Fwd: Re: Timing being pulled back? With links to the graphs

Sun Dec 15 17:27:07 EST 2002

Claus,

I'm glad you accept the explanation :-)
WRT O2 sensors, open loop and so on: the ECU runs the engine closed loop
when the TPS is indicating a throttle opening <80%. After that, it goes
open loop and uses the values in the lookup tables. I thought originally
that the ECUs had target lambda (AFR) values such as 0,88 to 1,30 etc but
actually the ECUs are so dumb that you have to tell them for how long to
open the injectors. Those are the values in the fuel maps. So this means
that there is no basic injector opening time that can be modified when you
use bigger injectors, you have to modify all values in the fuel maps in
order not to run too lean. This is how I got to know that a DigiTec chipset
that I have was made for running on RS2 injectors and a very large
intercooler otherwise the engine can just blow because of the high ignition
advance values and of the short injector opening times.

Mihnea

At 21:33 14/12/2002 +0100, Claus Vegener wrote:
>Fine Mihnea
>I have no problems with that, because it
>explains why a minor leak  gives fat running. Thanks.
>And Probst is not my GURU
>The orignal issue were O2 sensors running
>closed or open loop and maybe I used a wrong explanation of why, the ECU
>use tables and not just adjust injector duty cycles depending on the ideal
>14.7 ratio
>for air/gasolin.
>The fuel chip have to be programmed to
>injector size and fuel pressure. Feed
>back don't work - of some reason or other
>above 4800 rpm (my experiense) under boost.
>Let's see the formulas for these conditions - thanks
>Claus
>----- Original Message -----
>From: "Mihnea Cotet" <mik at info.fundp.ac.be>
>To: <vegener at post7.tele.dk>; <200q20v at audifans.com>
>Sent: Saturday, December 14, 2002 11:26 AM
>Subject: Re: Fwd: Re: Timing being pulled back? With links to the graphs
>
>
> > Well, Claus, now I have the verdict and this proves that either you didn't
> > remember correctly what Ned told you, or Ned told you BS or Ned doesn't
> > know what the chips are doing????
> >
> > Here is the answer WRT MAF sensor (I did a copy/paste of what you wrote to
> > me and sent it to him) from a person I know in Germany and who is a Dipl.
> > Ing. in engine management systems (also chiptuning) and who's a tuner
> himself:
> >
> > ""absoluter quatsch. ich habe die damos beschreibung von bosch mit allen
> > formeln.""
> >
> > So this means that the ECU uses the MAF sensor from idle to redline... I'd
> > rather spend 4 years looking at the maps inside the chips than reading
> > Probst's book because maybe he's right on the basics and on general ECU
> > description, but when it comes to the 20vt engines Motronic systems, it
> > just ain't right.
> >
> >
> > HTH,
> >
> > Mihnea
> >
> >
> >
> >
> > >>Well Mihnea - long story
> > >>I could be wrong.
> > >>I have checked all my mails with Ned without finding the
> > >>exact statement - so misunderstandings from phone calls may exist
> > >>but I have had this opinion for a quite long time and some other things
> > >>seems to convince me in that opinion
> > >>When the engine is accelerating you have to accept, that the ECU use
> > >>look-up tables with different input other than closed loop -
> > >>and feed back - from the Lambda.
> > >>There is a lot of talking about old type Lambda and wide band sensors
> > >>(not used for Motronic year 90) usable at any load.
> > >>So my guess is, that closed loop (feed-back) is not possible at
> > >>a lot of running conditions.
> > >>Charles O. Probst in Bosch Fuel Injection & Engine Management
> mentions on
> > >>page 36 Pulsed Injection - Full Load Acceleration
> > >>that the WOT switch disables the air-flow signal and base the fuel
> > >>enrichment solely on rpm.
> > >>To my opinion he should have written "on rpm and boost" too !!
> > >>I am sure temperature and boost are input to tables too.
> > >>
> > >>My own experience is,
> > >>a) that when cruising at constant speed
> > >>the Lambda changes lean-normal-fat some times a second - all the
> time. If
> > >>you start pulling up-hill or accelerating
> > >>  the mixture is enriched showing the use of tables and not closed loop ?
> > >>b) at very hard acceleration - if the fuel pressure is too high -
> > >>the engine hesitates close to 4800 rpm and wont go to 7000.
> > >>Lowering pressure fix this problem. The Lambda is not able to
> > >>adjust. Just show fat mixture. But coasting and idling is still fine.
> > >>To be honest - the only doubt I have is whether I was told 4200 or 4400
> > >>rpm :-).
> > >>But I have to admit, that measured air escaping due to un-tightness also
> > >>give problems at acceleration.
> > >>
> > >>MAPsensor upgrade?
> > >>If the boost can't be measured - the fuel can't be calculated -
> > >>to my opinion and a over-boost condition would arise.
> > >>A 2.0 Bar sensor delivers 5.0 V from 2.0 Bar and up to damage. The boost
> > >>chip run out of tables?
> > >>
> > >>WG spring: I bought it from a Danish manufacture of springs.
> > >>I choose a length of 48 mm close to 2 "; a diameter 46 mm
> > >>as the original and coresize is 5  mm. And made the perch adjustable.
> You
> > >>can only compress a few mm with your hands.
> > >>Test-drive carefully watching boost in a high gear.
> > >>
> > >>The real reason for playing with WG springs were the break down of my
> > >>Garrett turbo. I had to re-install my k24 and I didn't had
> > >>a standard MAF, only my RS2 MAF. So in order to save the live
> > >>of the k24 with the IA V set-up at 2.7 Bar I want to run at max 2.4
> Bar -
> > >>and that works real great with the 3 Bar chipset, RS2 injectors and MAF.
> > >>
> > >>I am interested in the truth about chips and ECU so please inform an
> > >>correct me.
> > >>
> > >>I have decided, that next time I want to enhance my car, it should be
> > >>based on user programmable
> > >>systems in order to get rid of the restrictive Motronic.
> > >>Like a 034 from Javad perhaps for my Urq WR engine.
> > >>But 5 coil ignition is not released yet - ...
> > >>
> > >>Claus
> > >>
> > >>----- Original Message -----
> > >>From: "Mihnea Cotet" <mik at info.fundp.ac.be>
> > >>To: "Claus Vegener" <vegener at post7.tele.dk>; "audifan20v"
> > >><200q20v at audifans.com>
> > >>Sent: Wednesday, December 04, 2002 9:29 PM
> > >>Subject: Re: Timing being pulled back? With links to the graphs
> > >>
> > >>
> > >> > Claus,
> > >> >
> > >> >
> > >> > Where did you get that statement about the ECU not using the MAF
> sensor
> > >> > above 4200 RPM? I am sure this is false because I have seen more
> than once
> > >> > that the fuel/timing maps are a function of MAF vs. RPM, i.e.
> Lambda= f
> > >> > (MAF/RPM) or ign adv= f (MAF/RPM) and that they cover the full
> engine RPM
> > >> > range. If the MAF sensor had been disabled, then maybe the maps
> would have
> > >> > only been from 600 to 4200 RPM, which isn't the case. There are
> also other
> > >> > legends about the Motronic systems on these lists, such as the MAP
> sensor
> > >> > function, and I mean the MAP sensor isn't involved in anything
> else but
> > >> > controlling boost pressure, no timing (vacuum advance/boost
> retard) and no
> > >> > enrichment either are based on the MAP sensor in an Audi 20vt I5
> Motronic
> > >> > system. So this leads us to the point where a MAP sensor upgrade isn't
> > >> > really necessary for people who like to "play" like you with
> stiffer WG
> > >> > springs and no WGFV. BTW, where did you get your 2.3 Bar spring
> from? I'd
> > >> > like to have one on my engine so I can play a bit with higher boost
> > >> > settings without having to mess with the chips in my ECU yet....
> Yes, I'm
> > >> > playing with chiptuning software and I know quite a few things
> about the
> > >> > way a Motronic works and when I say something I can prove it,
> otherwise I
> > >> > won't say it... :)
> > >> >
> > >> > Thanks for your answer,
> > >> >
> > >> > Mihnea
> > >> >
> > >> >
> > >> > At 19:32 4/12/2002 +0100, Claus Vegener wrote:
> > >> >
> > >> >
> > >> > >Brian
> > >> > >I always use 98 octane even if I have to drive long way
> > >> > >to find it. (I have all DK 98 octane stations on my Garmin
> Streetpilot)
> > >> > >For competition - just to be safe because the engine gets hot -
> > >> > >I use the 98 + 30% of a ochtanebooster home brew of
> > >> > >http://www.team.net/sol/tech/octane_b.html
> > >> > >using Xylene (117 ocht)
> > >> > >but at the same price I also use Sunoco 102+ to mix with.
> > >> > >
> > >> > >The only events I had a timing delay was with the original engine
> > >> > >3B . but worn - pumping oil through the breathe hose to turbo intake.
> > >> > >The oil mist decrease the octanerating and gives a temporary
> > >> > >loose of maybe 50 Hp. And after the run oil was dripping
> > >> > >out of the IC. After loosing some runs for that reason, I
> > >> > >installed a not-so-worn 3B (76.000 km) instead of the 250.000 km.
> > >> > >
> > >> > >The ECU uses only the MAF up to 4200 rpm. At boost and above
> > >> > >the dutycycles for fuel injectors is calculated based on rpm and
> boost.
> > >> > >(That's why the chips and injectors have to fit together and fuel
> > >> pressure)
> > >> > >If one want to mesh with high boost, I advise to install a O2 meter
> > >> > >just to follow what's happen. The signal can be taken from the
> original
> > >> > >but take care - the cord have a tinny shield outside the engine bay..
> > >> > >
> > >> > >Claus
> > >> > >
> > >> > >----- Original Message -----
> > >> > >From: "Brian Link" <BrianL at starsys.com>
> > >> > >To: <200q20v at audifans.com>
> > >> > >Cc: <vegener at post7.tele.dk>
> > >> > >Sent: Wednesday, December 04, 2002 6:31 PM
> > >> > >Subject: Re: Timing being pulled back? With links to the graphs
> > >> > >
> > >> > >
> > >> > >Claus,
> > >> > >Now everyone is going to shim their wastegates down and
> disconnect the
> > >> > >WGFV :)   Clearly your car is doing fine at 22 - 23psi without
> > >> > >detonation.  Which doesn't make much sense to me.  How can our
> 9.3 : 1
> > >> > >compression engine not detonate at 22 - 23 psi on pump gas.  What
> fuel
> > >> > >do you use in Dk?   I am forced to run 91 octane with 10 - 15%
> ethanol
> > >> > >here in Colorado.  Do you know if your cut off was due to your MAF
> > >> > >signal maxing out?
> > >> > >
> > >> > >Brian
> > >> > >
> > >> > >
> > >> > > >
> > >> > > >Yes Patrick
> > >> > > >That's my very own experience.
> > >> > > >Changing from k24 to G T04/50 and adjusting fuel pressure
> watching my
> > >> > >O2 readout - all other unchanged. 0-60 Mph from G-TechPro changed
> from
> > >> > >5.52 sec. to 4.96. The WG springloaded and not changed.
> > >> > > >
> > >> > > >I have a problem with the IA st. 4 running into over boost
> cutting my
> > >> > >fuel supply. My chips didn't >not have the falling slope as it should
> > >> > >from  24 (2.6 Bar abs) to 18. It stays stable until cut off >at 6.000
> > >> > >rpm. I have placed a dyno run together with
> > >> > > >a) original 220 (226 - my case) Hp and IA III with the
> > >> > > >timing retard before reaching 277 Hp
> > >> > > >b) Hp and Nm curves
> > >> > > >c) The flat boost not dropping but giving a
> serious  acceleration until
> > >> > >cut-off New pages are http://home7.inet.tele.dk/vegener/audi
> > >> > >
> > >> > >
> > >> > >
> > >> > >_______________________________________________
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> > >> > >200q20v at audifans.com
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> > >> >
> > >> > _______________________________________________
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> > >
> >