Self made ram air
#42
The diameter of the pipe is 3".....what I had lying around....wonder if I should do one with 4 inch?
#45
New Members
Joined: Dec 2012
Posts: 571
Likes: 10
From: Montreal Quebec Canada
My Ride: 2005 545i, premium package, 6sp manual, cold package, navigation package.
Model Year: 2005
Engine: N62
Well I got some more results just As a note I was carrying 130 lbs more in the car, tires pressure was the same, I ended with 27.6 mpg arriving at my destination, that is .6 better even with the 130 increase in weight....I'm sure if I had the same weight in the car I'd been above 28mpg the computer has adapted to the increased airflow! So my first 650 mile trip gave me 27mpg and even with an increase in weight I still gained another .6 over the original 27 mpg I'm very happy with the functionality of my ram air.
So I'm gonna estimate 3mpg increase from 25.3 to over 28!
So I'm gonna estimate 3mpg increase from 25.3 to over 28!
Any small benefit that you might have gained, would be negated by the small decrease in overall coefficient of friction due to the modification of the air intake. IOW, you increase the drag by 'collecting and raming in' more air.
Respectfully, Bob P.
#46
I am afraid that your estimate is not based on results which would be considered statistically signiifcant. You need much more before and after data to establish if the difference in mileage is really significant and not just due to normal variability. The difference in air pressure at the inlet of your air collecter is probably not more than if the barometric pressure had changed that day.
Any small benefit that you might have gained, would be negated by the small decrease in overall coefficient of friction due to the modification of the air intake. IOW, you increase the drag by 'collecting and raming in' more air.
Respectfully, Bob P.
Any small benefit that you might have gained, would be negated by the small decrease in overall coefficient of friction due to the modification of the air intake. IOW, you increase the drag by 'collecting and raming in' more air.
Respectfully, Bob P.
Last edited by 545IblupasdU; 07-21-2016 at 02:11 PM.
#47
New Members
Joined: Dec 2012
Posts: 571
Likes: 10
From: Montreal Quebec Canada
My Ride: 2005 545i, premium package, 6sp manual, cold package, navigation package.
Model Year: 2005
Engine: N62
If thats the case then everyone who has purchased the RPI ram air which is basically a shovel that doesnt guide or force any air into the intake box have been robbed! That is correct, those devices are useless, just like "cold air boxes"..
At the very least my ram air is a true ram air. And with over 2000 highway miles of testing after the installation my fuell economy went up. by 3+ miles per gallon. Those are my results! The same air that was going to hit the radiator went into the pipe.......its not like I collected some extra air from another area to change the drag. I would think that air that is getting sucked into the engine has less drag than air hitting the flat surface of a radiator blocked off from behind by mechanicals.
At the very least my ram air is a true ram air. And with over 2000 highway miles of testing after the installation my fuell economy went up. by 3+ miles per gallon. Those are my results! The same air that was going to hit the radiator went into the pipe.......its not like I collected some extra air from another area to change the drag. I would think that air that is getting sucked into the engine has less drag than air hitting the flat surface of a radiator blocked off from behind by mechanicals.
Also, the only proper way to calculate mileage is to use fuel consumed with miles traveled. The on board computer has too much variability and lack of repeatability to be used as a statistical tool. Unless you calculated your mileage properly before and after the change, then I find your claims suspect.
Respectfully,
Bob P.
Thread
Thread Starter
Forum
Replies
Last Post
PelicanParts.com
Vendor Classifieds
0
07-23-2015 12:41 PM