Re: RE: Re: Re: RE: Re: Help!! Get rid of the Z-tube??

From: Canucker Trucker (mal5@ualberta.net)
Date: Wed Jul 03 2002 - 13:07:01 EDT


It could be just something that was missed during fabrication or
something....

--
Canuck
--------------------------------------------
Y2K 4.7L 2wd 5spd

"Stlaurent Mr Steven" <STLAURENTS@MCTSSA.USMC.MIL> wrote in message news:5F7587961057D211ABE9004095102F7803C5A9AC@ex.mctssa.usmc.mil... > > Yes...looked down the inlet portion of the TB unit to check for any sharp > edges. > > I had the F&B/Z Tube and it was smoothed everywhere but never experience > what is occurring on your truck. . > > -------------------------------------- > Steven St.Laurent > C4i System Engineer > C4i Engineering Branch, PSD, MCTSSA > MARCORSYSCOM, U.S. Marine Corps > Office (760) 725-2506 (DSN Prefix: 365) > "Never be content with somebody else definition > of you. Instead, define yourself by your own beliefs, > your own truths, your own understanding of who > you are. Never be content until you are happy with > the unique person GOD has created you to be." > > -----Original Message----- > From: Canucker Trucker [mailto:mal5@ualberta.net] > Sent: Wednesday, July 03, 2002 9:44 AM > To: dakota-truck-moderator@bent.twistedbits.net > Subject: DML: Re: Re: RE: Re: Help!! Get rid of the Z-tube?? > > > From what I can gather from all the posts is that the problem may be caused > by the TB alone: > 1) Steve has the Z-tube only - no problems > 2) Someone said they have an F&B TB - no problems > 3) You have the problem with the stock airhat and the Fastman TB as well as > with the Z-tube > 4) You mentioned Fastman has had this problem in the past ... > > (thanks Dr. Watson) > > So here's my theory: It **MAY** be caused by a phenomenon call 'vortex > shedding.' Basically, as air passes over an abrupt edge, the boundary layer > will 'stick' to the edge for as long as it can, until finally releasing > (like an elastic band breaking). When the boundary layer lets go (or the > 'elastic breaks'), it creates a vortex which vibrates the edge it was shed > from ... At a particular wind velocity, the vortex shedding occurs at a > particular frequency ... if this frequency happens to be close to the > natural frequency of your engine or the TB mounts or something, it will > vibrate the hell outta it. ... so basically, the air velocity going through > the TB @ 2400RPM causes vortices to be shed at the same frequency needed to > shake the engine ... This phenomenon is the cause of the Tacoma Narrows (I > think?) Bridge collapse (but in that case the wind passing over the guy > wires caused vortex shedding at the same frequency as the wires ... like a > guitar string) > > This phenomenon can also be seen on most radio antennae as you drive down > the highway ... ANYWAYS, > > So how do you fix it? --- disrupt the air flow where the vortex shedding > occurs ... i.e. at the TB. > > To get around the problem of the antenna ripping off as you drive down the > highway, DC wrapped a thin wire around the length of the antenna (take a > look at it next time you're at your truck)...this disrupts the airflow > around the antenna and reduces the size of the vorticies being shed. ... > you'll want to do something similar to your TB: > > You could try dremelling off any sharp edges that were left in the TB after > fabrication ... check the bore and the butterfly plate ... maybe round the > edges of the butterfly plate ... any sharp edge that the air might get > 'caught up on' is a potential culprit .... it's tough to say what would > cause it without looking at it ... OR just before the air enters the TB, you > could make some kind of flow disrupter like you were planning. Maybe just > some vertical fins in the Z-Tube. The key there would be to get the > disrupter as close to the TB as humanly possible. > > > Like Bernd said though, it's nothing harmful to the engine ... it may wear > some fasteners out or your throttle cable eventually, but who knows? > > sorry for the length of my essay :) hope it makes sense. > > > -- > Canuck > -------------------------------------------- > Y2K 4.7L 2wd 5spd > > > > ""crm"" <tb.crm@verizon.net> wrote in message > news:007e01c222ab$e6f3e210$7c6445a1@vatican2... > > > > Steven, the vibration is felt in the gas pedal. it occurs when i > accelerate > > enough to where it would shift at about 2800-3000rpm. starts at about 2400 > > though. > > > > it didnt happen when i had just the Z-tube on there though. i only noticed > > it after the Fastman TB. i had been told it was because of the lack of a > > resonator from the stock airhat and it appears to have been amplified by > all > > the extra air flowing thru the new TB. so last night i went back to the > > stock setup with the exception of the TB. still had the vibration. Bernd > and > > Dan Arcand both said it was nothing dangerous for the engine, but i'll > still > > see if i can fix it with the little vortex wing thingie inside the tube > that > > they told me how to make. > > > > other than that, the truck really seems to be liking the mods i've added. > > i've got about 175 miles on it since the TB swap and PCM reset and i can > > definitely tell a difference in performance. i'll prolly drive it another > > week and then take it back to the dyno to tell for sure. and then i'll > have > > another baseline prior to the cams and intake install. > > > > -adam > > > > ----- Original Message ----- > > From: "Stlaurent Mr Steven" <STLAURENTS@MCTSSA.USMC.MIL> > > To: <dakota-truck@dakota-truck.net> > > Sent: Wednesday, July 03, 2002 10:26 AM > > Subject: DML: RE: Re: Help!! Get rid of the Z-tube?? > > > > > > > > > > When I installed the Z-tube I never did experienced this problem. > > > > > > Where is the vibration occurring and what RPM range is the resonation or > > > vibration is being felt, Adam? > > > > > > -------------------------------------- > > > Steven St.Laurent > > > C4i System Engineer > > > C4i Engineering Branch, PSD, MCTSSA > > > MARCORSYSCOM, U.S. Marine Corps > > > Office (760) 725-2506 (DSN Prefix: 365) > > > "Never be content with somebody else definition > > > of you. Instead, define yourself by your own beliefs, > > > your own truths, your own understanding of who > > > you are. Never be content until you are happy with > > > the unique person GOD has created you to be." > > > > > > -----Original Message----- > > > From: crm [mailto:tb.crm@verizon.net] > > > Sent: Wednesday, July 03, 2002 7:51 AM > > > To: dakota-truck@dakota-truck.net > > > Subject: DML: Re: Help!! Get rid of the Z-tube?? > > > > > > > > > just to let you guys know, i installed the stock intake last night and > > still > > > had the vibration. so it's either always been there and i never looked > for > > > it and therefore didnt notice it. or, it's all the extra airflow from > the > > > TB, which in one sense is cool since it's obviously flowing more. > > > > > > either way, i am keeping both the Z-tube and the new TB. i bought some > > stuff > > > last night to make a little vortex wing (or whatever it should be > called) > > > inside the tube so i might get to that this weekend. and even if it > doesnt > > > completely fix it, i'll not worry about it... > > > > > > thanks to all who offered suggestions! > > > > > > -adam > > > > > > ----- Original Message ----- > > > From: "Bernd D. Ratsch" <bernd@texas.net> > > > To: <dakota-truck@dakota-truck.net> > > > Sent: Wednesday, July 03, 2002 12:04 AM > > > Subject: DML: RE: RE: Help!! Get rid of the Z-tube?? > > > > > > > > > > > > > > The vibration is not due to the intake or throttle body...but rather a > > > > resonance from the intake plenum. If you look at the factory airbox > (on > > > > the TB)...you'll notice a resonance chamber (or two depending on year) > > > > which cut the noise to a minimum (if not completely). > > > > > > > > - Bernd > > > > > > > > -----Original Message----- > > > > From: owner-dakota-truck@dakota-truck.net > > > > [mailto:owner-dakota-truck@dakota-truck.net] On Behalf Of Ronald Wong > > > > Sent: Tuesday, July 02, 2002 6:03 PM > > > > To: dakota-truck@dakota-truck.net > > > > Subject: DML: RE: Help!! Get rid of the Z-tube?? > > > > > > > > > > > > > > > > I have no problems with a K&N FIPK but then I have an F&B TB instead > of > > > > a Fastman. I don't know what the differences are but I know there's > no > > > > vibration. The only time I've ever had a vibration problem was one of > > > > my headers being too close to the transmission case. > > > > > > > > Ron > > > > 00 PB SLT QC 4X2 5.9 46RE 3.92 LSD > > > > For modifications see my DML Profile (URL follows) > > > > http://www.twistedbits.net/WWWProfile/dakota/Kw9pV1EkFeOYY > > > > > > > > > > > > -----Original Message----- > > > > From: owner-dakota-truck@dakota-truck.net > > > > [mailto:owner-dakota-truck@dakota-truck.net]On Behalf Of crm > > > > Sent: Tuesday, July 02, 2002 11:38 AM > > > > To: dakota-truck@dakota-truck.net > > > > Subject: DML: Help!! Get rid of the Z-tube?? > > > > > > > > > > > > > > > > hey guys, i have quite a quandry on my hands. i am having the gas > pedal > > > > vibration problem that some seem to get after installing an intake and > > > > new/ported TB. it's serious enough to where i know it should be fixed, > > > > but i am not sure how i wanna fix it. > > > > > > > > i feel fairly confident that the problem can be resolved by going back > > > > to the stock airhat that has the resonator on it, but that would mean > > > > getitng rid of my Z-tube. the dyno doesnt lie, and i know it helped > out > > > > in the power. but, i know i want to keep the Fastman TB, so that means > > > > finding a fix somewhere else. > > > > > > > > Dan (the Fastman) suggested putting a little piece of sheet metal in > the > > > > Z-tube perpendicular to the TB butterfly to help create some > turbulence > > > > and help cancel/dampen the harmonics to where the vibration lessens. > > > > however, he said he cant guarantee that it would completely resolve > the > > > > vibration. his idea was similar to what Bernd posted a while back. > > > > > > > > my other options would be to send back the Z-tube and exchange it for > a > > > > Stage II. or, i could go back to the stock setup with a drop-in K&N, > > > > minus that oddly directed airhorn and a larger opening in the front of > > > > the airbox. > > > > > > > > so help me out PLZ! i wanna make the best decision that will produce > the > > > > most power while at the same time getting rid of the vibration. i only > > > > have a couple days left to my 30 days on the Z-tube and i'm definitely > > > > keeping the TB. any help would be greatly appreciated. > > > > > > > > -adam > > > > > > > > > > > > > > > > > >



This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:05:00 EDT