200 10V By Pass Valve Modification


200: 10 valve 1990 Avant shown here.


I am not a mechanic use any info here at your own RISK!

The information listed here is provide by

a fellow lister Konstantine Bogach and his experience

The photos are in NO particular order.  Just quickly posted for reference. 


I pickup the idea on http://members.rogers.com/pjberr/ECU_resis_mod.htm - Peter Berrevoets site. 

I just routed hoses differently to place BPV futher from turbo's heat. 

I have bad experience with PVC fitting and elbows - they deform and create leaks no matter how tight are clamps.
Stock intercooler was drilled and CPVC flange was glued on top of the hole

(excellent glue, made by 3M, is called 2216 B/A. Holds well after 2.5 years.).

Flange: McMaster part # 4589K83 (material is CPVC - tolerates hight temp better than PVC).

Fitting: McMaster # 53055K198 (1'' tube to 3/4 pipe elbow, material is PVDF, don't use CPVC or PVC, CPVC is ok for the flange).

Hose is 1'' ID. Flange was cut to the shape of plato around the hole in IC to have max surface for glueing.

Intake elbow pipe was drilled and steel/brass fitting was welded/brazed in.

Note: configuration used with DOT lights does not fit cars with

Euro headlights - as the latter have much tighter space around intake pipe.

Positioning of the fitting to be brazed into the intake pipe should be very accurate.  

I used clay to model the fitting in order to  braze it at right place and at right angle.

From: Konstantine Bogach <>
Subject: Bypass valve plumbing pics
To: quattro@audifans.com

Relatively recently someone was asking for examples of bypass valve
installation.   I have 2 type 44 cars, one  equipped with Euro lights. 
I had to redo plumbing when installed Euros.  I made pics the
istallation in the car with stock lights - e-mail me for pics.   I will
make pics of the plumbing with Euros maybe tomorrow.  Your e-mail, if
interested,  will speed it up.

200tq '89
200tqa '89 (2nd day after rebuilding/changing everything under the
hood,except engine bottom. Plus, new cushions in the driver seat.  Nice!)
UrS4 '93

HTH - Scott by BOSTON