Boost Gauge

[minsu515]

Hey guys,

I have a boost gauge in my car, had it since when I got this car,

But I noticed that unlike other boost gauge they install with T-fitting,

My car boost gauge hose is from intake vaccuum to boost gauge only(No T-fitting)..

and when I boost, gauge goes up and when I take foot off, I see gauge needle bouncing up and down really fast and can hear flutter noise from the gauge..

Is this normal?

[Guest]

got a pic of were its plumbed? if it directly plumbed into the plenum it should be fine.

-smurff

[wrx_lou]

Should be fine. What sort/brand gauge is it?

[minsu515]

 smurff said:

got a pic of were its plumbed? if it directly plumbed into the plenum it should be fine.

-smurff

It is plumed onto the turbo

[minsu515]

 wrx_lou said:

Should be fine. What sort/brand gauge is it?

so the flutter noise(form gauge as needle bounces) and bouncing gauge needle is normal?

It is just a AutoGauge .

[wrx_lou]

Isnt that normaly plumbed to the wastegate? ???

[Guest]

plumbed in there is a bit odd, the fluttering your getting is the extra boost when the throttle closes and then the bov opening i would say.

i would suggest moving it from that location to being feed off the intake plenum.

and for everything i have seen normally that is for the wastgate/bleed system for the standard boost control solenoid.

odd place to put it really. what type of boost control do you have OP?

-smurff

[minsu515]

 wrx_lou said:

Isnt that normaly plumbed to the wastegate? ???

my external wastegate is plumbed here on the thick one

middle one plumbs the blow off valve

and the other one is plumbed on this below:

the thinner one

[minsu515]

Im not sure what boost controll it is but I guess its standard as old owner didnt state he had changed the boost controller. but I see the hose from the bottom of the boost controller is plumbed onto the intake pipe.

Sorry, Im not expert on boost controller, wastegate, vaccuum etc..

[Optical]

jesus christ

firstly, the flutter noise is the boost gauge leaking because autogauge is shit

secondly, you will measure negligible vacuum as you're not measuring after the throttle body

thirdly, plumb it up properly, tee it to a vac line connected to the plenum

[Guest]

wow, that seems wack. the wastegate is normally off the turbo (were ur gauge is currently) and the gauge is generally off the plenum (were your wastgate is)

someone else may have an idea as to why urs could be slightly different. maybe someone mixed up there tubes ?

-smurff

[minsu515]

 Optical said:

jesus christ

firstly, the flutter noise is the boost gauge leaking because autogauge is s***

secondly, you will measure negligible vacuum as you're not measuring after the throttle body

thirdly, plumb it up properly, tee it to a vac line connected to the plenum

hahaha yes I agree, autogauge is S*** , will try to sort the plumbs tomorow.. Thanks!!

[minsu515]

 smurff said:

wow, that seems wack. the wastegate is normally off the turbo (were ur gauge is currently) and the gauge is generally off the plenum (were your wastgate is)

someone else may have an idea as to why urs could be slightly different. maybe someone mixed up there tubes ?

-smurff

Yeah I was thinking wtf has happend here as dont seem usual as others..

but the hose for wastegate is too big to fit on the turbo. maybe I need to get a smaller vaccuum hose for the wastegate? but I dont know how wastegate is working fine and boost gauge is reading 12psi which is right..

[Guest]

hes a quick pic of how the waste gate is roughly done from standard.

the gauge will read the correct positive pressure, as its on the turbo side. im not sure if teh wastegate would be working fine or not, you said its an external.

but i would think that as it is feed off the plenum side, when you take your foot off the gas, it would go into vacuum, which would then close the wastegate causing your turbo to spool and letting all that air out ur BOV.

(note this is just me thinking off the top of my head, if someone could say if this sounds right or wrong, please do )

-smurff

[marc]

 smurff said:

hes a quick pic of how the waste gate is roughly done from standard.

the gauge will read the correct positive pressure, as its on the turbo side. im not sure if teh wastegate would be working fine or not, you said its an external.

but i would think that as it is feed off the plenum side, when you take your foot off the gas, it would go into vacuum, which would then close the wastegate causing your turbo to spool and letting all that air out ur BOV.

(note this is just me thinking off the top of my head, if someone could say if this sounds right or wrong, please do )

-smurff

Yeah ither way the gate is going to close when you take your foot off the gas. (spring pressure) as mentioned above swap the hoses over Gate one and gauge one and shud be fine. The flutter is coming from the pressure chages in that boost hosee (turbo outlet) due to the bov not opening correctly or cant flow enough air. You wont get the flutter through the gauge when you swap the hoes over cus the throttle butterfly will block the pressure changes and ul just get a nice vac reading (wich is correct). And the wastegate doesnt need vacume so it will be happy just coming off that pressure hose where your gauges is in the first pic.

[Guest boostcut]

you buy a boost guage to read manifold pressure/vacuum. and someone hooked it up to the turbo? fail. the needle will be rapidly bouncing as the turbo compressor wheel is probably stalling.

[minsu515]

 marc']

[quote name='smurff said:

hes a quick pic of how the waste gate is roughly done from standard.

img]http://i543.photobucket.com/albums/gg467/jamieinauckland/Car/cobb1.jpg[/img]

the gauge will read the correct positive pressure, as its on the turbo side. im not sure if teh wastegate would be working fine or not, you said its an external.

but i would think that as it is feed off the plenum side, when you take your foot off the gas, it would go into vacuum, which would then close the wastegate causing your turbo to spool and letting all that air out ur BOV.

(note this is just me thinking off the top of my head, if someone could say if this sounds right or wrong, please do )

-smurff

Yeah ither way the gate is going to close when you take your foot off the gas. (spring pressure) as mentioned above swap the hoses over Gate one and gauge one and shud be fine. The flutter is coming from the pressure chages in that boost hosee (turbo outlet) due to the bov not opening correctly or cant flow enough air. You wont get the flutter through the gauge when you swap the hoes over cus the throttle butterfly will block the pressure changes and ul just get a nice vac reading (wich is correct). And the wastegate doesnt need vacume so it will be happy just coming off that pressure hose where your gauges is in the first pic.

hey thanks! I changed them today.

the gauge hose was abit small to fit on the fat one where wastegate use to be on,, I did put them on but the hose isnt all the way in, its half way in.

it is tight tho