Let me know if it doesn't work. Ask questions below.

http://www.supermotors.net/getfile/5...tter-video.wmv

 

good video!!!!! I feel lucky, I've never heard any thing like that from my exhaust. Would i if I put a new y-pipe on? My exhuast is loud,maybe a little louder than yours.

 

GREAT video Ken, thanks a whole lot for that one.

Now, my dissertation on this:

Definitely sounds like a resonance in the exhaust pulses. Something mismatched side to side, so that two cylinders are firing at once, or so close that the pulses smack into each other and cause problems.

What's really funny? My '74 highboy's 390 that I built did the EXACT SAME THING at about the same RPMs. Why? My machinist listened to it, and said the firing order on the FE's was not "even" in terms of side-to-side. Multiple times per revolution, the FE lets exhaust out the same side of the V one right after the other. The headers I had on it led to some feedback in the pulses. They were "almost" equal length long-tube headers. So, at certain RPMs, the pulses would hit the collector at the same time. He said change the headers and it would either move the resonance up or down the RPM range, or get rid of it totally, depending on how "equal" the tube lengths were. I always thought it sounded cool...

I think that's really the point of the restrictions on the stock y-pipe.

I WONDER why the 3-valve doesn't have any restrictions, AND the Y is way down the line much further away than the 2-valve pipe? Is it possible they were able to make both sides equal length? Or is it just too soon for the Y? Maybe the side of the Y should be elongated.

With all the work I did, I never got around to measuring the length of each side of the Y-pipe and seeing if they are equal or not.

Thanks Ken. I'm no longer afraid of "flutter" - as a matter of fact, I miss my highboy more than ever

 

Depends on the Y, I guess. We'll have to wait an hear if the folks who have Stan's Y-pipe get the flutter or not.

 

Ken, that sounds pretty close to my noise. Was your window up or down? I would guess up as when my window is down you can really hear it.

Art, are the 3valve manifolds more of a header style? I would think that is probably why they don't have the flutter. And yes the restictive "T" is to stop flutter noise.

 

The passenger window was down, all the others were up.

 

They are "slightly" more of a header style. They stick way out from the engine more, and have actual bends before they merge into the main "log".

However, and I may be wrong, I think we've heard from people with headers that still have the flutter.

Without changing anything else on my '01, the headers didn't change anything. I still get a slight drone between 1700 and 2000RPMs, just like stock.

 

Ok, if that sound is what we are calling flutter, then I have it too. Oh, wait, no, I can't have exhaust flutter, the neck on the Y-pipe on the 2002s fixed that. Right? /sarcasm

 

My 2001 has the necked-down pipe, and it was manufactured in 10/2000 - and I picked it up brand-new w/25 miles.

I'm really starting to wonder... well, I'm done wondering now with that video, but still, I wonder if it's really a big issue for me. Like I said, I loved it when my FE 390 went da-da-da-da-da, it sounded mean It just meant it was working...

 

And after listening to it again, not an issue for me... OK - where's that $150 I had saved up for a y-pipe mod? Oh, THERE it is - in my paypal account!

 

I definitely have the flutter on my X also. It's kind if nice knowing others have it. Misery loves company. I originally thought the sound was a leaky manifold gasket but could never find it. How do you write down that sound? How about "Psthbbbt, thbssspt, pssthbtsspt", you know, with your toungue half hanging out and blowing out all slobery.

 

I checked my V10 yesterday, and there's definitely a flutter at the same RPM range as Monsta's... and that's with the stock y-pipe.

I always thought it sounded cool - it's not quite as loud as Monsta's, but I'm no longer afraid of it

 

I want to hear the banks at WOT

 

I can do that for you. Outside the truck or inside the truck?

 

Just like the flutter video if you don't mind. I'm still not sure I hear the flutter.. is it that kind of hissing sound?