RAM Air Scoops

N52UNED · 03-15-2018, 09:22 AM

Yup ... another Ram Air Scoops thread. I've read through all the threads that contain the subject, but there's really no thread that give any definite answer. Too many threads are ... "it does nothing" / "it's nothing but a bug catcher" OR "it works" / "it works but ... "

I'm in the camp that ... it does work. However I understand that in order for it to give any actual performance gain ... a certain rate of speed must be met - or else the performance increase is negligible.

I'm not expecting a turbo or a Ram Air hemi effect ... but I'd imagine there's some butt dyno effect. With that ... what is the rate of speed one needs to achieve for the scoops to have any butt measurable effect?

(FYI ... I will be doing a K&N w/ Carbon Delete and Silicone Intake to complement the scoops. Also I do a fair amount of highway with speeds 75+ -- mostly in the 85 mph range. Plus my in town driving is 50-60 mph in many areas).

Thanks ... please don't let this become another Scoops bashing thread. Quite a few members have them and believe in them ... others, like myself, would like more info that's not spread over 30 threads to get concise information.

TomD335xicoupe · 03-15-2018, 09:42 AM

I put them in , they are cheep and I can not think how it could hurt but I have no idea if they help either. Just something else to buy for the car, I like to buy it presents. I know this answer does not help but I am board, and nobody else is giving you anything so WTF I will put my half cent in, need the other 1.5 cents for parts.

Phyrexia · 03-15-2018, 11:44 AM

It's not a discrete cutoff point, it's a continuous function. It would also be dependent on wind direction and speed, altitude, and relative humidity. If they did anything. They probably don't, cars often have low pressure cells in that region, not high pressure cells. There's a high pressure cell on the fenders which is why the BMW PI has a sealed intake opening there.

Generally speaking, drag is more important than weight after 60 mph, and so that is probably the rough inflection point for this sort of thing.

e92_bryan · 03-15-2018, 11:48 AM

Again...
No gains
And will probably “hurt” to some extent
I can only imagine all the crap that gets sucked into the intake now plus possible flooding in heavy rain?

M.Etreby · 03-15-2018, 02:40 PM

120km/hr and above this is when you shall feel a little something. IMO it makes the engine breathe easier where the intake box is always rich with cold air, so its better instead of asking the engine to suck by itself, a draw back is that you will need to regularly clean up the box and filter more than the normal periods

N52UNED · 03-15-2018, 04:42 PM

Quote:

Originally Posted by M.Etreby

120km/hr and above this is when you shall feel a little something. IMO it makes the engine breathe easier where the intake box is always rich with cold air, so its better instead of asking the engine to suck by itself, a draw back is that you will need to regularly clean up the box and filter more than the normal periods

Thanks for the input ... 75 mph is a bit higher than I was hoping, but it will work when traveling on the highways. I'd hoped it was closer to 60 mph so I could get a bit of gain around town.

The cleaning is a point of contention ... if I had a Euro box or AFe Stage 2 then I'd be a bit more apt to do it, since popping a top is a lot quicker and easier than having to take out the whole box every so often.

rjahl · 03-15-2018, 05:27 PM

Quote:

Originally Posted by N52UNED

Yup ... another Ram Air Scoops thread. I've read through all the threads that contain the subject, but there's really no thread that give any definite answer. Too many threads are ... "it does nothing" / "it's nothing but a bug catcher" OR "it works" / "it works but ... "

I'm in the camp that ... it does work. However I understand that in order for it to give any actual performance gain ... a certain rate of speed must be met - or else the performance increase is negligible.

I'm not expecting a turbo or a Ram Air hemi effect ... but I'd imagine there's some butt dyno effect. With that ... what is the rate of speed one needs to achieve for the scoops to have any butt measurable effect?

(FYI ... I will be doing a K&N w/ Carbon Delete and Silicone Intake to complement the scoops. Also I do a fair amount of highway with speeds 75+ -- mostly in the 85 mph range. Plus my in town driving is 50-60 mph in many areas).

Thanks ... please don't let this become another Scoops bashing thread. Quite a few members have them and believe in them ... others, like myself, would like more info that's not spread over 30 threads to get concise information.

It seems that I say this often but I think it needs said again on this thread.

Try logging your changes. It's easy and cheep. Support your statements with actual data logs.

A stock N52 will draw something like 700kg of air per hour at full load and 6,800 RPM. Manifold pressure drop will be about 30 millibars.

Make a few runs develop a baseline and then start making changes and log after.

The best tool for us right now is TesTo and it's a Windows based program. Having laptop in the passenger seat is a pain but having real data in invaluable.

There is no way I could have learned as much as I have without logging. Not saying I am anything more than an amateur.

CobraMarty · 03-15-2018, 09:16 PM

I'm a believer and have them on both 328s.

One into EURO intake stock elbow.
Other into -first- carbon delete, aFe dry filter, silicone elbow.
then -second into aFe Momentum PRO 5R and supplied filter and included larger aFe molded elbow.

The aFe PRO box has 2 vents about 1"x4" each in the front of the box and I think that they are 'venting' any ram/pressurized air and just let 'noise' out. I want to block these vents and test. Just my theory.

Ram effect 60, 70, 100 mph probably 0.1-0.15 psi. I don't have anything that sensitive to test with.

hassmaschine · 03-15-2018, 10:56 PM

If its not possible to test it because the difference is so small - what makes you think it makes any difference at all?

Rjahl is being modest. The stock N52 hardware & sensors have sufficient resolution to measure any small changes. If you can't even measure a difference, its definitely nonsense.

Eagle1oh7 · 03-15-2018, 11:26 PM

Quote:

Originally Posted by e92_bryan

Again...
No gains
And will probably “hurt” to some extent
I can only imagine all the crap that gets sucked into the intake now plus possible flooding in heavy rain?

That's an old wives tale. I've had these things on my E90 since the very beginning, my first mod actually. 65000 miles later, still going strong.

Taskmaster · 03-16-2018, 07:50 AM

Quote:

Originally Posted by rjahl

It seems that I say this often but I think it needs said again on this thread.

Try logging your changes. It's easy and cheep. Support your statements with actual data logs.

A stock N52 will draw something like 700kg of air per hour at full load and 6,800 RPM. Manifold pressure drop will be about 30 millibars.

Make a few runs develop a baseline and then start making changes and log after.

The best tool for us right now is TesTo and it's a Windows based program. Having laptop in the passenger seat is a pain but having real data in invaluable.

There is no way I could have learned as much as I have without logging. Not saying I am anything more than an amateur.

I have a working copy of INPA, I may be able to give it a shot.
CraZy how it's taken this long to get any data...

CobraMarty · 03-16-2018, 08:13 AM

Quote:

Originally Posted by CobraMarty

I don't have anything that sensitive to test with.

Pressure gauge or transducer, not BMW hardware/software.

hassmaschine · 03-16-2018, 08:31 AM

I guess what I'm saying is, the engine already has the necessary sensors/hardware to measure any difference. It has a MAP sensor, it can datalog at a high-rate, etc. That was Rjahl's point as well.

rjahl · 03-16-2018, 08:32 AM

Quote:

Originally Posted by TheAxiom

Quote:

Originally Posted by rjahl

It seems that I say this often but I think it needs said again on this thread.

Try logging your changes. It's easy and cheep. Support your statements with actual data logs.

A stock N52 will draw something like 700kg of air per hour at full load and 6,800 RPM. Manifold pressure drop will be about 30 millibars.

Make a few runs develop a baseline and then start making changes and log after.

The best tool for us right now is TesTo and it's a Windows based program. Having laptop in the passenger seat is a pain but having real data in invaluable.

There is no way I could have learned as much as I have without logging. Not saying I am anything more than an amateur.

I have a working copy of INPA, I may be able to give it a shot.
CraZy how it's taken this long to get any data...

You know where I work.

Will only take a few minutes to set up.

N52UNED · 03-16-2018, 08:52 AM

Quote:

Originally Posted by TheAxiom

CraZy how it's taken this long to get any data...

Absolutely agreed ... scoops have been around for quite some time now and all I read is theory to prove one's belief that it works or doesn't.

As rudimentary as this youtube video is ... it's the closest thing I've seen to the idea of scoops working; or perhaps more like proof they route more air to the air box. And this is based upon up to 25mph wind speeds ... not the amount of wind chill factor / forced air pressures one would get at highway speeds. (plus you get to hear a bit of classic Michael

)

.... However it does not answer the question of percentage of increase ... if any relevant increase ... or decrease for that matter. I highly doubt you're going to get anywhere near a 10% gain. Heck a silicone intake has been purported to give a slight increase ... so why not scoops?

Plus for the price ... if they can aid you car in efficiency in any way, that might be something to think about.

Needbmwpartzz · 03-16-2018, 08:56 AM

Anyone here fab up scoops themselves?

rjahl · 03-16-2018, 05:54 PM

Quote:

Originally Posted by N52UNED

Absolutely agreed ... scoops have been around for quite some time now and all I read is theory to prove one's belief that it works or doesn't.

As rudimentary as this youtube video is ... it's the closest thing I've seen to the idea of scoops working; or perhaps more like proof they route more air to the air box. And this is based upon up to 25mph wind speeds ... not the amount of wind chill factor / forced air pressures one would get at highway speeds. (plus you get to hear a bit of classic Michael

)

.... However it does not answer the question of percentage of increase ... if any relevant increase ... or decrease for that matter. I highly doubt you're going to get anywhere near a 10% gain. Heck a silicone intake has been purported to give a slight increase ... so why not scoops?

Plus for the price ... if they can aid you car in efficiency in any way, that might be something to think about.

While working on another problem, the math made me think about this conversation.

Here is some interesting "tid bits".

At 50 MPH the wind pressure on a flat wall is about 6.4 Lbs / ft^2.

That's 0.044 PSI or 0.003 Bar / 3 millibar.

Sorry, you are not going to feel that on a butt Dyno.

The front end of a car is designed to slip through the air and is anything but flat. The 6.4 Lb's /Ft^2 could be reduced by at least 50%.

Does anyone see any error in my math?

desertman123 · 03-16-2018, 07:24 PM

If the question is, "is there a difference?", even after you install/remove them to test, there is no difference.

Phyrexia · 03-16-2018, 07:26 PM

The math checks out.

Phyrexia · 03-16-2018, 07:33 PM

Behold!

CobraMarty · 03-17-2018, 08:22 AM

Quote:

Originally Posted by Needbmwpartzz

Anyone here fab up scoops themselves?

Why, they are only $50-$80

Quote:

Originally Posted by CobraMarty

Ram effect 60, 70, 100 mph probably 0.1-0.15 psi. I don't have anything that sensitive to test with.

Posted chart support this.

+0.15psi (92mph) will add 1% increase in power, for us about +2HP for $50.

hassmaschine · 03-17-2018, 10:29 AM

yeah, 2hp at 92mph, sure - makes sense if you track the car all the time I guess. But otherwise, I hardly ever go that fast, so I would never see a difference. The N54 guys will claim you can't feel 10hp, but I know you definitely can't feel 1hp.

In the end it's a cheap mod and people have fun working on their cars - personally I just don't care about 2hp.

03-15-2018, 09:22 AM	#1
N52UNED Captain 179 Rep 601 Posts Drives: '07 328i/330BPC Join Date: Mar 2017 Location: Sunshine State iTrader: (1)	RAM Air Scoops - what speed needed Yup ... another Ram Air Scoops thread. I've read through all the threads that contain the subject, but there's really no thread that give any definite answer. Too many threads are ... "it does nothing" / "it's nothing but a bug catcher" OR "it works" / "it works but ... " I'm in the camp that ... it does work. However I understand that in order for it to give any actual performance gain ... a certain rate of speed must be met - or else the performance increase is negligible. I'm not expecting a turbo or a Ram Air hemi effect ... but I'd imagine there's some butt dyno effect. With that ... what is the rate of speed one needs to achieve for the scoops to have any butt measurable effect? (FYI ... I will be doing a K&N w/ Carbon Delete and Silicone Intake to complement the scoops. Also I do a fair amount of highway with speeds 75+ -- mostly in the 85 mph range. Plus my in town driving is 50-60 mph in many areas). Thanks ... please don't let this become another Scoops bashing thread. Quite a few members have them and believe in them ... others, like myself, would like more info that's not spread over 30 threads to get concise information. Last edited by N52UNED; 03-15-2018 at 09:30 AM.. Reason: added FYI
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03-15-2018, 09:42 AM	#2
TomD335xicoupe First Lieutenant 319 Rep 378 Posts Drives: 08 335XI me ,19 x3 M40 wife Join Date: Jul 2014 Location: North Jersey iTrader: (1)	I put them in , they are cheep and I can not think how it could hurt but I have no idea if they help either. Just something else to buy for the car, I like to buy it presents. I know this answer does not help but I am board, and nobody else is giving you anything so WTF I will put my half cent in, need the other 1.5 cents for parts. __________________
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03-15-2018, 11:44 AM	#3
Phyrexia Resident Pedant 503 Rep 792 Posts Drives: '15 335i 8AT Join Date: Nov 2017 Location: Limbo iTrader: (1)	It's not a discrete cutoff point, it's a continuous function. It would also be dependent on wind direction and speed, altitude, and relative humidity. If they did anything. They probably don't, cars often have low pressure cells in that region, not high pressure cells. There's a high pressure cell on the fenders which is why the BMW PI has a sealed intake opening there. Generally speaking, drag is more important than weight after 60 mph, and so that is probably the rough inflection point for this sort of thing. __________________ '15 F30 335i 8AT Estoril II/Black (12.218 @ 114.94mph) MHD Stage 2+ 93 / XHP Stage 3 / M-Goodies / K&N Filter / ER CP / CSF IC / NGK 97506 / ER DP / Michelin A/S 3+ Last edited by Phyrexia; 03-15-2018 at 01:47 PM..
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03-15-2018, 11:48 AM	#4
e92_bryan First Lieutenant 127 Rep 345 Posts Drives: ‘11 e92 328 Join Date: Aug 2013 Location: So cal iTrader: (0)	Again... No gains And will probably “hurt” to some extent I can only imagine all the crap that gets sucked into the intake now plus possible flooding in heavy rain?
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03-15-2018, 02:40 PM	#5
M.Etreby First Lieutenant 36 Rep 306 Posts Drives: 2011 Black Sapphire E90 330i Join Date: Aug 2011 Location: Egypt iTrader: (0)	120km/hr and above this is when you shall feel a little something. IMO it makes the engine breathe easier where the intake box is always rich with cold air, so its better instead of asking the engine to suck by itself, a draw back is that you will need to regularly clean up the box and filter more than the normal periods __________________ M.Etreby F M double Grills, 19"313, Perf.Exhaust with dimisatips, RPI red scoops, K&N filter, LUX-H8 160, Aluminum strut bar, PBX, Perf. Suspension, F30 M-Perf. Brakes
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03-15-2018, 09:16 PM	#8
CobraMarty Major 619 Rep 1,402 Posts Drives: 2007 328xi e90 + e92 Join Date: Sep 2010 Location: BimmerMILVs.com iTrader: (7)	I'm a believer and have them on both 328s. One into EURO intake stock elbow. Other into -first- carbon delete, aFe dry filter, silicone elbow. then -second into aFe Momentum PRO 5R and supplied filter and included larger aFe molded elbow. The aFe PRO box has 2 vents about 1"x4" each in the front of the box and I think that they are 'venting' any ram/pressurized air and just let 'noise' out. I want to block these vents and test. Just my theory. Ram effect 60, 70, 100 mph probably 0.1-0.15 psi. I don't have anything that sensitive to test with.
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03-15-2018, 10:56 PM	#9
hassmaschine Major General 3973 Rep 7,215 Posts Drives: "NBO" 330i Join Date: Jun 2014 Location: earth iTrader: (0)	If its not possible to test it because the difference is so small - what makes you think it makes any difference at all? Rjahl is being modest. The stock N52 hardware & sensors have sufficient resolution to measure any small changes. If you can't even measure a difference, its definitely nonsense.
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03-16-2018, 08:31 AM	#13
hassmaschine Major General 3973 Rep 7,215 Posts Drives: "NBO" 330i Join Date: Jun 2014 Location: earth iTrader: (0)	I guess what I'm saying is, the engine already has the necessary sensors/hardware to measure any difference. It has a MAP sensor, it can datalog at a high-rate, etc. That was Rjahl's point as well.
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03-16-2018, 08:56 AM	#16
Needbmwpartzz Colonel 851 Rep 2,793 Posts Drives: 2009 bmw 328i x-drive Join Date: Feb 2014 Location: Kitchener/Waterloo iTrader: (0)	Anyone here fab up scoops themselves?
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03-16-2018, 07:24 PM	#18
desertman123 E82 Mudflap Ambassador 2214 Rep 2,219 Posts Drives: '08 128i Join Date: May 2016 Location: Orlando, FL iTrader: (0) Garage List 1992 Honda Beat [9.50] 2008 BMW 128i [10.00] 2014 BMW 528i [10.00]	If the question is, "is there a difference?", even after you install/remove them to test, there is no difference. __________________ My 2008 128i - Sparkling Graphite/Beige - Sport pkg - 6MT - Click me! Parents' 2014 528i - Mineral White/Ivory White - fully loaded Instagram @Andreys_128i and @Honda.Bito
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03-16-2018, 07:26 PM	#19
Phyrexia Resident Pedant 503 Rep 792 Posts Drives: '15 335i 8AT Join Date: Nov 2017 Location: Limbo iTrader: (1)	The math checks out.
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03-16-2018, 07:33 PM	#20
Phyrexia Resident Pedant 503 Rep 792 Posts Drives: '15 335i 8AT Join Date: Nov 2017 Location: Limbo iTrader: (1)	Behold! Attached Images __________________ '15 F30 335i 8AT Estoril II/Black (12.218 @ 114.94mph) MHD Stage 2+ 93 / XHP Stage 3 / M-Goodies / K&N Filter / ER CP / CSF IC / NGK 97506 / ER DP / Michelin A/S 3+
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03-17-2018, 10:29 AM	#22
hassmaschine Major General 3973 Rep 7,215 Posts Drives: "NBO" 330i Join Date: Jun 2014 Location: earth iTrader: (0)	yeah, 2hp at 92mph, sure - makes sense if you track the car all the time I guess. But otherwise, I hardly ever go that fast, so I would never see a difference. The N54 guys will claim you can't feel 10hp, but I know you definitely can't feel 1hp. In the end it's a cheap mod and people have fun working on their cars - personally I just don't care about 2hp.
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