[s-cars] Current Confirmation list for ECU software GP and I. A. VS MTM

Sun Jun 16 23:26:06 EDT 2002

Kirby:

The code is quite different, on both the timing and boost chips.  Both the
2.5 and 3.0 bar boost chips have a primary map that has 10 steps for load
(as measured by throttle position) and 16 rpm points for each load step.
The map in the 1+ chip allows much higher boost levels up to 5750 rpm, then
cuts boost levels quickly to keep the k24 from overspinning.

Each chip is written with a specific MAP sensor in mind.   At 15 lbs of
boost, a 2.5 bar sensor has a voltage output of 4.0 volts, but a 3 bar
sensor has an output of only 3.18 volts.   Taking this example (real data,
BTW) a step further, if a chipset that was written for a 3 bar sensor was
installed with a 2.5 bar sensor, and was taken to 15lbs = 4.0 volts, the ecu
would think it was seeing around 22 psi of boost. You can imagine the
drivability issues this mismatch would cause.

A word on motronic vs. aftermarket boost controllers:

The boost side of our Motronic ECU is a very sophisticated boost controller.
Compare  the boost map on the motronic eprom which has a specified boost
level for each of 160 load/rpm points, and integration with saftey systems
such as knock sensors and overboost protection to an aftermarket boost
controller where you will get 1 boost setting per 500 rpm, no load
compensation,  and a disregard for all the safety systems.  The motronic is
much more sophisicated.

Unfortunately, the mechanical side of our boost control system isn't as good
as the electronic side.   Bottom chamber boost control is IMO, signifcantly
slower than the former 3b ( and aftermarket boost controller) top camber
control.  I think this change was made for wastegate diaphram longenvity
since upper chamber control operates at higher pressure differentials, and
is harsher on the WG diaphragm. Also, the stock WGFV seems relatively slow
to respond but this can be due to age/lack of maintenance.  I've read that a
good cleaning with carb cleaner will often make response much snappier (I
haven't tried this yet though)

Bob

-----Original Message-----
From: Kirby Smith [mailto:kirby.a.smith at verizon.net]
Sent: Sunday, June 16, 2002 1:58 AM
To: Robert Pastore
Cc: Peter Anderson; James Murray LMC; 'TM'; chris chambers; 'Scar'
Subject: Re: [s-cars] Current Confirmation list for ECU software GP and
I.A. VS MTM

On my S6, the Stage 1 chip (which I now believe is Lehmann) boosts to
1.3 kg/cm^2, or close to 2.3 bar absolute.  This may be compared to 1.1
for the stock setup.  2.3/2.5 < 4.85/5.00.  I doubt I have a problem
with the non-linear region.  YPMV

Clearly the Stage 1+ you are familiar with generates a higher pressure
and thus needs the 3-bar sensor.  My impression from the previous group
buy was that the Stage 1+ of that buy differed only in the addition of
the 3=bar sensor, and that other than adapting to the new sensor
scaling, the maps were the same.

kirby

Robert Pastore wrote:
>
> Kirby:
>
> I have to strongly disagree.
>
> The pressure transducers measure absolute pressure and out a linear
voltage
> from 0-5vdc.  So the stock 2.5 bar sensor can only read 1.5 bar of boost
or
> 21.75 PSI.  The reality of the sensor is that it peaks around 4.85 vdc,
and
> if to the maximum, loses it linearity.  The ECU then uses this voltage
> signal to determine boost level. Once the signal loses linearity, you are
> asking for trouble because you lose control of boost.  BTW, the TAP 3.2
bar
> pressure transducer is nothing more than a bosch 2 bar transducer, with 2
> resistors added to try to emulate the output of the 3 bar sensor.  I've
> mapped the output of many different sensors, and can assure you , the TAP
> sensor is not linear and doesn't work.
>
> > All of the Hot k24 chipsets need the 3 bar pressure transducer.  I
posted
> a stage 1+ boost map that I produced in excel directly from the chip'hex
> dump to the old s-list yahoo files.
>
http://groups.yahoo.com/group/s-car-list/files/stage%201%20plus%20%20boost%2
> 0map.xls  This chipset has a target boost level at full throttle  above
the
> limit of the 2.5 bar sensor from idle all the way up to 5750 rpm.
>
> >Playing with different chipset, modifying code, cataloging "what is what"
> has become a hobby/obsession.   I can tell you without reservation that if
> you run a chipset that uses the 2.5 bar sensor (either with a stock k24 or
a
> bigger turbo) you are foregoing a huge torque/HP advantage that the MTM 1+
(
> or whatever Ned is calling his 3 bar sensor version) gives.  If you'd
like,
> I can map and post the 2.5 bar chipset map from hoppen or Tap for
> comparison.
>
> regards,
> Bob
>
> -----Original Message-----
> From: Kirby Smith [mailto:kirby.a.smith at verizon.net]
> Sent: Saturday, June 15, 2002 4:56 PM
> To: Peter Anderson
> Cc: James Murray LMC; 'TM'; chris chambers; 'Scar'
> Subject: Re: [s-cars] Current Confirmation list for ECU software GP and
> I.A. VS MTM
>
> When the last group buy of Hoppen software was in process, we did it
> through Anderson Bros.  Stage 1 (which I got) differed from Stage 1+
> only in one respect -- the 1+ included a new 3-bar transducer.  However,
> this transducer has no added benefit to Stage 1 performance.  It only
> matters when one upgrades later to a higher pressure turbo and perhaps
> suitable software to go with it.  Thus, I suspect here that unless one
> is planning on staged upgrades and wants the 3-bar transducer for future
> upgrades, then there is no point to buying it now.  Although I don't run
> his software, I think Ned is correct in his approach here.  You may as
> well pay later for the sensor when you upgrade further, as pay now,
> unless you suspect that all units will be sold by then.
>
> kirby
>
> Peter Anderson wrote:
> >
> > I share James' point of view here.  I have been on this list for well
over
> > two years and while I have heard of the "Lehman" software, I have never
> > heard any mention of where / how to obtain it.  As for "binary"
> performance,
> > my car (stock motor & software) feels that way now.  If the MTM 1+ feels
> > similar -just faster, then I'll take it.  If your suggesting that IA
will
> > improve low end torque I'm skeptical but willing to hear more from those
> > with first hand experience.  Is that what you are saying Chris? If Ned
is
> > not willing to part with his 3-bar sensors except for those who want
full
> > bore turbo mods then he has effectively separated himself from my money
> > unless he can explain how I get the same performance w/o it.  Let's see
> some
> > dyno graphs.  He should note that I live at sea level and there is
plenty
> of
> > dense air to pump into the combustion chambers - no need to worry about
> > altitude compensation her in Portland Maine.  I am presently not
> interested
> > in changing my turbo as I do not want the torque curve I saw in the dyno
> > graph from the nationals (Mance's car).  I have no plans to take my car
to
> > the track.  I just want more usable street / highway power and no, I'm
not
> > talking about stoplight drag races.  I would like to hear more from
those
> > that have driven both.
> >
> > Peter Anderson
> > 93 S4 6-speed
> >
> > On 06/15/02 11:36 AM, "James Murray (LMC)" <James.Murray at ericsson.ca>
> wrote:
> >
> > > Does anyone know what software IA use? Is it there own or do they use
> > > Lehmann. Who sells Lehmann S/W?
> > >
> > > I guess I would want to know why IA doesn't include the 3-Bar sensor
> while
> > > MTM at least does if they are equal power outputs. At least with the
MTM
> you
> > > have the option for more powerful S/W upgrade later on since they
> provide
> > > the 3-Bar sensor...
> > >
> > > Cheers, /James.
> > >
> > > -----Original Message-----
> > > From:    TM [SMTP:t44tq at mindspring.com]
> > > Sent:    June 15, 2002 11:20 AM
> > > To:    'chris chambers'; 'Scar'
> > > Subject:    RE: [s-cars] Current Confirmation list for ECU
> > > software GP and I.A. VS MTM
> > >
> > > Chris,
> > > Why are you all so set on getting the MTM software? My drive of
> > > MTM software was not all that impressive. Igor Kessel has described
> > > it as "binary," a characterization supported by several others.
> > >
> > > IMHO, Lehmann and IA software has a much more progressive power
> > > curve
> > > that simply feels much better and generally is more refined with
> > > equal
> > > power outputs.
> > >
> > > Taka
> > >
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