03-25-2007 12:34 AM
Someone please confirm... Stock MAP sensor limit? fc3swrx Engine Management & Tuning 0 06-13-2004 01:12 PM
stock map sensor? Midwayman Normally Aspirated with bolt-on Forced Induction Powertrain 1 05-07-2003 10:39 PM


All times are GMT -4. The time now is 01:26 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2015 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.