I have read about this issue many times here, but have not found a resolution to the high pitch whistle that happens when you accelerate (Usually between 2.5rpm and 3.5 rpm) The only resolution I have received is to put the plastic fire wall cowling back in.. Ok.. Is it just me or is it only the Alta that does this? If anyone has a fix (And not the VGS mod) please let me know.. I think I might have to go back to the stock intake and get my money back from Alta.. The noise is almost as bad as when the break pads are worn down.. Ouch.. Talk about Nails on a chalk board.. Thanks everyone.

2005 MCS Auto with Alta CAI..

 

I installed my Alta intake a few months ago, and found the same problem. I searched a bit on the forums, and found this is common... I have decided to live with it based on how the vehicle now responds.

 

I have a MINI-Madness CAI and it also whistles, but I don't find it annoying at all. I heard they all (all the CAI's) whistle a bit. Sure is intimidating to those on the outside. Some kid in a Civic wanted to pass me on the right at a stop light the other day and backed off as soon as he heard the supercharger whine and whistle of the CAI. I would have let him go as long as he didn't pull anything stupid (I do not believe in street racing) but I guess he got intimidated.

 

At that RPM range, it's likely throttle whistle. If it's the throttle, you'll find that you can modulate it with the pedal... push or release just a little it it goes away... hold it in one position and it continues...

If it's the throttle,the fix is a JCW intake.

 

^ or pressing down harder on the gas

 

Yeah, that's what I MEANT to say.

 

Ive also experienced this in my 06 MCS even before i went from stock to a K & N typhoon intake, i always wondered if it was normal or not, even with the stock intake

 

this isnt a problem!!! its a by product of an open intake. the noise you hear is air going by the throttle plate and the noise is part of the performance ( feature ). embrace the noise. i wonder if theres a way to make it louder ?

 

You happen to have a dyno that shows how much torque just the noise part makes?

By the way, anyone that wants my whistling noise can come by and pick it up - FREE!
Bargain for such a great performance mod.

 

Just would like to say if any Alta people are reading this.. Maybe you should have the CAI box top as part of the Intake kit.. I installed the box top and no more CAI Whistle!! Thank god... I was ready to go back to the stock intake. Thanks everyone

 

It's not gone the box top just muffles it for you. like it has been said the whistle is a by product of the open air.

 

I don't care - As long as I cant hear it anymore....

 

Resurrecting this thread back from the dead...

I installed a JCW CAI (but removed the flap) shortly after I got my 2005 MCS in July. I noticed immediately after the high-pitched whistle, that starts around 2500 rpm.

I've searched the forum and have read that it could be anything from a leak in the bypass valve to air flowing into the intake. Whatever it is, it's pretty darn irritating (as the earlier posters noted!)

Anyway, first, I'd like to figure out if the noise I'm hearing is the same as everyone else. After that, I'd like to figure out a way to fix it (if one can!)

Here are two .WMA files of the noise that I have recorded today in the car.

http://www.aefuniforms.com/images/MINI1.WMA

http://www.aefuniforms.com/images/MINI2.WMA

Any thoughts/comments are appreciated!

Dave

 

I have the same thing, do you really think it's that bad? just turn up the radio

 

Hard to tell for sure from the audio file.. but that SOUNDS like the dreaded throttle whistle. Does it correspond to a specific position of the THROTTLE or a specific RPM? In other words, when it does it, can you pretty much make it come and go just by giving the car a tiny bit more or less throttle with your toe?

If it's the throttle whistle... I think it's actually the reason the flap is in the JCW intake in the first place... and why the flap doesn't open until higher RPMS... That's my theory, anyway.

You can easy isolate whether the intake has anything to do with it... simply by disconnecting the intake pipe from the throttle body (in a clean, non-dusty garage)... if it still does it, then it's the throttle - air rushing through the partially cracked throttle makes it whistle like a teakettle... Nothing you can do about it... but it's WHY I changed from a Dinan to a JCW intake, and it's why my flap is still in place. You can STILL hear it in my car, but it is greatly muted with the JCW w/flap, versus any other "open" intake.

 

And decible meters are much cheaper than dynamometer, and easier and faster to use.

My answer was going to be "That's Alta telling you to accelerate faster."

 

Thanks for the feedback...yes, the whine is there at both peddle pressure AND RPM...though chances are they go hand in hand. I haven't heard the whine when the car is below 1800 RPM, and I can control it (and make all sorts of neat pitch changes) with pressing on the gas...mostly though in the 2300-2600 RPM range. My guess too is that it's an issue with the throttle.

An odd question would be...would replacing the throttle fix the problem?

Dave

P.S. I actually first noticed the whine when I lowered my radio volume to hear my "new" CAI when I first installed it. I love listening to the sound of my car though, so having the tunes cranked up (as much as I love them) doesn't always work for me...sadly...

 

AFAIK, no one has done a throttle swap to try it... the fact that some cars do it and others don't suggests to me that it *might*... I seriously considered removing mine and grinding a different edge profile on the throttle plate...

 

That's what I'm talking about. I have a Mini Mania 15% pulley with madness CAI and I love the noise. I'm trying to make it so loud my wife won't want to drive the car any more.