Yet another 4" exhaust question
Thread Starter
|
New User
Joined: Feb 2002
Posts: 19
Likes: 0
From: San Diego USA
Yet another 4" exhaust question
2003 F250 2wd 7.3 Crew 4" turbo back exhaust
Hey Gang....another question related to this new 4" exhaust I put in. Between 1200 and 1600 RPM I seem to get a noticeable and annoying flutter noise out of the exhaust. I think they call it "picket fencing"???? It almost sounds like a miss on a gasser. I remember hearing that when headers and free flow exhausts were added to gassers they would get a similar noise. Most noticeable when not fully warmed up and a little less noticeable when at temp but still there none the less. Waste gate? Back pressure issue? Any ideas? I guess this was something else I should have been aware of before I put a 4" exhaust on. I seem to remember someone discussing this in another post but a search didn't bring anything up. Thanks again......
Hey Gang....another question related to this new 4" exhaust I put in. Between 1200 and 1600 RPM I seem to get a noticeable and annoying flutter noise out of the exhaust. I think they call it "picket fencing"???? It almost sounds like a miss on a gasser. I remember hearing that when headers and free flow exhausts were added to gassers they would get a similar noise. Most noticeable when not fully warmed up and a little less noticeable when at temp but still there none the less. Waste gate? Back pressure issue? Any ideas? I guess this was something else I should have been aware of before I put a 4" exhaust on. I seem to remember someone discussing this in another post but a search didn't bring anything up. Thanks again......
Fleet Mechanic
Joined: Aug 2003
Posts: 1,773
Likes: 95
From: Phoenix, AZ
Are you runninga chip? or stock?
In either case you'll here the fluttering sound with the 4" exhaust, just more pronounced with a chip.
A way to eliminate or minimize the sound and prevent any potential future turbo stall is to install a Wicked Wheel and / or an ATS vented turbo shroud.
In either case you'll here the fluttering sound with the 4" exhaust, just more pronounced with a chip.
A way to eliminate or minimize the sound and prevent any potential future turbo stall is to install a Wicked Wheel and / or an ATS vented turbo shroud.
Thread Starter
|
New User
Joined: Feb 2002
Posts: 19
Likes: 0
From: San Diego USA
Hey Heatstroked.....thanks for the suggestions. In your opinion would going back to a 3.5 downpipe help with it? Otherwise.....you are right, I'll just deal with it. I took a look at the Wicked Wheel, it looks interesting, however it's beyond my level of automotive expertise to do the install. Now.....if it involves rebuilding a vintage Airstream from the ground up.....that's a piece of cake for me. Thanks again for the suggestions.
Fleet Mechanic
Joined: Aug 2003
Posts: 1,773
Likes: 95
From: Phoenix, AZ
No, don't go back to a 3.5". Won't change the noise problem but it will increase the low end grunt a little.
If you're pulling a trailer you'll want to keep the 4" all the way. You want to move as much air in and out as possible through the stroker!
I have Wicked Wheel instructions if you ever decide to do it. Can't be nearly as hard a restoring Airstream's!
If you're pulling a trailer you'll want to keep the 4" all the way. You want to move as much air in and out as possible through the stroker!
I have Wicked Wheel instructions if you ever decide to do it. Can't be nearly as hard a restoring Airstream's!
Senior User
Joined: Nov 2003
Posts: 331
Likes: 0
From: Abilene TX
not to disagree with heatstroked, but if i may offer my take on the noise you are describing, I interpreted it to not be related to any turbo surge or stall rather what I think you are hearing is the exhaust impeller whipping up the sound of what would otherwise be the sound of a normal exhaust. The reason you did not notice before is probably due to the fact that either you were running a muffler before the exhaust swap and/or the restriction of the stock DP made it more difficult to hear in the first place. My take on it is that it is completely normal. You will hear the same thing on any big rig with an exhaust upgrade. In addition, i don't think you would be experiencing any surge or stall at your turbo running stock, and if so you would not hear it in stock form through the airbox. I'm almost certain it is the exhaust side and if so, completely normal if not COOL in my opinion. Hope that helps..
Trending Topics
Elder User
Joined: May 2004
Posts: 637
Likes: 0
From: Forest Hill, MD
The sound you are hearing is compressor surge. All stock Ford turbos do it, its just more noticeable with mods. Not sure if it causes any problems though.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
Fleet Mechanic
Joined: Aug 2003
Posts: 1,773
Likes: 95
From: Phoenix, AZ
I realize he wasn't experiencing any turbo surge. I only stated that the Wicked Wheel and the ATS housing would eliminate the flutter he is hearing and as an added benefit, prevent any future potential turbo surge. Because we all know, he wont stop modding!hehehe!
Thread Starter
|
New User
Joined: Feb 2002
Posts: 19
Likes: 0
From: San Diego USA
Thanks for all of the great info and comments. I'm going to live with it for awhile and see if I adjust to the sound. If not, I'll check out some of the suggestions above to see if I can reduce it. Now, if I could get the turbo whine to cover it up that would be GREAT! Thanks again!
And yes the disease has started......decided to spend money I don't have and ordered an AFE Intake, gauges, and a Diablo tuner. Yikes......will it never end? So, if you charge it on your credit card you really didn't spend any money.....right?
And yes the disease has started......decided to spend money I don't have and ordered an AFE Intake, gauges, and a Diablo tuner. Yikes......will it never end? So, if you charge it on your credit card you really didn't spend any money.....right?
Senior User
Joined: Nov 2003
Posts: 331
Likes: 0
From: Abilene TX
Originally Posted by HeatStroked
I realize he wasn't experiencing any turbo surge. I only stated that the Wicked Wheel and the ATS housing would eliminate the flutter he is hearing and as an added benefit, prevent any future potential turbo surge. Because we all know, he wont stop modding!hehehe!
and by the way, the disease is contageous, bloodbourne, airbourne, and pshycological. There is no escape
Elder User
Joined: Jan 2000
Posts: 661
Likes: 1
From: Villa Ridge, MO
I don’t see how this could be a turbo surge noise. Like was stated, you would hear it in the intake rather then the exhaust. More of a sucking like whoosh in the intake. Also its more of an off WOT issue rather than just WOT accelerating. You usually don’t get surging until you run lots of fuel with a larger intake and exhaust. (Turbo Surge: A situation where pressures in the intake manifold are greater than the pressures in the exhaust manifold before the turbo. This results in the intake pressure forcing back out of the turbos compressor side into the air box. This can damage the turbo if violent enough due to the wheel suddenly stalling for a brief moment.) I personally have not heard or have gotten a stock truck to do it. I agree about the turbo whipping the noise to make it sound like a helicopter. Every PSD will have that sound (Except the new 6.0L) with an opened up exhaust.....i personally don’t like it....but some do....Tomato.....Tomato.......
Last edited by mudinford; May 25, 2004 at 04:49 PM.
Postmaster
Joined: Feb 2002
Posts: 2,773
Likes: 0
From: Bonney Lake, WA
I'm with Heatstroked on this one. When it was originally described as "picket-fencing", I knew he was talking about turbo flutter, which was described very well by bigdieseldave.
Turbo stall is another, totally different thing, and typically happens at much higher rpm levels than 1200-1600.
Turbo stall is another, totally different thing, and typically happens at much higher rpm levels than 1200-1600.
Elder User
Joined: May 2004
Posts: 637
Likes: 0
From: Forest Hill, MD
Turbo Surge: A situation where pressures in the intake manifold are greater than the pressures in the exhaust manifold before the turbo. This results in the intake pressure forcing back out of the turbos compressor side into the air box. This can damage the turbo if violent enough due to the wheel suddenly stalling for a brief moment. You sure your not thinking of a gas turbo? As far as I know without a throttle blade you can't stall the compressor side of a diesel turbo. Compressor surge is when the impeller ( exhaust side ) spins the compressor faster then the compressor housing can flow the incoming air allowing the compressor to spin without load to slow it down. Thats why aftermarket housings and compressor wheels eliminate or reduce the problem, they flow more air. Check out the ATS ported shroud housing that sucker will flow. At least thats what I thought.
Last edited by psdpower; May 25, 2004 at 10:54 PM.
Fleet Mechanic
Joined: Aug 2003
Posts: 1,773
Likes: 95
From: Phoenix, AZ
Wow, this thread got way off track.
I know what "flutter" is, I know what "surge" is. I know what causes both.
Please go back to the original statement, "picket fencing" = the flutter sound Airstream was hearing.
I simply stated that installing a Wicked Wheel and/or an ATS housing minimizes if not eliminates the "flutter" or "picket fencing" sound he was hearing and that there were added benefits of course. I didn't imply that the sound he was hearing was surging, etc.
READ THE REPLIES CAREFULLY. GETTING TIRED OF THIS ONE.
I know what "flutter" is, I know what "surge" is. I know what causes both.
Please go back to the original statement, "picket fencing" = the flutter sound Airstream was hearing.
I simply stated that installing a Wicked Wheel and/or an ATS housing minimizes if not eliminates the "flutter" or "picket fencing" sound he was hearing and that there were added benefits of course. I didn't imply that the sound he was hearing was surging, etc.
READ THE REPLIES CAREFULLY. GETTING TIRED OF THIS ONE.