+1 -- need to know how much to set aside

 

Appologies if this has been asked in here before (37 pages of posts - wow)...

Just installed my CAI... Loving it so far:



QUESTION: I'm noticing that under gradual acceleration I can hear the intake "breathing" much more than before. At several points as the RPMs mount, the intake emits a thin, high-pitched "whistling" noise. It's obviously an air noise - when I'm really listening I can hear additional undertones that sound like air movement. Obviously when I'm accellerating hard all I can hear is the lovely whine of the supercharger fans spooling up, but I can't hard accelerate EVERY time.

I figured that I was simply hearing more than other users because I have a cabrio and I have the top down, but I drove this morning with it up and I could still notice the "whistle". Since I haven't heard of other users complaining about this noise, I wonder if I did something in my install that's causing some sort of unexpected turbulence?

Hope you can help - thanks!

 

Others can confirm, but I think this behavior is 100% normal for the Alta CAI. I think most learn to love it.

 

Interesting... I read a lot of threads before deciding on the Alta and don't remember anyone mentioning this... Can anyone confirm the whistle?

All I can think that I could have done differently (it's a pretty simple install) is that there's a SLIGHT bend in the silicone tube - if you look at my picture, you'll see that the "Alta" logo is not precisely at the top where I suspect it should go. I connected the hose to the throttle body first and then to the box after it was bolted down (as per the How-tos I read), and I might not have had it precisely straight. Should this matter?

 

I can confirm the whistle. It is quite clear with my application, which includes the Alta box lid. I don't mind it, but I guess some have found it annoying. There are some who claim the VGS eliminates the whistle, but I doubt that.

 

I get this "whistle" too, especially in the manner you state, when I'm cruising and change the throttle ever so slightly, and it sounds like the filter is dirty or there's a leak somewhere. This sound is a bit annoying, as I often hit the throttle in this manner on the highway, or in the city as I let off the throttle I always hear it too. At first I thought it might have been just mine, but I've seen others talk about the whistle as well, and I think this whistle is more than the noise from the air sucking in.

 

I was wondering about the box top - thanks for adding that. OK, so I didn't screw up the installation it sounds like. Whew!

 

I have installed several of these intakes for friends.. I even had the whistle on mine CAI too.. What fixed it (or made it very quiet) was triming the extra "lip" around the vent tube entrance to the intake hose. A bit ackward to trim because of the reach inside the tube.. But when that is trimmed flush - no whistle.

Hope that helps..

 

Hmmmm... which end of the silicone tube? The box end or the throttle body end?

 

With out taking one apart.. I will try to describe this..

Hold the intake tube in your hand.. with the logo face up.
Look up the large diameter end -that connects to the thortle body..
About half way up on the inside you might see a lip lefto over from wheren the vent tube that enters the inside of the large diameter tube..

If you see that... trim it flush with a very sharp razor blade and a gentle touch (dont want to slip and cut all the way through)..

Maybe that helps??

 

AH!! I know exactly what you mean. Yes, if there were a lip in there then I bet that would cause turbulence and noise.

I'll check this when I have the car open for my pulley install - I can live with the noise until then if it's not hurting anything. Thanks!

 

eager2own: Bring lots! We are happy to take it home with us. ;-)

ImagoX: Thanks for your purchase and the photos. The Intake System removes the intake muffler (mush the same as the exhaust muffler) and as such you get to enjoy the sounds of the Supercharger etc. The whistle varies from car to car, and is most commonly reported on automatic vehicles. It stems from the throttle plate mating to the throttle body.Most clients don't feel this is excessive and revel instead in the new power and whine from the S/C. Let us know if we can every help further. Thanks again for choosing ALTA Performance!

 

I'm running a 6-speed and still get the whistle at several points on the tach. I'll try the suggestion of trimming the inside of the hose and see if that helps. It's not terribly annoying, although it's high-pitched enough that I keep finding myself cocking an ear - it sounds at first blush like a brake pad sensor just starting to scrape or something. I'll get used to it eventually, I'm sure, if I can't eliminate it altogether.

 

Just for the record.. I still have the thorttle body "whoosh" sound even still with my setup.. But that can be "controled" by your throttle position and honestly Istopped hearing that after awhile..

I feel the real High pitched whistle is due to the lip on the inside of the intake tube.. If after triming the lip from the inside ... and you still hear "sounds" that are not preferred. Perhaps reinstalling the plastic "firewall" back in will help mute those sounds - of course that would limit the air flow from the cowl vent..

Good luck and enjoy the CAI ..

 

I have the stock intake tube and have the whistle

 

tavis1: Good point. The whistle stems from the throttle plate, I am skeptical that the inlet tube is the source of the concern. BUT, if it works to make a change to it and that makes the client happy; more power to them

Thanks again NAM!

 

Ah... so you think that the whistle is there even with the stock intake, but that it's muted by the OEM muffler? Interesting...

Thanks for the follow-up!

 

Sorry, the point I was trying to make is the OEM intake system acts as an intake muffler. Much in the same fashion that your OEM exhaust system includes an exhaust muffler. The motor itself produces noise on both sides. BMW attempts to mask both as best it can. When you remove the OEM intake system and replace it, these noises come out (whistles, chirps, suction etc.)

My apologies for the misunderstanding.

Thanks again for choosing ALTA Performance Products!

 

Pat at Wallace Motorsports did an awesome job at showing how to install a supercharger pulley. And yes it is a Version 2.0! Check this out!

http://www.motoringfun.com/2007/04/1...ulley-install/

 

Hey there, I'm just purchased an Alta 17% v2.0 S/C pulley and a 2% crank pulley. Some people are telling me know that installing the 2% pulley can pose a threat by producing excessive heat.

What is the real story with installing a 17% and a 2%?

Thanks in advance!

 

I just got ALTA CAI, Exhaust, end links front and rear, and Control arms how many warranty cards do I need to fill out?

 

This was already asked, but I haven't seen a response yet, unless I missed it, so I'll ask again

What will you guys be doing at MOTD? Will you have something similar to what you had for AMVIV? Details, man, I need details.

 

+1
I've noticed other vendors are filing up their appointment times, and I'd like to be able to plan for a pulley install before I miss an opportunity to do so.
Thanks

 

Mine whistled a bit with the stock intake setup. Now with the Alta it is quite loud. I love the sucking whooshing sounds and the extra pulley whine, but even after 6+ months the whistle is hard for me to take. I guess I'm just sensitive to it.

 

SORRY I WAS ON VACATION!

Mini Tyler: The answer is yes and no. That will net a total reduction of 19%. That is not excessive, but we do NOT recommend running around at redline all day as in the case of a track event. This can cause damage to the S/C. However, if this is a street car, then there is no known issues. Hope that helps!

Putz: Thank you for your business. Send in one, but note all the items in question. That will be sufficient. Thanks again!

acej80 & eager2own: Thank you for asking. They are loading the trailer right now with goodies! An announcement on pricing, and installations etc. will be released shortly. Expect to see something similar to AMVIV with a dragon twist! Also, you may wish to contact Detroit Tuned as they are also attending the event and have already mentioned they are doing ALTA installs and specials. For specifics e-mail me directly!