Boost Gauge - Which Vacuum Pipe?

Hi everyone,

I'm looking to fit a turbo boost/vacuum gauge to my 147 JTD but am confused as to where to connect the vacuum pipe bearing in mind that it has to pick up the inlet vacuum as well as pressure.

There are 3 small pipes coming from the vacuum reservoir,
1 goes to the throttle body,
1 goes to a T-piece of which one end goes to the vacuum pump on the end of the camshaft,
1 goes down to the air box.

Does anyone know which of these the gauge pipe should be connected too or doesn't it matter?

Cheers!

It needs to come from somewhere between the throttle-butterfly and the engine.

I will take a picture and show you how I did it on mine...tomorrow.

Originally Posted by David C

It needs to come from somewhere between the throttle-butterfly and the engine.

Oops, I thought they went in the main pipe between the turbo/intercooler and the throttle body.
Anybody know why they go where they do?

Originally Posted by alfafamily

Oops, I thought they went in the main pipe between the turbo/intercooler and the throttle body.
Anybody know why they go where they do?

Because you are measuring the pressure of the air going into the engine.

Originally Posted by kgb

I will take a picture and show you how I did it on mine...tomorrow.

Cheers kgb, that would be brilliant!

sorry that I didn't do it today....tomorrow I will try not to forget.

David is right....but I installed mine before the butterfly...

here are the pictures:

http://kgb.alfaromeo-bg.com/147tuning/others/

Thanks for the info guys, i'll have to take the engine cover off and have a poke around.
I don't suppose there's a removable blanking plug in the manifold anywhere that I can put a fitting into (wishful thinking)?

Originally Posted by 147daytona

I don't suppose there's a removable blanking plug in the manifold anywhere that I can put a fitting into?

I'm sure there isn't because I know it is a pain when the mechanics need to measure the boost levels in the workshop.