3 bar map max reading
09-08-2007, 11:56 AM
#46
Originally Posted by T S M
when it eventially arrives I intend to install it zap back to 1973 and get a fookin refund roflol 
. My brain hurts from thinking about this paradox situation .
09-08-2007, 12:24 PM
#56
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You guys crack me up!Sorry if my post was misleading. I wasnt implying interpolation was a bad thing. As I understood it, the number of positions on the map of an L8 is fixed on the y axis (with the y axis being MAP). given that you have to map for 0-5v, you are constrained by the ECU technology as to how many different map settings you can select for value. BEtween these points, as I understand it, the ECU interpolates between the two valid points of data.
In my oversimplistic way, I assumed that becuase the 0-5v now has to cover 5 bars of pressure absolute, rather than 3, then the gap between these fixed points by necessity (assuming that you cannot simply add lines to the Fuel MAP) are greater.
I visualise this as a number of straight lines (joining points on a curve) to represent a curve. The further apart the straight lines, the more likely the interpolation is to be further away from the desired position on the map.
Is this wrong?
Sorry if I explained it badly!
JJ
09-08-2007, 02:39 PM
#60
Testing the future
JjCoDeX75 that would be correct if the lines of the map had to go the full scale of the MAP sensor - but they don't. you can change the value to what you like
you could use the ecu for a NASP engine and rewrite the maps to use all of the breakpoints for up to 1 bar (absolute)
you could use the ecu for a NASP engine and rewrite the maps to use all of the breakpoints for up to 1 bar (absolute)
09-08-2007, 03:15 PM
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Originally Posted by foreigneRS
JjCoDeX75 that would be correct if the lines of the map had to go the full scale of the MAP sensor - but they don't. you can change the value to what you like
you could use the ecu for a NASP engine and rewrite the maps to use all of the breakpoints for up to 1 bar (absolute)
you could use the ecu for a NASP engine and rewrite the maps to use all of the breakpoints for up to 1 bar (absolute)
That was the point I was trying to make
JJ
09-08-2007, 03:39 PM
#63
Testing the future
yes james, the number of them is fixed - but you only need to spread them out from -1 bar to +2.1 bar (for example). you don't have to spread them from -1 to +4 just because you have a 5 bar MAP sensor 
09-08-2007, 04:08 PM
#64
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Originally Posted by foreigneRS
yes james, the number of them is fixed - but you only need to spread them out from -1 bar to +2.1 bar (for example). you don't have to spread them from -1 to +4 just because you have a 5 bar MAP sensor
But hopefully the point I was trying to make makes a little more sense though!
JJ
10-08-2007, 09:47 AM
#65
Originally Posted by JjCoDeX75
Originally Posted by foreigneRS
JjCoDeX75 that would be correct if the lines of the map had to go the full scale of the MAP sensor - but they don't. you can change the value to what you like
you could use the ecu for a NASP engine and rewrite the maps to use all of the breakpoints for up to 1 bar (absolute)
you could use the ecu for a NASP engine and rewrite the maps to use all of the breakpoints for up to 1 bar (absolute)
That was the point I was trying to make
JJ
10-08-2007, 04:03 PM
#66
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Originally Posted by T S M
Originally Posted by JjCoDeX75
Originally Posted by foreigneRS
JjCoDeX75 that would be correct if the lines of the map had to go the full scale of the MAP sensor - but they don't. you can change the value to what you like
you could use the ecu for a NASP engine and rewrite the maps to use all of the breakpoints for up to 1 bar (absolute)
you could use the ecu for a NASP engine and rewrite the maps to use all of the breakpoints for up to 1 bar (absolute)
That was the point I was trying to make
JJ
10-08-2007, 04:10 PM
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on the topic of map sensors does anybody know how I power 1 up independant of the ECU to datalog with a LM1?
11 = sensor ground
30 = power?
15 = signal
I'm not too sure about how to go about it
any help would be apreciated.
11 = sensor ground
30 = power?
15 = signal
I'm not too sure about how to go about it
any help would be apreciated.
10-08-2007, 04:17 PM
#68
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You have to provide the map sensor with exactly 5 volts DC on the ground and power input.
The LM1 may have this available ?????
The signal output connects to your equipment.
Cant remember off hand the pin numbers for the sensor itself.
Alternativley....
You could data log of the existing sensor in the car.
Just connect the LM1 signal ground to the ecu pin 11 then pin 15 on
the ecu connector goes to the LM1 input.
The LM1 may have this available ?????
The signal output connects to your equipment.
Cant remember off hand the pin numbers for the sensor itself.
Alternativley....
You could data log of the existing sensor in the car.
Just connect the LM1 signal ground to the ecu pin 11 then pin 15 on
the ecu connector goes to the LM1 input.
10-08-2007, 04:22 PM
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Originally Posted by 68332
You have to provide the map sensor with exactly 5 volts DC on the ground and power input.
The LM1 may have this available ?????
The signal output connects to your equipment.
Cant remember off hand the pin numbers for the sensor itself.
Alternativley....
You could data log of the existing sensor in the car.
Just connect the LM1 signal ground to the ecu pin 11 then pin 15 on
the ecu connector goes to the LM1 input.
The LM1 may have this available ?????
The signal output connects to your equipment.
Cant remember off hand the pin numbers for the sensor itself.
Alternativley....
You could data log of the existing sensor in the car.
Just connect the LM1 signal ground to the ecu pin 11 then pin 15 on
the ecu connector goes to the LM1 input.
I didn't want to use the existing sensor as I don't want to mod the loom and want the unit to use on my other cars.
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