Which vaccum lines?? (Long)

[Raymond A. Kawski]

Jorge wrote:

> One thing that I have always wondered is, what vaccum lines are
> used for the wastegate and BOV when going turbo? What's the best
> place to hook these things up to? TIA

Interesting you should ask.  I've recently (yesterday) finally got
my POS yes POS Greddy Type R BOV to work properly under most
conditions.  First the product is crappy because the adjustment
screw stripped after adjusting it about 6 times.

Anyhow it really depends on the BOV.  I've seen HKS's connected
to just a 1/8" vacuum line.  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.  So I had to have it that tight.  And
since A I had to retap the adjustment screw I don't like
messing with it and B my ass is lazy.  If I change boost settings
I don't want to have to get out and mess with the BOV.
Now finally after getting the proper fitting I have to *TRY* to get
the BOV not to open.  Even at 6psi it will open properly.  Before
at 12 psi it would pop wooosh.  The pop being a split second
compressor surge then the BOV opening.  So Again I say
it depends on the BOV and how much boost you plan to run too.
You'll know if you need to change things if when you let off
the gas your car sounds like Larry Curly and Moe.  Or it pops
then wooshes sometimes and wooooshes other times.

For the wastegate it depends on if you have a boost controller
or not.  Most boost controllers have 3 connections on them.  One
goes to the wastegate, One goes to the manifold after the
throttle plate for it monitor and the third the instructions
say should go to the compressor housing.  However others have
told me it should also go to a port after the throttle plate.
This is where I have mine.  Some people put all of these on
the line for the Fuel Pressure regulator.  This probably isn't
a good idea.  I put my boost guage and the boost controller
monitor port with the FPR only.  Since both shouldn't be messing
with it too much.

RK
Addicted to Turbo
--
Ray Kawski
1998 Sentra SE Turbo picks on WS6 Trans Ams
1991 NX 2000 drove 850 miles in the last 4 months.
340K mile 1991 Sentra SE-R next oil change 345K