natural or resonance frequencies are not soley dependent on material ...
they are the result of a combination of material and part size and geometry
(your exhaust resonance for example is a combination of the pipe material,
pipe diameter, and pipe length ... most critically the diameter and length
... the air density and temperature in and out of the pipes will also have
an effect on it)
my $0.02 CDN worth :) ... that's about 1/8th of a cent for most of you :)
-- Canuck -------------------------------------------- Y2K 4.7L 2wd 5spd"Stlaurent Mr Steven" <STLAURENTS@MCTSSA.USMC.MIL> wrote in message news:5F7587961057D211ABE9004095102F7803C5A9A9@ex.mctssa.usmc.mil... > > Is your truck an auto or manual transmission? Matt Barret has not > experience this either and he has the TB, HO cams, exhaust system, tube, and > so forth. > > I cannot understand that this is the cause of the problem, referring to the > TB unit. > > I was the beta development for both the Bruce B. 70mm TB unit and JBA > headers and never experience this problem. > > I know it is very annoying to have this vibration occur under power. I am > constantly retuning the rice car to overcome different resonation frequency > when adjusting the HP/TQ band. > It is possible the resonating frequency of the TB unit may be the same as > the metal material of the pedal. What I would do in this situation is > remount the stock TB, if you still retain it, and validate to see if this is > the case. If the resonating is gone then remount the TB unit and check to > see if all the pedals are filling the resonation effect or is it just the > gas pedal. Then the resonation must be coming through the cable to the > pedal. > > I would talk to Bruce Bridges (I have his private mail if you need it > offline) about this to check to see if the air velocity is causing the > resonation. > > Certain type of steel metal (depending on metal construction) will resonate > around mid 2K to low 3K. I have found that steel exhaust system have a > frequency of 3200-3400 RPM range. > > > > -------------------------------------- > 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 9:08 AM > To: dakota-truck@dakota-truck.net > Subject: DML: Re: RE: Re: Help!! Get rid of the Z-tube?? > > > 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