Go Back   EcoModder Forum > EcoModding > Instrumentation
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 09-22-2008, 09:24 PM   #1 (permalink)
dcb
needs more cowbell
 
dcb's Avatar
 
Join Date: Feb 2008
Location:
Posts: 5,038

pimp mobile - '81 suzuki gs 250 t
90 day: 96.29 mpg (US)

schnitzel - '01 Volkswagen Golf TDI
90 day: 53.56 mpg (US)
Thanks: 158
Thanked 267 Times in 210 Posts
Reading a MAP sensor

Here's my notes on experimenting with a map sensor on the bench with a brake bleeder pump and a duino. using a 5 volt reference.

inches of mercury, pin value
ambient, 762
3, 667
5, 619
8, 543
10, 493
14, 390


~25.18 units per inch

Map pinout (your sensor may be different)
Code:
connector  _________
front     (_________)
              ||
            A  B  C
           +5  -  Signal (on analog 1)
looks pretty linear till you get near ambient. The cheap gauge on the pump probably has a lot to do with that.

Code:
int mapPin=1;
void setup(){
  Serial.begin(9600);
}
void loop(){
  Serial.println(analogRead(mapPin));
  delay(500);
}

__________________
WINDMILLS DO NOT WORK THAT WAY!!!

Last edited by dcb; 09-22-2008 at 09:38 PM..
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 09-17-2010, 10:12 PM   #2 (permalink)
cmj
Team Honda
 
Join Date: Sep 2010
Location: Greenwood
Posts: 39

Honda - '96 Honda Civic EX
90 day: 36.12 mpg (US)
Thanks: 0
Thanked 1 Time in 1 Post
If you don't mind, I'll be adding my .02 to this thread very soon!
  Reply With Quote
Old 09-18-2010, 12:58 PM   #3 (permalink)
Administrator
 
Daox's Avatar
 
Join Date: Dec 2007
Location: Germantown, WI
Posts: 11,173

CM400E - '81 Honda CM400E
90 day: 51.49 mpg (US)

Daox's Grey Prius - '04 Toyota Prius
Team Toyota
90 day: 49.53 mpg (US)

Daox's Insight - '00 Honda Insight
90 day: 64.33 mpg (US)

Swarthy - '14 Mitsubishi Mirage DE
Mitsubishi
90 day: 56.69 mpg (US)
Thanks: 2,471
Thanked 2,537 Times in 1,529 Posts
Whatcha thinking about doing with map sensor info dcb?
__________________
Current project: A better alternator delete
  Reply With Quote
Old 09-18-2010, 03:00 PM   #4 (permalink)
...beats walking...
 
Join Date: Jul 2009
Location: .
Posts: 6,190
Thanks: 179
Thanked 1,522 Times in 1,123 Posts
...a computerized VACUUM gauge path toward realtime BSFC?
  Reply With Quote
Old 09-18-2010, 09:49 PM   #5 (permalink)
dcb
needs more cowbell
 
dcb's Avatar
 
Join Date: Feb 2008
Location:
Posts: 5,038

pimp mobile - '81 suzuki gs 250 t
90 day: 96.29 mpg (US)

schnitzel - '01 Volkswagen Golf TDI
90 day: 53.56 mpg (US)
Thanks: 158
Thanked 267 Times in 210 Posts
looking around it seems like there might be different map sensors in circulation, so folks would probably have to borrow a vacuum gauge and pump to do their own calibrating.

__________________
WINDMILLS DO NOT WORK THAT WAY!!!
  Reply With Quote
Old 09-19-2010, 05:13 PM   #6 (permalink)
...beats walking...
 
Join Date: Jul 2009
Location: .
Posts: 6,190
Thanks: 179
Thanked 1,522 Times in 1,123 Posts
...both of those plots look very linear to my eyes!

...what R-squared values do you get--three-9's or better?
  Reply With Quote
Old 09-19-2010, 05:27 PM   #7 (permalink)
dcb
needs more cowbell
 
dcb's Avatar
 
Join Date: Feb 2008
Location:
Posts: 5,038

pimp mobile - '81 suzuki gs 250 t
90 day: 96.29 mpg (US)

schnitzel - '01 Volkswagen Golf TDI
90 day: 53.56 mpg (US)
Thanks: 158
Thanked 267 Times in 210 Posts
yes linear, but different all the same, you still have to figure out your own personal slope and offset for the map sensor in your car if you are looking for absolute numbers. Of course as a "beat your own high score" semi-arbitrary indicator then it is fine.
__________________
WINDMILLS DO NOT WORK THAT WAY!!!
  Reply With Quote
Old 09-19-2010, 07:29 PM   #8 (permalink)
...beats walking...
 
Join Date: Jul 2009
Location: .
Posts: 6,190
Thanks: 179
Thanked 1,522 Times in 1,123 Posts
...it looks like a "normally aspirated" sensor (blue) vs. a "supercharged" sensor (pink) to my eyes.

...and, both are 'full-scale' max'ed at 5.0Vdc.

Last edited by gone-ot; 09-19-2010 at 09:49 PM..
  Reply With Quote
Old 09-19-2010, 07:44 PM   #9 (permalink)
dcb
needs more cowbell
 
dcb's Avatar
 
Join Date: Feb 2008
Location:
Posts: 5,038

pimp mobile - '81 suzuki gs 250 t
90 day: 96.29 mpg (US)

schnitzel - '01 Volkswagen Golf TDI
90 day: 53.56 mpg (US)
Thanks: 158
Thanked 267 Times in 210 Posts
feel free to research it It may be that there are only a couple slopes and offsets in practice and that you can make a good guess by taking an engine off reading.
__________________
WINDMILLS DO NOT WORK THAT WAY!!!
  Reply With Quote
Old 09-19-2010, 09:22 PM   #10 (permalink)
Master EcoModder
 
Join Date: Sep 2009
Posts: 5,927
Thanks: 877
Thanked 2,020 Times in 1,303 Posts
If you know the MAP, RPM, and fuel consumption, shouldn't you be able to map BSFC for any engine?

regards
Mech

  Reply With Quote
Reply  Post New Thread


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Best spark plugs / wires with FE in mind? noopy7 EcoModding Central 12 10-29-2010 03:18 PM
My Kingdom for a NOx Sensor cfg83 EcoModding Central 19 08-25-2010 06:55 PM
VX Info...WARNING: lots of info! TomO Off-Topic Tech 1 01-05-2010 12:39 PM
Oxygen sensor gauge reading at wider throttle openings markweatherill Instrumentation 4 08-28-2008 05:18 PM
MAF sensor life Daox Off-Topic Tech 9 03-25-2008 02:29 PM



Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com