Boost hose plumbing question

[UltraFlynn]

I've recently re-plumbed my boost gauge in properly so that it uses the vacuum tube going into the turbo pressure sensor but I have a question about my original plumbing.

 

You see, when I got the car the t-piece was plumbed into the vacuum line which goes from the inlet manifold (very close to the turbo pressure sensor) through to a VSV on the underside of the inlet manifold. The line itself goes under the inlet manifold.

 

I know that the plumbing is right now, but does anyone have any ideas what difference it would have made to the readings on the boost gauge when it was plumbed into that other line?

[UltraFlynn]

Anyone got any idea on this? I'm intrigued to know whether the boost gauge could have been reading right with the pipes set up the old way.

[D8MOA]

well if it went to a vsv. when the vsv opend the vacum pressue would of changed (well depending what else the vsv goes to)

 

have you noticed any diffrence in the gauage since u have changed it?

[UltraFlynn]

That's a good point, I hadn't considered what would happen once the VSV opened.

 

To be honest my boost gauge stopped working a while ago because the hose cracked so it's difficult to remember what it was reading.

 

The only other slightly strange thing is that the t-piece which is used has a little brass restrictor fitted into the connector which goes to the boost gauge. You can just get a needle to fit through it.

 

The boost gauge seems to read right though.

[D8MOA]

thats only there to try and stablize the needle when the car is at idle

[Homer]

The restrictor you mention is a pulsation dampner, as mentioned it helps smooth out any fluctutations while the engine is under vacuum/very low boost.

[UltraFlynn]

That's for the info guys. I've learnt something new there.

 

I'm not convinced that the way my boost gauge was plumbed originally would have given the right readings all the time. Glad I've got it done properly now.