re. 5ktq Diverter Valve install?

[ben swann]

This was the most difficult part of my turbo conversion.  I expect you
will have similar difficulties and tradeoffs.  Part of my problem at
the time was going to the larger cold side of about 2.5" on my hybrid
t03/k26.  As a prototype, I fabricated a piece of 2.5" PVC U with 2
ports, the larger one for the bypass was directed at the turbine
vanes.  The smaller port was to plum in the additional connection to
the freq. valve/fuel recovery can(found later this was not necessary
and did away with it.  I took a lot of time drilling at an angle and
tapping in a fitting by cutting threads with a hot copper fitting, and
then screwing in the same sized plastic.  Part of my problem was
finding piping of the proper size, and that is why I went with PVC
which held up quite well until all of that nice work was smashed with
the accident.

The hose routing from the bypass to the above was also tricky.  There
is not much space.  I could not even take a decnt picture since you'ld
have to get a look from various angles to see what was going on.

I made multiple trips to hardware stores and trial and error fitments -
fabricated 3 of these before coming up with the final cold side hose
since the first and second version did not clear the intercooler when
installed.  I found the right size rubber adaptors with hose clamps to
marry the fabrication to the turbo and other side to the larger PVC
hose I made to go to the air intake boot.

In the end all of the effort paid off, and was working quite well until
the car met its demize when another made a left turn in front of it.

I was planning to remake the cold side hose out of some copper or
aluminum pipe someday.  Alternatively, one of the things that seemed
that would fit quite well and similarly modified, would be the air
intake horn that goes into the airbox pre-filter.  If you check it out,
it has exactly the right U-shape required to clear the intercooler and
other surrounding obstructions - that may be your easiest bet.

I know it might have been easier just to tap into the steel tube, but I
had to change that out anyway, due to the larger turbine inlet.  Maybe
I went to far into trying to get the bypass flow directed at the turbo,
as even Audi did not go through this pain.  I did it because it made
sense to be the best configuration for performance, and despite my
initial scepticism and self criticism, the thing held quite well. The
PVC did tend to deform a little on one of the pipes, not the one
connected to the turbine, but the replacement for the steel one - but
not enough to come apart or cause any trouble.  Also - it was cheap!

I have seen some of the 1.8T pipes that would seem to work from
Nuespeed, Techtonics, but couldn't stomach the cost.  That is why I
fabricated my own.  I bet Samco make something too, perhaps a little
less expensive.

[Hey everyone.  I'm ready to install a d/v on my 10vt, I'd love to hear
everyone's thoughts on this.  I understand that in theory the closer to
the t/b, the better.  However, I know the factory S6 d/v is plumbed in
pretty much right after the turbo.  I'm thinking the best spot for a
good quality install is to make a flange in the intercooler itself, on
that flat spot between the inlet and outlet tubes.  I'd also like to
divert the air as close to the cold side intake as possible.  I'm
planning on welding a bung to the intercooler pipe... we shall see.
What has everyone else done?  I don't like the idea of modding the i/c
to t/b hose, as that seems like a weak point as it is.  Thanks.  :)]



Chris