[s-cars] Re: wrt pushing RS2 to the edge...

Sat May 10 23:41:35 EDT 2003

It's absolutely normal to see negative timing numbers while datalogging
with VAG-COM because timing is in degrees ***BEFORE*** TDC, i.e. negative
compared to TDC.

Can you send me the .csv file so I can figure how your car runs?

Thanks,

Mihnea

At 13:33 10/05/2003 -0700, Joseph Pizzimenti wrote:
>WRT timing advance, upon datalogging group 3, I
>believe with VAG-COM, I only saw negative numbers,
>will post a graph this week.
>
>Time for water injection, I suppose, as a FMIC is a
>bit more of an undertaking for me right now.
>
>Joe
>--- Mihnea Cotet <mik at info.fundp.ac.be> wrote:
> > Mike,
> >
> >
> > At 11:24 10/05/2003 -0600, mlp qwest wrote:
> > >Mihnea -
> > >
> > > >From my limited experience, and I readily admit
> > it is both limited and
> > >probably suspect at best, but on a "BTDT" basis I
> > do feel comfortable saying
> > >that 28 psi @ 350F+ isn't the same as 28 psi at
> > 225F +/- a degree or two.  I
> > >further suspect, but again admit that I also don't
> > really know, 28 psi at
> > >350F+ wouldn't be quite the same, or necessarily
> > better than 26 or 25 psi,
> > >or maybe even 24 psi at 225F or less.
> > >
> > >I think a KKK RS2 K26 pushing 28 psi at anything
> > over, oh say 5,000 rpm or
> > >so is going to be more likely to be in the former,
> > i.e. 350F + camp, than
> > >the latter.
> >
> > Of course I've never said 28 psi should happen at
> > over 5000 RPM, nor should
> > it happen otherwise than in overboost.  More than
> > 1.5 Bar or about 21 psi
> > at 5500 RPM is the maximum an RS2 turbo can take,
> > and hopefully I've never
> > Been There Broke That yet because I've always
> > limited boost correctly in my
> > programming. Please, what's 350F???? Is that
> > chinese? ;-)
> > This is why I mentioned about "maximum boost
> > pressure" or overboost figures
> > and "continuous" or after overboost pressures. 2.0
> > Bar for a short period
> > of time in overboost isn't bad for the turbo, if
> > boost is lowered enough
> > past 5500 RPM.
> >
> >
> >
> > >Before going off on maximum psi figures, I wish
> > someone had the
> > >instrumentation at hand to correlate those with an
> > actual charge air intake
> > >temperature and power perceived",
> >
> > I have. with 1.8 Bar overboost on an RS2 turbo and
> > 25°C ambient air temps,
> > the intake air temps in the IM go to around 70
> > degrees C, and timing is
> > being pulled off a few degrees (professional secret,
> > I won't say how many).
> > This is still good for 520 Nm of torque (~380 lb/ft)
> > even though with 15
> > degrees ambient temps and 55-60 degrees intake temps
> > torque bumps to 540,
> > and IMHO 20 Nm is something that one's 'buttdyno'
> > can feel. Thus, yes, too
> > hot isn't really good but it's still better than 1.6
> > Bar with less timing
> > retard (because of lower intake temps).
> >
> > >.... like, as I understand, the ECUs are
> > >already measuring & doing and report on via "the
> > VAG display group 03, Field
> > >4 (Bentley Table J 01-76) off the air temp sensor
> > located, I think, in the
> > >intake manifold after the intake charge passes the
> > throttle plate.  That
> > >particular sensor is there, and in that specific
> > place for a reason, right?
> >
> > Yes, it is there in order to correct the following
> > things:
> >
> > -timing advance at WOT and part throttle
> > -fuel enrichments
> > -boost control.
> >
> >
> >
> >
> > >mlp
> > >
> > >~-----Original Message-----
> > >~From: On Behalf Of Mihnea Cotet
> > >~Sent: Saturday, May 10, 2003 10:43 AM
> > >~To: QSHIPQ at aol.com; robert at s-cars.org;
> > pizzoman at yahoo.com;
> > >~s-car-list at audifans.com
> > >~Subject: Re: [s-cars] Re: wrt pushing RS2 to the
> > edge...
> > >~
> > >~
> > >~Scott et al.,
> > >~
> > >~
> > >~28 psi *does* gain over 26 or 21 ....
> > >
> > >snip
> > >
> > >~RS2 torque is 420 Nm at max. 1.4 Bar. I know 28
> > psi isn't efficient, but
> > >~for torque no one needs 100% efficiency. So what
> > does your statement of 28
> > >~psi being almost double the factory boost levels
> > mean? Stock AAN boost?
> > >~Maybe, okay but what's the point? What's the point
> > in comparing apples with
> > >~oranges?
> > >~
> > >~So, sorry to insist, boost means torque and if
> > timing is properly
> > >~programmed (sorry to insist on that point again),
> > 28 psi will be a lot of
> > >~times better than 21, I've personnally BTDT many
> > times.
> > >~
> > >~Then, according to several serious tuners here in
> > Europe (what do you say
> > >~of Dupre Motorsport's racing engine management
> > director during the 90's?
> > >~He's the guy that helped me with most of what I
> > know about chip tuning),
> > >~stock rods (including the crappy AAN units which
> > are the worst Audi ever
> > >~used, i.e. the thinnest) are known to break at 600
> > Nm crank torque, meaning
> > >~in excess of 2.5 Bar or PR. This also means that
> > running 30 psi (or 2.0 Bar
> > >~or PR) won't break rods, except if the timing/fuel
> > chip is done by an a$$
> > >~and if knock sensor function is suppressed or the
> > threshold raised.
> > >~
> > >~Furthermore, maximum boost people are stating
> > doesn't mean anything to me
> > >~in terms of HP, what boost levels are you guys
> > seeing at 5500, 6000, 6500
> > >~and 7000 RPM? This is more relevant than maximum
> > boost you see for a few
> > >~seconds during overboost.
> > >~
> > >~HTH and my 0.02 Euro,
> > >~
> > >~Mihnea
> > >~
> > >~At 12:27 10/05/2003 -0400, QSHIPQ at aol.com wrote:
> > >~>Hmmm...  I personally think running 28psi on an
> > S-car is silly (I'd say
> > >~>stupid, but long nerdy posts about effective
> > compression ratios I don't
> > >~>need).  IMO, you are "safer" increasing the
> > Density Ratio than the
> > >~>Pressure Ratio.  I'd also venture to say that
> > 28psi probably isn't gaining
> > >~>any performance over 26psi, which means Motronic
> > is probably saving a lot
> > >~>of butts here.  I'd also venture to say that the
> > difference between 24psi
> > >~>and 26 psi is barely measureable.  I'd also
> > venture to say that the
> > >~>difference beyond 21 psi (RS2 equipped only)
> > comes at a massively
> > >~>diminishing rate of return.
> > >~>
> > >~>I'd further venture to say that rods are known to
> > pop at 30psi, which
> > >~>means the closer you get to it, the higher the
> > danger.
> > >~>
> > >~>All anecdotal "evidence" so noted, 28psi is
> > almost double the factory
> > >~>boost levels.  For street driving, probably not
> > there long enough to worry
> > >~>about it.  The long straight and intense 30minute
> > track session?  I'd be
> > >~>worried about it.
> > >~>
> > >~>Boost, specifically Pressure Ratio, is only part
> > of the equation in tuning
> > >~>for performance gains.  Cars *can* run at maximum
> > parameters, but small
> > >~>hiccups in any of the ancillary systems can cause
> > catastrophic failures
> > >~>because of boost.  The good news Joe, is that you
> > can respond in the
> > >~>"takes one to know one" concept.  Specifically,
> > if it's stupid to run
> > >~>28psi, in reality, with no other changes, it's
> > really no "smarter" to run
> > >~>it with race gas.
> > >~>
> > >~>HTH and my .02
> > >~>
> > >~>Scott Justusson
> > >~>
> >
>=== message truncated ===
>
>
>=====
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