M.a.p sensor infomation for all

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D-P DEVELOPMENTS

Member +
Been asked about these on numerous times so thought i would put a post up explaining what they are what they do and why we use them:rockon::rockon:

Here goes....

Firstly map is its short name it is a "Manifold Absolute Pressure" sensor

You will find these on pritty much all fuel injected cars as they gauge the pressure of air in the inlet manifold to fuel the car correctly. When on a N/A car they are typically a 1 bar M.A.P sensor as this is all you need as the rate of pressure will not increse or go over 14.7 PSI so that is all a n/a car needs as there is no forced induction to raise the pressure in manifold.

On a Turbo/Supercharged car the pressure is boosted in the inlet manifold to above atmosphere (14.7 PSI) so the map sensor has to read higher than 1 bar (14.7 PSI) So a 2 bar sensor is commanly found on turboed cars.

The pressure a MAP sensor can read is matched to the amount of boost the turbo is making,thus if you crank the boost up beyond what a MAP sensor can read it will only fuel the car to its maximum limit set by the MAP sensor which will cause the ECU to under fuel your car, makeing poor performance and damaging you engine.

Its easy to get around this with a tuner that noes his stuff but the best way is to replace with the like of a 3 bar sensor, as the 3 bar can read 2 bar above atmosphere or 44 PSI.

This is just a brief insight but seen the MAP sensor commanly overlooked in past and its such a integral part of the engine if doing a turbo conversion but now i hope more can understand why its such a integral part of the engine and tuneing :teach::rockon:


If you belive anything i have stated to be wrong or incorrect please step in and edit as i am no expert but this is just what i have picked up through tuners and relevent infomation about them :beer:
 
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starlet666

Member +
a 1 bar map sensor found on n/a cars doesnt read any positive presure therfor it reads under the atmosphere....
a 2 bar map sensor will read up to 14.7 (say 15 for easy refrence)psi...
it will read one bar under and one bar over

a 3 bar map sensor will read up to around 30 psi.....
it will read 1 bar under the atmosphere as a base and 2 bars over.....

and not pretty much all fuel injected cars run them.... 99% of new cars do not run them as they all use a MAF sensor or Mass Air Flow meter......

cars like alot of the new turbo cars run a MAP and a MAF to be alot more accurate

most nissan turbos use just a MAF
most toyota turbos use just a MAP

MAF works by the hotwire inside it being cooled down by the air flowing across it and letting more voltage through it therefore acting just like a map sensor to a certain extent

cheers guys
 
D

D-P DEVELOPMENTS

Member +
starlet666 said:
a 1 bar map sensor found on n/a cars doesnt read any positive presure therfor it reads under the atmosphere....
a 2 bar map sensor will read up to 14.7 (say 15 for easy refrence)psi...
it will read one bar under and one bar over

a 3 bar map sensor will read up to around 30 psi.....
it will read 1 bar under the atmosphere as a base and 2 bars over.....

and not pretty much all fuel injected cars run them.... 99% of new cars do not run them as they all use a MAF sensor or Mass Air Flow meter......

cars like alot of the new turbo cars run a MAP and a MAF to be alot more accurate

most nissan turbos use just a MAF
most toyota turbos use just a MAP

MAF works by the hotwire inside it being cooled down by the air flowing across it and letting more voltage through it therefore acting just like a map sensor to a certain extent

cheers guys
Click to expand...



Cheers bud suppose most was the wrong word to use there been a long day haha but 1 thing i do no is a 3 bar sensor will boost all the way to 44PSI without fear of your map sensor hitting limits that i have black and white in front of me :cool:
 
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starlet666

Member +
it will kinda fuel it to 44 psi... but if it was hooked up to a gauge it wont read to 44psi.... i know cause my 3 bar map sensor on my emange goes to 33psi max..... trust me i tried to make it read more lol... seems the car runs out of fuel at 30 psi anyways without 65psi base fuel pressure at the rail lol
 
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hardcoreep

Member +
1: MAP sensors for NA car is called vacuum sensor. MAP sensor for boosted car is Pressure sensor. Some NA cars like the Honda actually have a Pressure sensor you just have to turn it on in the ECU using something like Hondata.

2: Any MAP sensor will fuel to whatever boost you put it at, what will happen is that the car will just use the last known value in the ECU for its peak boost pressure, or will switch to a load map using rpm or injector duty cycle matched with a/f ratio. The car will just go into open loop.

3: Toyota MAF uses a flap method.
 
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starlet666

Member +
1 Bar Map Sensor
A 1 bar MAP sensor is capable of reading intake pressures below or equal to atmospheric pressure, for this reason a 1 bar MAP sensor is suitable only for naturally aspirated engines (ie not turbo or supercharged).



2 Bar Map Sensor
A 2 bar MAP sensor is capable of reading intake pressures up to 1 bar of positive pressure above atmospheric (otherwise known as boost). This is equivalent to around 14.7psi of boost or 100kpa of positive pressure. This sensor is suitable for turbocharged or supercharged vehicles running 15psi of boost or less.




just a bit of an add on as something more complete than i said b4.....
3 Bar Map Sensor
A 3 bar MAP sensor is capable of reading intake pressures up to 2 bar of positive pressure above atmospheric (otherwise known as boost). This is equivalent to around 29.4psi of boost or 200kpa of positive pressure. This sensor is suitable for turbocharged or supercharged vehicles running between 15psi and 30psi of boost.
 
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Starbus

Member +
D-P DEVELOPMENTS said:
Cheers bud suppose most was the wrong word to use there been a long day haha but 1 thing i do no is a 3 bar sensor will boost all the way to 44PSI without fear of your map sensor hitting limits that i have black and white in front of me :cool:
Click to expand...

I'm afriad it doesn't a 3 bar map sensor will go to 30ish psi before you need to upgrade.

Usually you find most n/a car's have higher than 1 bar MAP sensors, 1 bar would only go to "normal" pressure but there are occasions when n/a car's go slightly higher than this, but we'll save that for another day.

Also LOTs of car's don't have a MAP sensor at all, and just have a MAF.

Even some boosted car's don't have map sensors, Earlier Evo's for example.
 
Idrees

Idrees

Banned
It's on the Bulkhead mate. Behind the inlet manifold, on the left hand side. It has one vacuum pipe going in to it, and a plug with 3 wires (I think its 3). It has an orange sticker with the part number on it, and it says something along the lines of pressure sensor on it.
 
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1300wipass

Member +
so just a final comfirmatiom for the super noob here, this is the one you reffering to here right???.. yes?...... no? (see image below please)

thanks

mapsensor.jpg
 
Sheldon

Sheldon

Malta Area Rep.
1300wipass said:
so just a final comfirmatiom for the super noob here, this is the one you reffering to here right???.. yes?...... no? (see image below please)

thanks

mapsensor.jpg
Click to expand...

no thats not the map sensor... thats the iat if im not wrong.. the map sensor is after the plenum with a vac pipe going from the plenum to the map sensor itself
 
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1300wipass

Member +
so thats the Intake Air Temperature sensor?

any pics of the map sensor? as i was trying to find it, but couldnt..

was trying to locate the orange sticker Idrees was talking about, this was the only sensor i could pickup on the left side..

i will look again for a vaccuum pipe on the left hand side of the plenum
 
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