Boost Pressure

[Dgc333]

Can someone explain to me barometer pressure in relation to our Ranger and how to tell if something is not working correctly if barometer pressure is "so and so". Please

Barometric pressure is the pressure that is applied to everyone and everything on the surface of the earth by the atmosphere that surrounds the earth. Your altitude in relation to sea level will will vary the barometric pressure as well weather conditions. Barometric pressure is in reference to no pressure at all as in outer space. The weather guy talks about it in "Hg (inches of Mercury) so you see numbers like 30 +/- "Hg it can be expressed in psi absolute (psia) or typically around 14.7 psia.

Here in North America we talk about boost in pounds per square inch or psi and manifold vacuum in "Hg. Typical Boost gauges will display both manifold vacuum as well as boost pressure. On the boost side it will be graduated in psi and on the vacuum side "Hg. When the engine is not running the gauge will read 0 or in relation to barometric pressure 14.7 psia. If you have 10 psi of boost that would be 24.7 psia. On the vacuum side 15"Hg would be approximately 7.3 psia.

It has been mentioned in this thread that the engine produces less boost in cooler weather. The reason for this is the 2.3 Ecoboost control strategy is for the engine to meet torque targets. In cooler denser air it does not require as much boost to meet the torque target.

Sponsored

 

[yamahaSHO]

Barometric pressure is the pressure that is applied to everyone and everything on the surface of the earth by the atmosphere that surrounds the earth. Your altitude in relation to sea level will will vary the barometric pressure as well weather conditions. Barometric pressure is in reference to no pressure at all as in outer space. The weather guy talks about it in "Hg (inches of Mercury) so you see numbers like 30 +/- "Hg it can be expressed in psi absolute (psia) or typically around 14.7 psia.

Here in North America we talk about boost in pounds per square inch or psi and manifold vacuum in "Hg. Typical Boost gauges will display both manifold vacuum as well as boost pressure. On the boost side it will be graduated in psi and on the vacuum side "Hg. When the engine is not running the gauge will read 0 or in relation to barometric pressure 14.7 psia. If you have 10 psi of boost that would be 24.7 psia. On the vacuum side 15"Hg would be approximately 7.3 psia.

14.7 PSI is roughly what you'd see at 'sea level', barring any high or low pressure front. Where I live at 8k feet above sea level, I generally see 10-11 PSI (12's when I drive into Denver) of atmospheric pressure (vacuum readings of -7PSI/14.x inHg on one of my cars, where near sea level, it reads -10 to -11 PSI/20-22 inHg and -3.8 PSI on one of my cammed vehicles). Manifold pressure of 25 PSI over atmospheric, here, is more like 35-36 PSI, absolute.

Power loss is real up here. You lose power, run out of compressor efficiency, and have less air to remove heat. If you can keep a vehicle cool up here, you can easily keep it cool at lower altitudes.

It has been mentioned in this thread that the engine produces less boost in cooler weather. The reason for this is the 2.3 Ecoboost control strategy is for the engine to meet torque targets. In cooler denser air it does not require as much boost to meet the torque target.

I don't have any Ford software available as the Ford's I generally tune are a bit older and we move to stand-alone ECU's, (this being one of them: ), but here some tables from a Subaru:


Boost Target vs Barometric Pressure:

Wastegate Duty Cycle vs Barometric pressure (this is a stock map, you don't need negative values in to make less boost at altitude, it will automatically do that, so my tables generally look different):

And like mentioned above, some vehicles will use torque request... They all implement them a little different... From the same Subaru map, this is one of three different throttle maps that a user can select on the fly:

2 of 3:

You can also set a hard limit between the 3 selections, so it's like having 3 maps on-the-fly:

Which this correlates into how much boost you'll run:

Then here is a VW with lots of torque tables :

I'll start using Ranger tables when I receive my Ranger and get some software. I wish Cobb supported it as they support other EcoBoost stuff.

 

[Smprfiguy]

Here is some light reading for you it should just about cover all your questions.

 

[dondonbabyraptor]

Barometric pressure is the pressure that is applied to everyone and everything on the surface of the earth by the atmosphere that surrounds the earth. Your altitude in relation to sea level will will vary the barometric pressure as well weather conditions. Barometric pressure is in reference to no pressure at all as in outer space. The weather guy talks about it in "Hg (inches of Mercury) so you see numbers like 30 +/- "Hg it can be expressed in psi absolute (psia) or typically around 14.7 psia.

Here in North America we talk about boost in pounds per square inch or psi and manifold vacuum in "Hg. Typical Boost gauges will display both manifold vacuum as well as boost pressure. On the boost side it will be graduated in psi and on the vacuum side "Hg. When the engine is not running the gauge will read 0 or in relation to barometric pressure 14.7 psia. If you have 10 psi of boost that would be 24.7 psia. On the vacuum side 15"Hg would be approximately 7.3 psia.

It has been mentioned in this thread that the engine produces less boost in cooler weather. The reason for this is the 2.3 Ecoboost control strategy is for the engine to meet torque targets. In cooler denser air it does not require as much boost to meet the torque target.

Appreciate the very detailed response. Hello my me figure out more about this world, thank you Dave

 

[Dr3wDrop]

This looks soooo good!

I am going to reach out to P3 first to see if they plan on making an air vent boost gauge. If they have no intentions, I will certainly get in touch with HN Customs for one of these.

Based on your pictures, looks like a lot of the cutting under the vent was for that blue air tubing. I may go with an electric gauge this one to minimize my butchering skills.

 

[Dr3wDrop]

P3 got back to me within the hour. They have no intention on making a Ranger boost gauge as the market is too small. They did point me to their universal diy gauges though.
https://www.p3cars.com/diy/

 

[Dgc333]

I am finally getting around to adding a boost, oil pressure and volt gauge to my Ranger. This thread piping up in my unread list got me to go back through it.

Where is this kit purchased from? I was thinking I was going to have to cut the line and patch a tee in.

 

[Dr3wDrop]

Where is this kit purchased from? I was thinking I was going to have to cut the line and patch a tee in.

Here you go. I bookmarked it.
https://cp-e.com/shop/product/ford-ecoboost-2-3l-turbo-maptap/

 

[Dgc333]

Here you go. I bookmarked it.
https://cp-e.com/shop/product/ford-ecoboost-2-3l-turbo-maptap/

Thanks, I found it after I made that post and it should be arriving in a day or two.

 

[RARE5.0]

I would highly recommend HN Customs out of Australia if anyone else wants a vent pod!

I know it's been a few years. But how long did it take you to get the pod? I ordered in August of 2022 and still don't have it. And messaged him and he said it was shipped and I emailed and messaged a few times and no response

Sponsored