×

Sale ends todayGet 30% off any course (excluding packages)

Ends in --- --- ---

MGP vs MAP vs BAP

General Tuning Discussion

Forum Posts

Courses

Blog

Tech Articles

Discuss all things tuning in this section. News, products, problems and results. 

= Resolved threads

Author
149 Views

Hi All,

I have a hard time grasping diffrences between them and appreciate if one can explain this.

BAP is atmospheric pressure which is 14.7 so where does MAP and MGP play in?

it is my understanding MGP is BAP-MAP .

MAP is simply a sensor which measures pressure using silicone chip and resistence wire so when I see 4.7 on map, does that mean 4.7 psi pressure is excerted against the silicone of the full bap 14.7 pressure available and if engine is boosted then you would see much bigger values?

why is map always positive number as I am getting confused between this and MGP

Manifold has vaccume so see MAP of 4.7 psi as positive number but mgp is negative number of -10 -(14.7-4.7).

MAP = Manifold Absolute Pressure

MGP = Manifold Gauge Pressure

The difference between Absolute and Gauge is the zero point. Absolutes zero point is a hard vacuum, there is not a negative scale on Absolute values. Absolute is used over gauge as it has a fixed reference point (the zero is always the same, irrespective of location) and it makes calculations a lot easier not having to deal with negative values in the formula.

Gauge uses either a fixed absolute value (typically 100kPa) or the current barometric pressure as it's zero point, this means that it is a variable and makes calculations and comparisons difficult.

We usually reply within 12hrs (often sooner)

Need Help?

Need help choosing a course?

Experiencing website difficulties?

Or need to contact us for any other reason?