tech session report (long)

[Brett Dikeman]

Just got back from the tech session and there was plenty of fun to be 
had.  Please note this is all from memory- if it comes down to me vs. 
some article on the web or audi press release, trust them, not me :-) 
While I've spent a good hour or two on this writeup, it's not going 
to be perfect.

Due to incompatibility with catalytic converters(exhaust gas temps 
get too low is one problem), the FSI system will not use the special 
lean-burn "stratified" mode (where a tiny pocket of ideal-mixture is 
ignited dead center); in the US market FSI will stand for Fuel 
Straight Injection- Europe, Fuel Stratified Injection.  "To avoid 
confusion".  Uh...right :-)  There is the possibility the 2.0 FSI 
block will use stratified mode since it is apparently able to 
generate the higher exhaust temps needed for proper cat function. 
And no, Europe won't get stratified injection in their V6 either; 
market has little to do with it.  No, you won't be able to "turn on" 
stratified mode; the piston heads are different, since 
stratified-mode bounces the fuel charge off the center of the piston 
to pool it around the spark plug.

It's a sleeveless aluminum block using eroded silicon casting that 
sounded similar to how the 944 block is made(I believe aluminum is 
chemically removed, leaving a denser silicon layer).  Graphite is 
used somehow; I didn't hear clearly.  A small actuated vane (in the 
head, I think) moves varying with RPM for different effects on the 
flow into the combustion chamber to make sure FSI works properly, and 
a valve further up the intake path in the manifold is used for 
variable intake.  The 3.2 FSI is a 24V engine NOT 30V, the flow 
patterns of the 5V head (designed to give a turbulent airflow to mix 
up the fuel/air mixture for traditional injection) did not suit FSI, 
which doesn't need help atomizing the fuel at well over 1,000 PSI...

Compression ratio is pretty high- 12.5:1, "So this will NOT run on 
cheap gas."  Fuel delivery is via an ECU-managed, variable speed low 
pressure pump, coupled with an electronically controlled, 
cam-actuated (passenger side, I think) high pressure pump that puts 
pressures into the 1200PSI range; pressure varies like any other fuel 
injection system and is directly measured at both stages by the ECU; 
no mechanical fuel pressure regulators.  Hitachi-made injectors 
sitting in the head inject fuel right between and underneath the two 
intake valves, and are driven at 65V.  The diagram did not show a 
return, I believe.  Someone asked if hard lines were used throughout, 
and the answer was yes.  The presenter also cautioned that the system 
was much more dangerous to "tinker" with or repair.  The same 
concerns exist as with diesel; pressures are high enough that leaks 
themselves can inflict injury and cause fuel to penetrate the skin at 
close distances.

The car is a nightmare of electronic modules- something like 50 of 
them; everywhere there are interface modules (control stalks and 
steering wheel for example) and command modules that drive 
motors/actuators and report on their condition and have associated 
sensors.  Power doesn't flow directly from the wiper stalk to the 
wiper motor; the rain sensor and even the hood sensor get in on the 
action; wipers won't operate with the hood open.  The 
audio/visual/nav stuff is all tightly integrated, and yes, the car is 
bluetooth compatible.

That's great for wire savings, function integration, and 
troubleshooting for people with the right tools; however, VAG-COM or 
ProTools (along with factory repair manuals) will be an absolute 
requirement for people like us who want to own them outside their 
warranty period, because it's simply not going to be possible to 
troubleshoot otherwise.  Of some concern is how much of the coding 
information will be made available even to those who buy the factory 
repair manuals.

CAN is used predominantly, along with a special media-only, 
fiber-based ring-topology.  Yup- if a module dies, it takes out a 
good chunk of the ring.  So if your TV tuner module (I kid you not) 
goes on the fritz, your radio, nav, etc could go bu-bye until it's 
fixed.  I didn't think to ask if the connectors were designed to be 
set up to bypass a disabled module by plugging them together, but I 
seriously doubt this is the case.  Automotive engineers have yet to 
learn the lesson IBM did with Token Ring 20 years ago- and even token 
ring had some pass-through.  It'll also be fun if the fiber starts 
breaking; glass fiber doesn't like vibration, although that's 
armchair-engineering-supposition on my part.  The highly integrated 
audio/nav/vehicle control will also make aftermarket audio equipment 
virtually impossible to install.

The presenter warned that with the increase in control units would 
come the potential to cause damage (I could imagine some fun 
fireworks possible with the FSI system if you're a dolt and go 
messing where you shouldn't) or interoperability problems when 
untrained people "recode" units; with 50 units, a recode in one 
module could affect at least one other module and cause all sorts of 
problems.  Audi/VW have discovered what system administrators like 
myself have had to deal with for a decade plus- software version 
compatibility problems.  Dealership techs will have the ability to 
get electronically info from Germany about what software versions on 
all the various modules are known to work together, and get new 
updates.  And yes, even the tail lights can be coded to one of three 
region settings for regulatory compliance.  Oh boy...

Enough with the pessimism.  Our hosts were very friendly, and the 
session was not rushed along; I was late by almost an hour and a 
half, and I still felt it was a great event; even if it had been 
twice the drive I still would have enjoyed it.  From when I arrived, 
they had finished up a tour of the classroom/garage areas, and people 
were eyeballing the cars and socializing.  We watched a few Audi 
movie clips that were pretty nice; one in particular featured a ton 
of old racing and rally clips- but unfortunately internal use only, 
so no copies for us.  Doh.

  There was something for everyone- a couple of dealership customers 
were there (dressed better than the rest of us so easily picked out 
;-), and they wandered off to the back of the classroom/garage area 
to kick the tires so to speak with a salesman while the rest of us 
checked out an accelerated walkthrough of part of the A6 training 
presentation dealership techs get.

Safety features were covered comprehensively; the seats feature 
cantilever headrests for whiplash protection like the Saabs and 
Volvos; airbags are dual-stage and trigger more quickly if the 
control unit doesn't sense the seatbelt being worn, so that you are 
not too close to the airbag when it goes off if you're not belted in. 
Deployment consists of single-stage in a minor accident followed by 
activation of the second stage after the head is clear, to prevent 
"presenting rescue crews with a live airbag charge".  A more serious 
crash will activate both charges at the same time (or more closely in 
sequential fashion, it was not made clear).  A pressure sensor 
determines the weight of the person in the seat, and if it's under 
55lb or so, the airbag is not activated.  Additionally, a tension 
sensor on the receptacle-side senses if the belt has been cinched too 
tight, ie for a child seat, and also will deactivate the airbag 
(makes me slightly uneasy, as it's standard practice for many DE 
attendees to tighten the belt and move the seat forward to secure 
yourself tightly in the car.  Also, what about when harnesses are in 
use?  Ugh).   Deactivation flashes a passenger-visible light in the 
cluster, and a bright indicator in the driver's door for them.

  Following that were some quick words about the A6 design changes and 
what they were intended to do for the car stylistically. I will 
refrain from comment on this area as my view on the A6 styling is 
rather pessimistic.

   Scott Downs and I of course had to poke around, and we picked the 
most obscure place in true Audifans spirit; the trunk!  It uses an 
electronically actuated latch (bah, humbug) although there was a 
keyhole- upside down next to the handle.  Under the floor cover is 
where you will find an ENORMOUS battery (12v, no exotic 48V system 
yet) way down in the bottom of the trunk.  The real fun, however, is 
a pyrotechnic disconnect on the positive side which disconnects power 
to the starter and alternator if the airbag control unit thinks the 
crash is bad enough to move the engine- and thus risk the starter or 
alternator positive terminals contacting bodywork and starting a 
fire.  Yes, power is maintained to locks, lights, windows, and 
necessary control units.  Different cables, ie no under-floor-Y like 
on the type 44.  On the negative side of the battery between the 
ground strap and the body is a large module which turned out to be 
exactly what I thought it was- a current sensing module.  The 
alternator is managed now by computer control- so the car presumably 
knows state of charge, not just battery voltage, and exactly how much 
power needs to be put into the system by the alternator.  Clever- 
laptops have had this kind of ability for a decade; it's about time 
cars did.  Oh, and guess what- the car uses 20-30 Amps just sitting 
there with the key in the ignition, engine/headlights/etc off. 
YIKES.  Alternator is 195 amps(!) and I would guess it's almost 
certainly water-cooled; it'd have to be at those power levels.

   After poking around we heard a loud clunk.  "What was that?"  "I 
dunno, but you're the one holding the cover up, I think it's your 
fault!" :), and we ran off to join everyone for food; Audi provided 
free sodas/coffee/tea etc, the club provided sandwich fixin's.

Peter Schulz commented that the whole car is loaded with explosive 
devices.  Two igniters per front airbag.  Two side airbags up front, 
optional in the rear for two more.  Pyro seatbelt tensioners.  Pyro 
battery disconnect.  Peter's point was that the number of parts that 
require special handling/shipping keeps going up up up...

Last goody of the evening was a ride in the prototype 3.2 FSI.  With 
four people, no luggage, mostly full tank- it was decently quick. 
255hp and I think 244 ft-lb, I think?  One of the presenters said 
that the FSI was "noisy, you can hear the injection", but you could 
have fooled me; sounded fine, though I have admittedly not rode in 
many new Audis lately.  The prototype is reportedly getting around 
28-29mpg on 'spirited' highway driving; the 4.2 gets more like 23-24. 
Both are decently impressive, though one does seriously wonder if 
they'd be much better without all the electronic dodads that require 
the 195A alternator...

As for the dynamic oil change functionality- there's a sensor in the 
oil pan which senses oil flow(or viscosity, sorry- I forgot) similar 
to how a mass airflow sensor works; a heater feedback loop.  Based on 
that and fancy figuring based on driving pattern, the ECU decides 
where between the min+max settings to pop up the change-my-oil light. 
US cars come coded with min+max set to the same value, so the oil 
change light comes on at the fixed interval.

All in all, a good evening, and thanks to Chris Miller for setting it 
up and making it happen; this is exactly why we wanted people like 
him on the national board.  Two things of note.  The presenter guys 
were very interested in whether we liked the evening, and everyone 
said they did; they're keen on doing more, but keeping them at a 
reasonable size, as that lets them do things like take people on 
rides and generally be more one-on-one with people, talk with them in 
small groups and so on.  So if you want to see more of these- talk 
with your ACNA board member (people like Chris), talk with your 
dealer, etc.  Having enthusiasts and club members writing in gives 
ammunition to support further events like this.

   Second, during the drive Scott mentioned we needed more 
stickshifts- and the response was that AoA staff in Michigan have 
been leaning heavily on Audi to bring more sticks into the country, 
but not much noise comes from customers, and stickshifts end up being 
hard to move, supposedly- so Audi says "you're not getting 'em" 
except in models where it's been proven they'll move.  And yes, a 
manual DOES have to be crash tested, emissions tested, etc separately 
from an automatic model; every drivetrain is considered different. 
So- if you want more manuals, you need to start writing letters to 
AoA so they can bang on the door in Germany and say "yes, we have 
people who want these cars, in numbers great enough to justify going 
through the expense of federalizing them".

Oh, and while you're at it, beat on the door of your congressman so 
they understand that Euro-NCAP testing is just as good if not better 
as the crash testing done in the states, same thing for emissions- 
it's time to get over this petty BS protecting the US auto industry 
and let european makers bring in cars more easily.

Phew.  That's all for tonight.  I have some photos I might post 
tomorrow(er, later today? :-)

Brett
-- 
"They that give up essential liberty to obtain temporary
safety deserve neither liberty nor safety." - Ben Franklin
http://www.users.cloud9.net/~brett/