W How to make your car faster: unichip and performance exhaust Androniki Pouris

How to make your car faster:
unichip and performance exhaust
Androniki Pouris tells us
how to improve a car’s
performance without
paying a fortune.
A turbocharger. Image: http://www.australianturbo.com.au/
A supercharger.
Image: http://rricketts.com/wp-content/uploads/2012/02/supercharger.jpg
hen people want to
buy a new car they
make their choices
using a number of
criteria – implicitly or explicitly. How
the vehicle looks, its safety (e.g. air
bags), comfort (e.g. air conditioning),
reliability and of course fuel economy.
Similarly, some people look for cars
that have turbos, superchargers, high
break horse power or high kilowatts in
the car. In simple terms, how fast the
car can go from point A to point B, or
how fast the car can pull away from a
standing start.
Many younger people now buy
vehicles and then modify them – to
make them look better or to drive
faster. The challenge is that while
people would like to have a fast
car, they don’t really understand
engines well or how their car works.
Modifying a car without knowing
what you are doing may cause damage
rather than make the car faster – and
of course you may spend more money
than necessary.
This article is based on my own and
others' experiences of modifying a car.
But before I describe my
findings, just a little information on
turbochargers, superchargers and
other devices that everyone wants in
their cars to make their cars faster.
General background
Superchargers and turbochargers are
devices that are attached to the engine.
They force air into the cylinders, so
creating a pressure that is greater than
the atmospheric pressure in order to
increase engine output.
What is a turbocharger?
The turbocharger is a device which
uses the exhaust gas as energy to
rotate the turbine wheel at high
speeds. There is a compressor wheel
on the same shaft as the turbine
wheel which compresses air into
the cylinders when it rotates. This
increases the engine output.
What is a supercharger?
A unichip.
Image: http://www.unichip.com/Images/Products/Unichip478.jpg with DASTEK permission
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A supercharger is a device that
compresses air and so increases the
density or pressure of the air that is
supplied to the internal combustion
engine. This gives each cycle of
the engine more oxygen, letting it
burn more fuel and do more work,
therefore increasing power.
What is a unichip?
A unichip is an electronic engine
enhancement product. The unichip is
also called a piggy-back computer. It
is connected with the vehicle’s existing
engine control unit (ECU) and
greatly enhances the capabilities and
functions of the original computer. It
essentially turns the original computer
into a supercomputer.
When a unichip has been installed
in an engine and mapped to that
engine, you can tune the vehicle
in any way you wish – you can
program the unichip to lower the
revolutions per minute (RPM) or you
can program it as an immobiliser.
Another chip can be set up for high
boosts if the car has a turbocharged or
supercharged engine.
The unichip is a plug-and-play
system, so if you decide to sell your
vehicle, the unichip can be removed
and installed in a different vehicle. But
you need to remap for each individual
vehicle’s unique specifications.
Although the unichip was
originally designed for diesel vehicles,
modifications have been made to
accommodate petrol vehicles.
What is an exhaust?
An exhaust transports exhaust gases
from the engine away from the
passengers to the rear of the vehicle
while conforming to noise and
emission regulations.
An exhaust was originally designed
to let air flow from the engine to the
rear of the vehicle as quietly as possible
by using silencers. Silencer boxes are
installed in the exhaust at strategic areas
to maximise sound reduction while
retaining drivability. They slow down
the exhaust gases to reduce sound, and
restrict the airflow out of the engine,
which reduces power.
A performance exhaust, on the other
hand, expands airflow by increasing
pipe diameter from standard size and
reducing the size or number of silencers.
This speeds up airflow, allowing the
❚❚❚❙❙❙❘❘❘ Everyday science
A car exhaust system.
Image: http://hdabob.com/wp-content/uploads/2009/11/Exhaust.jpg
The author’s BMW 330ci. Image: Androniki Pouris
engine to run more efficiently. The
exhaust will be louder than standard,
creating a sportier engine noise, which
enthusiasts love. A more free-flowing
exhaust gives small power gains to the
engine output.
Observation and
The motivation for this article came
from my own experience of modifying
my car after a friend spent a lot of
money buying a supercharger. I started
searching for an alternative and possibly
more cost-effective method.
I found that unichip and
performance exhausts can both be
available and effective. DASTEK, a
large Pretoria-based supplier, assisted
by providing all the information on
devices, as well as other examples of
modified vehicles.
I decided to add a unichip to my
own BMW 330 ci and was pleasantly
surprised by the additional power –
easily felt, although the actual increase
was only 5%.
The figures on the right show the
power increase after modifications of
three DASTEK vehicles.
The three graphs show the power
readings at the wheels as the engine
revolutions change. In the first run
shown, the vehicles are standard
(without any modifications), while
runs two and three show the power
at the wheels after the modifications,
which include the unichip and
performance exhausts. You can see
that as the modifications are made,
the power of the vehicles increases.
Table 1 summarises the findings
at the highest revolution points,
performance without modification
(standard) and with the unichip
and performance exhaust. The two
petrol cars (BMW and Golf) show
an increase of approximately 10%.
The diesel vehicle (Fortuner) shows
an increase of 36.5%. It should be
mentioned that the unichip was
originally designed for diesel vehicles.
Why do this?
Many people would like to improve
their car’s performance without
spending a lot of money. Social media
and films such as Fast and the Furious
movies also contribute to the desire
for speed.
In my experience it is possible to
significantly improve the performance
of a car without spending more than
R10 000 using the unichip and the
performance exhaust systems. Adding
superchargers or turbochargers could
set you back between R60 000 and
R100 000. So, for a relatively modest
amount, you could improve your car’s
performance by around 10% in petrol
vehicles and 36% in diesel vehicles.
In the future it would be interesting
to find out if other external ECUs
(e.g. Chipbox) provide equal or better
power enhancement. Q
Androniki Pouris is at the Faculty of
Information and Communication
Technology, Tshwane University of
Technology. She likes driving fast cars!
The author would like to thank DASTEK for providing the
relevant information as well as Mrs A Pouris, Prof A Pouris,
Dr Inglesi Lotz, Mr M Piperakis and Mr P Roebuck for the
valuable comments.
DASTEK, Unichip – Take control with the unichip q; accessed
December 2013 at http://www.dastek.co.za/Unichip.pdf
Toyota, 2013, Diagnosis Technician: Engine; Toyota South Africa
Supercharging Performance Handbook, 2011, Jeff Hartman,
page 182
The Turbo Hydra-matic 350 Handbook, 1987, Ron Sessions
BMW M3 power readings at wheels: standard,
performance exhaust, unichip. Image: DASTEK
VW Golf 1.4l power readings at wheels: standard,
performance exhaust, unichip. Image: DASTEK
Toyota 3000 Fortuner 4x4 power readings at wheels:
standard, performance exhaust, unichip. Image: DASTEK
Table 1: Power increase from standard to
modified versions
Car type
Run 1
Run 3
% increase
Golf 1.4l
Toyota Fortuner
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