Converting from MAF to MAP
Senior Member

Joined: Nov 2004
Posts: 768
Likes: 32
From: Lansing, MI
Car: 1988 IROC-Z
Engine: 5.7 TPI
Transmission: 700R4
Axle/Gears: 3.45
Re: Converting from MAF to MAP
My understanding is yes, but the later MAP cars used 3 plugs instead of 2. Also there is some slight mounting differences. So you will need to do re-pinning and plug changes, but it is all available. - I have not done this, just based off my reading.
Have you looked into EBL? You re-pin your two plugs and MAF connector. Keep the same ECM chassis and gain the ability to flash tune and do VE learns to optimize your tuning. This is the route I am going. Have my EBL, MAP, and pigtail all waiting for garage weather to hit.
Have you looked into EBL? You re-pin your two plugs and MAF connector. Keep the same ECM chassis and gain the ability to flash tune and do VE learns to optimize your tuning. This is the route I am going. Have my EBL, MAP, and pigtail all waiting for garage weather to hit.
Joined: Dec 2004
Posts: 16,774
Likes: 1,002
From: Mile High Country !!!
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Senior Member

Joined: Nov 2004
Posts: 768
Likes: 32
From: Lansing, MI
Car: 1988 IROC-Z
Engine: 5.7 TPI
Transmission: 700R4
Axle/Gears: 3.45
Re: Converting from MAF to MAP
No Code 36 
MAFs are expensive and hard to properly diagnose
MAFs are a restriction on air flow
MAFs can be maxed out
MAPs handle boost very well.
MAP is a direct measure of load on an engine rather than the computer having to figure it out with other sensors. All though a MAP system uses other sensors as well, but for different purposes
MAP allows you to use vent to atmosphere blow off valves
MAP keeps small boost/vacuum leaks from causing major problems.
MAP sensor is also closer to the actual intake valves and will give slightly more accurate values than a MAF sensor in terms of what is actually happening in the engine.
Now MAFs can be very accurate but you are reading flow and have to calculate that into a load.
MAFs are less sensitive to changes since they are directly measuring the volume (and equating it to mass based off calibration) of air the engine is consuming flow but once you reach the threshold where tuning is needed the MAP becomes easier.
Obviously both systems work, and the truth be told a hybrid system that uses both is actually ideal. And some newer cars use both. I wish I could find the source where I read how and when it used both and the why as well.
I think the biggest issue with a TPI MAF system is the age and level of technology leaves our MAF cars prone to a lot of issues that can come from a sensor that is extremely difficult to properly diagnose.
MAFs are expensive and hard to properly diagnose
MAFs are a restriction on air flow
MAFs can be maxed out
MAPs handle boost very well.
MAP is a direct measure of load on an engine rather than the computer having to figure it out with other sensors. All though a MAP system uses other sensors as well, but for different purposes
MAP allows you to use vent to atmosphere blow off valves
MAP keeps small boost/vacuum leaks from causing major problems.
MAP sensor is also closer to the actual intake valves and will give slightly more accurate values than a MAF sensor in terms of what is actually happening in the engine.
Now MAFs can be very accurate but you are reading flow and have to calculate that into a load.
MAFs are less sensitive to changes since they are directly measuring the volume (and equating it to mass based off calibration) of air the engine is consuming flow but once you reach the threshold where tuning is needed the MAP becomes easier.
Obviously both systems work, and the truth be told a hybrid system that uses both is actually ideal. And some newer cars use both. I wish I could find the source where I read how and when it used both and the why as well.
I think the biggest issue with a TPI MAF system is the age and level of technology leaves our MAF cars prone to a lot of issues that can come from a sensor that is extremely difficult to properly diagnose.
Last edited by KyleF; Mar 3, 2020 at 08:05 AM.
Re: Converting from MAF to MAP
Here's some example MAF data to counter some of the stated cons: https://datazap.me/u/tequilaboy/test...rk=195-214-124
In this particular log, the 3500 kg/hr meter did peg 5.10 volts around 483 gm/sec at about 5,000 rpm (second marker). With some creative tuning, the use-able flow and rpm range was extended by about another 100 gm/sec or another 1,000 rpm or so to provide some safety margin to protect for a pegged meter. Compare the unlimited airflow signal to the mass airflow signal for some clues as to how this was done. Beyond this the car is already at the limit of its fuel system (48 lb/hr injectors). The third marker is near the flow/hp peak simply as a reference point.
Note: the car was already working pretty hard at the first marker due to the applied dyno load which happens to be similar to a naturally aspirated car's peak load.
- No code 36
- inexpensive sensor
- not hard to diagnose (with scan data)
- not an airflow restriction if properly applied (3" housing in blow-through configuration)
- atmospheric bypass valve installed upstream of maf
- a maxed sensor is easy to mitigate via tuning, increased housing diameter, range extension devices such as a mafia (or simply adding a resistor), or selecting the proper sensor in the first place. Maps can also be maxed out.
- handles boost very well
- handles air temperature variation very well
In this particular log, the 3500 kg/hr meter did peg 5.10 volts around 483 gm/sec at about 5,000 rpm (second marker). With some creative tuning, the use-able flow and rpm range was extended by about another 100 gm/sec or another 1,000 rpm or so to provide some safety margin to protect for a pegged meter. Compare the unlimited airflow signal to the mass airflow signal for some clues as to how this was done. Beyond this the car is already at the limit of its fuel system (48 lb/hr injectors). The third marker is near the flow/hp peak simply as a reference point.
Note: the car was already working pretty hard at the first marker due to the applied dyno load which happens to be similar to a naturally aspirated car's peak load.
Last edited by tequilaboy; Mar 14, 2020 at 08:28 AM.
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Re: Converting from MAF to MAP
Here's an example of a more modern hybrid system with both MAF and MAP sensors: https://datazap.me/u/tequilaboy/log-...mark=2812-2798
Interesting to note is that this controller clearly favors MAF over MAP for fuel control past the first marker which is roughly near the boost peak. Its a 25 psi turbo car for reference. With rising exhaust back pressure, MAP is not the best indicator. The Load signal actually follows the minimum of the MAF and MAP based load values, so the behavior is also subject to calibration.
It is nice to have both, but if forced to choose one or the other I will choose MAF.
Interesting to note is that this controller clearly favors MAF over MAP for fuel control past the first marker which is roughly near the boost peak. Its a 25 psi turbo car for reference. With rising exhaust back pressure, MAP is not the best indicator. The Load signal actually follows the minimum of the MAF and MAP based load values, so the behavior is also subject to calibration.
It is nice to have both, but if forced to choose one or the other I will choose MAF.
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