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View Full Version : AFE Intake and Dinan Throttle Body


JHJenkins4th
05-28-2007, 09:42 PM
I recently installed the AFE cold air intake and the Dinan high flow throttle body into my 2006 530i. I notice an immediate increase in performance, and I enjoy the racey sound when the car revs above 3500 rpm's. Just today, I took my car to some higher speeds to check it out. I noticed that when I got above 110 mph, a loud whistling started to develop. As I continued faster, the whistling became very loud. I wanted to know, is normal or do I have a serious problem?

Roleez
05-28-2007, 10:24 PM
It's the sound of the rushing air making a whistling sound as it hits the angled throttle body butterfly valve. CAIs whether the exposed intake tube is metal or plastic can make this sound more pronounced. However, the whistling can be decreased or eliminated if the material of the tubing is more insulated; even better if there's a sealed box for the intake filter cone. If the factory air intake tubing (sealed plastic) was used, such a sound won't be audible. I have the Dinan V8 throttle body in my 550i/Dinan5 with stock intake (but with drop-in K&N filter), and I have no whistling sounds from idle to redline. I've even test driven Steve Dinan's own 645Ci with the carbon fiber cold-air intake which has a sealed plastic box, but still no whistling.

vegastrashed
05-29-2007, 11:31 AM
The 530i AFE CAI
http://i211.photobucket.com/albums/bb76/vegastrashed/530_afe.jpg
http://i211.photobucket.com/albums/bb76/vegastrashed/530_afe_2.jpg

The 550i AFE CAI
http://i211.photobucket.com/albums/bb76/vegastrashed/550i_afe.jpg
http://i211.photobucket.com/albums/bb76/vegastrashed/550i_afe_2.jpg

It would appear that without the top enclosure like on the 550i, the 530i AFE CAI is causing quite a loud sound. Not sure why AFE wouldn't design the 530i CAI similar to the 550i. :dunno:

JHJenkins4th
05-29-2007, 03:40 PM
I figured that by removing the dampening aspect of the factory intake a great deal of noise would occur. I also noticed that when Dinan bored out the factory throttle body to allow a larger butterfly valve, the edges are not as rounded as the unaltered throttle body. The high velocity air over that kind of edge could cause a whistle.

When this sound is being generated, it seems that the original flow path is definately being disturbed for this to occur. Would this result in power losses?

JHJenkins4th
06-05-2007, 03:04 PM
I ran my car up to 130 mph again the other day and this time I heard no audible noise. I'm wondering if maybe the outside conditions (humidity and temp) could have something to do with this. Other than this issue, everything else seems to be fine.

S54 M Rodie
06-07-2007, 06:23 AM
The 530i AFE CAI
http://i211.photobucket.com/albums/bb76/vegastrashed/530_afe.jpg
http://i211.photobucket.com/albums/bb76/vegastrashed/530_afe_2.jpg

The 550i AFE CAI
http://i211.photobucket.com/albums/bb76/vegastrashed/550i_afe.jpg
http://i211.photobucket.com/albums/bb76/vegastrashed/550i_afe_2.jpg

It would appear that without the top enclosure like on the 550i, the 530i AFE CAI is causing quite a loud sound. Not sure why AFE wouldn't design the 530i CAI similar to the 550i. :dunno:

Actually, I think the design for the 530i is better than the 550i. With the 530i, the hood seals the intake compartment. With the 550i, it appears engine bay heat soak is inevitiable. Either way, CAI's are more eye/ear candy than butt candy.

Charles
06-07-2007, 02:09 PM
With the N52 using valvetronic, I didn't think it had a throtle body?

jordan23junkee
06-07-2007, 09:00 PM
Thats what i thought ,but the dinan site mentioned that its misconcepted.

JHJenkins4th
06-07-2007, 09:40 PM
well yeah there definately is a throttle body, just like any other internal combustion engine on the market.

nahugry
06-07-2007, 10:38 PM
I enjoy the racey sound when the car revs above 3500 rpm's.
at this time, air moving throught the intake is moving into the manifold up-and-down, bouncing from one side of the intake pipe to another side... and the sound you hear is colder, denser air moving through a bigger and steadier (temperature and motion)girth pipe. The airflow is fairly low relatively, and steady. or Relatively lower pressure. Most people find this sound very attractive, and feel powerful at this time.

Just today, I took my car to some higher speeds to check it out. I noticed that when I got above 110 mph, a loud whistling started to develop. As I continued faster, the whistling became very loud. I wanted to know, is normal or do I have a serious problem?
At this time, whistling sound comes from the intake, and it is NOT a warning sign in anyway.
It just means that air moving through your pipe is now flowing at a much higher pace, and the flow itself is moving from bouncing up and down the pipe to whirling through now, due to the increased volume and speed of the air coming into the intake and manifold.(Again, through bigger and steadier (temperature and motion)girth pipe). Which just means higher pressure

Just try whislting right now. You'll notice that the whistling sound becomes noticeably high pitch as you make the air channel (the round space you make using your lips) becomes narrower, thus, causing the pressure of the air EXITING your mouth higher (much like increasing the volume and speed of air coming IN through your intake).
Same logic.... there is nothing wrong with the whistling noise. If anything, it means that your intake is stable and working correctly. If it is not stable enough to handle the air coming through the intake, you'll either hear LOUDER growling noise, or feel the vibration from the car.

nahugry
06-07-2007, 10:46 PM
Oh and the type of air your intake is "intaking" at the time (outside temperature, humidity, and engine bay temperature) would effect the sound your intake generates, thus, the sound you hear

Charles
06-08-2007, 02:31 AM
When you do a search on valvetronic, everything I have found, mentions that it susposed to eliminate the use of a throtle butterfly. http://www.bmwworld.com/technology/valvetronic.htm I thought that it was probably an air horn/ ventury with a mass air flow sensor in it. Is the throtle plate weighted, or does it have a servo to regulate air flow?

JHJenkins4th
06-08-2007, 12:37 PM
Here is a link to look at the exact bmw 530i throttle body. Dinan uses the factory throttle body and just mills the internal diameter 3mm larger, but it is the factory part.

http://www.dinancars.com/Series.asp?Series=15&Chassis=40&Model=106

Charles
06-09-2007, 12:43 AM
Here is a link to look at the exact bmw 530i throttle body. Dinan uses the factory throttle body and just mills the internal diameter 3mm larger, but it is the factory part.

http://www.dinancars.com/Series.asp?Series=15&Chassis=40&Model=106

Is the price 399. with a 325. core charge = 74. , or 399 in addition to a 325 core =399 after core?

JHJenkins4th
06-11-2007, 06:31 AM
you pay $724 for the throttle body. Once you are done installing the new throttle body, return the original for a $325 refund. Hence, the product cost only $399.

Zed2Zee
06-11-2007, 07:40 AM
Your car has a throttle body that is basically a default in your car if your valvetronic stops working. The throttle body is wide open at all times and the valvetronic controlls everything unless valvetronic stops functioning the throttle body is instated as control.

ANother 3 mm of flow seems like so little to me but ya never know with these things.

I have an AFE by the way and that dude posted a pic of my engine bay that he swiped from e60.net I believe

JHJenkins4th
06-11-2007, 03:15 PM
If you think about the area increase from 76mm diameter to 79mm, that is a dramatic 8% increase.