I agree. It would make a real symphony with the converter rattle and the loose exhaust shield. Must be some violent vibes in there.

 

That seems like a good idea using header wrap for the eBay Y-pipe...to help control flutter.


biz

 

Thanks all for the replys. While hauling milk yesterday, I was pondering the fluttering. I don't know if any of you have delt with any Harley Davidson motorcycle's. But I have a bit. If you put drag pipes on them with no baffles they have an exhaust flutter and don't run quite as good as they should. There are two ways to usually get rid of that. One is to put torque cones inside the pipe, by the flange. The other is to put a 1/8" bolt or screw into the drag pipe. It doesn't seem like it would do anything, but it does.With the addition of that bolt it give you a small amount of back pressure and the flutter goes away and bike will run better.
I am thinking that this might work if you put a bolt threw each of the side of the Y pipe.
I'm not ready to try it yet due to lack of parts and cold weather, but if one of you wants to experiment. Please do.

Was also pondering those throttle body spacers. I got a look at some of the picture of them. Well, my opinion on SOME of them is they are more like a fine threaded nut. You can't have the splines running a pitch like a nut. I'm not sure what amount of pitch it would take to do anything, but I'm sure you don't need much to do more than some of these other ones. Unless they do it just to make them whistle and make you thing they are doing something?

Just my thoughts, any more about my thoughts, please add to them.

Boris

 

I have a ebay y-pipe, I hear something that sounds like spark knock after installing the Y. Is this the flutter? It is at light to moderate throttle and under 2500 rpms.

 

Yup, so it seems.

I had something that sounded like a BAD knock in my '74 highboy at just around the same RPMs - the 390 I built had some sort of harmonic where it really had a bad case of flutter. The headers I used, an uneven (not side-to-side) firing order, etc, caused it. Probably an H/X pipe would have cured it.

When I heard Monsta's sound clip of flutter, I thought "Gee, sounds like my 390" ...

 

Talked to my exhaust guy yesterday. He's going to make my a Y-pipe and said it will have no restriction. He's ordering my a cat for a big block engine, he has the muffler that he figures will sound good behind the V 10. I'm waiting for my E-bay headers to show up, then have to find time to pull the exhaust, drill out the broken studs and install the headers. I will haul the truck up to the exhaust shop and let them do there thing. I'm hoping for a +2 mpgs out of this.

 

My 2000 Excursion had this flutter noise when I bought it.
Bought it used but was still under warranty.
The dealer replaced the Y-Pipe with one that was necked down
for a short distance just before the merge and fixed the problem.
I experienced no loss of power or gas milege.

 

The early "PI" engines (started in 2000) had flutter, and Ford came out with the necked-down y-pipe. It got installed on vehicles where the customer complained about flutter. Which, in many cases, was the bellhousing cover flutter, and not the exhaust flutter.

By 2001, the modified y-pipe was standard from the factory - my '01 came with the necked-down pipe.

 

I just installed the complete Banks kit. I will share the results once I have some good data

 

Has anyone ever tried 89 octane to get rid of this flutter? I have it with 87 octane, but it goes away with higher octane, and don't go thru gas like water. I get the best mileage with 89 also. I get around 14 highway, 12 city, only mod so far is a k&n filter and cut the plastic out infront of the air box. No exhaust mods yet either.

 

True "flutter" doesn't go away with different gas.

Sounds like you have a ping

 

Yep sounds like pinging. A tune-up and some custom tuning will help get rid of it.

I get a super tiny amount of ping on my 04' when I lug the truck in OD below 1400rpm. I couldn't hear it until after I put my headers on. I'm hoping custom tuning will get rid of it.

 

The headers "tinking" is different than pinging.

The bung plug on my air box fell out one of the many times I was playing around in there, allowing unmetered air past the MAF - my headers were pretty noisy to the point where I though there was a leak.

Replaced the rubber plug, mixture went back towards rich, no more "pinking" from the headers.

Big diff.

 

My e-bay headers showed up today, from what I can see they are made as good or better than some of the others I have bought. Now to find time to pull of the OEM manifolds and exhaust. Drill out the broken studs and get an new system installed.

 

anyone tried using header wrap to quiet things? i have used header wrap on my old race car and it mad ea world of difference. made it very quiet under the hood and underhood temps dropped drastically. just a thought?