Thursday, February 10, 2011

DFAS Performance Chip Punk Performance

The
Digital Fuel Adjustment System

Tuning with Punk Performance

On this page we will cover some of the basic details and uses of the DFAS.
For full information please visit our website

http://www.punkperformance.com/

Wanting to control the air-fuel ratios on your vehicle, Car, Bike, Boat or Truck? 
Want the most power friendly or economical mixture right through your rev range?
Do you have the dredded flat spot and have tried everything to fix it?

If you have run in to the problem where your ECU can no longer keep up with your engines capabilities, Punk Performance PROBLEM SOLVED, even if your just wanting to make sure your stock rocker can handle it when you do give it some stick, The DFAS will make sure it loves it!, If you tuning for economy, We'll guarantee the DFAS will pay for itself. 

Easy, Reliable, Affordable  



What will you need?

A multimeter, heat shrink, solder and soldering iron.
All available from this our website or at any electronics store.

For any enquiries on our products please email: ceo@performanceautochip.com

 





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Overcome boost cuts
Tune and Modify air/fuel ratios for power or economy
Allow air-flow meter or injector swaps
Change closed loop running characteristics

FREE LCD Controller used to program the
Digital Fuel Adjustment System
(No laptop or computer required)
Unlike any other commercially available interceptors on the market.

It is affordable in cost and very easy to fit and tune. It offers fantastic
drivability and it is no exaggeration to say the release of the Digital
Fuel Adjustment System (DFAS) is set to revolutionize the electronic performance
industry. With over two years in development by the best electronic minds
in the world, numerous of prototypes and hundreds of hours spent testing
and tuning on an enormous variety of vehicles, The DFAS is immense with
capabilities! Do not be fooled by its apparent simplicity (four wires
to connect). In use the DFAS has left many experts out there speechless
after driving a vehicle equipped with the Digital Fuel Adjustment System!



Adjusting Air/Fuel Ratios
vehicle to run very rich mixtures at high loads to provide a measure of safety
if the car is held at a sustained full throttle for an hour or two. So instead of
an air/fuel ratio of (say) 12.5:1 at full throttle/high load, the standard
Electronic Control Unit (ECU) will provide a much richer air/fuel ratio
of 10.5:1. In most modified cars running the standard electronic management,
the air fuel ratios can be even richer! If these mixtures can be leaned
out, power will improve. So what does all this have to do with intercepting
your air-flow meter? Well the ECU decides how much fuel to inject into
the engine primarily on the basis of the airflow meters signal. When the
engine is consuming a lot of air, the air-flow meters output voltage will
be at the high end of its range. This means that if an air-flow meters
output signal varies from 1V at idle to 4V at peak power, the signal output
in the 3V to 4V range will need to be changed to lean out high end mixtures.
Specifically, to lean out the top end mixtures, these voltages need to
be slightly reduced.

The DFAS can make these sorts of tuning changes with ease, reducing or
increasing just those voltages that need to be altered while leaving the
rest of the signal untouched.


Changing Full Load Air/Fuel RatiosA typical use for DFAS will be to adjust full-load mixtures by modifying the
out put of the Air-flow meter. In RUN mode, the display can be used to work

out which load points need to be changed. For example, at low loads
(e.g. Idle), the minimum load point displayed might be 30. In cruising
conditions, the loads points around 50 might be shown, while at wide open
throttle at high revs, load points in the 100-120 range might come up on the
display. In this case, it’s the latter area where changes will need to be made.
In other words, if you have an assistant watching an Air/Fuel ratio mater and
the LCD Controller, It will soon become obvious at which load points changes
need to be made.

if you have the DFAS connected in Coarse mode, don’t change the
output voltage in large steps, as the air/fuel ratio might then dangerously
lean. Instead, start off by making small reductions or increases until
you get a feel for sensitivity of the system to changes.

As described above, keep the voltage changes at adjoining load points
smooth so that there’s no sudden jump in values that could cause
the engine to stutter. Then it’s simply a case of adjusting the
voltage levels up or down at the different load points until the desired
air/fuel ratios are achieved. If it is well-tuned, the DFAS gives absolutely
factory drivability- and tuning is very easy.



Overcoming a turbo boost cut


If the vehicle cuts fuel and/or ignition on the basis of the signal received

from a MAP sensor or Air-flow meter, the DFAS can be used to limit
the sensor’s output voltage so that the ECU never sees a high enough
level to trigger the boost cut. The load point at which the ECU cuts fuel
can be read in real time by monitoring the input in RUN mode. The load
points above this point can then be reduced just enough so the cut no
longer occurs. Note that depending on the vehicle, the air/fuel ratio
may also be changed by this process – it’s wise to check the air/fuel ratios
before and after implementing this modification.


Changing Injectors


If larger injectors are fitted, the DFAS can be used to reduce the

output of the Air-flow meter so that the correct mixtures are retained.
In order that the ECU can still stay working roughly within its normal
operating envelope, such an injector change shouldn’t be radical, otherwise
idle stability may suffer and the car may also not drive very well. Larger
injectors require changed values at all load points which are accessed and
this tuning is best carried out on a dyno with a good air/fuel ratio meter.


Changing Air-flow meters An air-flow meter electronically compatible but slightly lager can be
fitted and then the DFAS used to recalibrate its output. As with injector
swaps, in order that the ECU stay working roughly within its normal operating
envelope, such a change shouldn’t be radical. Again all load points
accessed by the engine are going to require mapping and this is best achieved
on a dyno.


Changing Oxygen Sensor Signals


The DFAS can be configured for the 0-1V signals commonly outputted
by the oxygen sensors. The resolution remains at 128 load points and
the tuning calibration at 127 adjustments up or down, giving extremely
fine tuning. The DFAS can be used to alter closed loop mixtures
(in the same manner as for Air-flow meter signal modification).
Although because of the sudden step in the oxygen sensor
voltage as mixtures pass through stoichiometric, some experimentation
will be needed to get the right results.
 

The DFAS can be used in a number of different ways- more commonly it is
used to intercept the Air-flow meters signal. In many vehicles, the air/fuel
ratios are not set for maximum power. Normally the manufacture sets up the




Conclusion

Extensive testing on the DFAS on a wide variety of vehicles showed
that it has extremely effective tuning control over air/fuel ratios,
together with very easy tuning and simply brilliant drivability it is the
best performance for its price.