Team3S: 3000GT & Stealth Wednesday, August 13 2003 Volume
02 : Number 228
----------------------------------------------------------------------
Date: Tue, 12 Aug 2003 15:51:54 -0400
From: "Ken Stanton" <
ken.c.stanton@usa.net>
Subject:
Re: Team3S: Datalog - convert airflow
> The injector duty cycle (pulse width) is your most accurate indicator
of
fuel economy.
Naturally, but fuel density combined with spray duration and fuel
injector
flow capacities give me an accurate calculation. This is more
than just an
estimate I'm looking for, this is part of a big project...
> From there you could estimate what MAF Hz corresponds to what air
flow
> (cfm, etc.). Just see how much fuel is coming in while your A/F
gauge
shows
> stoic, multiply the incoming fuel by 14.7, do appropriate
unit conversions
> and compare it to the MAF Hz reading.
Well, I can't record my A/F gauge with datalog, and i don't have an
A/F
gauge anyway. O2 crossings are a possibility certainly,
though. But I also
believe that ECU's occasionally inject extra fuel
for cat cooling,
emissions, etc and I don't want to get thrown by
those. If I can convert
Hz, then I can calculate how much fuel it
should be getting and watch what
a/f ratio the ECU is actually
commanding...
Ken
------------------------------
Date: Tue, 12 Aug 2003 15:57:44 -0400
From: "Ken Stanton" <
ken.c.stanton@usa.net>
Subject:
Re: Team3S: a/f guage - knock ?
>EGT. Again, retarded timing (and higher EGT) is not a
reliable
>indicator of knock.
That is certainly correct, I have many datalogs recently where the ECU
is
retarding my spark but there is no knock whatsoever. I think it has
learned
from previous knock problems, which I am correcting.
I think we're focusing too much on -exhaust- temperature to determine
knock
here... the real cause is in the intake temperature and spark
plug temp, if
I'm not mistaken? Combustion efficiency determines
exhaust temperature,
therefore I hardly think that it can be much of an
indicator.
Ken
------------------------------
Date: Tue, 12 Aug 2003 15:56:20 -0400
From: "Ken Lovell" <
wklovell@yahoo.com>
Subject: Team3S:
60K Questions
Thanks for all the answers on what to have done. Two more
questions:
1. Anyone know what "fuel induction service" is?
2. Is it worth doing the manual transmission service, tranaxle
service
or transfer case service suggested by a dealer during the 60K
service?
(Some of these may be duplicates... Sorry for the ignorance.)
Thanks,
Ken
'97 VR4
------------------------------
Date: Tue, 12 Aug 2003 19:58:34 -0000
From: "Jeff Lucius" <
jlucius@stealth316.com>
Subject:
Re: Team3S: Datalog - convert airflow
Perhaps a flow bench is required. The bench knows the volume flow and if a
circuit is simulated to the MAS then the MAS output signal could be directly
correlated. Just an idea.
With datalogs, I have tried to use idle Hz and IPW with the assumption of
14.7 A/F but the result was less than what I would call accurate (same IPW for
various Hz suggests the 14.7 A/F assumption is invalid and that the ECU will
only "go so low" for IPW).
------------------------------
Date: Tue, 12 Aug 2003 13:03:46 -0700
From: "Geddes, Brian J" <
brian.j.geddes@intel.com>
Subject:
RE: Team3S: a/f guage - knock ?
Exactly! EGT is a byproduct of so many different variables, that it's
hard to glean much information from EGT data. Intake charge temp, fuel
octane, spark plug temp, cylinder hotspots, ignition advance...these are things
that actually contribute to knock. It's certainly of great benefit to
monitor these and control them when possible to prevent knock.
The bottom line is though, that if you want to actually watch for knock you
have to monitor the knock sensor. There's just no other way to do
it.
- - Brian
>I think we're focusing too much on -exhaust- temperature to determine
knock
>here... the real cause is in the intake temperature and spark
plug temp, if
>I'm not mistaken?
------------------------------
Date: Tue, 12 Aug 2003 16:19:04 -0400
From: "Bob G" <
Rguirlinger@cfl.rr.com>
Subject:
Team3S: Can this be right?
Oops! Think I may have forgotten to send my last post in "plain
text".
Sorry...
Here goes again:
Hey all,
Last week a late model Z28 blew my doors off in a roll-on from about 45
mph.
Today, a late 90's Thunderbird stayed glued to my rear bumper while I
gave
the VR-4 everything it had.
Is there something wrong with my car? It runs great, but lately it
is
suffering from ego-bashing defeats. I wonder if I expect too much
from it?
It is completely stock.
I love the VR-4, but now I'm thinking "more power". What's it going
to take
for me to get her up to 400? Will it hurt less than getting
whooped by a
T-bird?
Desperately seeking horsepower,
Bob Guirlinger
92 VR-4
------------------------------
Date: Tue, 12 Aug 2003 16:43:14 -0400
From: "Trevor Paciotti" <
sam_or_i@hotmail.com>
Subject: Re:
Team3S: Can this be right?
Bob,
I think it's just a simple matter that the AWD eats up
horsepower and 2
wheel drive cars have an advantage when racing from a roll.
Try racing from
a stop and you'll see how none can touch you. I don't
think there is
anything wrong with your car, so long as they didn't just
'own you gently'
like it was their job. Then again, I did hang with a
Firehawk in my TT from
a roll. . .
- -Monk
91 R/T TT
------------------------------
Date: Tue, 12 Aug 2003 16:58:05 -0400
From: "Ken Stanton" <
ken.c.stanton@usa.net>
Subject:
Re: Team3S: Can this be right?
Simple mods would bring you up to 350-375hp and give those cars a
very
respectable adversary. Check Team3S and 3Si webpages for basic
upgrade
guides, but personally my favorite simple mod is boost control.
Right now
I'm running 13-14psi and am hard to touch, and previously with
19psi and a
handful of inexpensive goodies I hung with an NSX to
150mph.
Happy boosting,
Ken Stanton
91 Pearl White Stealth
TT
Overboosted
------------------------------
At 03:57 PM 8/12/2003, Ken Stanton wrote:
>I think we're focusing too
much on -exhaust- temperature to determine knock
>here... the real
cause is in the intake temperature and spark plug temp, if
>I'm not
mistaken? Combustion efficiency determines exhaust
temperature,
>therefore I hardly think that it can be much of an
indicator.
Hold it, hold it. Nobody said that EGT is a reliable indicator of knock.
But we do not have many other indicators to look at. Neglect your EGT while
running on a dyno and you will almost certainly melt your pistons. And for
many, EGT is the only noticeable indicator of something not being right.
Again, not having a high EGT does not mean that everything is perfectly
fine. EGT is just one of the indicators. One of the most practically useful
indicators.
Philip
------------------------------
Date: Tue, 12 Aug 2003 16:43:10 -0500
From: "Matt Jannusch" <
mjannusch@comcast.net>
Subject:
Re: Team3S: Timing belt
> I was thinking of using a Comtitech Timing belt.
> Any one in
this group had any experience with this
> German made belt?
It is almost always the tensioner that fails, or the bearings in one of
the
idler pulleys - or improper installation of the tensioner by an
uncaring
mechanic. The factory Mitsubishi belt almost never fails on
its own. The
stock belt is perfectly fine for almost any car here - and
has a proven
track record.
The timing belt is one of those areas where you just don't want to take
a
chance.
- -Matt
'95 3000GT Spyder VR4
------------------------------
At 03:58 PM 8/12/2003, Jeff Lucius wrote:
>With datalogs, I have
tried to use idle Hz and IPW with the assumption of
>14.7 A/F but the
result was less than what I would call accurate (same IPW
>for various Hz
suggests the 14.7 A/F assumption is invalid and that the
>ECU will only
"go so low" for IPW).
A flow bench would certainly work the best. But if you do not have one, you
need to be cruising at a steady low-medium load to reach the stoic
condition. The MAF readings at idle are EXTREMELY noisy, that is why, Jeff,
your test at idle did not work. I do not know how ECU can read that MAF at
idle at all. Perhaps it averages a lot and then throws in a bunch of fudge
factors. The MAF signal/noise at higher engine speeds is much better.
Philip
------------------------------
At 03:51 PM 8/12/2003, Ken Stanton wrote:
>Well, I can't record my
A/F gauge with datalog, and i don't have an A/F
>gauge anyway. O2
crossings are a possibility certainly, though. But I also
>believe
that ECU's occasionally inject extra fuel for cat cooling,
>emissions, etc
and I don't want to get thrown by those. If I can convert
>Hz, then
I can calculate how much fuel it should be getting and watch what
>a/f
ratio the ECU is actually commanding...
You can safely use a regular voltmeter as an O2 gauge. A voltage of 0.5V is
stoic.
Are you trying to reverse engineer the stock ECU? It has hairy brains. One
day it thinks one thing, the other it thinks the opposite. That is why all
the tuners have given up on it and write their own maps.
------------------------------
Date: Tue, 12 Aug 2003 19:00:04 -0400
From: "Zobel, Kurt D" <
Kurt.Zobel@ca.com>
Subject: RE:
Team3S: Can this be right?
Er.. No, can't be right. Unless they were supercharged.
TBird specs..2002
0-60 mph, sec 7.04
1/4-mile, sec/mph 15.28
/ 92.0
Braking, 60-0 mph, ft 123
Braking, 100-0 mph, ft
356
Should not even be close against a stock TT.
Skyrider
------------------------------
Date: Tue, 12 Aug 2003 16:58:00 -0700
From: "fastmax" <
fastmax@cox.net>
Subject: Re: Team3S:
Datalog - convert airflow
LOL --- "hairy brains" ?!?!?!?! Is that like fuzzy logic ???
BTW, I've noticed that folks are using preignition and
detonation
interchangeably, they are not the same and they are not controlled
in
the same manner. Preignition is usually caused by hot spots and occurs
before the timed spark. Detonation is the uncontrolled and simultaneous
ignition of end gases in the combustion chamber which results in
very
high cylinder pressures, and the resultant broken pistons and
scuffed
rod bearings. IMHO, detonation is one of the prime causes of spun
rod
bearings in rebuilt engines --- folks tend to turn up the wick after
what
they think is the proper break in. Back in the old days people would
tune
their cars in an iterative manner --- ask Matt Monet about tuning in
small
steps and monitoring what's happening.
Jim Berry
------------------------------
Date: Tue, 12 Aug 2003 20:16:39 -0500
From: "Steve" <
denon11@insightbb.com>
Subject:
Team3S: 60k service sprocket jumped time
I was doing a 60k tune up and the first bank (Head}
both sprockets moved
I mean they sprang out of time.
I put them back in time one at a time and
wile putting the belt on they
sprang the opposite way they did before.
The
back bank Head)sprockets did not move....
Is there any way I bent the valves I hope I did not.
It is my fault for not putting the safety bolts in before tacking
the
belt off. Live and learn.
Any info would be helpful.
Steve
1995 Artic White 3000GT SL
------------------------------
Guys, I need some help. Here's me delima, My car will be running fine
then
will suddenly shut off. I took it to the local dealership, we replaced
the
coil pack and the power transistor. It seemed to run OK for about a
week
then started doing the same thing. The service tech had me disconnect
some
of the mods. Like the turbo timer and the boost-a spark which I did but
it
wasn"t any better. I can be driving on the fwy just cruising along around
70
and it will shut off for about 3 seconds then it will turn on. Or I can
be
at the intersection ideling and it will die. Some times it will back
fire
like a big dog. But when it runs its fine. I haven't checked the ECU yet
but
the tech tested all the cam sensors etc and it checked out on the
computer
fine. I was told to check the fuel filter but that doesn't sound or
feel
like a filter problem to me. The Mods Ive done to the car is Blitz
sbcid,
supra fuel pump, Magnecor wires, iridium denso plugs gap 32, Stillen
down
pipe, Borla exhaust, Keene Bell boost-a-spark, blitz turbo timer,
suspension
and brakes but that doesn't matter about this problem. Any help
would be
greatly appreciated.
Pete, 91VR4
------------------------------
Date: Tue, 12 Aug 2003 23:31:52 -0500
From: "William J. Crabtree" <
wjcrabtree@earthlink.net>
Subject:
RE: Team3S: Help again tranny gurus!
Don,
There is NOTHING holding those
shift forks in the tranny case except the
gear shafts themselves. You
need to use a socket on the OUTSIDE of the case
and tap the end of that shaft
that you pulled the allen headed bolt out of.
this will get all of the
assembly you are referring to out of the back of
the case. DO NOT
remove those pins that are in the shift forks, there is no
reason to do
so.
- -Jeff C.
------------------------------
Date: Wed, 13 Aug 2003 00:38:29 -0400
From: "Vedran" <
1994TT@comcast.net>
Subject: Team3S:
Painting my engine bay???
Should I put a clear coat over acrylic paint? Right now it looks
great to
me and I would not do anything else, but will the acrylic paint
flake off
without the clear coat.
Thanks
Ved
94 Yellow TT
------------------------------
Nope! There are those detents that hold the shifter forks in place. They
are the reason why the transmission clicks when we shift it. There are
three positions for every shift fork.
Find a small plate on the case at the end of the shift fork. It held by (2,
I think) small M6 or M5 bolts. Remove it. There will be a small spring
underneath it and a steel ball. Get them out and the forks will come out
without effort. You will also need to have that plate off the case and the
spring out when you insert the fork back in.
Philip
------------------------------
Date: Wed, 13 Aug 2003 00:17:08 -0700
From: Billy Nickerson <
banickers@earthlink.net>
Subject:
Team3S: A/C recommendation for fix
I finally found a reputable A/C tech who took a look at my Stealth and
found
the problem. In the interim, he found that the prior service center
that
tried to fix the A/C had installed a supposed OEM "O" ring, but it was
the
wrong size. (I'm in the process of getting my $400 back from them.)
Apparently, the problem is leaks in the low side A/C hose and also in
the
discharge hose. The recommendation is to replace both hoses at a cost to
me
of about $630, of which almost $400 is the cost of the two hoses alone.
I
have the part numbers and wonder if I can get them cheaper online
somewhere,
but I have no clue as to whether I can do that or where I might
try.
Anybody know if this is reasonable, or is this dealer - like my car
-
blowing hot air?
------------------------------
Notice two separate cracks on two spokes of exact same type and length.
That is a stock '95 Stealth R/T TT chrome 18" rim that was "trued" earlier
this year and then powder coated white. Maybe this is when the cracks
started. Well, I have four other bent rims in my garage that I can send to
the wheel shop since they did not finish them last time. That one wheel was
the ugliest one among the two sets of bent rims that I had. It used to have
the worst curb rush and I kinda don't feel sorry for it too much. The
replacement rim will look better.
All the weird things happen to me on the 13th!
- Beat up a
classmate - 05/13/87
- A few other things happened -
**/13/**
- Bought Supercar - 04/13/01
- Cracked Rim I -
04/13/03
- Got bumped in Chicago - 07/13/03 (got $410.87 for a small
scratch!)
- Found Cracked Rim II - 08/13/03
Spooky!
- Cracked Rim III? - It's INEVITABLE!
Philip
Rim Terminator
------------------------------
Date: Wed, 13 Aug 2003 03:28:51 -0700
From: "Bob Forrest" <
bf@bobforrest.com>
Subject: Re:
Team3S: A/C recommendation for fix
Hey, Billy,
Since you've been off-list for a couple of years, make sure
to check out our
latest FAQ pages. One of the most popular pages on the
Team3S site is the
"Good Guys" Page, which lists the dealers who give 20-25%
discounts on parts
to our members. (Check the FAQ Index-- 'Basics'
section). Right down the
road from you is San Rafael Mitsubishi - get
their number from the "GG" page
and ask for Mike. Compare them with
other (Tallahassee, Conicelli, and Norco)
Mitsu dealers for the best quotes
on the parts you need. Best prices are from
Mitsubishi dealers - even
for Stealth.
www.Team3S.com/FAQ.htmGood
luck!
- ---Forrest
------------------------------
Date: Wed, 13 Aug 2003 07:43:34 -0400
From: "Starkey, Jr., Joseph"
<
starkeyje@bipc.com>
Subject:
RE: Team3S: Timing belt
Ditto Matt's comments. When I did my 60K service and took my belt
off, the belt looked brand spankin' new. No signs of wear, no signs of
stress. I'd stick with stock if I were you.
------------------------------
Date: Wed, 13 Aug 2003 06:43:24 -0500
From: "cody" <
overclck@satx.rr.com>
Subject: RE:
Team3S: Datalog - convert airflow
I think I can help a little here....
First off, why can't you datalog o2? Both of my cars have o2 voltage
as
an option to datalog... 91 talon/93 3000
Secondly, the ECU doesn't rely on the MAS heavily under
partial
throttle, instead it takes the incoming airflow, uses it as a
"starting
point" then adjusts accordingly via the o2 sensor. Using the
fuel trims
for "low" stored in the ECU, they will vary from an original base
map.
The MAS frequency is where the base map is read from, but the
ECU
watches o2 more than anything - that's why you are able to
disconnect
the MAS entirely and still be able to drive, however in limp mode,
and
full throttle doesn't work... (Well, not well at least)...
Also, you will never get a perfect stoich reading no matter what...
The
ECU tries as best it can, but o2's will fluctuate at idle or
steady
cruising from rich to lean - I have never seen o2's be dead
center.
(mainly because factory o2 sensors aren't too accurate in that
range,
they know more about rich and lean than stoich)
- -Cody
------------------------------
Date: Wed, 13 Aug 2003 12:47:22 -0000
From: "Jeff Lucius" <
jlucius@stealth316.com>
Subject:
RE: Team3S: Datalog - convert airflow
Cody,
You have it backwards. Our "narrow band" factory O2 sensor are most
accurate and precise when A/F is in the range of 14.6 to 14.8, Beyond these
ranges, only relatively small voltage changes result when A/F changes by whole
numbers.
The O2 sensors are simple monitoring devices. The reason they "oscillate"
at idle (or should) is because the ECU is changing the A/F. If the ECU could
hold the A/F right at 14.7 then the O2 sensor should hold a steady output
voltage of about 0.45 v.
Also, the ECU always starts with airflow sensor and CAS and then midfies
the fuel injector activation time from there. Read through my web page below for
more info on how the ECU controls fuel delivery.
One more thing. "Limp mode" for when the volume airflow sensor has
malfunctioned is to use the throttle position sensor and the crank angle sensor
and preset maps, not the O2 sensors. This is documented in the "Fail safe/Back
up functions" section of the service manual.
------------------------------
Date: Wed, 13 Aug 2003 10:04:54 -0400
From: "Starkey, Jr., Joseph"
<
starkeyje@bipc.com>
Subject:
RE: Team3S: engine dies
I had a similar problem once after I installed a new battery. Turned
out that the battery was slightly too tall, and when I'd hit a bump the positive
terminal would contact the underside of the hood, short it out and stall the
car. You might want to check that.
------------------------------
Date: Wed, 13 Aug 2003 10:31:27 -0400
From: "Ken Stanton" <
ken.c.stanton@usa.net>
Subject:
Re: Team3S: Datalog - convert airflow
Quoting from 'Office Space:' Yeah, I'm gunna have to go ahead
and
disagree...
I believe that the O2 sensor is oscillating because it is deadly close
to
stoich, not because the ECU is changing a/f. Looking at my datalogs
(many),
at both idle and cruising conditions where the O2 is crossing
heavily, the
fuel pulse is unbelieveably constant. This would indicate
that the ECU is
holding a/f steady, as our dataloggers record the -commanded-
fuel injection
time (not actual).
And as far as holding a/f right at stoich, the O2 sensor should
actually
oscillate at a ridiculously fast rate (probably maximum
oscillation
frequency of the sensor) rather than hold steady. Jeff, I
know where you're
coming from, if you look at the response graph of a sensor
it looks as if it
can have a voltage of 0.45v at 14.7 a/f, but in actuallity
the hysterisis of
the sensor will never allow it to sit there - rather it
would oscillate.
Looking at my logs, I see -no- instance of the O2's ever
holding 0.45v, and
I know the engine runs very close to stoic, at least for a
moment if nothing
else. Even if we did see a 0.45v signal, it would be
erraneous due to the
sampling rate of the ECU/datalogger.
I have a feeling the counterargument is that the engine is a very
turbulent
machine and that it could never maintain stoic even for a
moment. Well, I
agree, but I still maintain that the O2 cycles due to
the hysterisis, and
that the O2 sensor can be -treated- as a digital sensor
of a/f - a 0 being
lean, a 1 being rich.
Ken Stanton
91 Pearl White Stealth TT
MSEE, Virginia
Tech
Automotive Control Systems =)
------------------------------
I sent two sets of wheels to a shop near Indianapolis. Then I drove
there
to pick them up. I do not recommend the place because they promised
"one
day turnaround" which stretched into one month. They also picked 4 easy
to
fix rims out of 8 and fixed only those. Now I have to package and ship
one
or two rims to them or to some other shop again. They charged me less
for
the easy rims though. The place is called Mr. Wheel of Indy,
(317)485-7046.
I will look for another place first this time. I just called
then and they
tell me that they are always backed up and there is a 30 day
wait.
Depending on what kind of rims you have, and if you can get a
replacement
rim easily, you might want to consider buying a new one. If your
rim costs
under $200, I would get a new one. The things to consider
are:
- labor cost to fix the bent rim
- shipping and packaging
costs and PITA
- waiting
- possibility of the rim not being
repairable
- possibility of the rim not being fixed fully
-
possibility of micro cracks
- wheel being less strong after it is bent
back.
How did you bend a rim at MAM? Did you go off course?
Sorry to hear about your rear end damage. Damaging our cars on parking
lots
and driving off should carry a death penalty and a minimum $10K fine on
top
of that. Rrrrrr. :-)
Philip
------------------------------
Date: Wed, 13 Aug 2003 11:25:24 -0400
From: "Ken Stanton" <
ken.c.stanton@usa.net>
Subject:
Team3S: Knock and its definitions
Can someone help to clarify this mysterical word?
I think the terms pre-ignition, detonation, and post-ignition need to
be
defined first. Then, which of these is the knock sensor actually
relaying
to the ECU/datalogger?
Most appreciated,
Ken Stanton
91 Pearl White Stealth TT
Headache
over knock....
------------------------------
Date: Wed, 13 Aug 2003 11:38:07 -0400
From: "Starkey, Jr., Joseph"
<
starkeyje@bipc.com>
Subject:
RE: Team3S: Knock and its definitions
Here's how I've always understood the terms. Knock (or "spark knock")
is a knock which is recurrent and repeatable in terms of audibility. It is
controllable by the spark advance: Advancing the spark increases the knock
intensity and retarding the spark reduces the intensity.
The other two do not involve the spark plug firing at all. Some refer
to them as Surface Ignition. This is ignition of the fuel/air charge by
any hot surface other than the spark discharge. It may occur before the spark
ignites the charge (pre-ignition), or after normal ignition
(post-ignition).
I suppose that the knock sensor detects and relays all three of these,
since there is no way it can discriminate between them. The knock sensor
is really nothing more than a piezoelectric microphone screwed into the manifold
that "hears" pinging, then attempts to adjust the air/fuel mixture and engine
timing to compensate for it.
------------------------------
OMG! Don't read that!
I am have never heard of such a problem as "post-ignition". Is that
the
same as "ignition"? I have only heard of two irregular
combustion
processes.
Detonation (or knock) is an ultra fast combustion of the A/F mixture.
The
A/F mixture burns way too fast and in burns in bursts, creating
huge
pressure spikes that bend rods, smash pistons and squeeze out oil from
rod
bearings. I think someone called is a "snake rattle" or a "rattle
of
death".
Pre-ignition is an early ignition from a source other than the spark. It
is
usually a hot piece of soot, a hot edge or a red-hot spark plug
electrode.
When piston goes up and the cylinder pressure rises, conditions
occur for
these hot spots to ignite the mixture. This is also called
"dieseling"
because it is very similar in its mechanism. An early ignition
causes the
engine to run very hot and melt pistons. It feels and sounds
normal and the
knock detonation sensor does not hear it. Watch your EGT
though.
Someone suggested last time that pre-ignition can also cause
detonation.
Perhaps it is true. When it goes wrong, it all goes wrong. Just
do not get
there too often and you will be okay.
Philip
------------------------------
Hmm. All this talk about bending and cracking wheels has me worried.
I
still run stock chromies and haven't had a problem in four years, but I
can
see how it might pay to get some track wheels. I am cornering at
much
higher speeds now, and it's only a matter of time before I break a wheel
at
a very inconvenient time.
Still, you guys are bending and cracking aftermarket forged wheels. WTF
is
going on here? Do we gotta spend thousands of dollars on wheels now?
Does there exist a strong 17 in. race wheel that doesn't cost a fortune?
Rich/slow old poop
------------------------------
There are those Mustang Cobra replica rims at $170/piece at Discount
Tire
Direct. They come in different widths, up to 10.5" (this is the one I
am
looking at). I might have to trim the fender lips to fit them in
though.
Can I get fender flares (is that what they are called) for 3/S
cars
somewhere?
Philip
------------------------------
Date: Wed, 13 Aug 2003 18:42:43 +0200
From: Roger Gerl <
roger.gerl@bluewin.ch>
Subject:
Re: Team3S: Knock and its definitions
Don't make it too hard for yourself. Just see "knock" as a situation that
results in an audible noise, also called "pinging". the source for this
situation can be many, e.g. pre-ignition, piston slapping, valve train
noise and others. Whatever it is, it is not healthy.
The knock-sensor is a microphone (piezo-electric) device that converts the
noise into electrical signals that are analysed by the ECU. This part in
the ECU is something like a microphone amplifier that includes a specific
filter that eliminates all the other noise around the engine specific
pingig characteristic. But the ECU does more. It recognizes the noise only
within a time window when a spark occurs. This way, it can occur when the
noise appears, e.g. if there is pre-ignition or piston slap. This way it
counts the amount of knock pulses the the circuit sends to the
microcontroller that appear within these windows.
Now, our aim is to fight against this knock pulses and we never want to see
any of them appearing on our logger screens. But if there is knock, how can
we tell what the cause really is ?
Here the other tools like EGT gives us the next data. If EGT's are high and
knock occur then we know that the mixture may be too lean or preignition
occurs due to hot spots (carbon on the pistons). If EGT's are low but there
is still knock, it can even be a too fat mixture. But also here, hot intake
temperatures may force preignition and the EGT is not fast enough in
recognizing this situation. Again, other sensors like intake temperature or
backpressure helps to analyse an engines behaviour.
It's obvious that we can't find out everything nor can we isntall hundereds
of sensors. This is why the engine engineers develop a behaviour into the
ECU that takes care of such situations. One of them is typical as we do
have two fuel maps in the ECUs program. One is for good, one for bad fuel.
The paramters taken from these map define the igntion timing and the
injector duty cycle. If one is only driving with 91 octane the ECU may see
knock due to the low octane rating. The ECU then switches over to the more
safer map what results in loss of power and higher mpg too. Also it retards
the timing so the ignition happens later during the pistons move to the
head. With this some energy is wasted as the fuel may not be fully burnt
within one cycle as it is used to "cool" the combustion chamber. But this
again results in a rich mixture although in most cases knock disappeares or
is limited.
All in all, I listen to the data on the logger screen and how knock
develops over the rpm band. Keeping the intake temperature low, using high
grade gasoline and good internals are key for a healthy engine. With the
logger it is possible to see how much a water injection did to the cooling,
what larger turbos that still run in their efficiency field can to to keep
the engine healthy or what difference the brands of gas make to your car.
Doing everything against the knocking evil is what we want as with low
knock (or even zero) boost and power can be upped what results in power
:-)
------------------------------
Date: Wed, 13 Aug 2003 09:43:49 -0700
From: "James Mutton" <
james@playstream.com>
Subject: RE:
Team3S: 60k service sprocket jumped time
That's happened to me before the cam's spring under valve spring
tension
when released. In my case one valve actually smacked a piston
giving
off a nice little riiiiinnnng. No damage though, valves are
fragile but
not THAT fragile. They probably see more abuse just being
involved in
the combustion process. Now having a cam jump time while
the engine is
running and 320HP of engine force being directed at the valve
is another
story, that'll bend valves in a heartbeat.
- -James Mutton
95 Green VR-4
------------------------------
Date: Wed, 13 Aug 2003 09:46:29 -0700
From: "James Mutton" <
james@playstream.com>
Subject: RE:
Team3S: engine dies
Sounds like ECU capacitors, have they been changed?
- -James
95 Green VR-4
------------------------------
Date: Wed, 13 Aug 2003 12:12:08 -0500
From: "Canney, Charles C" <
charles.c.canney@lmco.com>
Subject:
RE: Team3S: 60k service sprocket jumped time
Steve,
I am not an expert, but went through similar process after
reinstalling
rebuilt heads. When the cams jump, it is due to valve spring
tension against
the slope of a cam lobe. When the cam gear jumped, it
actually was allowing
valves to close, ie. moving away from the piston vs.
against it. The manual
shows a "safe" range of cam angle, when the number 1
cylinder is at top dead
center. As long as the cams didn't move beyond that
window, you should be
ok.
Charles
------------------------------
With all this talk about knock, and some various posts
already
mentioning the fact that the '94 and '95's can't be datalogged, it
begs
the question (at least in my mind), Can a knock sensor light, like I
had
for my '93 Talon, be made and installed in a '94-95 3/s easily?
-Patrick
- -"The definition of insanity is doing the same thing and
expecting
different results."
Patrick Purviance
'94 Dodge
Stealth R/T TT, Dark Green/Blk Leather
Open Air Filter, 1g DSM BOV, ProBoost
MBC, Blitz DATT, Indiglo Gauges
(even the center ones)
------------------------------
Date: Wed, 13 Aug 2003 13:42:39 -0400
From: "Starkey, Jr., Joseph"
<
starkeyje@bipc.com>
Subject:
RE: Team3S: Knock and its definitions
Well, Phillip, just because you never heard of something doesn't mean that
you should counsel others not to consider it. Post-ignition is a well
documented occurrence. Have you ever heard of dieseling or run-on?
That is post-ignition, and generally occurs because of a super-heated combustion
chamber--it doesn't really matter what's heating it (be it carbon deposits, hot
plug, or whatever) and the presence of a near-full air/fuel charge in the
combustion chamber after engine shut down (usually caused by the sudden decrease
in intake vacuum once the engine is shut off). Pre-ignition and
post-ignition (dieseling) are two entirely different concepts.
Pre-ignition is NOT dieseling because the key is still on, and the engine still
running during pre-ignition. Post-ignition IS dieseling because of the
absence of spark (i.e., the ignition is off).
Yes pre-ignition MAY sound and feel normal to you, but it does not sound
normal to a knock sensor that can "hear" sounds and sense pressure changes many
times beyond the range of humans.
------------------------------
Ahh, okay, thanks for explaining. I have heard about dieseling and
I
mentioned it here (maybe incorrectly). Dieseling with the key on is
the
same as pre-ignition and with the key off is post-ignition. Both are
almost
the same since the spark occurrence does not matter. Post-ignition can
only
happen on old carbureted cars. Newer cars shut off the injectors and
fuel
pump once you turn the key off. For the sake of sticking to
proper
terminology, let's talk about pre-ignition, since this is what we can
get
in our car and this is what we are interested in.
I do not think the stock $1 knock sensor is smart enough to know
everything
what is going inside the engine. A pre-ignition will sound to it
like a
normal ignition that happened earlier than expected. Do you have any
proof
that the stock sensor was tuned to listen for anything else besides
knock,
like pre-ignition? I want to hear about it.
Philip
------------------------------
Date: Wed, 13 Aug 2003 12:12:06 -0600
From: "Donald Ashby" <
dashbyiii@earthlink.net>
Subject:
Re: Team3S: Knock and its definitions
Uhhm, how can there be a post ignition? After ignition the fuel and air is
all burned away, or at
least most of it is, I can't imagine there being
enough left in there for it to accidentally
combust?
Pre-ignition is not picked up by a knock sensor, all the knock sensor does
is listen for an actual
"pinging" noise that will resonate the engine and
thus the sensor. Take a steel ball mallet to your
engine block and your knock
sensor will pick it up.
Donald Ashby
'93 3000GT VR-4 (RIP)
'92 3000GT VR-4 (Vroom!)
------------------------------
Knock is the same as detonation but is not the same as pre-ignition.
Let's
call it knock Detonation instead. It is a distinct event characterized
by
an ultra fast flame propagation within the combustion chamber. That
is
basically the definition of detonation. It causes extremely high and
spikey
cylinder pressures (several times higher than normal) and is
loud.
Knock <> Pre-ignition.
Pre-ignition is the same ignition that is triggered by something other
than
the spark plug. It is as quiet as a normal ignition.
Philip
------------------------------
Date: Wed, 13 Aug 2003 18:21:35 +0000
From:
mjannusch@comcast.netSubject: RE:
Team3S: Knock and its definitions
> Post-ignition IS dieseling because of the absence
> of spark
(i.e., the ignition is off).
That concept is outdated on fuel injected cars. It only happens on
carbureted
cars since fuel is pulled into the chamber by crank rotation
alone, and cannot
occur on fuel injected vehicles.
If anything, on a fuel injected vehicle a "post-ignition" would likely be a
misfire and then preignition due to the heat of compression and a hot spot
in
the cylinder.
- -Matt
'95 3000GT Spyder VR4
------------------------------
Date: Wed, 13 Aug 2003 14:24:44 -0400
From: "Starkey, Jr., Joseph"
<
starkeyje@bipc.com>
Subject:
RE: Team3S: Knock and its definitions
The only "proof" I have is the way in which a piezoelectric device, such as
a knock sensor, is designed to operate. A piezoelectric device doesn't
"hear" things like a conventional microphone or the human ear. It doesn't
"listen" for a metallic pinging. That's what we listen for. Rather, the
typical device contains either a quartz crystal or ceramic element that responds
electrically to changes in pressure, such as those caused by metallic pinging
and the high pressures that pre-ignition can cause. The greater the
pressure, the higher the voltage output, and voila, a "knock" is detected.
In an engine, pressure changes can be caused by a number of things, including
unexpected changes in sound waves (metallic pinging--something that is off the
"standard" set by the ECU) and unusual vibrations and pressure changes
associated with pre-ignition (again, something that is off the "standard" value
set by the ECU. The question is whether the time frame in which the ECT
tells the knock sensor to "listen" is long enough to pick up pre-ignition.
------------------------------
Typo: "Let's call knock Detonation instead"
They are the same, but this way nobody will think that we are talking
about
lifter tick or something.
Philip
------------------------------
I just sold my both front stock beige leather seats, got a 50%
downpayment!
:-) The guy will pick them up within days. I need to find
myself
replacement seats fast.
I was thinking about Sparco's. Maybe EVO I, II, or III. Does anyone
know
the difference?
Which other models should I consider? The reclining ones are nice but
they
are more expensive and are not real racing seats. Are Recaro's sold in
the
US?
Philip
P.S. Yes, Flash, I will get a roll cage/bar in too someday. :-)
------------------------------
Date: Wed, 13 Aug 2003 14:35:18 -0400
From: "Starkey, Jr., Joseph"
<
starkeyje@bipc.com>
Subject:
RE: Team3S: Knock and its definitions
You're correct. For the most part, post-ignition is unlikely in
fuel-injected cars, but can occur in rare instances, such as if you rev the
engine real high and shut the engine off, or perhaps if you have a leaking
injector.
------------------------------
Ah, I can follow your logic now and I see the incorrect assumption.
The
knock sensor has a quartz element in it that is sensitive to pressure,
but
it is not the cylinder pressure. It is the mechanical pressure from
its
mount. It is kinda hanging there on the engine block and it senses
every
high-frequency vibration of the block. Yank the block with a hammer and
it
will heat it. Pressurize the cylinders with zillion psi and it will
not
notice anything.
As opposed to detonation, the pre-ignition is quiet, so the
detonation
sensor will not pick it up, unless we put a really high-end
sensor(s) there
that can hear every combustion event and distinguish a "good"
one from a
"bad" one. With my limited NVH testing experience I can tell you
that this
$1 sensor cannot tell the difference.
Philip
------------------------------
Date: Wed, 13 Aug 2003 14:44:15 -0400
From: "Starkey, Jr., Joseph"
<
starkeyje@bipc.com>
Subject:
RE: Team3S: Knock and its definitions
As pointed out in other posts, post-detonation is unlikely in fuel injected
vehicles. In carbureted cars, gasoline could enter the combustion chamber
through crank rotation alone, even after the car was turned off. That's
the source of gas, and that's why carbureted cars had dashpots on their carbs
that allow the throttle to close the whole way once the engine was turned
off.
------------------------------
Date: Wed, 13 Aug 2003 14:04:43 -0500 (CDT)
From: Geoff Mohler <
gemohler@www.speedtoys.com>
Subject:
Re: Team3S: Painting my engine bay???
Most people I know who bother with it..prep and work it the same as
the
exterior.
------------------------------
Wayne has a set of bona-fide racing wheels for sale.
------------------------------
Date: Wed, 13 Aug 2003 14:22:30 -0500 (CDT)
From: Geoff Mohler <
gemohler@www.speedtoys.com>
Subject:
Team3S: Re: 3S-Racers: Racing wheels
Make em.
------------------------------
Date: Wed, 13 Aug 2003 15:27:20 -0400
From: "Bedrock" <
r.bedrick@comcast.net>
Subject:
Team3S: Recall and Red Line oil
I took my car to the dealer yesterday for the recall, They took me out
to
the bay and showed me the Red Line oil drippings in the pan and told
me
someone had put the wrong oil in the case and ruined the vent. They said
the
vent was blocked up, my question was if the oil ruined the rubber why
didn't
it fall apart. So they couldn't fix my car because they couldn't
locate a
vent. They took me home at 3pm and said they would call when
its ready. Has
anybody had any problems with the Red Line Oil? Its now day 2
and its not
ready.
When I spoke of the oil he said he's never see it so watered down? I
think
he's just never seen Red Line? There was less than 5,000 on the
oil.
Bob
White/Red 91 RT/TT, Original at 140,000+
------------------------------
Date: Wed, 13 Aug 2003 15:50:58 -0400
From: Mark Frouhar <
mfrouhar@bear.com>
Subject: Re:
Team3S: Sparco seats - ASAP!
No personal experience with those seats but from what I've heard &
gathered
it's just sizing. small < I < II < III <
large. Best thing to do is to find
a dealer near you and try some of
these seats on to see if you like them and
what their fit is like.
I have a pair of the Sparco Rev's because they're the narrowest seat they
make.
I need to keep my skinny ass planted. I love my Sparcos they're
extremely
comfortable for a racing seat. I've driven over 1000 miles in
one day sitting
in them.
Check out OG racing:
They know they're sparco's pretty good, they will be able to explain
the
differences to you.
If you foresee getting into open tracking I would suggest you go with the
non
reclinable racing seats as they have a one piece fiberglass shell that
protects
you much better than the traditional tube frame "street"
seats.
good luck
------------------------------
End of Team3S: 3000GT & Stealth V2
#228
***************************************