Boost Gauge Help (not showing Vacuum, show's boost)

[vas85]

Hi Guys,
This might be a simple fix depending on where I placed it (which I believed to be correct) or a faulty Gauge.

I thought before I get around to install the three gauges in the single din slot above my stereo that i'm going to get my boost gauge working first as from when we set it on the dyno @ 10psi I have moved it up and down since and then until I installed the boost gauge I have just put it down so many clicks.

Eitherway the car now is showing 6.8psi or so just under 7psi of boost under WOT but when you start the car and normal driving (without giving it any) the car should be runing in Vacuum mode...(n/a pretty much) but I dont see the needle drop below 0 boost. it just sits there.

I have a pic below showing how I placed the T piece from the boost gauge.



Should I have placed it on the other end... before the boost controller is limiting the boost? Everything else went good as far as wiring / and aesthetics.

I did about 8-9pulls and all came to just under 7psi.

Any help would be much appreciated guys.

 

[Fletch124]

You need to source your "vac and boost" from some place behind the throttle body. There is a nipple coming off the back of the intake manifold that goes the cruise control and the factory boost pressure sensor.

 

[Fozbo]

You need to run the "Wastegate >" side directly to the wastegate. That boost signal coming out of the "Wastegate >" nipple is going to read lower than the real amount of boost because a manual boost controller "tells" the wastegate that it isn't at full pressure yet. This keeps the wastegate from opening for a little longer.

So in short, yes, the "Wastegate >" side needs to go directly to the wastegate and the boost gauge signal needs to come somewhere off the intake manifold after the TB.

 

[BlackMKIII]

The wastegate never sees vacuum. Fletch is correct. Find a source of MANIFOLD vacuum/boost and the gauge will work properly.

 

[vas85]

Interesting... as the boost contrller was installed by my mechanic a while back when doing dyno pull so that's all fine... but i'll look at a different location for placing it, is there anywhere people generally plug it into before/around our throttle bodies? (3000pipe)

Actually that makes sense.. thinking back to when it was on the dyno he had a tubing coming off around the 3000pipe for intake manifold pressure to determine how he will tune the boost... interesting... now i'm recalling.

 

[Fozbo]

I use the nipple coming off the back of the intake manifold (closest to the firewall) that runs a T to the cruise control and heater. I took out my cruise control and changed around the T, so I can't remember exactly what it is like stock.

 

[jtran8]

Vas85 , you or your mech hooked it wrong. just like those above said , boost controller is use to control boost only ; you need to hook one side to turbo pressure nipple and hook other side to wastegate actuator , that's all you need to control boost up and down . Now for boostgauge , you need to hook that vac/boost hose from boostgauge to vacuumm hose that just above egr port ( after throtle body ) like those above said .The true vacuumm and boost reading are from inside intake manifold and not anywhere else . 10 out of 10 people on this forum done that .

 

[vas85]

Vas85 , you or your mech hooked it wrong. just like those above said , boost controller is use to control boost only ; you need to hook one side to turbo pressure nipple and hook other side to wastegate actuator , that's all you need to control boost up and down . Now for boostgauge , you need to hook that vac/boost hose from boostgauge to vacuumm hose that just above egr port ( after throtle body ) like those above said .The true vacuumm and boost reading are from inside intake manifold and not anywhere else . 10 out of 10 people on this forum done that .

Yeah I was hooking up the boostgauge myself. I am going ot be re-doing it now, just bought some adaptors for the hoses etc.. and I think the engine would be cooled down enough to be able to meddle around in there.

Cheers guys for all your replies!

 

[vas85]

I've now fixed it all, I used to have with my car a HKS EVCIV that was faulty where it would always spike so when my mechanics put on the boost tee for dyno'ing they had left one hose untouched. Which in this case would've been the vacuum, as the hks unit needed 3 and two were used for the Boost Controller. I re hooked that up yesterday and she's all sweet now.

 

[jtran8]

I'm glad you got it fixed:icon_bigg . I have hks evc ez and here is how i hook mine second picture is for boost gauge connection:icon_bigg

 

[vas85]

Love your Cam Cover, true SupraMania(C)!!!!!!!

 

[CajunKenny]

Hey vas! What are your dyno numbers and at what boost? :naughty:

Thanks...

Your car looks great by the way. I like your wheels!

 

[vas85]

Thx for the compliment to my car Makes me never regret going honeycomb hehe...

Power is not much, it's 170rwkw I have a 3" turbo back, fuel cut defender, mhg, upgraded CT26 and running it at 10psi. To come is my better intercooler installed and an engine bay looking somewhat like this:



Wouldn't mind knowing who's engine bay that is by the way...love it.