Today we’re going to talk about car tuning. No, not cartooning, but car tuning! How do
you tune your car to get max horsepower? And can you even tune modern cars? Horsepower comes from explosions. You squeeze as much air as you can into the
cylinders, add just the right amount of fuel, and then ignite it with a spark. And boom! The mix of air to fuel, or air-fuel ratio,
determines how much energy is released and how
much emissions are produced. Carmakers tune for the ideal air-fuel ratio,
which is 14.7 parts of air to one part fuel. But here’s the thing. That ratio might be ideal for maximum economy
and emissions, which is what carmakers want. But it isn’t ideal for maximum power, which
is closer to 12 to 1. This means your car is capable of more power. And that’s where tuning comes
in. The challenge is that cars have gotten a lot
more complicated and so has tuning. When engines first appeared, the air fuel
mix was controlled by a carburetor. This
simple device worked by sucking the fuel into the engine along with the airstream. Adjusting the fuel to air mixture was pretty
simple. You fiddled with a few screws to
allow more or less fuel to enter the engine. Then you listened. It was pretty much like
tuning a musical instrument. If it sounded right, it was going to drive
right. Pretty simple. But it wasn’t long before carmakers invented
a more efficient way of delivering fuel to the mix. Fuel injection! The carburetor doesn’t distribute the air-fuel
mixture evenly, which results in higher fuel consumption and
emissions. Fuel injection delivers a fine
mist directly to each cylinder so you get better combustion and less unburned fuel. Then to get even better fuel economy, engineers
needed to vary the ratio depending on things like altitude, engine temperature and
speed. But varying the spray mechanically
was pretty limited. So things got even more complicated. Carmakers started working on
electronic fuel injection, which needed a computer. Electronic fuel injection uses sensors to
measure things like speed and temperature. The measurements then get fed to a computer
system. This system has saved settings
that are applied to different situations. These settings are known as “maps” or
“tunes”. So, let’s see how this works. You get into your car and start the engine. The car is cold. A little sensor on the engine measures the
temperature and sends a message to the engine control unit or ECU. “Hey, it’s pretty cold over here.” So the ECU sends a
message to the fuel injector. “Hey, spray more fuel.” As you drive and the engine
warms up, the same little sensor starts getting hot. So it sends a message to the ECU. “Things are getting hot here.” At the same time another sensor sends the
ECU a message saying “The speed is currently 40
mph”. So the ECU consults its map. The
map tells it what fuel radio is best given the heat and speed. It then instructs the fuel
injector on the amount of fuel to achieve that ratio. It was the challenges of fuel injectors that
drove the car into the computer age. The earliest version of an electronic fuel
injection system goes back to 1953. It was
invented by the Bendix Corporation, but never used. Then Bosch brought out the
Jetronic electronic fuel injection system, which used engine speed and a pressure pad. By the 1970s and 1980s laws became stricter
on emissions and by the 1990s almost all cars had fuel injectors. Today’s automobiles have computers that
control everything. It’s not just one computer
but a collection of electronic control units that together are referred to as the car’s
computer. Some cars have up to 80 electronic control
units or ECUs that control different electrical systems or subsystems in the vehicle. Typically the biggest processor is the engine
control unit we talked about before. It’s sometimes also called the Engine Control
Module or ECM. This is probably so you don’t confuse it
with the generic electronic control unit. It’s not hard to get confused. There are just so many electronic control
units and modules. You can have Powertrain Control Module (PCM),
Transmission Control Module (TCM), Brake Control Module (BCM) and
more. They all talk to each other via
CAN which stands for Controller Area Network. It was developed in the 1980s by Robert
Bosch. Mercedes-Benz was the first carmaker to use
the CAN system back in 1992. CAN allows messages to travel together on
the same wire but it gives priority to more urgent messages. So remember the Engine Control Unit from before,
which sent messages to the fuel injectors. Well those messages are pretty important. So are messages from the Brake
Control Module for example. But now you’ve also got messages from the
infotainment system like “Hey connect this phone to the
Bluetooth.” And all these messages are
travelling around as fast as they can. It's pretty busy out there on the CAN highway. So,
what happens if there’s a traffic jam and the messages can’t get through? Very good
question! This might be ok for the infotainment messages. Your teenagers can wait a
few seconds for their phones to connect. But its not ok when it’s a message to the
brakes. “Stop right now” is pretty important. Well that’s where the CAN acts like a traffic
copy. It tells the infotainment message to back
off and waves the brake and other priority messages through. So what does this have to do with tuning? Well nowadays, if you want to tell your
engine to do something, you’ve got to do this digitally rather than mechanically. And
you do that via the OBD port. OBD stands for on-board diagnostics. It’s the access to the car's computer. Mechanics
use devices that plug into the OBD port to see what needs to be tested and repaired
when things go wrong. The port is usually located somewhere near
the dash. An OBD
reader checks the trouble code and then clears it from the computer’s memory when it’s
fixed. So, it’s key to fixing problems. But it's also the key to tuning your car. Every decision your Engine Control Unit makes
depends on how it was programmed or tuned. Like we’ve mentioned before, you could take
one car and give it completely different characters simply by changing the software
on the ECM. Your car can be Dr Jekyll but it
could also be Mr Hyde. One character could have a need for speed
and be tuned for maximum power. The other could be conservatively tuned for
and maximum fuel economy. Your car will come out the factory tuned for
economy and reliability. This
often means they mute the performance of the car. A different tune could make the car
go much faster. Tuning means the right software and knowing
how to use it. This hacking art has
advanced so much that home-brewed engine remapping software is available to
download for the brave or tech-savvy. There is no shortage of devices that are
available to tune your car. You can use the software to read the current
settings, modify parameters and then write them to the computer. Pretty much how you would save the changes
to a Microsoft word document. Of course there is so much information and
so many parameters that if you didn’t know what you were doing, you could drown in all
the data. And if you did tinker, you’d want
to make really small, incremental changes and then test what effect they have on the
car. It’s also a very good idea to save the original
settings so you can revert back to the standard factory map. You know that feeling when you push save on
a document that writes over the old document and you suddenly
remember that one paragraph you should have kept. You don’t want to have that feeling when
you’re tuning your vehicle. There’s other things that can go wrong too
which is why we’re flashing this disclaimer. Bad tunes can damage engines and be dangerous
to drivers. They can also shorten
engine life, lead to greater fuel consumption, void the cars warranty and might even be
illegal. Car manufacturers obviously don’t want you
messing around so ECUs have protection locks. This is also to prevent high-tech carjackers
or car hackers from plugging in to your OBD port to steal your
car. There are a lot of professional tuners who
will tune your car for you. You’d want to make
sure of their credentials before you let them get their hands on your car. In fact, they
wouldn’t need to even touch your car. You can buy a programmer online, download
your ECU file, upload it to the tuning company who then re-tune or flash or chip it and
send it back to you for downloading. Or if you’re on a budget, there are performance
chip plug-ins off the internet for as low as $50. Not sure what you’re really going to get
for that! Sounds like something we need
to test. Other companies have taken advantage of the
OBB port as well. Insurance companies
use it to analyze driving habits and give discounts based on better driving habits. You
can also plug dongles in that connect to your iphone to provide alerts. This includes
making sure your teenager keeps to the speed limits. Pretty much a telematic system. They’re not expensive but you have to pay
monthly subscription fees. Be careful about plugging dongles into your
car. Think about your car as you would
your computer. You’d be careful about viruses and hacking
on your computer. The
same applies to your car. After all, it really is becoming a big computer
on wheels. Which all means tuning modern cars is hard. But it’s not impossible. If you want my
opinion, tuning older mechanical cars is more fun. I really like the sound of an
unplugged guitar that’s tuned by ear. Same goes for the sound of a perfectly tuned
mechanical car. We have more exciting car content coming very
soon. So subscribe below and ring that
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