[Mk1gti] on "euro" injection.....

[pmcgarvey@fcg.com (McGarvey, Peter)]

I'll take a stab here, I would say your assumption that 'more fuel' = 'more
power' could be argued.  From what I know: the o2 sensor keeps the A/F ratio
at stoich for the greatest amount of power, economy and emissions at normal
conditions, except for WOT.  The O2 has less sensitivity at WOT, so the full
throttle enrichment runs a fuel map to predict how much fuel it will need.
I think the only way to adjust WOT fueling is to use an EGT gauge.  

Your euro fuel injection, probably has worse overall economy/emissions and
probably power b/c of the lack of an o2 sensor.  I'm not sure *exactly* what
the thicker lip of the fuel dist 'cone' does, but it may have something to
do with how much or at what speed, air flows through it, since that's where
the metering plate actually tells CIS how much fuel to provide to the
injectors.  But, I would think I thinner lip would provide more air (and
fuel) due to its larger opening - but then again, a small opening would
actually increase velocity, right?  As far as which is more important,
velocity or volume of air at WOT, I'm not sure - I would say velocity -
which would follow the thicker lip theory.  

So I think the only difference in the end is how either system handles WOT
conditions.  I think for the street, I would stick with the lambda system,
b/c I can't see any real worthwhile gain in hp b/t the two, over stuff like
emissions and mileage for a street car.  For a race car, I don't know, I
know some racers pull the o2 sensor, and tune the car with an EGT and run it
that way - possibly the only way to know exactly what's going on inside the
car - since economy/emissions are not an issue.  
Of course the other way, would be to put both on a dyno.

As far as shimming the control press. reg., the book 'Bosch Fuel Injection'
by Robert Bently publishing has some good info on CIS tuning, and may have
something about this, but I don't remember it that well. I could check and
find it if you're interested in getting the book for that reason - either
way it's a good book for learning about Bosch FI.  

PJ

-----Original Message-----
From: Andrew Stauffer
To: 'mk1gti@yahoogroups.com'; 'scirocco list'; 'vwautox@yahoogroups.com'
Sent: 1/8/2002 2:58 PM
Subject: [Mk1gti] on "euro" injection.....

Okay gang, it's winter time, garage projects are well underway,  there
isn't
much seat time, a good time to do some bench racing and
engineering................

The topic is CIS"euro injection".  I'm going to ramble on a bit about
the
subject, please correct or adjust my thinking as necessary.  
At any rate, this has puzzled me for some time and I'd love to hear some
thoughts.   AutoXers, I know this is a little OT, but please bear with
me,
there isn't alot of traffic these days.......  

Euro Injection- It's a thick lipped 80mm CIS flow cone/fuel dist/control
pressure(or warm up reg) regulator.   I'm under the impression that it
will
add some power over conventional CIS and CIS lambda.  This is the way
the
eBay add reads, the way that RPI sells it, and the way that the end
users
seem to feel about it from conversations that I've had.   In a nutshell,
it
drops the O2 sensor/frequency valve from the fueling equation, runs
richer,
and therefore provides more power.  Accurate so far?  

But-and here's where I get confused- If I want my CIS lamda fueled 2.0
8v
motor to get a richer mixture, I can dial it in with the 3mm mixture
control
adjustment in the airbox/fuel dist.   So I'm left to wonder, if I
unplugged
the O2 sensor and dialed in more richness, were is the benefit to Euro
injection over this?  I know from experimenting/experience that
unplugging
the sensor will result in higher emissions and lower mpg, as I'm told
the
Euro inj will.   I don't see where the euro inj is any diff than cis
lambda
with the O2 sensor unplugged.  Anyone got any ideas on that?      Doing
this
for CIS lambda will make the full throttle enrichment non functional,
which
is not a good thing in my experience.  Dan Bubb can back me on this.  Is
the
Euro inj air cone shaped such that this full throttle enrichment is not
necessary, it's already "in there" and accounted for? 


Going beyond this simple a/f mixture adjustment , I've heard folks say
that
you could also reshim the control pressure reg. in the fuel dist
itself(not
the block mounted cpr or warm up reg), and arrive at a richer(via higher
system pressure) mixture.  What's  this offer that dialing in a richer
mixture as above  via the 3mm  does not?    I assume you'd have to uplug
the O2 sensor for this trick to be of any benefit, but again, I must be
missing something.  I have never tried this, no first hand experience.
But
again, richer is richer, there must be a reason that this doesn't equate
to
"euro" standards as well.   Still with me? 

The crux of the issue:  If I want rich, I can get rich with the stock
stuff.
So if there is truly any benefit to euro injection, it doesn't soley lie
in
it's ability to run rich.  What makes this stuff special?  It comes
highly
recommended from some, I'm thinking it's supposed performance benefits
wouldn't be that hard to emulate with any ole CIS fuel dist.  

 Whaddya think? 


Andrew Stauffer
Cannondale Purchasing
www.cannondale.com
andrew.stauffer@cannondale.com
ph. 814 623 4516
fax 814 623 8917



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