5ktq and boost ...........

[Ken]

Quoting Ben Swann <bswann at worldnet.att.net>:
>
> On Thursday, June 13, 2002 11:34 AM, Ken [SMTP:auditude at get.net]
> wrote:
>
> [Ben, it really seems like you may have the boost valve hooked up
> incorrectly.  I would perhaps take it completely out of the equation,
> plugging the holes, and see what kind of boost you build then.]
>
> Ok I will try that, especially since I have tried most everything
> else.
>
> I did hook this up referencing a diagram on the SJM website.  Hooking it
> up this way did strike me as being "bass ackward" now I recall.  I did
> test it remained close while control port under pressure or atmospheric
> and opened when vacuem applied.  That didn't really tell me which way
> the flow should go - for that I referred to the diagram.

What I didn't understand was why you would have hoses blowing off before they were tightened more.  You wrote before that you shifted, and the hoses popped off.

I only know what I've read, because my bypass valve is sitting in a box instead of on the car (yeah, yeah), but it doesn't seem like there should be enough pressure after the bypass valve to blow hoses off.  Perhaps at the moment it opens, before the pressure goes down (if it does at all), there is a spike that cause them to pop off.

This may not be related to you problem, so don't let me get you sidetracked.  I don't know how loose your hoses were before they were tightened.

> > Let's assume the bypass might be leaking (internally) -
> > why/how would that effect the observed boost pressure?
>
> Because the turbo is spinning around and around, but the boost isn't
> "building" because it's not filling cylinders with a fixed volume.  It
> just circulates, even with the throttle open (if it's hooked up wrong or
> incompletely)
>
> > > Also, since it wasn't entirely clear in your post, I just wanted
> > > to make sure that the bypass is sending it's air to the
> > > intake (compressor) of the turbo and not into the actual
> > > turbine...I am guessing by turbine you just meant turbo.....
> >
> > Right - I have a fitting installed in the turbo intake, and
> > directed toward the impeller.  I did this so the bypass flow
> > would enter already going in the right direction.

I think the boost from the turbo is supposed to be aiming at the side of the internal diaphragm, and not directly against it.  It will still open this way, because the small nipple will suck it off it's seat when you shift.  I think it's the opposite that people generally thing it should be.

Here's a pic of Jim's setup, but I don't know if this is before or after he re-oriented it the correct way.

http://www.geocities.com/jeg1976/conversion_home2.html

Well, this is consistent with the correct way as described on SJM's site:

http://www.sjmautotechnik.com/turbo.html#bypass

It reads that the "side" port is supposed to be connected to the turbo outlet.  This would be more correct if it said "intercooler outlet", as that is probably how it is typically installed.  Right before the throttle body seems like the best place.

It also says that the "inline" large port is supposed to be connected to the turbo inlet.  This is a good way to describe that.

> I'll replace it with a "cork" inline and see what happens.  I hope I
> don't blow anything..else.

While testing how much boost you get, try to avoid slamming the throttle shut all the way after you figure it out.  But you might have to, depending on how fast you end up going by then!

Good luck!  I think many of us are anxious to hear how your car performs when things are sorted out.

Later,

Ken