team3s
Sunday, February 20
2000 Volume 01
: Number
062
----------------------------------------------------------------------
Date:
Fri, 18 Feb 2000 22:07:17 -0600 (CST)
From: Mike Myers <
mimyers@prairie.NoDak.edu>
Subject:
Re: Team3S: apex blow off valve and erratic idle
The reason why your cars
are stumbling is because your venting metered
air.
The mass air sensor
measures the air flow as X. If there are no leaks,
the engine uses
X. If air escapes between the MAS and the engine, X will
no longer be
consumed by the engine. Instead it's X - Y = Z. As far as
the
computer is concerned, the engine needs enough fuel for X amount of
air, but
it's not actually getting X, it's getting Z. So the fuel mixture
is
extra rich.
When the idle switch is closed and the rpms are above a
certain level, the
computer cuts all fuel injection. In the period
between letting off the
throttle and the idle switch is closed, the computer
continues to run the
injectors. However, your blow off valve has
started to vent air during
this period causing air leaks, hence, extra rich
air.
Why is you blow off valve venting?
The opening of the blow off
valve is simplified to the following
comparison:
Pressure in
Intercooler pipes (PIP)
vs
Pressure in intake manifold + some spring
constant (PIM + SC)
Note: pressures are in comparison with atmospheric
pressure, vacuum will
have a negative value
When the PIP > (PIM +
SC), the valve starts opening
When the PIP < (PIM + SC), the valve stays
shut
Example: your idling
PIP is going to be 0psi or slightly
higher(turbos spin, even at idle)
PIM is approx. 9 ~- 10 psi vacuum
(-10psi for simplicity)
0 < (-10 + SC)
10 < SC - as long as the
spring can generate the equivalence of 10 psi of
spring pressure or greater,
the valve will remain shut.
What is your SC?
Remove your blow off
valve from your car. Grab your mitivac. Hook it up
to the port
which leads to the intake manifold. Start increasing the
vacuum, when
the valve begins to open, you have the approx. SC.
Anyone who has a VPC
can get away with venting their blow off valve. They
measure air (temp
and pressure) after the blow off valve. What happens
previous to this point
is irrelevant.
If you have a 1G talon blow off valve, you can increase
the SC by slightly
crushing the blow off valve in a vice. It's the only
way I could get my
former talon to idle with the blow off valve venting to
the atmosphere was
to crush it slightly. However, when racing,
everytime I would shift, a
puff of black smoke would come out my exhaust
(running really
rich). Also, my mileage fell nearly 5 mpg.
The
following idea is based on Talons which is similar to
3000GT/Stealths.
Your aftermarket BOV may differ.
-Mike
***Info:
www.stealth-3000gt.st/Team3S-Rules.htm***
------------------------------
Date:
Sat, 19 Feb 2000 02:46:31 EST
From:
TrboDrvr@aol.comSubject: Re: Team3S: Toe
Adjustment on Rear Wheels
Cory, do the 96 TT's have all wheel
steering? If so, I thought there was a
special procedure that you
needed to follow to adjust the toe that would
essentially lock the rear rack
while the adjustment is being made. My
brother in law (who was a one
time car mechanic) told me that they had a heck
of a time adjusting the rear
toe because he didn't know of this special
procedure. He described the
exact thing you are talking about. Now whether
its true or not I don't
know. My brother in law has been known to BS once in
a
while!
Joe 91TT
***Info:
www.stealth-3000gt.st/Team3S-Rules.htm***
------------------------------
Date:
Sat, 19 Feb 2000 11:53:33 -0800
From: Errin Humphrey <
errin@u.washington.edu>
Subject:
Re: Team3S: apex blow off valve and erratic idle
"Barry E.
King" wrote:
> Am I the only one who has not ever experienced any
problems whatsoever
> associated with an aftermarket BOV, except for
leaking above 19 psi?
>
> My Blitz was installed early on before big
blowers and the like. It worked
> excellent. After all the
mods it would leak above 19 psi (the rated maximum
I've also had minimum
problems with the Blitz. I only recently
re-installed it, so I'm still
playing with the spring. Right now it
idles fine and stumbling is
fairly negligible.
I currently have it installed with the stock BPV, but
I leave the
small tip (normally connects to the post-TB hose) unplugged.
I
originally assumed this would keep it from ever opening, but
I eventually
figured out that this probably isn't the case. Since
the from-post-TB
side of the spring constantly sees 0 psi, the
BPV should open somewhat
whenever the Blitz opens, right?
I'd like to disable or remove the stock
BPV completely. Maybe
one way to do this would be to use a pre-TB hose
on the tip
instead of a post-TB hose. I wanted to just plug up the side
of
the pipe which came with the Blitz so I wouldn't need to use the
stock
BPV, but after searching for hours in a hardware store, I
wasn't able to find
anythingto do the trick. Help! :)
-
--Errin
***Info:
www.stealth-3000gt.st/Team3S-Rules.htm***
------------------------------
Date:
Sat, 19 Feb 2000 11:52:38 -0800
From: Errin Humphrey <
errin@u.washington.edu>
Subject:
Re: Team3S: apex blow off valve and erratic idle
Jim Matthews
wrote:
> Confusing thing is that I get the stumble consistently about
one second I let
> off the throttle, even after very mild acceleration
with boost not getting above
> vacuum. Under these conditions, the
BOV should not be venting at all!
The reason why you still get stumble is
because the BOV could be
activated by even small pressure differences between
the pre-TB
(Y-pipe) and post-TB (intake plenum) sides. Mike Myers just
did an
excellent post detailing the mechanics behind this, and I'll respond
to
his email in a bit.
So whether or not you are actually boosting
might be irrelevant given
the fact that there is a vacuum in the
plenum. Also keep in mind that
even when you aren't producing
measurable boost, that doesn't mean
that your turbos aren't pushing quite a
lot of air. It isn't yet significant
enough to boost over atmospheric
pressure and register on your boost
gauge, but it will further increase the
pressure differences between the
pre-TB and post-TB sides once you start
closing the throttle plate.
> Note
> that unlike some BOVs, the
Blitz is installed along WITH the stock BPV, again
> leading me to believe
that the car should run like stock under the conditions I
> described
above, with the Blitz only venting under large pressure
>
differentials. Apparently not.
I used to have the Blitz installed
in tandem with the stock BPV. I
had the screw so far down that I never
even heard the Blitz at all
(and thought it was a waste of money), but I
~never~ had any
stumbling or idling problems ~at all~. Once I started
loosening up
the spring I started experiencing the stumbling and learned to
live
with it. Nowadays, I have the BPV installed, but I leave the
hose
to it unplugged. This way, I think it will only open up a bit
when
the Blitz has already opened up. The car now idles fine and
the
stumble isn't very noticeable except if I let off high throttle
really
quickly.
It might be possible to find that perfect spring
setting where the
Blitz only blows off under high boost and everything else
is handled
by the stock BPV. However, the only BOV which I think
would
do this really well is the HKS super sequential BOV which has
two
different levels of blow-off response.
> At any rate, a 1G DSM
BPV sounds like the way to go.
A couple more options for those who prefer
bypass valves:
Turbonetics makes both a competition as well as a street
BPV:
http://www.turboneticsinc.com/catalog/bypass.html-
--Errin
Seattle
***Info:
www.stealth-3000gt.st/Team3S-Rules.htm***
------------------------------
Date:
Sat, 19 Feb 2000 12:24:48 -0800
From: Errin Humphrey <
errin@u.washington.edu>
Subject:
Re: Team3S: apex blow off valve and erratic idle
Matt Jannusch
wrote:
> If the BOV is installed and functioning correctly, why would
the car have to relearn how to idle? It should be fully closed at vacuum
with no boost in the Y-pipe - same behavior as the stock valve. If it does
something different than this, then that would be undesirable as you would be
sucking in unfiltered (as well as unmetered) air through the BOV.
It's
possible that because of the responsiveness of the spring on
the stock BPV,
weak design of the stock BPV, as well as the
pressure/vacuum differences
between pre-TB and post-TB, the
stock BPV is bypassing some air during
idle. Thus, if you install
an aftermarket BOV/BPV, it would would be
necessary for the
ECU to relearn in order to idle properly.
-
--Errin
Seattle
***Info:
www.stealth-3000gt.st/Team3S-Rules.htm***
------------------------------
Date:
Sat, 19 Feb 2000 18:04:09 -0500
From: "Bob Rand" <
rtr@vnet.net>
Subject: Team3S: Ground
Control Installed
Hey Gang, The ground control suspension and
new struts are installed. All
I can say is I am very happy with the
results. The handling on curves is
far superior to the stock set up.
The overall ride is a little bouncy but
not unbearable and worth the trade
off in my book. I used 550 lb front and
325 lb rear and lowered the car about
and 1.25 inches all the way around.
Test drove the car in downtown
Charleston, SC which is very bumpy and not a
rattle or disturbing spring
noise was heard.
I have a couple of installation photos that may help the
next guy and notes
and comments on the installation. This information will be
forwarded to Bob
Forrest and compiled along with the already fine work done
by Dennis Bretton
for use on the team 3s web site. I did 100% of the work so
got to experience
100% of the problems encountered.
Now scheduling an
alignment. The manager at Firestone has agreed to allow me
to work with his
alignment expert so I can learn a few things that might be
useful. If
anyone has alignment info that they would like to share email me
as I have a
week before I can get it in.
Bob
93 Stealth
TT
***Info:
www.stealth-3000gt.st/Team3S-Rules.htm***
------------------------------
Date:
Sat, 19 Feb 2000 17:44:15 -0600
From: Merritt <
merritt@cedar-rapids.net>
Subject:
Re: Team3S: Ground Control Installed
>Now scheduling an alignment. The
manager at Firestone has agreed to allow me
>to work with his alignment
expert so I can learn a few things that might be
>useful. If anyone
has alignment info that they would like to share email me
>as I have a
week before I can get it in.
I put in the exact same GC system, and
lowered it as much as you did, and
here's what I ran into:
My
suspension/alignment guy did NOT want to elongate the upper rear arm
mount to
bring the rear camber back to 0 deg.
When you get to the alignment shop,
you'll find that you are at -1.5 deg in
the rear (one reason why it handles
so well!). The standard fix is to drill
out and elongate the upper control
arm mount, and essentially push the top
of the wheel back to zero deg camber.
I showed my guy the explanation and
diagrams on how to drill it out, and he
said no way, because there would
be nothing holding the bolt in place
in the new "slot." He said it would
stay for a while, but as soon
as I started working the suspension hard, the
bolt would come loose and the
camber would start changing as the bolt moved
in the slot. If you (or
anyone else) have a solution, I'd like to hear it.
I just left mine at minus
1.5 deg.
In the front, I had to drop my brake cooling ducts so the
alignment
equipment could see across the car. It just barely cleared the
underside of
the bodywork. You might want to check with your alignment guy
first to see
if this will be a problem. Some systems simply can't get down
low enough.
If you are successful, please note the make and model of the
alignment
equipment for future reference. All us lowered guys need to know.
We were able to get my car within factory specs in the front, but
just
barely. My guy had to make some compromises with castor and toe to
get
everything to work, but there is no negative camber adjustment left.
I
ordered camber plates from GC, and will put them in one of these
days,
because I want to dial in some big caster and negative camber for
open
tracking.
It's great that you and Bob Forrest will be
supplementing Dennis Bretton's
already excellent web page. It would have been
a genuine pain in the butt
if I had to do that job without Dennis'
instructions, because the GC
instructions are nearly worthless.
This
is such a great list!
Rich/old poop/94 VR4
.
>
>
>Bob
>93 Stealth
TT
>
>
>
>***Info:
www.stealth-3000gt.st/Team3S-Rules.htm***
>
***Info:
www.stealth-3000gt.st/Team3S-Rules.htm***
------------------------------
Date:
Sat, 19 Feb 2000 17:52:15 -0800
From: "Bob Forrest" <
bf@bobforrest.com>
Subject: Re:
Team3S: Ground Control Installed
- -----Original Message-----From:
Merritt <
merritt@cedar-rapids.net>
>>>Bob
Rand said.>>>. The manager at Firestone has agreed to allow
me
>>to work with his alignment expert so I can learn a few things that
might
be
>>useful. If anyone has alignment info that they
would like to share email
me
>>as I have a week before I can get it
in.
>I put in the exact same GC system, and lowered it as much as you
did, and
>here's what I ran into:
>My suspension/alignment guy did
NOT want to elongate the upper rear arm
>mount to bring the rear camber
back to 0 deg.
>When you get to the alignment shop, you'll find that you
are at -1.5 deg
in
>the rear (one reason why it handles so well!). The
standard fix is to
drill
>out and elongate the upper control arm mount,
and essentially push the top
>of the wheel back to zero deg camber. I
showed my guy the explanation and
>diagrams on how to drill it out, and he
said no way, because there would
>be nothing holding the bolt in
place in the new "slot." He said it would
>stay for a while, but
as soon as I started working the suspension hard,
the
>bolt would come
loose and the camber would start changing as the bolt
moved
>in the
slot. If you (or anyone else) have a solution, I'd like to
hear
it.
>I just left mine at minus 1.5 deg.
-
--------snip-------
The recommended procedure is that the washer be
*welded* in place over the
new end of the elongated hole. (Supposedly,
it's a well-known
workaround...). It's safe, secure and a permanent
fix, whether you stay
with that CG setup or another. Whatever way you
go, just don't let them
mess with that adjustment too much -- if they try
putting a tool on the cam
end of that eccentric cam adjuster (instead of the
other end), they'll
trash it and it will take days to get another...
Unless you're going to do
a lot of racing, I'd go with the weld. You'll
lose about 5000 miles on
those tires otherwise, at -1.5 degrees... (but oh
what handling!).
My guy assembled everything, tightened it down to make
sure the elongated h
ole was long enough (he only moved it over 3/16"),
and marked the position
of the washers on each side. Then he took it
all apart and welded the
washers over the marks, and did the install
again. After that, the
adjustment was a snap (with the new eccentric
cam adjusters - yup, he
trashed mine, just like I described).
:-)
Good luck!
Forrest
***Info:
www.stealth-3000gt.st/Team3S-Rules.htm***
------------------------------
Date:
Sat, 19 Feb 2000 22:24:21 EST
From:
MerisaPDX@aol.comSubject: Team3S: I did
a bad thing....... anyone got a motor for a 1991 RT?
I need a motor for
my 1991 RT 24 valve. I flooded the engine crossing a
puddle of water
that in reality was way too deed and siezed the engine. Now
I have to
replace it. ARRRRRRRGGGGG!!!
If anyone has or knows of a motor for
my car please let me know.....
Merrisa
***Info:
www.stealth-3000gt.st/Team3S-Rules.htm***
------------------------------
Date:
Sun, 20 Feb 2000 14:45:09 +0100
From: "R.G." <
robby@freesurf.ch>
Subject: Re:
Team3S: Ground Control Installed
Ok, I finally installed the thing
including the tach adapters needed for our
stock ignition system (they
simulate the coils). The system runs nice and
the rev limiter is much
smoother than the stock one.
I haven't done any datalogging but also I do
not expect any visiable change
in the data. Of course I have to drive the car
around and to gather more
information but this is what I want to share from
my first snow-drive today
:
- - The DIS-4 has double spark below 3000.
This is very noticeable as with the
ARC idle and lower rpm became a little
more "rough". With the DIS-4 it's
back to smooth and fine.
- -
Accelleration is the same as before, maybe a little more smooth, although
I
still run a gap of 0.032" and MSD recommends to gap the plugs up to
stock
(0.044"). I'll do soon.
- - There is a slight hesitation around
4500. This could be caused by the too
low gap as well as water-injection
starts to deliver the juice there. I'll
disable it soon and log the
runs.
Installation was easy as I had two connectors for the stock
ignition coil
harness. Therefore only splicing the wires together and connect
the power to
the batt and go. Of course, the adapters for the ignition had to
find a
place and this is not easy !!
The two pictures below show the
installation how I did for now. I'm not that
happy with the tach adapters
there but sicne I don^t plan to relocate the
batt it must work that way. The
underhood clearance is about 5mm and
therefore no problem. The tach adapters
are sealed and no problem with water
or dirt.
The MSD box is below the
fuse box and fits nice there. It's not easy to
mount and is currently only
fixed by a nut on the bolt that is attached to
the fender. K&N users know
this bolt as one bracket is mounted there. The
MSD just fits in
there :)
http://www.geocities.com/swisscars/dis4_5.jpghttp://www.geocities.com/swisscars/dis4_6.jpgI
keep you updated :)
Roger
93'3000GT TT
***Info:
www.stealth-3000gt.st/Team3S-Rules.htm***
------------------------------
End
of team3s V1 #62
********************
