DasTT

kinds of pressure readings are you seeing? Trying to decide if 0-100 psi or 0-150 psi is the right gauge. Interested in cold start pressure and hot idle pressure to scope the range. I've got one of the anodized black gauge-paks getting ready to go in.

I know it's hard to get to that side of the engine for the sender. Any of you use the dual sender with the low contact? I assume it's M10x1.

--bob

VenTTed

<ul><li><a href="http://www.ttstuff.com/gauges_gaugepak.php">go here..</a></li></ul>

TTschwing

<center><img src="http://images2.fotki.com/v23/photos/7/7305/222059/DSC00705-vi.jpg"></center><p>
You'll see pressures from 25-70 psi. I used the VDO "T" fitting. Remember though, the OEM hole is 10x1 non tapered, most pressure senders are 1/8 NPT tapered. The VDO uses both. One for the aftermarket, and the 10x1 for the OEM. It would be much easier though to use the VDO extender, which is about a 10 inch extension hose. Allows you to do the T's and such in the open to the right looking down at the motor, rather than trying to work in impossible places.... In this pic, the Defi sender is on the top, OEM on the right. VDO T is the brass piece. All this is ABOVE the OEM oilcooler sandwich plate. Hard to get to without removing this and almost impossible to get to from the top..

TTschwing

Temp is easy...Pressure is a Beetch!

VenTTed

True, but if I can do it... anyone can. :-)

DasTT

so you used the OEM switch. My continued research this morning shows the switch is supposed to close at 20 psi. Integrated VDO senders have a choice of 7 psi or 26 psi. Neither will do I guess. Looks like T-fitting all the way.

I actually found the spec in the service manual. It is idle min at 1.4 bar (19 psi), at 2K rpm it is 3.5 to 4.5 bar (50 to 65 psi). I think I'll go with 0-100 psi.

--bob

DasTT

gauge-pak since I already have a HUD for boost. Just want the slow moving gauges down low.

--bob

TTschwing

<center><img src="http://images2.fotki.com/v23/photos/7/7305/222059/DSC00698-vi.jpg"></center><p>

TTschwing

Slow idle is about 22psi, cruise 60-65...

mel g

2001 TTQ 180
Parts needed:
VDO mechanical oil pressure gauge. Uses US-style 1/8" copper tubing
Vdo tee fitting # 240-850 all 3 ends(2 female, one male) threaded the same non-tapered 10mm x1
Adapter to accept male 1/8 copper fitting, and enter into female metric 10x1 (which is on the vdo tee) part # r7960
Aluminum crush washers ( I got a whole box cheap of different sizes from J.C. Whitney)

Mechanical gauges all have a 270 degree movement of the needle, as opposed to the harder to read 90 degree rotation of (easier to install) electric gauges.
Autometer uses 1/8 inch copper tubing, which you run from engine to the gauge. Electric gauges , you insert a sender to the engine and the run a wire, which is more flexible than copper tube, to the gauge.

Threads and connections (to install a gauge, you need to know about threads. ):

The sensors on Audis are straight (non tapered) metric 10mm x 1 thread (10mm diameter, 1mm per turn). The seal is achieved by flat machined surfaces on the switch and the oil filter adapter body. No gasket is used. (I believe VDO electric senders are also 10mmx1 thread.)
Copper tubing is available at most hardware stores. It connects to fittings using a ferrule, which is a crushable copper cone-shaped donut washer. The washer fits on the outside of the copper tube and is crushed between 2 parts of a hollow fitting, when you tighten the two parts together.(the tubing goes thru the fitting and the fitting's nut. As you tighten the nut, the washer crushes and seals.) Ferrule is good for one use only.

1/8 inch copper tubing uses a standard 2-part American fitting, male end of which is threaded, size: 1/8 inch NPT (National Pipe Thread, a tapered thread system. Named for the very-approximate ID of the pipe, not the diameter of the threads themselves, which are approximately 3/8 inch diameter). The seal between the copper tube and the NPT fittings is achieved by the crushing of the cone washer between the tapered threads.

Although the tapered male end of the 1/8" NPT may start to thread into the non tapered 10mm x 1 Audi threads, Don't Do It! It will leak. That's why you need to get the adapter: its is female NPT on one side and male metric non-tapered on the other end 1/8" NPT to 10mmx1.

You screw the tapered male NPT into the matching female, and as you tighten, the threads get harder and harder to turn, until it is water tight




Installation:

Step 1. remove current Audi electric sender , use 24mm deep socket wrench. Save for reinstallation later, (so the sender will still operate the warning buzzer and lights).

Step 2. modify the vdo tee, if necessary, to allow the Audi sender to fully enter the tee, so that the surfaces touch and can crush the alum washer you will put there to provide the seal. I had to tap the threads a little deeper using a normal hand tap.

Step 3. install the Audi sender into the tee, such that it is in a similar position, horizontal, as it was before. And tighten it to crush the sealing washer.

Step 4. insert the vdo tee +sender to engine , but put an alum washer on the tee to seal when it enters the engine
Step 5 Install the US-metric adapter onto the vdo tee, using the alum weahser to seal (cant do this before entry into the engine, or the adapter will block rotation of the tee)
Step 6 Place the fitting nut on the copper tube, then the ferrule, then the other half of the fitting. Then insert it all into the already installed female adapter, and tighten( this is tapered thread and no washer needed.)
Step 7 To run the copper up to the a-pillar, where I used the 2 pod supra gauge holder: the copper can be pushed from under the dash up through the crack at the base of the windshield just below the a pillar, and no modification needed. Use the grommet above the accelerator pedal to next enter the engine compartment. Some flexing and wiggle and jiggle is needed, but it does all fit in.