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Have you got anything connected to the servo connection in the middle? If not, use that. If so, put a t-piece into the hose that goes to the servo.

The other option is to tee into the hose that goes into the side of the plenum. It will read boost only, but it will be an easy solution.

As Phil says, drill and trap the manifold and install a hose barb to suit the size hose for the gauge.
As for order that depends on your set up, assuming you have a stock/or close to metro turbo OE spec instal;
Disconnect throttle and choke cables.
Disconnect hose connections from the carb and plenum (noting their positions If your novice)
Remove the two bolts that connect the plenum to the carb and disconnect the boost hose (if replacing the gasket on reassembly ensure the gasket has the correct quantity of holes).
If the coolant circuit is connected through the manifold then drain the coolant and disconnect the hoses.
Remove the manifold and carb as one assembly, unbolting engine steadies can allow the engine to can't forward giving more space to extract parts.
Its a straight forward operation.

Shane

@MetroTurbo: do you mean this connection?



@Shane: Thanks for the explanation.

Edited by Yoda74 on 24th Oct, 2020.

I assume by that photo your car is left hand drive and you have servo assistance connected for your brakes?
There is a round flat spot on the manifold / to the right of the SG casting no', that would be a suitable position to drill tap.

Shane

Edited by shane on 24th Oct, 2020.

@shane: yes my car is lhd and a servo is connected. I already assumed the flat spot would a suitable place.
I’m considering @metroturbo’s option, is that a good option or is a newly drilled and tapped separate connection much better?

Edited by Yoda74 on 24th Oct, 2020.

I’d be mindful of connecting into the vacuum connection as I think the banjo bolt has a check valve in which would stop the servo being pressurised under boost (I may be mistaken).
Personally I’d use a dedicated reference point / drilling and tapping.

Shane

Can somebody confirm or debunk this?

Will these two options show Both boost and vacuum?

If there is a check valve present in the banjo bolt, removal and inspection should be easy to do to clarify, if connecting after the check valve you would only see vacuum.
Drilling and tapping the manifold you will see boost and vacuum.
What I can’t see in your picture is wether your carb has the part throttle lean off ports/connections. If it has and the lean off pipe connections havebeen plugged then one of these could potentially be used?
Connection 5 in the attached.

Shane

Attachments:

3.37mb

Edited by shane on 24th Oct, 2020.

If I see it right, Connection 5 is in the carbs mounting flange near the manifold. there is a hose going from 3 to 5.

Edited by Yoda74 on 25th Oct, 2020.

Or you could keep life simple and get the insulator / spacer with the take off built into it.

See attached picture.

Attachments:

3.69mb

HOSS

http://www.minispares.com/product/Classic/....aspx|Back%20to

There you go.

HOSS

I didn't realise these existed.

Connecting an Led / bulb into the circuit that controls the solenoid valve can help diagnose what is going on. We used to do it with the old Saab 900 to see what was going on with the APC system which also uses a solenoid to modulate boost.

Run the wires into the cab, so can see what is going on while driving.

HOSS

Nice, thanks for that Elfturbo, didn’t know that existed, the connection seems rather small, but I guess it’s large enough for turbo boost / vacuum gauge.

The light I already tried, see page 1, but with no result.

There are not many turbo boost gauges around that go to 15psi or less, most are 30, but I don’t like to use a small part of the reading.
Some mention they are for diesel’s, wonder what the difference is...

If its only for test purposes/diagnostics and aesthetics are not an issue....
https://www.ebay.co.uk/itm/Pressure-Gauge-4...lEAAOSwmRFaZ1J4

It’s not only for testing. Once I have installed it, it may stay.

On the Metro the check valve is physically on the servo, not the banjo end, which is a common fitment on servos to hold the vacuum in.

Thanks for that.
If it’s on the servo, can I see that from the outside of the servo?

It is a black piece of plastic that the hose pushes onto

Thanks Metroturbo.

Do you mean this black piece of round plastic in the centre of the picture?
It’s on the servo, the tube from the manifold connects to it.

Edited by Yoda74 on 30th Oct, 2020.

Yes, I believe that is the check valve.

So placing a t-piece in the tube between banjo and this valve is an option to connect the boost gauge to?
Does it have to be a combined turbo boost / vacuum gauge or is a gauge that only shows turbo boost also an option if I connect it there?

A gauge that shows vacuum and boost would be better as a gauge that shows boost only might end up losing accuracy after a being subjected to high vacuum a few times.

That’s what I meant.
I like the vdo 150-101 but that only shows boost.
The search for a nice combined gauge has started

If you want boost only you could put a check valve into the line to the gauge that pulls shut under vacuum and protects the gauge.