[s-cars] Re: fuzzy logic et. al.

[QSHIPQ at aol.com]

I just don't think any driver is that good all the time Hap.  Audisport 
always figured their drivers had better things to do.  I dare say after driving the 
RS6, when the 450hp is tearing up tires, I couldn't find a guage if it had a 
attached helmet hammer.  I find it oxymoronic that an external non integrated 
boost controller can do "more/better" boost control function than a motronic 
with less inputs.  For the input it ignores, boost will prevail by definition.  
Motronic has a couple hundred boost parameters in it's matrix.  I have yet to 
see a boost controller that has close to that.

Your best hope is that you are good enough to catch a problem.  My argument 
rests on the fact that you've taken one of the best integrated controllers 
made, and changed it out with one less sophisticated and with more tunnel vision 
to the task.  The possibilities in the Motronic are pretty high.  I'd certainly 
think just counting the number of boost controller bought on this list alone 
would easily top 10 large.  That's certainly enough to seriously consider a 
group purchase of software service to hardware already owned.  

Minhea, I believe a good stepper motor to be faster than a FV, and is capable 
of accurately delivering very small and very large boost parameters.  
Especially on a top feeder where to address initial wastegate cracking a DCFV hitting 
100% is theoretically impossible.  A larger more heavy duty controller will 
get slower, so fine tuning (low DC with high feed pressure) is gonna be a 
problem as well.  Put a DCFV based top or bottom, the problems stay constant, the 
givens just reverse.  Put another way, the useful range of a DCFV is at best, 
what 90%, and it's designed performance is probably less (read: at 5% and 90% 
it's not as accurate or quick as at 50%)?  I argue a stepper motor range is 
100%, and performance is constant within that total range.

Kirby, without the input to boost, then the ck engine light is expost facto 
damage.  The motronic can use the input that gave the ck engine light to curve 
the boost profile.  The conroller doesn't know it's there = doesn't care = 
primary directive of boost profile maintained.  Potential bad?

Feico, the fact that you are doing the math is a good thing as far as I'm 
concerned.  The first step might be as simple as finding a better solenoid if 
there is such a thing.  The AVC-R uses one...  Better?

Pastore...  The delta between map and desired boost could be the danger zone 
by definition.  The way I understand these machines in learn mode is that the 
map is looking for flutter vs desire, which is an indication of surge line by 
definition. Fuzzy logic, in other words, takes over control of the "gain" 
function found on my (really basic) Profec B in my turbo 4Runner.  The AVC-R adds 
the trick of FL 'gain' in each gear.  I'd rather see more inputs than that 
feature, frankly.  WRT your bottom feeder vs top feeder, I'm not sure I'm with 
you.  No boost at all to the bottom of a WG all but eliminates wastegate 
cracking assuming the valve works properly.  WRT slow and soft (don't go there 
Pizzo;), I certainly think one might go back to my trivia question of a couple 
months ago, "why did audi change the location of the reference pressure (WGFV) from 
the manifold to the turbo"?  A follow up to that to the controller boys, 
where is the reference pressure for the boost controller?

Scott "generating some thought just might generate better boost" Justusson

In a message dated 1/22/2004 7:58:41 PM Central Standard Time, 
CaptMagu at aol.com writes:
Come on Scott

I have all the functions that you assume I no longer have since I use the 
Apexi. I still get check engine lights, MAF airflow overspeed cut, and 
ignition 
retard protection just to mention a few I have experienced when using the 
controller and exceeding a parameter. I keep a very close eye on a lot of 
engine 
parameters with boost pressure, EGT, wideband digital air/fuel ratio gauges 
plus 
the stock gauges. Besides I'm a very sensitive 21st Century kind of guy and 
really pay close attention to my Baby.

Hap, kickin back with a smile on my face in Everboost, Maguire