Team3S: 3000GT & Stealth Friday, February 14
2003 Volume 02 : Number 081
----------------------------------------------------------------------
Date: Thu, 13 Feb 2003 23:51:57 +0100
From: "Roger Gerl" <
roger.gerl@bluewin.ch>
Subject:
Re: Team3S: new turbos?
Well, I dunno what the 268's are but my 368's compressor wheel was as wide
as two inches the last time I measured them. probably the difference between the
368s and sx line ?
- ----- Original Message -----
From: "Trevor James" <
trevorlj@cox.net>
Sent: Thursday,
February 13, 2003 11:34 PM
------------------------------
Date: Thu, 13 Feb 2003 18:29:48 -0500
From: "Zobel, Kurt" <
Kurt.Zobel@ca.com>
Subject: RE:
Team3S: 265's on 8.5 rims?
Yes, I'd say 245 in a performance street tire, but 255 is ok for an R1 DOT
type track tire on 9in. Depends a little on the specific tire and specific
driver.
Kurt
- -----Original Message-----
From: Geoff Mohler
[mailto:gemohler@www.speedtoys.com]
Sent: Friday, February 07, 2003 5:33
PM
Incorrect. The stiffest part of the tire is ONLY the tire directly
supported by the wheel.
The sidewall will be far outside the edge of the wheel.
Technically,. the BEST fit for a performance tire on a 9" rim is 245.
> I would not mind trying. This is the size that I am going to buy when
> all six of my Kumhos 712 wear out. I also have 8.5" wide rims. I think
> I will love a better grip of the wider tires and, since the O.D. is a
> tad smaller, I would be able to use my gearbox better.
>
>
I have seen OEM tire/wheel packages with ratios worse than that and
>
they handle fine. Another comparison, even though 275x35-18 on a 9"
>
rim, which is not a controversial setup according to the formula, has
> a
better ratio than 265x35-18 on a 8.5" rim, the "excess width" of the
>
latter tire is only 1.35 mm larger on each side. But that tire has a
>
profile which is lower by 3.5 mm, which should improve sidewall
>
stiffness.
>
> Both setups must handle better than 245x40-18 on a
8.5" rim, IMHO.
>
> I was told by some unrecognized experts that an
AWD car is a different
> animal and that it needs some extra flex in the
suspension to be able
> to go fast. Anyone can comment on that?
>
> Philip
------------------------------
Date: Thu, 13 Feb 2003 19:42:05 -0500
From: "Philip V. Glazatov" <
gphilip@umich.edu>
Subject: RE:
Team3S: Cat Instead Of Testpipe Yields More Boost, Less Spiking
At 07:51 PM 2/12/2003, Geddes, Brian J wrote:
>Secondly, opening up
the exhaust will increase the volumetric
>efficiency of the engine,
allowing it to consume greater amounts of
>air. Most people think
that putting on a downpipe will allow them to
>run more boost to
redline. I don't think this is true. Exhaust
>modifications
(downpipe and precats especially) will allow the engine
>to ingest more
air (greater VE). If the turbo is already at the limit
>of its
output with stock exhaust, I'd expect to actually see LESS boost
>to
redline after exhaust modifications. The turbos are putting out
the
>same amount of air, but because the engine is more efficient, and
taking
>in more air per rev, we'll actually see a LOWER boost
level.
>
>Hmm...I've actually never thought about it that way
before. Erik, by
>the way, that may be the answer to your question
about the higher boost
>with the cat on. :)
Glad you guys figured this one out on your own. :^) A cat is a
restriction. You deadhead the engine - it will build up more pressure in
the cylinders, "eat" less air, and would be content with smaller turbos, or
would be able to build up more boost with the same small turbos.
An anecdotal confirmation to this would be the words of one of our resident
gurus (forgot who that was), who said that those who claim to be able to
hold 1 bar to the redline on stock turbos do not have their precats gutted
yet.
A smaller boost spike could be explained by the intricacies of your boost
controller. Is that a Protec or something? Anywho, I bet it is a good
controller that uses the PID control algorithm. The D part (derivative)
looks at how fast the boost builds up. If the boost is rising faster, then
it would try to bring it down more. What must be happening is that this
boost controller compensates for a faster boost rise better than for a
slower boost rise and therefore it overboosts less.
Erik, I wish you had tried your Road Dyno before and after to tell us what
adding a cat does to a car.
I will be getting a custom exhaust for my car later this month. My stock
downpipe cracked and now my car stinks a little. I am environmentally
unconscious, but I hate beautiful but stinky cars. The new exhaust will
have a new cat. I bought one from Summit Racing for $95
http://store.summitracing.com/partdetail.asp?part=18620.
Dunno if it is
much better than stock or not, but it is a close second
highest-flowing and
the most heavy-duty cat in the Catco lineup. We'll see
how well it works. :-)
Philip
------------------------------
Date: Thu, 13 Feb 2003 17:52:50 -0700
From: "Trevor James" <
trevorlj@cox.net>
Subject: Re: Team3S:
new turbos?
Oops...typo...I meant 368's.
Inducer Diameter:
368: 1.830"
Small 16G: 1.830"
Exducer Diameter:
368: 2.367"
"Small" 16G: 2.365"
Like I said...the "small" 16G and 368 (T3 60 trim) compressors are roughly
the same physical size.
Trevor
- ----- Original Message -----
From: "Roger Gerl" <
roger.gerl@bluewin.ch>
Sent:
Thursday, February 13, 2003 3:51 PM
> Well, I dunno what the 268's are but my 368's compressor wheel was
as
> wide as two inches the last time I measured them. probably the
> difference between the 368s and sx line ?
>
> Roger
G.
> 93' & 96'3000GT TT
>
www.rtec.ch
------------------------------
Date: Thu, 13 Feb 2003 17:17:21 -0800
From: "Gross, Erik" <
erik.gross@intel.com>
Subject: RE:
Team3S: Cat Instead Of Testpipe Yields More Boost, Less Spiking
> > Hmm...I've actually never thought about it that way before. Erik,
by
> > the way, that may be the answer to your question about the
higher
> > boost with >the cat on. :)
>
> Glad
you guys figured this one out on your own. :^) A cat is a
>
restriction. You deadhead the engine - it will build up more pressure
>
in the cylinders, "eat" less air, and would be content with smaller
>
turbos, or would be able to build up more boost with the same small
>
turbos.
Yeah, that makes sense... so following that line of thought, one
would think that Roger was right in saying that the main cat is not that much of
a restriction if I'm seeing only a 0.01-0.02kg difference in redline boost with
cat on vs. cat off. Or am I missing something else? :-)
> A smaller boost spike could be explained by the intricacies of your
> boost controller. Is that a Protec or something?
Yeah, I suppose, but I still don't know how the dang Blitz DSBC really
works. I don't think it has any learning algorithm because it works the same no
matter how long you drive/play with it. I know what happens when I play
with the settings, but I have no idea what it's doing internally or what it does
with the solenoid duty cycles. Maybe I should put a boost gauge on the
wastegate line and measure what it's doing...
> Erik, I wish you had tried your Road Dyno before and after to tell us
> what adding a cat does to a car.
Don't worry, that's on the list of things to do - I still have the 3"
testpipe and it's not THAT much of a PITA to swap out. I'll do some
comparative runs one of these days. That and some comparative runs where
the only difference is OEM plugs gapped at 0.040 vs. 0.032 :-)
- --Erik
------------------------------
Date: Thu, 13 Feb 2003 20:09:54 -0600
From: "cody" <
overclck@satx.rr.com>
Subject: RE:
Team3S: Cat Instead Of Testpipe Yields More Boost, Less Spiking
I have been reading this discussion since it's introduction... I have
a question - who uses a real good manual boost controller on their
VR4's???
I have a Joe P MBC on my Talon, and once set it's rock solid
repeatability. Whatever final pressure I have it set for, it spikes 1 psi
above that when boost comes on quick, and levels out at the desired boost, to
never spike again. Only when jabbing the throttle at just the right RPM
does it spike. No matter temperature outside, no matter humidity, rain,
etc, it never spikes or does boost pressure change.
The only thing I dislike is the part about changing it under the
hood...
It's so simple too...
- -Cody
- -----Original Message-----
From: Gross, Erik
Sent: Thursday,
February 13, 2003 7:17 PM
> > Hmm...I've actually never thought about it that way before. Erik,
by
> > the way, that may be the answer to your question about the
higher
> > boost with >the cat on. :)
>
> Glad
you guys figured this one out on your own. :^) A cat is a
>
restriction. You deadhead the engine - it will build up more pressure
>
in the cylinders, "eat" less air, and would be content with smaller
>
turbos, or would be able to build up more boost with the same small
>
turbos.
Yeah, that makes sense... so following that line of thought, one
would think that Roger was right in saying that the main cat is not that much of
a restriction if I'm seeing only a 0.01-0.02kg difference in redline boost with
cat on vs. cat off. Or am I missing something else? :-)
> A smaller boost spike could be explained by the intricacies of your
> boost controller. Is that a Protec or something?
Yeah, I suppose, but I still don't know how the dang Blitz DSBC really
works. I don't think it has any learning algorithm because it works the same no
matter how long you drive/play with it. I know what happens when I play
with the settings, but I have no idea what it's doing internally or what it does
with the solenoid duty cycles. Maybe I should put a boost gauge on the
wastegate line and measure what it's doing...
> Erik, I wish you had tried your Road Dyno before and after to tell us
> what adding a cat does to a car.
Don't worry, that's on the list of things to do - I still have the 3"
testpipe and it's not THAT much of a PITA to swap out. I'll do some
comparative runs one of these days. That and some comparative runs where
the only difference is OEM plugs gapped at 0.040 vs. 0.032 :-)
- --Erik
------------------------------
Date: Thu, 13 Feb 2003 22:08:13 -0500
From: "Philip V. Glazatov" <
gphilip@umich.edu>
Subject: RE:
Team3S: Cat Instead Of Testpipe Yields More Boost, Less Spiking
At 08:17 PM 2/13/2003, Gross, Erik wrote:
>Yeah, that makes
sense... so following that line of thought, one would
>think that
Roger was right in saying that the main cat is not that much
>of a
restriction if I'm seeing only a 0.01-0.02kg difference in redline
>boost
with cat on vs. cat off. Or am I missing something else? :-)
Sounds like a good justification for my catalytic converter! :-)
>Yeah, I suppose, but I still don't know how the dang Blitz DSBC
really
>works. I don't think it has any learning algorithm because it
works the
>same no matter how long you drive/play with it. I know
what happens
>when I play with the settings, but I have no idea what it's
doing
>internally or what it does with the solenoid duty cycles.
Maybe I
>should put a boost gauge on the wastegate line and measure what
it's
>doing...
No, it does not learn, you teach it. It always responds to the same inputs
in the same way. You just teach it how to respond.
Adding a boost gauge on the wastegate line should be pretty easy,
considering that you wastegate line H-connector is probably closed on one
of the sides. I guess you would see exactly what you would expect to see -
no pressure when you are building up boost, full pressure before it peaks
out, partial pressure after that, and no pressure at the redline.
Philip
------------------------------
Date: Thu, 13 Feb 2003 22:21:08 -0500
From: "Philip V. Glazatov" <
gphilip@umich.edu>
Subject: RE:
Team3S: Cat Instead Of Testpipe Yields More Boost, Less Spiking
At 09:09 PM 2/13/2003, cody wrote:
>I have a Joe P MBC on my Talon,
and once set it's rock solid
>repeatability. Whatever final pressure
I have it set for, it spikes 1
>psi above that when boost comes on quick,
and levels out at the desired
>boost, to never spike again. Only
when jabbing the throttle at just
>the right RPM does it spike.
That's the only main disadvantage of those MBCs. If it does not overboost
from idle to WOT, then it could overboost from 4000 rmp to WOT.
The other smaller disadvantage is supposed to be that it slows down boost
buildup before the boost reaches its peak, but most poorly-tuned electronic
boost controllers do the same thing too.
If you are happy with the small overboost when "jabbing" the throttle, then
keep it and look no further. Expensive electronic BCs are not guaranteed
against doing the same thing.
Philip
------------------------------
Date: Thu, 13 Feb 2003 22:58:31 -0600
From: "cody" <
overclck@satx.rr.com>
Subject: RE:
Team3S: Cat Instead Of Testpipe Yields More Boost, Less Spiking
Actually, the only overboost spike I get is when boost builds too rapidly
at like 2500 rpm... I did a few tests to compare... Even with the
wastegate 100% closed, and never opening, with my MBC, I found that it spooled
up the same either way. I also have a small boost creep problem, and even
with the wastegate 100% open, I get the same (too big of an exhaust)...
Another question, are some of you all retaining the stock boost control
solenoid?
- -Cody
- -----Original Message-----
From: Philip V. Glazatov
Sent: Thursday,
February 13, 2003 9:21 PM
At 09:09 PM 2/13/2003, cody wrote:
>I have a Joe P MBC on my Talon,
and once set it's rock solid
>repeatability. Whatever final pressure
I have it set for, it spikes 1
>psi above that when boost comes on quick,
and levels out at the desired
>boost, to never spike again. Only
when jabbing the throttle at just
>the right RPM does it spike.
That's the only main disadvantage of those MBCs. If it does not overboost
from idle to WOT, then it could overboost from 4000 rmp to WOT.
The other smaller disadvantage is supposed to be that it slows down boost
buildup before the boost reaches its peak, but most poorly-tuned electronic
boost controllers do the same thing too.
If you are happy with the small overboost when "jabbing" the throttle, then
keep it and look no further. Expensive electronic BCs are not
guaranteed
against doing the same thing.
Philip
------------------------------
Date: Fri, 14 Feb 2003 03:32:11 -0600
From: "Steve" <
denon11@insightbb.com>
Subject:
RE: Team3S: crank angle sensor
Should know for sure the extent of the damage if any by next week.
Steve Truskosky
Pearl white 1995 3000GT SL
- -----Original Message-----
From: Steve
Sent: Friday, February 07,
2003 12:30 AM
Well all looks good except
that my old auto tensioner does not
have
the spring in it that I expected.
compressing it in the vise was a slow
possess and it seemed to have plenty of
strength wile compressing
it.
As the service manual states that if
the old tensioner gives a lot of
resistance it is good.
But after installation and torque the belt tensioner
pulley
I can push or pull the timing belt with little or no effort about a
inch or so That just seems loose to me. And yes I did use the special tool to
tension the belt. I can see the auto tensioner plunger go in and out. This does
not seam normal to me.
In my opinion I think the tensioner should offer more
resistance. I would hate to buy a new tensioner if it is not needed. The car
does have 106800 Miles on it so maybe
it is time for a new one.
Any comments on this would be appreciated.
Steve Truskosky
Pearl white 1995 3000GT SL
------------------------------
Date: Fri, 14 Feb 2003 16:29:13 +0000
From:
mjannusch@attbi.comSubject: RE:
Team3S: Manual Boost controllers
> I have been reading this discussion since it's introduction... I
have
> a question - who uses a real good manual boost controller on their
> VR4's???
I'm using a Hallman boost controller on my car. It works really well,
spools
the turbos quick and doesn't overshoot the boost target. The
main key is to
use a restriction-style controller instead of a
bleeder-style. The Joe-P is
practically a clone of the Hallman
design. The other things you should do is
try very hard to reduce the
amount of hose in the boost control system. Make
the lines as short as
possible to reduce response time of the wastegates to
the controller sending
pressure. Also, when switching to any aftermarket
boost controller,
the stock boost solenoid and its lines should be removed to
prevent
spiking.
- -Matt
'95 3000GT Spyder VR4
------------------------------
Date: Fri, 14 Feb 2003 16:15:20 -0700
From: "Rivenburg, Pete" <
privenburg@firstam.com>
Subject:
RE: Team3S: Manual Boost controllers
So does the type of line (rubber vs metal) effect the action kinda like
brake lines?
Pete Rivenburg
>>
The other things you should do is try very hard to
reduce the amount of hose in the boost control system. Make the lines as
short as possible to reduce response time of the wastegates to the controller
sending pressure.
- -Matt
'95 3000GT Spyder VR4
------------------------------
End of Team3S: 3000GT & Stealth V2
#81
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