Thanks (to most) for the feedback. Of course my expectation was for increased intake noise and a pronounced s/c whine. Hell, that's what I wanted. As I mentioned, I did pick up a noise which was not expected, and I was simply wondering if it was normal for the Alta, and if anyone had any possible advice on what may be incorrect. On my past cars which I have installed a CAI, all of which were atmospheric, the sound was always lower frequency and more guteral. They never had the 'air rushing past the throttle plate' mid-frequency whoosh noise at tip-in. As I said, once the s/c builds boost, the sound is intoxicating, and I am quite pleased. The other sound is not bad, but my preference would be to not hear it every time I crack the throttle. I suppose I like the stealth approach unless I'm really making boost!

Thanks for the comments,
jeffro

 

randy - if an alta intake was, say, 100% louder than stock, in the opinion of your finrly tuned ear, how much louder than stock would it be with the panel installed? 50%? 75%?

I think i'll install it without the panel, and then decide if i want to put the panel back in when i do a pulley.

thanks!

-jac

 

I'll make that trade if you would like. . .

 

 

I'd say keeping the panel in place will be 30% or so of the "normal" Alta CAI noise - but that is totally unscientific data.

I have dyno'ed the Alta numerous times, and it certainly makes power. Some folks' "Butt dynos" are less sensitive than others. The Alta has made anywhere from 7-13 horsepower depending on mods and the particular car.

Hope that helps!
Randy

 

I recently installed an Ultrik CAI in my '05 MCS. Though it's a different intake, I have a few comments that may be relevant...

Re performance: I did a few timed runs from 3000 to 6000 RPM before and after installing the intake. (And one of these days, I'll get around to posting the data here on NAM.) But basically, I found little if any difference. Which is to say, any changes were within my run to run inaccuracies. (I found driving, watching the tach, and working the stopwatch to be much more challenging than I expected!) It's possible the car might even have been slower with the intake!

The Ultrik keeps the cowl partition in place. After doing the post-Ultrik runs, I cut a large hole in this partition and did a third set of runs. With the hole, I did find a small, but distinct improvement in my times, especially from 5000-6000 RPM. This makes sense - if the engine isn't getting enough air, it's going to happen at high RPM. Installing a freer breathing air cleaner is only part of the solution. There also needs to be a way for the air to get to the air cleaner. Opening the hole in the cowl partition makes that possible. (The JCW intake seems to be a tacit admission on MINI's part that the MCS design is marginal in this respect.)

Re sound: The Ultrik intake was a little louder than stock, especially at wide open throttle and high RPMs. Cutting the hole in the partition made a large increase in sound! Supercharger whine, plus this great sucking sound when I first hit the gas like I haven't heard since my little brother and I took the aircleaner off mom's Pontiac station some 40 years ago! I happen to like both sounds, but can certainly understand how others might find them objectionable. (Does the Alta hose affect the sound, too? The Ultrik uses the stock hose.)

But here's an important point I'd like to make: After a few days, I became very accustomed to the sound. First of all, in normal daily driving, it isn't much louder than stock. If I get on the gas for a lane change in tight traffic, I'll hear it and think, "Oh, yeah - there's my intake!" and grin a little. But most of the time, it isn't much louder. (Or are you on it all the time?)

So my point is... (keeping in mind that my intake isn't an Alta)...

If you install the cowl partition, you'll reduce the sound quite a bit. Based on my tests with the Ultrik, I suspect you will also probably reduce most of the performance gains, maybe substantially. I suggest you drive the car for a couple of weeks and see if you (1) get used to it and/or (2) find that in normal driving it just isn't a problem.

I hope this helps. Sorry for being so long-winded. I used to get paid by the word.

 

It's not the supercharger whine, it's the pre-supercharger whistle. The supercharger whine is great, but the whistle can be extremely annoying. The stock intake also whistles, but its not as obvious.

 

agreed to both of you guys

 

Okay, after my long missive above, I have to say that I'm not sure what this "whistle" is. Stock intake, Ultrik CAI with and without a hole in the cowling - I'm still not sure I've heard anything I'd call a "whistle."

There's a definite sucking noise - almost a "slurping," like a kid trying the last of his milkshake through a soda straw - right when the throttle is first pressed. Is that what you're talking about?

 

Is that the "whistle" you're describing? I thought your "mid-frequency whoosh" was what I call a "sucking sound." When someone says "whistle," I think high frequency. Are we talking about the same thing?

(Not trying to argue here... Using only words to describe sounds can be a real exercise in frustration!)

 

the whistle is the sound you hear that, well, whistles.

its higher pitched, and you hear it from about 1700rpm till the whine gets louder than the whistle, or the TB goes WOT and there no resistance anymore.

 

Look at the stock piece that goes from the airbox to the front of the car. See those useless looking plastic passages to nowhere? Those are tuned to dampen out some specific frequencies....

I've hear the whistle at different RPMs and throttle position, most notable at lower RPMs. Different TBs moved it a bit in the RPM range, and I can't honestly remember if it was worse or better with a clean filter. FWIW, it's there with the HAI, with no tube between the filter and the TB!

Matt

 

Randy,

that is close enough for me...thanks for answering that!

 

Well I took the plunge.
I installed an Alta CAI yesterday. I'm pleased with the fit and finish of the product. The install went according to the instructions with small exceptions for my ability to read(bifocals s**k). The jury is still out over the increased engine noise, as I only had time for a short run last night. Today I'll take out Spike for a real run and see what I see. Thanks to the guys at World One Performance and especially Jonathan.
Motor On!
Bill

 

Since we are discussing what the "whistle" sounds like. . .

I think it sounds like a metal brush being rubbed harshly against an old-style metal garbage can. . . .

 

Lombard Street,

1st, sorry for the multiple entries. Although I did not push 'Submit Entry', for some reason, it entered 2 partial messages before I could finish. Thanks for merging the threads. I was confused how a bunch of replies had 'snuck' in there. Now I know.

Sorry for the confusion on the sound description. I did not say whistle. The sound I am hearing seems to be, if you can imagine, the sound of air rushing past the throttle plate just as it barely opens. It seems to go away as the throttle plate opens more fully (Guess: >15 degrees) Because of this, the sound occurs every time you modulate the throttle. From prior CAI experience on other cars, I did not expect this. It is the reason for my post. I simply wanted to know if other Alta CAI owners experience the same noise. It's a very turbulent, high velocity sound. I think I said it was mid-frequency, but I just didn't want you folks to get confused with the high frequency s/c whine. It may, too, be high frequency. Not quite as bad as this --> http://ebaumsworld.com/bubbrubbvideo.html Sorry, but when thinking how to describe it, I thought of BubbRubb. Too funny.

Seems that this is a characteristic of the Alta. Anyway, I'm diggin' it.

Thanks,
jeffro

 

Yes, I agree. Or similarly, like a set of brushes on a snare drum.

 

I did the emotional purchase of the Alta after some research. I was not really prepared for the 'significant' increase in noise level. Don't get me wrong, the whine is a love/hate relationship. The whine is pretty cool at 3500+, but I am with jeffro on the annoyance of the mid plate whoosh.

I guess my butt dyno is not very sensitive and I am not seeing the 5-10% hp increase. However this is a cheap logical step to my next desired move of a 15% pulley which should really show the gain...

My jury is still out on whether the noise outweighs the slight performance gain. I personnally have outgrown the stage of straight pipes which wake the neighbors (but that doesn't mean it isn't fun for others!!!). I think the nice thing about the Alta is you can tinker with the cowl plate....

I would recommend anyone considering this option explore enlarging the opening in the stock cowl and switching to a K&N flat replacement filter in the stock filter box. this will be about $200 cheaper and might have comparable gains! I personnally did not see the hole in the cowl plate, which I could have enlarged before buying the ALTA, or I would have tried this first.
-azminied

 

and not do anything with the cowl plate...

Matt

 

let me be a little clearer. while I was pulling all of the stock airbox and cowl plate out, I discovered the stock airbox has a small opening through the cowl plate. This inlet allows cool air from the cowl vent into the AI.

One could experiment with enlarging this hole in the stock airbox and the cowl plate to allow more free flowing cool air to the filter with spending any $$. The stock airbox can easily and cheaply be replaced if there was a desire to revert back to stock. If this mod gains 5hp and the $250 Alta CAI gains 7hp, one needs to ask if the $$ is worth the gain. Plus it would look totally stock (some people like the Alta look when opening the hood, and others like the 'sleeper' look).

Now..... before you flame me...
Recognize this is different strokes for different folks. I wish somebody had informed me of other options before I spent the $$. I would have tinkered some before spending the bucks and making somebody else richer.

-Ed

 

This is pretty much what I did--significantly enlarged the hole in the back of the airbox and corresponding plastic wall leading to the cowl area. But I replaced the filter with a common AFE cone filter. Airbox and associated tubing appears stock! I figure it's a CAI, looks stock, and benefits from the cone filter and extra air thru the cowl area. Plus it was very cheap.

 

I love the Alta CAI sound. I don't mind the whoosh, whistle and sucking sounds. It always just reminds me that an IC engine is in a layman's sort of way, just a bitchin air pump.

 

Installed an Ultrik CAI yesterday and went motoring today. I hear no whistle. I'm either deaf or lucky. A bit more supercharger whine perhaps. At any rate I'm happy. I've had this intake in the garage most of the winter. I was really concerned the whistle I kept reading about on these forums would make me crazy. Sad I waited so long! Maybe the Alta foam is the culprit? Or the great looking Alta silicone connectors? I'd like blue ones thank you very much.

 

If what your talking about is a high pitch whistle and not a whine i have a solution. The alta CAI silicone tubing is awesome, but a downside to it sometimes is that where the air sensor whole is on the inside, it has a very "sharp" edge. It is almost the effect of someone blowing across the top of a rootbeer bottle. Take a razorblade and carve it out a little bit so air isn't screaming across it to make that whistle.

 

Time to revive this post...

I too use the Alta CAI and I too LOVE the added SC "whine" and I even like the additional "whoosh" (the air sound sort of like brushes on a snare drum). All that's GREAT...

HOWEVER... With my installation, I also get a very high-pitched, "nails on a chalkboard" whistle at about 2000RPM, which escalates in volume until about 3500-4000 RPM. Over 4000 RPM, the SC whine drowns it out, but seeing as how I cruise on the highway at about 3000-3500 RPM, the whistle is usually there all the bloody time. It's very intrusive.

I mailed Alta and spoke to one of their techs (they got back to me really fast, which was great) and they advised that the whistling noise varies from car to car (drat), and that the cause could be a build-up of carbon on the throttle body. He advised to pull off the CAI hose and use a commercially-available throttle body cleaner to remove all the carbon.

I asked about the interior surface of the silicone hose and he advised that he had not heard of a hard edge in there as a general cause for noise - I guess if all else fails and I still get the whistle after cleaning the throttle body I can temporarily reinstall the corrigated OEM air hose. If the whistle goes away 100% then I know it's turbulence in the silicone hose and if it persists then I know it's increased volume past the throttle body causing the whistling and the only solution will be to de-install the Alta unit in favor of a return to stock or a different unit such as the K&N Typhoon... I hope I don't need to do so, however - I really like the look of the Alta unit and love the additional noinse (other than the whistle, which absolutely, positively has to go).

I'll post an update when I make the change and clean the throttle body - can anyone suggest the right cleaner I should be using?