Custom Ford Mustang — Where do I start?

One of the most appealing aspects of the Ford Mustang is the ease of
modifying them to fit the driver’s personal needs and tastes.  There is
probably no other car available in the United States with such a
booming aftermarket, with options to make the car look and run exactly
how you want.

As you begin to modify your Mustang to make more power, keep in mind
that you want to increase air flow both in and out of the engine and if
you modify both ends of the combustion process equally you will see
greater gains as you go.  Starting off, the most common and easiest
modifications for newer Mustangs are cold air intakes, exhaust systems
and ‘tuners’. 

Cold air intakes are probably the simplest modification that you
can make to your Mustang and in most cases this will also be the
cheapest.  The cold air intake replaces your factory intake tubing and
filter box, allowing for better air flow to the engine but in most
cases, also making more engine noise.  The 2010 and newer Ford Mustang
GT comes with a factory cold air intake designed with optimum air flow
and minimum noise but changing to a aftermarket intake will often give
your Mustang a little more power and sound. 

A hand tuner is the next easiest modification and while these can
be a bit pricey, they provide more additional power than the intake or
cat-back exhaust system and they require no real technical knowledge. 
If you can locate your OBDII port under the dash and plug a cable into
it, you can use a hand tuner.  Along with changing the parameters of
your engine computer to make more power and often increase economy a
tuner can allow you to check and clear engine codes, alter the shift
point in automatic cars, and even monitor other engine diagnostics
while driving.  The price of these will usually be higher than the cold
air intake but may be less than some of the top of the line exhaust
systems.

Much like the intake, a cat-back exhaust system is the next easiest
modification, although prices will vary based on brand, quality and
whether or not you can install it yourself.  It only takes simple tools
and can be done in a driveway and this is a modification that can
really give your Mustang some personality.  Stock exhaust systems are
designed to dampen the noise where aftermarket exhaust systems often
amplify it – helping to make your Mustang sound like an American
performance car.

Once you have added the cold air intake, cat-back exhaust system and
the tuner you need to get into modifications that will cost more and
require more mechanical know-how to get more power from your Mustang. 
These are all modifications that can be done by a hobby mechanic but
care should be taken as with these mods, a poor job can cause damage to
your car.

Exhaust headers add more power but for a novice driveway mechanic,
these can be challenging and poor installation can cause more
problems.  However, when coupled with high flow catalytic convertors
and a good cat-back exhaust system, headers will help to increase the
overall flow of your exhaust gases thus making more power.

A larger throttle body and larger fuel injectors will help get more
air and fuel into your engine.  These will give you very minor gains
but as you continue to build your engine they will become necessary. 

Finally, we come to the high end modifications.  These are not for
the faint of heart or those without proper mechanical knowledge as poor
installation will ruin your engine.

Forced induction has become the most popular means to make big
horsepower.  Superchargers, turbochargers and nitrous oxide can provide
hundreds of horsepower depending on the application but should you
decide to go this route, do your homework.  Research the best forced
induction kit to fit your needs and find a reputable shop to do the
install work unless you are comfortable doing the work yourself.