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

Sat Dec 14 21:33:12 EST 2002

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
> >> > >
> >> > >
> >> > >
> >> > >_______________________________________________
> >> > >200q20v mailing list
> >> > >200q20v at audifans.com
> >> > >http://www.audifans.com/mailman/listinfo/200q20v
> >> >
> >> > _______________________________________________
> >> > 200q20v mailing list
> >> > 200q20v at audifans.com
> >> > http://www.audifans.com/mailman/listinfo/200q20v
> >
>