TUNING | How it Works

– Since we’ve had cars, car owners have been
trying to make them faster. Most manufacturers have been trying to make them more reliable. Cars come from the factory
with a bunch of stuff designed to make it run a certain way. So how do you make it faster? Tuning! Tuning is trying to get
the right mix of variables for peak engine performance. Back in the day, it was
actually quite similar to tuning a musical instrument. You tweak some screws and you’d listen. If it sounded right, you
did a good job tuning. And if not, it mostly meant tuning a carburetor. The carburetor’s where
the air and the fuel mix before they go into the engine. Too much gas and not enough
air makes the engine run rich. Too much air and not enough
gas makes the engine run lean. So it’ll either rev too high
or idle or it’ll sputter out if it’s not tuned right. The choke, wait a minute. We’ll talk about carburetors
in a different episode. We’re talking about tuning, the degree to which these
flaps can open and let in air, is determined by a screw. And the chamber where the gas and air mix is also tweakable on a car. A tuneup meant that a
mechanic would make sure your timing belt was adjusted properly, your ignition is happening
at the right time, and that the right mix of air and fuel is getting in the engine. We looked at torque curves before. An engine performs best right here. We’ve also talked about cams,
and lifters, and push rods. But back in the day, if you
wanted to change this peak, you had to change out some hardware. And essentially, you’re moving the peak
maybe from here to here. This new configuration meant
you had to tune the engine to work optimally at this point, thanks to the new hardware. Same thing with adding a blower. You have to tune the engine
to get the right air fuel mix into the engine because you’re
changing another variable away from how it was set at the factory. But even when you’re making
your engine perform better, you’re tuning it for this optimum spot at one place on the curve. You couldn’t really do
much about performance in these red ranges or these. Then something happened
in late 70s and early 80s. Manufacturers were tuning
down engines to make less horsepower and get
better fuel economy. And to stop people from
tuning your own cars, they put these little caps on
top of the carb adjustments. And make sure the air fuel
mix was staying efficient. They use E, C, Us. Early ECUs mostly measured oxygen, going into the engine and coming out. They used this signal
to control a solenoid that would determine how much
the carb would open or close and how much fuel would be
getting next with the air. They were effectively taking the tuning out of the hands of the owner. If you wanted a different air fuel mix, you had to either trick the computer or reprogram it. This is when tuning as we now know it started taking shape. It also opened the door
for computer controlled variable valve timing and computer controlled ignition timing. What? By the way, the ECU’s
the same thing as an ECM, or an engine control module. The ECU really only controlled
fuel mix in the early days. But it started becoming more
important as fuel injection started getting refined. Later on, manufacturers added
transmission control modules. Eventually, they started
putting them together with ECU in the same chip, which makes a powertrain control module. But forget all these alphabet soup. Most people now just
refer to the whole thing as the ECU. Now, we know that the
ECU’s a little computer that gathers information
from sensors placed all around your car. Then it gets sent in
from wheel speed sensors, engine sensors, O2 sensors,
zero flow sensors, temperature. Oh, there’s so many sensors. Relax. The ECU takes all of it and
does millions of calculations every second to determine
how to control everything from the air fuel mix to transmission shift to the engine’s redline. The ECU also identifies problems
while it’s sorting through all that info. As ECU’s becoming more common, engine and emissions equipment became increasingly electronic and complicated, car manufacturers started
putting diagnostic ports to make it easier to
figure out exactly why the engine light was on. But there was no industry standard. So they used whatever kind
of port they felt like. To figure out why the light’s on, you might had to connect
some pins to the port, or gently caress it,
tiny screw on the ECU. Then you’d wait for the warning
light to blink out a code. And then you’d look up the fault that that code corresponded to. Or maybe you could buy an
expensive proprietary scan tool, and/or computer to make things
a little easier on yourself. But every manufacturer had their own idea what these ports should look like. And eventually, the government mandated that all cars came with a
standardized on board diagnostic system so they can
better monitor emissions. And keep a car running clean. So from the 1996 model, every car is equipped with
a universal OBD II port. Why am I talking about OBDs? Because an OBD reader
can tell you all about the little things going
on inside the engine and that can help you tune your car. We mentioned all the things
that go into tuning a car. Valve timing, ignition timing,
air fuel ratios, and more. And now, these things are
determined by a computer. Tuning programs the computer
to optimize engine performance by changing any or all of these variables. Let’s look at that torque curve again. With old school tuning, you could change an engine’s performance but you’re really only gunning
for the best performance right here. Big cams, open valves, lots of variables, lots of gas. When you’re jetting a carburetor, you’re tuning it for this spot. When you tune the distributor, you’re tuning it for this spot. And everything else was off. But now, because so many things are controlled electronically and
valve timing can be varied, we can change things like ignition and valve timing without changing hardware and make it better at different RPM. So we can’t do too much
to this part of the curve because that’s where the
engine performs best. What we can do is fudge some valve timing. Intake fuel injection. In ignition to make it look
a little bit more like this in the low end. Budge a bit more and make
a little bit like this in the high end. With engine controls, we’ve
widened our peak performance from about a 15 RPM range
to a 400 RPM window. That’s… pretty good. The spark in the cylinder
is kinda like a wave. It got more force as it gets going. We wanna make sure we’re
getting the most force to the crank when we got the
best mechanical advantage. As the speed in the engine changes, the point where this optimization occurs changes as well. And that is why ignition
timing can be so important. In the early days of electronic tuning, people had to figure out what
meant what in the ECU coding. So they changed half the values in the ECU and see if it changed safe fuel. If it didn’t, they changed
the other half of values and it would change fuel. Then they’d just keep changing
half and half and half again and again until they found the value that affected fuel. Then they’d have to start all over again to maybe find ignition timing. Crazy. Nowadays, all that legwork’s been done. And it’s easier to know what
to change in your ECU’s coding to change what you want
in the engine performance. I mean, not for me. I don’t know how I could do that. Other ECU tweak seek
out performance without adding physical mods would
be raising rev limits. Fiddling with launch control settings and removing undefeatable traction and stability control programs. But don’t screw around with these things unless you really know what you’re doing. The people who do know what
they’re doing are really good at it. I’m talking like Beautiful Mind stuff. You shouldn’t tune your
engine unless you’re a professional engine tuner. If you wanna try around with
a car you’re not gonna try, do it as a hobby. There’s guys who’ve been doing
this since the early days of ECU. And they’re still learning stuff. Whoo, that’s a lot to talk about. You wanna take a break, click
on the subscribe button. So how do we know that all
the variables were changing? In fact, what’s happening under the hood? We go back to the OBD. This is a FIXD OBD II reader. But the guys that fixed are
constantly pushing to see how intuitive they can
make these interfaces. This transmits live
data from your car’s ECU to your phone or tablet. So when the car’s running,
it can display and record a ton of data. After you apply a new
tune with FIXD live data, you can closely monitor and … All of these things are
tractable and recordable and mappable with FIXD. That helps you make sure
your new tune is safe for your vehicle. And if you think there’s any improvements that can be made in the app, you can let the developers know. They’re constantly looking
for ways to make it better for people who use it. Ann OBD II reader can also
cue unit of things that are hurting your performance
outside in the tune. If one of your sensor’s is
malfunctioning or clogged, it’s gonna screw up your performance because the ECU doesn’t
have an authentic picture of what’s going on. You don’t use these OBD
sensors to tune the car. You need a separate computer for that and big brains. But an OBD II with a good
interface will let you know what’s going on inside
of it from the tune. But what about those chips? They’re clean, they can
eat you out an extra 25 or 50 more horsepower
without doing anything else. Look, most car companies are
factory tuning their cars for optimum performance
about a wide powerband. They want you to have
a well performing car. Unless you’re adding some
hardware and like a blower or maybe NOS injection, there is no way you’re cranking out an extra
50 horsepower from ECU alone. If you have hardware
like intake, an exhaust, or headers, injectors, well, the engine’s gotta be recalibrated and that is where tuning comes in. So a chip with no hardware? It’s bad news. Hardware with no tune? You’re in trouble, buddy. Good tuning companies use
in cylinder pressure sensors or knock sensors to keep
from blowing things up. Good tunes are warranted and tested for thousands
of miles and tracks. Tuning. Click the subscribe button
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mentioned FIXD in this episode. And that’s because this episode
is brought to you by FIXD. I also think it’s a
pretty cool OBD II reader. Go to fixdapp.com/donut and enter donut at the checkout
for 10% off your order. Click the link in the description
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