intake sound

[jhugh]

I heard it for the first time a couple weeks ago when my cousin called me on his cell phone... he was driving in his BMW 328is, getting on the thing as usual, and it made this fantastic sound which was clearly audible through the soundwall and over the phone... wwwrrrrrraahhh!!!! I rode in his car yesterday and then had a look under the hood. There's no aftermarket exhaust. Barely any sound at all comes out of the exhaust pipe. But he has a Dinan cone filter setup on the intake that gives off this fabulous combustion noise. I was reminded of the lovely sound my Ducati 900 used to make up through her flatslide carbs -- much higher-pitched than the booming coming from the tailpipes. And only there when the throttle is really chopped open.

So now the question... I have a K&N cone on my 3.2L. How come the only noise it makes is a very whispery whistling? Why doesn't any combustion note make it's way back through the intake?

Cheers,

[nhromyak]

I think it is because the 3.2s have a "barn door" to measure intake of air. Newer systems use a thin hot-air filament. I forget exactly how it is referred to.

Anyhow, this essentially limits the amount of air coming into the engine.

I hear the only time it is worth while to update to the THAF is when you have some bigger cams/displacement, and appropriately sized SSIs and exhaust.

Good luck.

[Early_S_Man]

Excuse, me, but ... front engine noise is closer, and has an acoustic path that is aided by the HVAC plumbing and perforations in the firewall!

Take out your sound pad over the engine, and see if that helps any???

[Steve W]

That's the best you're gonna get. I used to have a cut open airbox and that gave a little more grunt. I then replaced that with a K&N cone with a bell shaped intake venturi, sounded pretty much the same. Now I have a completely open Autothority hotwire, mass flow sensor with a large bell shaped intake and sound is not any louder or too much different, just a more open sound as air whooshes in.

[jhugh]

Hmmmm, sounds like no one's getting a combustion sound through the stock intake manifolds. What about carbs or FI stacks?

For the record, I took my sound pad out after it had started to come off. Having it off didn't make any discernible difference in the interior sound level. And the kind of noise I'm talking about, if it were being made, would be a hell of a lot louder than the sucking sounds I do hear.

I am thinking about the MAF, eventually. I'm pretty sure it would be a nice kick on top of the mods I have done (cams, flow, exhaust). But it's more fun to spread these things out over time, see what each one does.

Cheers,

[A Quiet Boom]

I can barely make out the sound of the intake on my carburated 3.0 over the exhaust note but only with the windows up and the K&N filters off. Remember that the intake sound is competing with the nearby exhaust and the fan to get to your ears. On a front engine rear exhaust car it's much easier to pinpoint the higher pitched intake because it's so far away from the exhaust. With my air filters on I can barely hear the carbs with my head in the engine bay! Just too many other sounds around to distinctively hear it.

One thing to add BTW, a restricted intake is generally louder than an unrestricted one, I hardly ever hear the carb on my drag car and it's got a cowl induction hood.

[NYSCAR]

Wow thati's wierd, I've pulled the airbox off my early S before and it sounds like a freakin race car (LOUD).

Brad

[jwill911]

I've witnessed the sweet induction noise a mod'd M3 makes. One morning early on Hwy 24 a guy in a M3 convertible (driving gloves and all) was trying to tempt me into a race. With my windows up and stereo on I could hear his intake as he jumped on it. Like I'm going to race a modified M3 (what's it 333 HP) on public roads. Besides I was holding my coffee in one hand.

I find it hard to believe a K&N code filter doesn't make enough noise for some of yous guys. I went back to my stock airbox after running mine for a while because I got tired of the volume of induction noise in the cabin. But mine is a daily driver. The kicker for me was is it doesn't add anything in performance. But it does make the car sound zoomier, I have to admit.

I might be coerced into selling it if someone wants to buy it. Bought it from Zucz Performance, it has the breather hose fitting which most don't. PM me if interested.

[masraum]

You could cut a 6" hole where the passenger side rear seat back is?

Another thought, the intake on a 3.2 is pretty long compared to most intakes (or it looks that way, could just be an optical illusion since it doesn't have to fit under a hood). Maybe the runner length and shape cancels out much of the noise compared to the short straight shot of a carbed engine or the fact that a frt engine the sound will come back to you.

You could always put a big block chevy with a quadrajet in the back.

[jabb]

No sound like the song of 6 webers transitioning to the secondaries right behind your head in a 914/6 3.0.....

It is an awesome sound....... 3.0 Headers Webers stock muffler..................

[jeff1hughes]

my 71 2.2S absolutely roars when the filters are off, well kind of a ssssffwwwooooooorrrrrrrooaarrrr noise if you can make that out. I use K&N ovals on the stacks but I am running with webers. Big difference over stock airbox though. I love it! don't even listen to the radio anymore.

[zuffenhausen]

Originally posted by jabb
No sound like the song of 6 webers transitioning to the secondaries right behind your head in a 914/6

Damnit, jabb, now I want a 914/6!

-zuff

[A Quiet Boom]

Originally posted by jabb
No sound like the song of 6 webers transitioning to the secondaries right behind your head in a 914/6 3.0.....

It is an awesome sound....... 3.0 Headers Webers stock muffler..................

uh? 3 Barrel Webers for 911 engines don't have secondarys.

BTW If you guys want better sound and performance, open up the exhaust a bit (probably the main reason I don't hear my intake very much)

[zuffenhausen]

Originally posted by A Quiet Boom
uh? 3 Barrel Webers for 911 engines don't have secondarys.

True, but there usually aren't six of them on one engine either, so obviously jabb has some trick stuff going on. He's got one triple throat Weber per cylinder, with one throat normally open and the other two coming online sequentially, thus secondaries. LOL!

If you guys want better sound and performance, open up the exhaust a bit (probably the main reason I don't hear my intake very much)

I haven't heard much induction noise from my cars either, for the same reason. I drove a 911 with megaphones (not recommended) on the street for nearly a month, and I had B&B make a straight pipe (highly recommended) for a 930 I once owned. Needless to say, I like a rather open exhaust.

-zuff