Team3S: 3000GT & Stealth Thursday, August 21
2003 Volume 02 : Number 235
----------------------------------------------------------------------
Date: Tue, 19 Aug 2003 23:51:43 -0600
From: "Donald Ashby" <
dashbyiii@earthlink.net>
Subject:
Team3S: Anyone who has disassembled the gear assembly?
Ok, well I have the gear assemblies out, and just to refresh your memory
I'm trying to replace the
3rd gear synchro.
So I have that shaft out,
there was one lock ring on the end of the assembly, pulled that out,
examined
it and looked everywhere, couldn't find anything else holding the 5th gear
counter on, so I
tried pulling it off, that didn't work, so I popped a
bearing separator around it, threw it onto my
shop press and put 2 tons down
on it, still didn't even budge....
Now my press will go to 12 tons, but I
really don't want to push too hard on it and have something
shatter and the
whole thing just fall apart or something. So am I missing some sort of lock pin
or
something that's still holding it on?
Or should I just put another ton
or 2 onto it and it will come off?
This is really getting to feel like I got
in over my head, I found a site that said how to replace
the 1st second
synchro, but they just used a gear puller and popped first off while it was
still in
the case and everything, I'm running out of patience, car has been
down for 2 1/2 months now... :(
Donald Ashby
'93 3000GT VR-4 (RIP)
'92
3000GT VR-4 (Vroom!)
"Don't drink and park, accidents cause people!"
------------------------------
Date: Wed, 20 Aug 2003 09:53:56 +0200
From: "Roger Gerl" <
roger.gerl@bluewin.ch>
Subject:
Re: Team3S: OT: hitting a 5k rpm redline on another twin turbo v6.
It's a badchip-tuning (cheap !) as the boost limiter on the S4 is
not
removed. The S4 first gets hesitation before it initiates fuel cut. The
5k
rpm barrier is known for this.
------------------------------
Date: Wed, 20 Aug 2003 10:30:30 +0200
From: "Roger Gerl" <
roger.gerl@bluewin.ch>
Subject:
Re: Team3S: MAS MOD Expanded
Matts explanation tells about everything. I go one step further and say
that
installing the MAS within the Intercooling parth is causing much
problems :
- - heat, the temp sensor of the MAS sees higher temperatures
(boost !)
- - the barometric sensor will be out of specs and sends strange
signals.
- - nothing else can be liminated, a BOV and everything else is
still needed
So what's the benefit of adding a Ford MAF into the path and simulating
a
fixed ambient to the ECU ? It will not eliminate lag (this is
turbo
related), it will not reduce restrictions compared to installation
before
the turbos and the bigger intercooler idea is bogus (you can use them
at any
time). Also heat dissipation has nothing to do with a MAS
relocation.
But what you guys are speaking here is a MAF replacement, i.e. removing
the
restriction and adding the ability of adding fuel control. And this
is
better done in the cool air path where the parts are made for.
Roger
93 & 96 3000GT
------------------------------
Date: Wed, 20 Aug 2003 08:24:10 -0400
From: "Bob G" <
Rguirlinger@cfl.rr.com>
Subject:
Team3S: Exhaust recommendations
This is a two-part question.
First, what exhaust system do members recommend for the VR-4. I'm
looking
for increased flow for mods down the line, but I don't want a lot
of
increased noise over the current "sport" setting.
Second, what creative uses have any of you found for the active
exhaust
control circuit after removal of the stock exhaust? Seems a waste to
leave
all that circuitry unused.
Bob Guirlinger
92 VR-4
------------------------------
Date: Wed, 20 Aug 2003 08:34:49 -0400
From: "Starkey, Jr., Joseph"
<
starkeyje@bipc.com>
Subject:
RE: Team3S: motor still shuts off
It sounds to me as if you have a grounding issue because the car starts
right up with no problems. First, check to make sure all of your ground
straps are intact. Second, trace both the positive and negative battery
cables from the battery to where they terminate. Make sure they are not
loose, make sure they are not touching anything they shouldn't be touching, and
make sure that they can't touch something they shouldn't touch when the engine
is under load. When you're tracing the wires, don't look just at the wires
themselves--look at their surroundings for signs of arcing. Third, did you
replace your battery lately? Perhaps your battery is shorting out under
load.
------------------------------
Date: Wed, 20 Aug 2003 05:37:30 -0600 (MDT)
From: Jim Floyd <
jim_floyd7@earthlink.net>
Subject:
Re: Team3S: Exhaust recommendations
Do the James Bond thing and have it activate a motor that changes or hides
your licence plate when the cops are after you.
------------------------------
Date: Wed, 20 Aug 2003 07:49:47 -0500
From: "William J. Crabtree" <
wjcrabtree@earthlink.net>
Subject:
RE: Team3S: Anyone who has disassembled the gear assembly?
Donald,
I know it feels like you're
going to break something. I was infinitely
worried about this too when
I did mine. I replaced ALL of my syncros on my
gearbox with little
instruction, except for that that's available on John
Adam's website and what
I could extract over the phone from the guys at
Kormex. If you're feeling
stuck, give Frank at Kormex a call. They are
REALLY, REALLY nice people
and will bend over backwards to offer advice over
the phone. No shame
in calling them, better safe than sorry,
RIGHT?.....RIGHT!
It's been some time since I did
my rebuild, but, study the exploded view of
the case that I sent you from CRS
(I'm pretty sure I mailed that to you a
while back). Also, Kormex's
Website has a pretty decent set of diagrams on
it of each shaft as
well. Those diagrams will tell you where the retainer
clips are on the
shafts and if you need to remove something before you can
pull an
assembly.
I will tell you that I managed
to get BOTH of my gear assemblies pulled
completely apart using a simple
puller(and a little down-home-ingenuity).
So if you've got a press, you're
one step ahead of me!! The only thing
holding the bearings, syncros,
and gears on those shafts are CLIPS....there
are no pins like you mentioned
in your post. Get those retainer clips out
of the way, and you're home
free!
Don't get frustrated, you can do
this!! And you'll be hella-proud that you
accomplished it on your own
when it's all said and done!
- -Jeff Crabtree
------------------------------
Date: Wed, 20 Aug 2003 13:45:20 -0000
From: "Jeff Lucius" <
jlucius@stealth316.com>
Subject:
Re: Team3S: Datalog - convert airflow
Heinz Heisler, 1995, Advanced Engine Technology: SAE International, p.
704-710.
John B. Heywood, 1988, Internal Combustion Engine Fundamentals:
McGraw-Hill, p. 301-303.
None of the above references make any mention of hysteresis. Heisler
actually goes into some detail explaning the operation of the sensor, stating
that near lambda = 1.0, "there is an almost instantaneous voltage rise or fall
as the air-fuel mixture ... changes."
The oxygen feedback trim shown in our datalogs illustrates the feedback
procedure used by the ECU and described in the books above. The ECU turns the O2
sensor signal into a square wave (perhaps this is the "binary on-off" aspect you
refer to). The ECU then constructs a triangular wave (shown in the datalogger
oxy feedback trim) that is out of phase with the square wave in a manner that
allows the ECU to inject increasingly more fuel amounts when O2 sensor voltage
is low and increasingly less fuel amounts when O2 sensor voltage is high.
I have seen periodic and systematic changes in IPW in some datalogs.
However, generally, IPW on the datalogs appears to remain relatively constant
during closed loop operation. I suspect this is a product of the limited
precision of the datalog. Perhaps if one more decimal place was presented we
would see the vey small IPW variations the ECU is causing. An automotive
oscilloscope could also verify this.
Heisler and the SAE paper url above show the voltage changes associated
with lambda changes for those that are curious. These are not exact values; but
do show the general nature of the O2 sensor response to changes in oxygen
content associated with A/F (or lambda).
------------------------------
Date: Wed, 20 Aug 2003 09:53:40 -0400
From: "Ken Stanton" <
ken.c.stanton@usa.net>
Subject:
Re: Team3S: Exhaust recommendations
Ahh.. a great question, I'm working on the same thing (but haven't
started).
I have the HKS dual exhaust (does anyone else??), and it sounds
-perfect-
for an exhaust system, HOWEVER I believe that flow is a major
issue. I was
very proud of myself for a while, as I found that I can
hold 12-13psi to
redline with stock turbos! However, as I raced a few
ppl and lost in the
top end, and did some reading, I learned that this meant
I was not getting
good flow in the top end and just making more room for
knock. The exhaust
comes to a T near the differential, and I assume
that that is causing
excessive backpressure at high flow.
But I'm also looking for a good sounding exhaust, streetability is
direly
important to me - I'm 26, and like being able to hear myself think on
the
highway. So that eliminates Borla and Apex and I'm sure a few
others. I'm
desparately seeking suggestions though.
As for the active exhaust, my thought was always to put another valve in
the
exhaust line, but the vent this time would be external - around the
T
junction (or other junction) and muffler directly to the air. No
emissions
danger, just noise but when you're on it, its a bit of extra
flow. Right
now, I have my ActExh switch wired to the A/C clutch - lets
me turn on the
Climate Control without the drag of the A/C.
OT - as for the little spat over the past couple of weeks, I want you all
to
know one thing - I was -never- angry. Yes, reading text leaves room
for
interpretation of emotion, and that is the downfall of email. I was
simply
trying to maintain a bit of respect in what I consider to be a
professional
group of ppl. But what disturbes me the most is when I ask
for the respect,
and someone else puts me down. Do you put your father
down when he
disciplines your brother/sister? Please, I'm not asking
for much, I have a
great sense of humor, am very mature and have a very high
"boiling point"
for getting angry. If you want to make snide remarks,
don't make them
towards the person - we have Getrag, Mitsubishi, RPS, and
many others to
pick on! Thanks, and apologies to those adversely
affected.
Ken Stanton
MSEE, Virginia Tech
91 Pearl White Stealth TT
4yr 3S
veteran =)
------------------------------
I was studying Jeff Lucius' site on turbo's last night, and it appears from
the turbo maps that a stock engine is only capable of barely producing
compressor surge with the stock turbos at redline at 14.7 psi boost. It doesn't
appear that the stock engine can cause compressor surge at 14.7 psi boost with
the TD04-13G turbos.
I dunno when the stock BOV/BPV kicks in or whether it enters into Jeff's
calculations.
The other puzzling thing I noticed was that using 13G turbos with a stock
engine, you would need to operate above 3000 rpms at 14.7 psi boost to avoid
inefficiency from "chopping" the air (left of the map).
Can somebody unconfuse me?
Chuck Willis
------------------------------
Date: Wed, 20 Aug 2003 14:46:59 +0000
From:
mjannusch@comcast.netSubject: Re:
Team3S: Exhaust recommendations
The stock downpipe is no work of art, but the reason there's no top-end
power
is because the turbos are simply too small and are just blowing out
superheated air that the intercoolers will have a difficult time cooling
down. The real solution is larger turbos, plus a better
downpipe. ;-)
Most any turbo upgrade will give you a lot more top-end than you are used
to... Lots of fun!
- -Matt
'95 3000GT Spyder VR4
------------------------------
> Right now, I have my ActExh switch wired to the A/C
> clutch -
lets me turn on the Climate Control
> without the drag of the A/C.
You can have the climate control on without A/C just by pushing Econ twice,
I
believe. I haven't driven my car with the top up in so long that I
don't
remember exactly how to do it. The operation is detailed in the
owner's
manual and its real simple to turn off the A/C but leave the fan on
and vents
open. No need to rewire your car. :-)
- -Matt
'95 3000GT Spyder VR4
------------------------------
Date: Wed, 20 Aug 2003 10:57:28 -0400
From: "Ken Stanton" <
ken.c.stanton@usa.net>
Subject:
Re: Team3S: Exhaust recommendations
Can you more directly address my observation? I don't know anyone
else who
can hold 12-13psi to redline EXCEPT for another 3Si-R member who has
the
exact same exhaust. Stock, Borla, and other exhaust systems only
hold
9-10psi to redline.
Ken
------------------------------
>First, what exhaust system do members recommend for the VR-4. I'm
looking
>for increased flow for mods down the line, but I don't want a lot
of
>increased noise over the current "sport" setting.
>
Wow,
that's a toughie.
I run a Stillen downpipe and a custom cat back to a single
side exhaust.
The Stillen removes 2 of the 3 cats, and really increases the
noise level,
no matter what you have for mufflers.
I run a straight through Xlerator muffler, and it is really LOUD,
because
my system is straight through all the way back, with the exception of
one
precat off the rear turbo. That will come out, of course, when I
upgrade
turbos.
Problem is, if you want to get the restrictions out of the exhaust, it
gets
LOUD. The cats are very effective mufflers.
>Second, what creative uses have any of you found for the active
exhaust
control circuit after removal of the stock exhaust? Seems a waste to
leave
all that circuitry unused.
Here's a creative idea: Fab up a custom dual exhaust with
an
electrically-activated valve at the T before the rear diff. You
can
probably get something from JC Whitney. On Tour, have the valve route
the
exhaust through a big, fat muffler on the driver's side, thus keeping
your
cat-less system quiet. On Sport, have it route the exhaust through
a
straight pipe out the passenger side. That would give you a
completely
unrestricted, straight through exhaust. Also, you'd have two big
3-in
exhaust pipes coming out the back, so it would look normal.
If you do develop this and it works, you could probably sell a ton of
them
right here.
Rich/slow old poop
------------------------------
Date: Wed, 20 Aug 2003 15:24:27 -0000
From: "Jeff Lucius" <
jlucius@stealth316.com>
Subject:
Re: Team3S: Ideas on reducing lag
>> Can somebody unconfuse me?
Confucious Lucius says: Only you can unconfuse yourself. :)
Short response:
Surge typically can occur only when the throttle plate
is *closed*.
Long response:
Compressor surge (high pressure, low flow, air flow reversals) only occurs
in the area to the "left" of the map lines. I would say in a practical sense,
when our engine speed and 13G turbine speed are increasing (when throttle plate
is open), getting surge would be unlikely. Surge should typically occur for our
engine and any installed turbo only when the throttle plate is closed. The
by-pass valve is designed to prevent surge by reducing the pressure that would
build between the turbo compressor outlet and the throttle plate. There are no
"calculations" involved on my part regarding surge or the by-pass valve.
From my web page:
"During spool up, the surge line represents the
combinations of flow and wheel speed that effectively start to compress the air.
"If the turbo is already spooled up, the surge line represents the stall
point for the impeller blades, that is, the minimum flow that can be maintained
at a certain impeller speed and pressure difference across the compressor.
"To help explain this, please consider the analogy of an airplane wing. As
an airplane is taking off, it does not lift off the ground until a certain speed
is exceeded. This is like the impeller spooling up. Once the air plane is
flying, if it goes too slow it stalls and starts falling. This is like
surge."
Hmmm, perhaps not the best analogy, but hopefully it illustrates the idea.
Surge occurs after the turbo is spooled up and the airpath is blocked (throttle
plate closed). It (generally) does not occur as the turbo is spooling up.
------------------------------
Gee, I have what I thought was stock exhaust on my '94 VR4 except for a
GReddy Super Drager muffler at the tail end. I don't think anything else
has been done to the exhaust, intack cats and stock downpipes. I think I have
stock turbos. I also think I am holding over 12 psi to the rev limiter at the
track, but I usually upshift early, like 6K rpm, and I am usually a little busy
to check the boost gauge at that particular moment.
If you look at the turbo maps on Jeff Lucius' site, it looks like with
stock turbos you would run into compressor surge at the rev limiter with stock
turbos and 14.7 psi boost.
Chuck Willis
------------------------------
Okay, in my original message replace the words "compressor surge" with the
word "choke" ...
(it was late last night, and I am a slow learner!)
Chuck Willis
------------------------------
Date: Wed, 20 Aug 2003 08:45:14 -0700
From: Michael Gerhard <
gerhard1@llnl.gov>
Subject: Team3S:
Tips on changing tire sizes
I'm considering changing tire sizes on stock VR-4 rims from the stock size
of 245/45ZR17 to 255/40ZR17. I'm wondering if I will have a clearance
issue. Also, if anyone has any other thoughts as to the possible issues or
wisdom of doing this.
My general driving for the last 2 years has been 65 percent freeway driving
to the track and 35 percent open tracking. I'm considering Kumho Victor
Racers V700 or Toyo RA-1 tires. The Kumhos come in both sizes (stock 245/45
and 255/40) while the Toyo tires only come in the 255/40 size.
Thanks for any comments you can provide.
-
--------------------------------------------------------------
Michael A.
Gerhard 1991 Mitsubishi 3000GT VR4 Pearl
White
------------------------------
I run 255R40ZR17 on both my commuter VR4 (Yoko ES100) and my track VR4
(Yoko AO32R). My son also runs the same size on his VR4 at the
track. There are ABSOLUTELY NO clearance problems, even with the cars
lowered 1" for the track.
I am about to buy a set of Toyo tires for the track. They will be
255R40Z17 also.
Chuck Willis
------------------------------
Date: Wed, 20 Aug 2003 10:06:23 -0700
From: "Gross, Erik" <
erik.gross@intel.com>
Subject: RE:
Team3S: Exhaust recommendations
> Can you more directly address my observation? I don't know
> anyone else who can hold 12-13psi to redline EXCEPT for
> another
3Si-R member who has the exact same exhaust.
> Stock, Borla, and
other exhaust systems only hold 9-10psi
> to redline.
I regularly hold 11-11.5psi to redline. It's not 12psi, but it's
better than 9-10psi.
Stock exhaust
TySpeed downpipe
High-flow rear pre-cat
OEM Main
cat
K&N
Stock turbos
------------------------------
Date: Wed, 20 Aug 2003 17:32:41 -0000
From: "Jeff Lucius" <
jlucius@stealth316.com>
Subject:
Re: Team3S: Ideas on reducing lag
Choke simply refers to the "point" where faster spinning of the impeller
does not produce any significant increase in air flow. It is not like the choke
limit itself can hurt anything on the engine or in the turbo. The only practical
use of the choke limit information is to inform us of the very maximum amount of
air flow the compressor is capable of. Choke is independent of the surge limit,
compressor efficiency, pressure ratio, and bypass valves.
The choke limit is easily recognized on the flow maps as where the fastest
impeller speed curve turns "vertical". Usually only a part of the upper length
of this curve is drawn. Using the 180,000 rpm curve of the 13G turbo flow map,
we could extrapolate a choke limit of about 380 cfm (or thereabouts). Normally
the impeller would also be very inefficient (that is, would heat the air alot)
near the choke limit, especially at lower pressure ratios.
------------------------------
Okay, so on the stock turbo (9G) compressor map, at 14.7 psi boost, at 7000
rpm, you are past the choke limit so the impeller is less efficient, heating the
air and putting more demand on the intercoolers?
I know this seems obvious to you and others.
If the impeller can't produce any more air flow than the choke limit, does
that mean that the boost pressure will decrease? More exhaust flow doesn't
produce any additional intake flow augmentation by the turbo?
Sorry to be so slow.
Chuck Willis
------------------------------
Date: Wed, 20 Aug 2003 18:51:02 +0100
From: "Jim Matthews" <
jim@the-matthews.com>
Subject:
Team3S: RE: adjustable exhaust mod (was: Exhaust recommendations)
That is exactly what I was thinking, only with the big muffler on
the
passenger (right) side to keep the path as short as possible for
Sport
(loud) mode, and with stock-looking dual tips. The stock valve
seems too
restrictive, but if someone comes up with an aftermarket
alternative for a
reasonable price, I'm in!
------------------------------
Date: Wed, 20 Aug 2003 14:05:32 -0400
From: "Zobel, Kurt D" <
Kurt.Zobel@ca.com>
Subject: RE:
Team3S: Turbo Lag WAS: MAS MOD Expanded
Well, now that I have a VR4, I'll be doing the leaf blower mod to it,
so I'll let you know how that works out.
..as soon as the heat dies down. Seems we all should become
Nocturnal
for
this summer.
Skyrider
------------------------------
Date: Wed, 20 Aug 2003 11:28:33 -0700
From: "Tyson Varosyan" <
tigran@tigran.com>
Subject: RE:
Team3S: RE: adjustable exhaust mod (was: Exhaust recommendations)
And in the process add 30 lbs to our already overweight car.
Guys, I have been watching this thread trying to keep my mouth shut,
but
here is the deal:
The stock DP is the main source of power gain on our cars. The F-joint
is
horrible and although it works well to muffle the sound it does rob a
fair
bit of power. The Cat-back on the other hand is perfectly sufficient for
a
stock or near stock car. The thing you all should be looking for
when
changing out the cat-back is weight reduction. The stock exhaust system
will
tip the scales at nearly 100lbs! Dual heat shielded piping with
unnecessary
dual exhaust using a gigantic muffler will do that... The exhaust
systems I
used to make (DP, TP and Cat-Back) used to come in at 32lbs. That
is what
you are shooting for. Elimination of the F-connection in the DP,
elimination
of the heavy and useless Cat and weight reduction in the cat-back
along with
MAYBE a TINY bit of opening of the exhaust diameter. Anything over
3" is
plain worthless.
Those are my two cents.
As a disclaimer, I used to make exhaust under the name of
TySpeed
Performance so my views may be skewed. The production for the time
being is
on pause :)
Tyson
------------------------------
Date: Wed, 20 Aug 2003 14:23:38 -0400
From: "Zobel, Kurt D" <
Kurt.Zobel@ca.com>
Subject: RE:
Team3S: motor still shuts off
You say no codes are stored when this happens. Very strange.
I'd check
your fuel pump wiring again. Maybe check with a gauge.
Some have reported
crank sensor being intermittent like this. Check it
and wiring connections
again.
Check MAS connections.
Don't know how easy it is to recreate, so
you could try swapping some
parts with another member?
Look through the
manual for conditions that have no 'limp' mode,
and could trigger
shutdown.
Skyrider
------------------------------
Date: Wed, 20 Aug 2003 14:37:18 -0400
From: "Zobel, Kurt D" <
Kurt.Zobel@ca.com>
Subject: RE:
Team3S: Exhaust recommendations
I was thinking more of it dumping a gallon of oil when the cops
are
after you!
Actually, it would be great to activate a cutout to use at the track.
Of course, you'd have to have a testpipe replacement for smogging.
Skyrider
------------------------------
Date: Wed, 20 Aug 2003 14:41:36 -0400
From: "Starkey, Jr., Joseph"
<
starkeyje@bipc.com>
Subject:
RE: Team3S: RE: adjustable exhaust mod (was: Exhaust recommendations)
<<<and in the process add 30 lbs to our already overweight
car.>>>
Am I right that a VR4/Stealth TT tips the scales at around 4120 lbs?
------------------------------
Date: Wed, 20 Aug 2003 12:23:37 -0500
From: "Canney, Charles C" <
charles.c.canney@lmco.com>
Subject:
RE: Team3S: Exhaust recommendations
I like the way you think Jim. When I was a teenager, I would have taken
your
idea and implemented it.
------------------------------
Date: Wed, 20 Aug 2003 14:49:47 -0400
From: "Zobel, Kurt D" <
Kurt.Zobel@ca.com>
Subject: RE:
Team3S: Exhaust recommendations
Does the HKS have a cat, or did you replace yours with high flow?
------------------------------
Date: Wed, 20 Aug 2003 12:02:56 -0700
From: "fastmax" <
fastmax@cox.net>
Subject: Re: Team3S:
RE: adjustable exhaust mod (was: Exhaust recommendations)
My current plan is precat eliminators [ I have these ].
A good downpipe
[ I don't have this yet ].
Test pipe with electric cutout like the McCord
power plate --- I have the
test pipe installed but no Power Plate.
Stock
cat back system with active exhaust intact.
Maybe some prettier tips.
In drug or self induced dream states I think of a true dual with oval
3"
tubing and the flattened boom tube side exhaust. The reason for
keeping it quiet is that tracks like Laguna Seca have a noise limit and
I
wouldn't be surprised to see more of that at tracks near
population
centers.
Jim Berry
------------------------------
Date: Wed, 20 Aug 2003 15:08:40 -0400
From: "Ken Stanton" <
ken.c.stanton@usa.net>
Subject:
Team3S: Emissions (was: adjustable exhaust mod)
OK, why is the cat useless? I think that aftermarket dealers (AAM,
3SX,
Tyson's business, etc) are all crossing the lines with EGR blockoffs,
cat
eliminating downpipes, test pipes, etc etc and saying that their product
is
'better' (implied by the fact that they're selling it). Better for
what!?
Honestly, does no one care?
Has anyone on here done emissions testing with precats removed, cat
removed,
EGR blocked, etc etc? I'm dying to know if the car is passable
after being
tampered with. And since they probably aren't, doesn't
anyone realize what
that means?
I removed my precats back when I first got my car, but was informed at
the
time that they were 'just for cold running and didn't matter if you
only
drove your car in the summer.' Now I have to deal with it stinking
half the
time, and I'm wondering if I'll pass my emissions when they actually
make it
mandatory.
This post may sound 'angry' or 'aggressive' but its not meant to be -
take
it as an honest question to ask yourself - am I doing the right
thing,
making my car a polluter to gain 4hp??
Comments please.
Ken Stanton
Official Tree Hugger
------------------------------
Date: Wed, 20 Aug 2003 12:17:14 -0700
From: "Tyson Varosyan" <
tigran@tigran.com>
Subject: RE:
Team3S: RE: adjustable exhaust mod (was: Exhaust recommendations)
The Spyder maybe. The Standard VR comes in at about 3800
Tyson
------------------------------
Date: Wed, 20 Aug 2003 12:09:30 -0700
From: "Ann Koch" <
akoch@sonic.net>
Subject: Re: Team3S:
RE: adjustable exhaust mod (was: Exhaust recommendations)
I weighed my '93 Stealth TT full of fuel and without driver last
week. The
certified scale weight was 3800 lbs. I don't have any
mods that would have
reduced weight.--Ann
------------------------------
Date: Wed, 20 Aug 2003 19:46:01 -0000
From: "Jeff Lucius" <
jlucius@stealth316.com>
Subject:
Re: Team3S: Ideas on reducing lag
>> Okay, so on the stock turbo (9G) compressor map, at
14.7
>> psi boost, at 7000 rpm, you are past the choke limit
so
>> the impeller is less efficient, heating the air and
>>
putting more demand on the intercoolers?
Basically, the choke limit cannot be exceeded (in terms of airflow).
For a stock engine, it *might* be possible to have about 15 psi of boost at
7000 rpm near the choke limit and have air flow of about 280 cfm.
For a modified (for better breathing) engine, 14.7 psi at 7000 rpm can
never occur with factory 9B turbos. This is because max airflow and the choke
limit will occur at various combinations of lower engine speed and/or
boost.
>> If the impeller can't produce any more air flow than
the
>> choke limit, does that mean that the boost pressure
will
>> decrease? More exhaust flow doesn't produce any
additional
>> intake flow augmentation by the turbo?
Correct on both accounts. But let's back up a bit to understand why.
On the compressor flow map, the vertical axis shows the ratio of the
pressure at the exit of the compressor to the pressure at the entrance to the
compressor. This is not necessarily the same as the work done by the compressor.
The demand of the engine works together with the supply of the turbo to
determine this pressure ratio (or boost level) - more on this below. Take a look
at the new figure I drew.
The thick black curve shows my guess at how airflow and boost would be
related in a modified engine using stock turbos from about 2000 rpm to 7000 rpm.
Up to about 3000 rpm, boost increases quickly but airflow does not increase
quickly. Then boost stays level as airflow increases. Finally, above about 5500
rpm airflow does not change (choke limit) and boost decreases.
Why does the boost decrease? Why doesn't the engine just sputter or
something at 5500 rpm?
The answer is the engine is sucking air and the turbo is pushing air.
If the turbo pushes more air than the engine sucks, boost increases (and so
does pressure ratio at the turbo) - this is the black curve up to about 3000
rpm. To keep boost from increasing too much, air is directed around the turbine
wheel and the turbo stops pushing so hard (this is the black curve between 3000
and 5500 rpm). If the engine sucks more air than the turbo can push (the black
curve "above" 5500 rpm) then boost pressure decreases (but airflow remain
unchanged).
Still confused as to what the compressor map and my "engine demand lines"
are showing? Let me explain some more.
The basic compressor flow map shows the impeller rotating speed and
compressor efficiency for various combinations of airflow and pressure ratio
(PR). If you just let the compressor spin with unimpeded airflow, all you would
basically have is a horizontal line, not a map. That is, the wheel would just
spin up to its maximum speed with hardly any pressure increase - lots of flow,
but little pressure. However, if you restrict air flow and control the PR then
you get the map. The airflow "restriction" is the limited ability of our engine
to pump air. The PR control is our boost controller, for the most part.
The engine demand lines show the airflow and PR through 3 cylinders (for
one turbo) at selected engine speeds assuming a certain volumetric efficiency.
The circles on the demand lines show boost levels in the plenum that account for
pressure losses before and after the turbo, but no temperature changes.
Does that help any?
------------------------------
Date: Wed, 20 Aug 2003 20:51:07 +0100
From: "Jim Matthews" <
jim@the-matthews.com>
Subject: RE:
Team3S: RE: adjustable exhaust mod (was: Exhaust recommendations)
> And in the process add 30 lbs to our already overweight car.
IMO, 30 lbs is a reasonable sacrifice for the ability to reduce volume
to
street-legal levels with the flip of a switch.
------------------------------
Date: Wed, 20 Aug 2003 13:48:12 -0700
From: "Gizmo" <
kdmorg@comcast.net>
Subject: Team3S:
Air conditioner relays?
Hi!
I have a 93 R/T Non Turbo Auto. The air conditioner only works if I open
the
relay box for the A/C (there are 4 relays in it), remove the bottom
left
relay(as you are looking towards the back of the car) and jump two of
the
terminals. I have replaced every relay in that box with no results.
The
jumper would work but who wants to dive under his hood every time he
shuts
the car off (the jumper drains battery power when connected because
it
engages the magnetic clutch).
Oddity about the system. It is fitted for and uses R134 instead of
Freon.
(Ask the previous owner? He's long gone. As they say, I haven't a
clue!)
Any thoughts for this old decrepid man?
Keith
------------------------------
Date: Wed, 20 Aug 2003 16:47:56 -0400
From: "Ken Lovell" <
wklovell@yahoo.com>
Subject: Team3S:
Carrier Bearings
Can anyone tell me what carrier bearings are and what happens if
they
fail?
Thanks,
Ken
'97 VR4
62K
------------------------------
They dampen the vibration of the driveshaft. There are 2 under the
car
between the transfer case and rear diff.
If they are shot you will get a vibration through the car
under
acceleration.
Curtis McConnell
1995 Vr-4 Spyder
------------------------------
Date: Wed, 20 Aug 2003 17:54:57 -0400
From: "Starkey, Jr., Joseph"
<
starkeyje@bipc.com>
Subject:
RE: Team3S: Carrier Bearings
There's actually a third. It's on the driver's side half-shaft.
------------------------------
Date: Wed, 20 Aug 2003 19:37:05 -0400
From: "anthonymelillo" <
anthonymelillo@sprintmail.com>
Subject:
Team3S: question on replacing stock ignition coils
I am thinking about replacing the stock ignition coils on my 1997
VR-4. I took a look at them, while doing regular maintenance, and
the
top of the metal cores are starting to rust, and I would like to replace them
before I have any problems.
I was told by a friend of a group buy for a kit but they are only taking
orders and it is over $300 right now and there is no way I
can afford
that.
I would like to use the MSD coils, mainly due to past experiences, nothing
definite. But what coils would I have to use ? I guess
I would
need three of them ?
As far as putting new connectors on the spark plug wires, that isn't a
problem, as I did a not of that in my old muscle car days.
But, if I replace the coils, how would I connect the wires to the stock
ignition connector ? Sorry if this sounds like a stupid
question, but I
have never had the coils or the bracket out.
Anyone know of a way to do this in the most inexpensive way ? I have
been out of work for a long time, and have very little money.
Any help is greatly appreciated. Thanks
Anthony Melillo
------------------------------
Date: Wed, 20 Aug 2003 18:53:51 -0500
From: "Steve" <
denon11@insightbb.com>
Subject:
RE: Team3S: question on replacing stock ignition coils
Just because there is rust on them that wont make the
coils go
bad.
You can take the coil assembly off and clean the three
coils
independently. A wire brush wheel in a dermal does the trick.
Steve
1995 Artic White 3000GT SL
------------------------------
Date: Wed, 20 Aug 2003 20:31:53 -0400
From: "Bob G" <
Rguirlinger@cfl.rr.com>
Subject:
Re: Team3S: Exhaust recommendations
I like the idea of the valve switching from eardrum shattering
performance
mode to civilized. I'll have to look on JC Whitney's site
an see if they
have 3" or better "Y" valve. Might be worth a
shot.
Short of that, however, if noise were not an issue (except for local
noise
restrictions) who has the best 3" cat-back system? I'll
eventually do the
down pipes and cats as well.
Bob Guirlinger
92 VR-4
------------------------------
Date: Wed, 20 Aug 2003 17:39:57 -0700
From: "James Mutton" <
james@playstream.com>
Subject: RE:
Team3S: Exhaust recommendations
I'd rather save the weight and have a good setup that flows nicely..
I
have the Stillen downpipe and the single-outlet 3" exhaust
Tyson
mentioned. It is low and grumbly @ idle and never "earsplitting"
even
under hard acceleration. I park underground and it doesn't bother
me or
anyone else, in fact I've had several comments from people in
the
building that my car sounds nice. The right muffler will do the
trick,
we used a straight through Magnaflo so it has very little
restriction.
The only time I notice an increase in noise is partial
throttle
acceleration where I can tell the wastegates are opening.
Noise is
definitely louder there but again not annoying.
- -James
95 Green VR-4
------------------------------
Date: Wed, 20 Aug 2003 17:46:16 -0700
From: "Erik Petterson" <
erik@microworks.net>
Subject: Re:
Team3S: Exhaust recommendations
Somebody on the 3SI.org forums has a link in his signature to a video of
his
custom exhaust. It is a Y valve in the middle of an aftermarket
custom
exhaust. I think it does a straight shot when it's open, and
then the
normal grumbling sound of the aftermarket when it's closed.
Might go look
on there and ask him some Q's?
- -Erik
'94 R/T
------------------------------
>Short of that, however, if noise were not an issue (except for local
noise
>restrictions) who has the best 3" cat-back system? I'll
eventually do the
>down pipes and cats as well.
>
I like my
single side system: it's lightweight, straight through, has only
two 45 deg
mandrel bends in it, and was CHEAP. As I recall, Denny's
Mufflers here in
Cedar Rapids did the whole thing (from the rear diff back)
for less than
$200, including the pipes and Xlerator muffler.
I don't know how it could be improved upon, except to spend another $200
to
make it a dual system for the sake of appearance. A dual system
wouldn't
improve performance.
Rich/slow old poop>
------------------------------
Date: Thu, 21 Aug 2003 01:17:19 -0000
From: "Jeff Lucius" <
jlucius@stealth316.com>
Subject:
Re: Team3S: question on replacing stock ignition coils
Before you decide to go with an aftermarket ignition coil, you should read
my thread at 3SI below.
The thread starts with the following.
=============================================
The DOHC 6G72 found in the
turbo and non-turbo 3000GT/Stealth uses the Diamond Electric F-608 12V coil.
This information is on the bracket for early production and is stamped into the
coil for later production. Diamond's web site publishes a small bit of
information about this coil.
One key piece of information on that brief web page is the following.
41,000 V @ 4 break amps
48,000 V @ 6 break amps
The stock coils are likely every bit as good as any of the aftermarket
coils I have seen advertised for our engines. Guys, the problem is not the coils
(if new and in good shape). The problem (misfires at reasonable boost levels,
say up to 15-17 psi) likely is the wires and resistor plugs. More on that later
..... Of course if you are boosting over 17-18 psi, our ignition certainly
needs some help.
=============================================
I am currently using MSD ignition wires, new factory coils , new factory
power transistor unit, and new NGK BCPR6ES-11 plugs gapped at 0.040" and not
getting any misfires felt or seen on datalogs up to ~15.5 psi boost at 7000
rpm.
The same ignition coils assembly is used on all years and models of the
6G72 V6 (turbo and non-turbo). It is part number MD152648 and includes all three
coils mounted on a bracket. I paid $100.89 for MD152648 at Tallahassee
Mitsubishi (1-888-825-5648).
------------------------------
Date: Wed, 20 Aug 2003 23:58:26 -0400
From: "Ved" <
1994TT@comcast.net>
Subject: Team3S:
Where does this harness go???
I was painting the engine bay and I removed the harness that is
branching
out to the headlights, fuse box, battery etc. I was able to put all
the
connectors back in place except these:
- -harness branching from the negative battery cable ( 2 cables with
"washers"
at the end, look like ground wires, one small plastic connector on
the same
harness)
- -harness branching from the positive battery cable.
Also where can I get good pictures of the engine compartment, it would
speed
up putting all the stuff back into the engine compartment? I do have
the CD
manual.
------------------------------
Date: Wed, 20 Aug 2003 21:17:27 -0700
From: "Andrew D. Woll" <
awoll1@pacbell.net>
Subject: RE:
Team3S: Air conditioner relays?
somebody on the list helped me Keith. The suggestion was to turn the
AC
system off before turning off the key. On restart hit auto on the ac
system.
Makes no sense but it has worked for me this summer - Thank the Car
God
cause its been realllllll hot here.
Andy
------------------------------
Hello again,
After a long summer away from the list I am beginning my
search for a passenger side tail light and the center
reflector piece
that is under the trunk (I have no idea
what this is called.) My
husband backed into my cousins
Neon and crushed the tail light and the
bumper...however,
we were lucky and the bumper popped out with minor stress
marks. While looking closely it looks like it "might" be
possible
to just get a cover, not the whole tail
light...is this possible? I
have strong doubts that it
is. Oh yeah....and the reverse light
reflector that goes
on the passenger side of the rear bumper. If
someone
could give me some prices if they have these babies laying
around somewhere for a 1991 Stealth R/T TT AWD that would
be
awesome.
Thanks,
Carol Decker
------------------------------
Last time we discussed that we concluded that you can hold a higher boost
pressure if your exhaust flows less. Erik was the one of the people who
started the discussion. More back pressure = less air flow through the
engine = higher boost pressure but less power. Is this still the
consensus?
Philip
------------------------------
End of Team3S: 3000GT & Stealth V2
#235
***************************************
