[ba] tweaking the Bosch CIS, is possible?

Buchholz, Steven Steven.Buchholz at kla-tencor.com
Wed Jun 2 15:35:55 EDT 2004

... while it is possible to chip the naturally aspirated engines from the
early '80s you really need to think about what the total potential is for
the amount of cash you will need to lay out to see if it is really worth the
effort.  Given this fact, I wonder how many vendors continue to offer any
products for these engines, so you may be out of luck there too.  The cars
of that vintage which could take good advantage of "chipping" were those
with turbocharged engines.  

If you really want to tweak the maximum performance from your current engine
you will most likely want to take a look at the big picture ... breathing
enhancement such as head/valve/cam and intake/exhaust optimization ... and
then make similar adjustments to the ignition and fuel injection system to
match.  While I tend to believe that Audi "tweaked" the engines a good bit
at the factory (look at the fancy multi-stage exhaust manifolds the NA Audis
have) perhaps one of the biggest restrictions is the fact that there is a
airflow sensor plate sitting in the intake.  If I were to look at optimizing
an early '80s Audi NA engine I would give serious consideration to dumping
the CIS completely in favor of a programmable EFI/Ignition system.  That way
adjustments to spark & fuel to accommodate breathing or cam changes can be
done easily.  

All that said, if my goal was to bump up the performance of an early '80s NA
Audi I would look seriously about swapping in a turbocharged engine ...
engines are pretty doggone cheap after all ... 

No matter what ... have fun thinking about the possibilities!
Steve B
San Jose, CA (USA)

> Is there any type of "chipping" or whatever available for the early 
> 80's CIS injection? From memory I'm thinking that these are pretty 
> rudimentary systems and that the chipping stuff didn't get started 
> until later in the evolution of fuel injection.
> If that's not possible is there anything to be had from a K&N filter 
> and a larger capacity exhaust system or am I just kidding myself?

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