Which vaccum lines?? (Long)

Jay Whitely jwhitely2000@yahoo.com
Wed, 3 Apr 2002 22:57:39 -0600


However for the POS
> Greddy Type R
> with Street Spring with 1.5 coils cut I needed to
> have a 3/8"
> line T'd off the brake booster line going to the
> lower nipple
> *AND* a 1/8" line straight off the compressor
> housing of the
> turbo going to the lower nipple on the BOV.
> Loosening the screw
> gave me leaks at 14psi.

***Ray, I have a few pointers that might make you a
believe in the Type R BOV.  First of all, as you have
done, use the street or standard spring and cut off
1-1.5 coils.  Wrap the adjusting screw with Teflon
tape to prevent galling of the threads and to avoid
air leaks.  It *will* leak 100% of the time without
the Teflon tape on the threads.

To adjust the BOV, attach a hand held vacuum pump to
the upper nipple of the BOV. Make sure the pump has a
built in gauge.  Squeeze the pump until the BOV just
starts to open (the plunger lifts off its seat). Then,
note how much vacuum is required to open the valve.
Adjust the screw until the valve just begins to open
at around 10 inHg of vacuum.  Tighter will make it
open later and at a higher amount of vacuum and looser
will make it open earlier and at a lower amount of
vacuum. It is okay if it starts to open at 8-13 or
so....just get close to 10 inHg of vacuum.

Tighten the locknut on the adjusting screw. With the
Teflon tape on the threads of the adjusting screw,
squeeze the pump several times until the gauge reads
very high, like around 20-25 inHg.  Now, the gauge
should hold steady at that reading and no leaks should
appear. It should hold vacuum for a long time if it is
air tight.

Lastly, only attach the upper nipple to a source of
vacuum after the throttle body. *DO NOT* attach the
lower port. Attaching boost to the lower port will
cause it to pop open at certain boost levels.  This
can overspin the turbo.

If you attach only the upper port, then the BOV will
hold any amount of boost you ever plan on throwing at
it!

If you were curious, you can hook up the lower port,
but there is a certain way to do it for it to work
correctly. You have to attach the source of boost to
an on/off solenoid that will only supply boost to the
lower nipple at closed throttle. This will cause the
BOV to open quicker and it will be louder.

I guarantee you 100% you will be happy with your Type
R if you take the 15 minutes needed to do this. Let me
know how it goes.

Peace,

=====
Jay Whitely
Tampa, FL
1996 200SX SE-R
GTi-R powered, F-MAX Stage 2