Dump/blow-by valve installation procedure

[i6941tb@gnn.com]

A while ago Chuck Clark asked me about installation of the dump valve:
 
> Hey Igor,
> 
>Well I looked at the intercooler and it looks as if I do have  a third outlet on the IC.

OK, Chuck, you're in business.

I think the subject might be of interest to a number of 10v Turbo
owners, hence I am posting it to the list.

Disclaimer: all of the lengths and sizes are as being recalled to the
best of my memory. Be creative and very JUDICIOUS. Trial fit EVERYTHING!
As they say in the old country: measure seven times, cut only once. 

You'll need:
1. The valve itself. Audi p/n 034 145 710, Bosch p/n 280 142 102.
2. 2' of rubber hose, 7/8" ID.
3. 2' of rubber hose, 5mm ID.
4. A copper "T", 2.25"x2.25"x7/8" (it's a 2.25" copper pipe with a 7/8"
side outlet).
5. A copper elbow, 7/8"x7/8", bent at 90°.
6. A brass "T", 1/8"x1/8"x1/8" OD.
7. A 2.25"x2.25" rubber coupling, encased in a goffered tin collar
w/hose clamps riveted at both ends.
8. 4 hose clamps, 25-35mm.

Items 2 and 7 can be bought at Home Depot. Items 3,6,8 at Pep Boys.
Items 4,5 at any professional plumbing supply.

You should install the blow-by valve as close to the throttle body, as
possible. The idea is to let the boost pressure escape IMMEDIATELY after
you lift off. The air charge gets dumped before the turbo inlet.

a) Prepair the piece, that will go between the turbo and the airbox.
Insert Item 5 into Item 4 and align the elbow with the main body of the
"T". BRAZE the connection with silver solder. NO REGULAR Pb/Sn solder!!!
Attempted ASCII:

     |-----\
7/8" |      \
     |___    \
         |____|braze this seam well!!
---------|    |---------
|                      |
|                      |
|2.25"                 |2.25"
|                      |
|                      |
|______________________|
           A

b) Remove the L-shaped black 55mm OD metall pipe, that connects the air
box rubber boot with the rubber turbo inlet hose. Insert Item 4 into one
end of Item 7, and the air box side of the L-pipe into another and make
sure they fit snug. Tighten up the warm hose clamps on both sides of
Item 7 and check that both connections are air-tight.
c) Disassemble Items 4 and 7 and the L-pipe. Carefully measure the
length of Item 4 ("A") and mark the same length on the L-pipe, starting
from the air box end. CAREFULLY cut off that piece using a plumber's
pipe cutter.
d) Reassemble Items 4, 7 and the L-pipe as per §b, but don't tighten up
the clamps yet. Now you should have basically the same L-pipe, only with
a 7/8" outlet on it's side. The 7/8" outlet should be pointing forward
in the intercooler direction.
e) Reinstall this modified L-pipe in the car. Aline Item 4 in such a way
that the 7/8" side outlet is clear of the fuel injector lines boot and
unobstructed. Tighten up all 4 hose clamps now.
f) The blow-by valve (hereafter "the Valve") has three openings: Inlet
(22mm OD, on it's side), Outlet (22mm OD, on it's bottom) and Vacuum
Port (5mm OD, on it's top, opposite to the Outlet). ACHTUNG! DO NOT
confuse it's Inlet and Outlet or your car will be slower than the
snail's sh*t (unable to develop the positive mfld pressure).
g) Cut a ~40mm long piece off Item 2. Fit it onto the Inlet of the
Valve. Secure it with a clamp.
h) Fit the remainder of Item 2 onto the Outlet of the Valve. Secure it
with a clamp.
i) Unscrew the clamp and pull the rubber cap off the third (central)
outlet of your intercooler.
k) Push the Inlet of the Valve (the open end of the 40mm hose) onto that
outlet. Orient the valve in such a manner that the 7/8" hose (Item 2) is
pointed upwards and can be run along and parallel the L-pipe. Secure
with a clamp at the intercooler outlet.
l) Push the free end of the 7/8" hose onto the 7/8" outlet of the
modified L-pipe (you will need to cut it to size on the spot). Secure it
with a clamp.
m) Push Item 3 onto the Vacuum Port of the Valve. Bend it, (while
avoiding pinching it) and run it to the rear end of the intake mfld.
n) Cut either one of the two vacuum hoses at the end of the intake mfld.
Reconnect them with Item 6. Push the remaining open end of Item 3 over
the remaining open end of Item 6.
o) DOUBLE, no TRIPLE check that the whole assy is air tight and does not
interfere with any OEM equipment.
p) Gentlemen, you may start your engins now.

Happy motoring with no turbine stumble under lift-off!

Igor Kessel
'89 200TQ
with 20psi worth of dumped boost at the lift-off.