[The Nightman]

Autospeed has an interesting read on eliminating "negative boost" in intakes if anyone is interested:

https://www.autospeed.com/a_0629/page1

[cdgatti]

i think the main disconnect in understanding here is how do you get a pressure reading (psi) from the mass airflow sensor? In fact if you had true mass of air change before and after scoops, the pressure of the air is irrelevant. All you need is the mass difference to know how much more fuel was burned.

[MOD.Works]

I don't want to open a new thread. There has been talk about intake manifold pressure here, so I thought I could ask here.

What unit is "Ladedruck" and "Saugrohrdruck"?


Both indicate intake manifold pressure, or rather vacuum.
When the Ladedruck value is high, at the same time the Saugrohrdruck is low and so on. When changing gear, the difference in values is the biggest, as shown in the second picture.


I could think that Saugrohrdruck could express hPa?




I use TestO.

[Volasko]

Ok ok fine I'll get the scoops and silicone elbow... lol

Great work E90jacob, glad to see actual engineering analysis behind the claims.

[rjahl]

Originally Posted by MOD.Works

I don't want to open a new thread. There has been talk about intake manifold pressure here, so I thought I could ask here.

What unit is "Ladedruck" and "Saugrohrdruck"?


Both indicate intake manifold pressure, or rather vacuum.
When the Ladedruck value is high, at the same time the Saugrohrdruck is low and so on. When changing gear, the difference in values is the biggest, as shown in the second picture.


I could think that Saugrohrdruck could express hPa?




I use TestO.

Don't think you will see these values on a naturally aspirated N52, these are values for the N54. Pressures are recorded before the throttle body for boost pressure and the other is after the throttle body for intake manifold vacuum.

[MOD.Works]

Originally Posted by rjahl

Don't think you will see these values on a naturally aspirated N52, these are values for the N54. Pressures are recorded before the throttle body for boost pressure and the other is after the throttle body for intake manifold vacuum.

I know that the N54 has two pressure sensors. I had a 335i years ago.
Then I made Log with JB4 and later MHD app.

In reality, I don't need the pressure information in the case of the N52. I've been using the MAF and other values to see if I'm getting more air and therefore more power.
I just wanted to know what units the pressure data is for the N52, and which is real data and which is calculated, etc.


I think I'll take a test today. I look at what the value of "Saugrohrdruck" is when the car is not running. The pressure inside the intake manifold should be the same as the outside air pressure. Or at least I can find out which reading corresponds to the outside air pressure at that moment.
I could still try to see if I can measure the boost and how it would appear in those N52 Log values.

[E90jacob]

Originally Posted by MOD.Works

I know that the N54 has two pressure sensors. I had a 335i years ago.
Then I made Log with JB4 and later MHD app.

In reality, I don't need the pressure information in the case of the N52. I've been using the MAF and other values to see if I'm getting more air and therefore more power.
I just wanted to know what units the pressure data is for the N52, and which is real data and which is calculated, etc.


I think I'll take a test today. I look at what the value of "Saugrohrdruck" is when the car is not running. The pressure inside the intake manifold should be the same as the outside air pressure. Or at least I can find out which reading corresponds to the outside air pressure at that moment.
I could still try to see if I can measure the boost and how it would appear in those N52 Log values.

Please update me on this. If my testing wasn't done correctly then I'll re run all my tests but I'm sure that my results are accurate, some are even dyno proven to correlate with my results.

[MOD.Works]

Originally Posted by E90jacob

Please update me on this. If my testing wasn't done correctly then I'll re run all my tests but I'm sure that my results are accurate, some are even dyno proven to correlate with my results.

I did a some testing.

N52 cannot measure boost. Only measure the vacuum. Just like rjahl said.
The sensor is very sensitive, it detects a very small negative pressure changes, but not a positive pressure.
I would think that Ladedruck is the real value from the sensor and Saugrohrdruck is calculate value. It is a calculation with several different parameters.

I notice, when the engine is not running, Saugrohrdruck is not active. But Ladedruck is active and reacts to pressure changes.


You have done a good job of the differences without and with scoops. But you can see the real difference in the MAF values ​​and by doing WOT driving in the full RPM range.
I'm sure that your measurements are in the right way, but how much more is air with Scoops you can only see the MAF values ​​or the clock.
By clock I mean e.g. the virtual Dyno app. Or you can compare time and speed from the Log.


Very very accurate and scientific testing.
At the end of the video, I quietly blow past the end of the hose. The sensor also reacts to this small pressure change.
https://youtu.be/PdoMrKDNnzE

A cold engine runs and the sensor is in the open air. I made vacuum and boost with my mouth.



The engine doesn't run:





Here in this comparison Stage 3IM and N54 intake.
The N54 intake has much higher MAF readings. As you can see, there is not much difference in vacuum values.
However, you can notice that the vacuum increases near the limiter, because the 3IM does not flow so well after 6500RPM. I could think that vacuum data could be used to find out intake and filter restrictions on WOT pull. The N54 air box is very small with a larger pressure fluctuation. When I used the S54 airbox Ladedruck the curve was a bit smoother.

[rjahl]

I've attached a breakdown of the DME reporting values, names, unit and conversion factors. English translation is just a google translate.

[MOD.Works]

Thank you.
This will help me make improvements to my TestO customjobs list.

[rjahl]

Originally Posted by MOD.Works

Thank you.
This will help me make improvements to my TestO customjobs list.

Try the jobs in my custom jobs for Testo, if you have an MSV80, you'll need to copy these over but they should be the same.

These are the parameters I used while logging and self tuning my Z4 E85. It covers just about everything useful.


My N54 MSD 80 parameters are also in this file.

[MOD.Works]

Originally Posted by rjahl

Try the jobs in my custom jobs for Testo, if you have an MSV80, you'll need to copy these over but they should be the same.

These are the parameters I used while logging and self tuning my Z4 E85. It covers just about everything useful.


My N54 MSD 80 parameters are also in this file.

I'll add this to my customjobs and try this next time I do a Log. Thank you.

[Torgus]

I am having a very hard time believe air is being compressed in any meaningful way AFTER going through the air filter.

I believe the scoops give the the air filter a positive pressure environment which is important and it is easier to scavenge air than if the filter was sitting in a negative pressure environment.

The scoops work, but not because they are helping compress the air in the intake manifold.

[rjahl]

Originally Posted by Torgus

I am having a very hard time believe air is being compressed in any meaningful way AFTER going through the air filter.

I believe the scoops give the the air filter a positive pressure environment which is important and it is easier to scavenge air than if the filter was sitting in a negative pressure environment.

The scoops work, but not because they are helping compress the air in the intake manifold.

I'd be interested to see a good data log showing full engine parameters including IATs.


Regarding pressure changed around a vehicle, check out this paper.

http://www.gcdataconcepts.com/carairflow.html

[Volasko]

Originally Posted by Volasko

Ok ok fine I'll get the scoops and silicone elbow... lol

Great work E90jacob, glad to see actual engineering analysis behind the claims.

Just swapped in a Mishimoto silicone elbow and aFe scoops, super simple install. It does seem like it has some more pep while at speed, hard to tell. I cannot tell any difference in intake noise levels but that might be because its already loud after I went the catless header route. That combined with the BMWPE she is a loud girl.

[tylerhart_21]

Based off just viewing the air-scoops there's no difference between eBay or a name brand like afe. (Well just the price difference)