[alfa] Alfa Chips and other Bosch mods

[drm <cimice2351@xxxxxxxxx>]

Ben Dorfman wrote:

>"Hi. There is currently a performance mod being
>advertised on Ebay (item# 2475385832). It is a
>piggyback resistor that is supposed to trick the 
>ECU into advancing the timing curve. These mods are
>available for all cars with EFI and I doubt this
>particular item is specialized for Alfa.. 
>Has anyone dared to install something like this on
>their Alfa? Given its function (tricking the car into
>thinking its breathing hot air), is there any reason
>not to give it a try? Thanks,
>Ben"

The added fixed resistor will richen your A/F ratio
ALL OF THE TIME.  You are actually fooling the ECU to
think the engine is COLDER than it really is.  The
problems with this...  You are stuck all the time with
a rich mixture which isn't always appropriate, plus
your fuel economy will go away... far away, according
to how much resistance you add.  The guy on EBAY
doesn't mention what value the resistors are (and he
isn't likely to) but there is a better way.

The hotter your engine runs, the leaner it will run
and the leaner it runs, the hotter it runs.  It
doesn't matter much under normal driving but if you
run hard, it will.

On our Bosch injected Alfa Spider race car, I did some
experiments with various sensors to determine range
and effect on mixture under different conditions. 
Altering resistance at the coolant sensor seems to
work pretty well.  (Test results on request) 

I added, not a fixed resistor, but a variable resistor
("potentiometer") in series with the sensor wiring.   


By adding this, we were able to richen the mix in
increments according to the weather, fuel and mood of
the car.  For racing, after a couple laps, it was
turned up to where the car burbled a bit and backed
off some, making adjustments as needed. Not very
scientific but adequate for racing where a little bit
rich doesn't hurt.  For the street, if you add a F/A
mix gauge, you can know exactly where you are.

The advantages with the "Pot" in series with the
existing sensor instead of using a fixed resistor are
twofold.  Being variable you can make minor
adjustments, like adding some fuel on a cold dry day
when the air is very dense.  Secondly, you can turn it
off.  Just by turning the knob to the bottom of its
range.  Without any added resistance, you are
operating off the sensor, just like it was stock. 

Don't expect to blow away turbo Civics or anything. 
In most cases, you might feel some difference in the
seat of your pants but it works better with a
combination of other things.

This works on most any EFI system.

Dave Miller
Deltona, Florida  


	
		
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