CAI Whistle???

[BlimeyCabrio]

I know there are (and I have read) tons of threads about this on NAM. I have a Dinan intake and Alta hose. I love the whine - and (maybe psychosomatic) performance gain from this. But the whistle is driving me CRAZY. I keep telling myself "that's performance you're hearing..." and some days I convince myself of that. But the other 90% of the days when Blimey is in utilitarian duty, the whistle just sucks. Heh, I made a funny...

Anyway, in my case the whistle is directly associated with a specific throttle position, maybe about 10-15% throttle. Happens all the time at that throttle point, which for me is my typical non-aggressive moderate acceleration point at city speeds. (yeah, I know, I should just accelerate harder).

Have any of you folks dealt with this? And whipped it? I've heard some people say VGS or DT BPV are solutions, but others who said they didn't work. And I don't know what other consequences I may have from trying those approaches. I've tried muffling it with some foam in the intake - which reduces it, but not enough and I don't want to restrict airflow (duh).

I can live with it, but I know my wife will complain about it when she drives...

[simplygriff]

What's filter are you running? Is it a foam or K&N style?
-G

[BlimeyCabrio]

What's filter are you running? Is it a foam or K&N style?
-G

Neither - it's the Dinan filter, which is (or appears to be) oiled paper. Looks a bit like K&N, but I don't think it's fabric... Dinan sells it as disposable, though some folks clean and reuse them...

I've been considering switching to either a K&N or Uni filter...

[minimark]

Try a different filter..It should change the sound in some way, maybe better or maybe worse...I'd try that before I did anything drastic..:cool:

[oznogonzo]

I personally like the whistle, but I'm a bit tone deaf so it's not that bad for me. One rather far out idea is to cancel out the whistle with another noise.

A white noise generator mounted under the dash and tuned to the frequency of the whistle might do the trick. You could test it out by making a cd with a white noise track and see if it works. The trick will be generating the correct frequency.

In all reality though it probably will not go away without changing some parts. An upgraded throttle body might change the pitch of the whistle enough to make it seem quieter... but this leads to other upgrades... cam, chip... bigger heads hehe :D

[MidnightDave]

I have a Helix CAI and it makes a whistle. I'm getting the Invidia exhaust soon, and that may drown it out, especially with my rear seat delete.

It's kind of like the GY MTRs on my Tacoma, they're LOUD but you just get used to it.

I also had a 5.0 Mustang with FlowMasters that would drone at low rpms, and THAT was annoying and I did adjust my driving style to eliminate it.

Anyway, I guess the point is misery loves company and you're in good company.

Good luck with it!

[BlimeyCabrio]

I just ordered a Uni foam filter and a K&N filter to fit - so I'll do a little filter experimentation. I was planning to do this anyway - we'll see if it matters. Maybe Dan will chime on at some point regarding the Vacuum Gain mod or bypass valve... Alta told me that the whistle is air whistling past the throttle butterfly, and happens because of the chamfer on the butterfly... if that's true, perhaps one could grind a different edge profile on the butterfly... others have said the BPV solves it because it's actually coming from the BPV... oy vey....

[flannery]

I know this is a very late post but I am wondering what the results of your different filter testing were. Did changing the filter change the whistle? I had a 1973 240z with a holly 4 barrel and a triangle foam filter on it. Whistled like an NBA ref fixing a game. I ask because I was thinking about adding a CAI but don't want a loud whistle.

[BlimeyCabrio]

The details of the saga are on my blog here. (http://blimey.gomotoring.com/?p=138)

Short version - my whistle has proven to be the throttle - filters make no significant difference. I'm going to install a JCW intake next weekend...

[MidnightDave]

My post mortem and a likely unwife friendly solution, but works for me: The Invidia with the RSD drowns out the CAI whistle. ;-)

[minimark]

A "Justacooper" might fix the whistle....:p:D

[BlimeyCabrio]

AHHHHHHHH......:):):)


That's a sigh of relief....

Installed my JCW CAI last night - with AMSoil Nanofilter - and reinstalled my Alta hose...

And it basically has the same amount of whistle as bone stock - which is verrrrry little - just what comes out the front snorkel - which would pretty much be inaudible in a coupe, and is just BARELY audible in the cabrio, if you know when to listen for it. If you didn't know it was there, you wouldn't likely notice it from inside the car.

Certainly don't get the permagrin inducing continuous supercharger whine anymore - only over 4500 RPM, and even then signifcantly toned down over even the Dinan... which is much quieter than all the sheet metal CAIs... but I'm willing to take that trade-off to retain what shred of sanity I have remaining... loud enough for me (especially with the top down) and makes the car sound more refined overall - which frankly I like, though others would not... I'm a happy camper... :D

[minianni]

I agree Paul, we put a JCW on minianni's cabrio and both she and I love it. Quiet around town and enough "noise" when you put your foot into it.
I've driven a few with the constant whine and if I had to live with that everyday I'd be whining too.

Steve

[DSRH]

I just added my JCW (see my web log for pics) and I love it. My MPG has increased by 1 MPG to average 26.5. I did use a K&N filter so that may be why.
Although I have been reading about K&Ns on my Land Cruiser forum and the guys over there don't like them. They say they are too much open weave and allowing too much dirt to get past. I haven't decided yet but I am still running one on my MINI and my Land Cruiser...although I have the TRD version of the K&N on there. I also increased my MPG by 1 on my LC after adding the filter.
:)
As far as whine...it starts around 4-4500 RPMs and I love the sound. Before that it sounds stock and I really like the way it turned out. But I am a Mr OEM type and very conservative on my mods. But I do enjoy looking at the aftermarket stuff on other peoples cars. Much fun!:)