TIA
In: 639
Depends which tune you’re talking about. A tune up could be replacing and cleaning small parts to freshen up the vehicle. Or a tune can be changing the mapping of the onboard computer to make the car drive differently, by adding horsepower, turbo boost, throttle response, gearing.
Tuning works similarly to how you tune instruments, you’ll be trying to find the balance needed for optimal performance of optimal longevity. When you change your car parts, be it to improve performance or for better ride quality, you need to tune the basics of how the car runs so it’s more compatible with its existing parts.
Here’s a (https://youtu.be/LjZlAzr8MuQ) by Donut Media (man I miss the old Donut Media) explaining it more detail.
Essentially, there are certain points you tune more or less of, and now with computers, you can tune the car more precisely than you can before. Maybe it’s for peak power or maybe a longer power band meaning more power throughout the gear rather than just the best power for one instance.
When you tune the engine to increase power the goals are:
Increase air intake efficiency – free flowing air filter, bigger inlet ducts, smoother intake ports, bigger valves, camshafts that open valves more and for a longer period of time. Much more to it than size but this is a simple answer.
Increase exhaust efficiency – bigger diameter exhaust piping, free flowing muffler, removing catalytic converter, smoother exhaust ports, bigger valves, high performance camshafts etc.
Increasing airflow must be adjusted for by increasing the amount of fuel delivered. That is adjusted in the ECU by flashing the new fuel map usually.
Ignition map can be adjusted in the ECU – advancing the ignition timing (firing the spark plug earlier) makes more power, up to a point. Too much advance causes detonation which is damaging to the engine.
Why isn’t it done from the factory?
Factory needs to balance fuel economy, noise, pollution and power. Also they need to manufacture parts quickly and cheaply, which leaves room for improvement in many areas, but this is mostly in the cylinder head. Longevity is also a factor. That’s why all of these improvements that I’ve listed have their drawbacks.
Free flowing air filter – more dust can go through in the engine, decreasing lifespan. Bigger valves and inlet ducts increase power at the top end of the rev range, while reducing efficiency in the lower rpm range, reducing day-to-day drivability and fuel efficiency while increasing pollution. Same story for the performance camshafts.
Exhaust – same story – bigger is only better at the top end power, not for daily drivability. Removing catalytic converter is illegal as it increases pollution by a big margin. Free flowing mufflers are louder, sometimes so much that it makes the car illegal to drive on the street and even some racetracks.
Fuel injection – factory ECU is tuned to balance pollution, fuel economy and power. Increasing power and engine responsiveness comes at the expense of more pollution and worse fuel economy. It is actually possible to increase fuel economy, but at the expense of increasing very harmful NOx pollution and very poor engine responsiveness.
Ignition advance – advancing ignition leads to higher temperatures and pressures inside the engine, decreasing longevity. It can lead to detonation and destruction of the engine. The higher temperature inside the engine also leads to increasing very harmful NOx pollution.
People who tune their cars and bikes for power are okay with increasing pollution, noise and decreasing longevity.
In a general sense it’s modifying the car to increase performance in some aspect, more strictly it’s adjusting the “settings” of components to increase performance.
It varies.
During the old times, pre-computer, a ‘Tune’ up consisted of replacing worn parts (points, plugs, belts, ignition wires, etc), tightening anything that was loose, adjusting the timing and gapping the sparkplugs. (Ensuring the gap the spark jumps across was optimized for the type of gas you’re using and your engine).
Some of those are still relevant (replacing belts, wires and gapping sparkplugs), but most Tune Ups are computer-based.
Now a ‘Tuned’ car usually refers to a car with many aftermarket replacement parts with the sold purpose of making it go faster.
Well, a few things. I use Holleys ECU in a few cars I built. From there I can completely change my fuel and timing map. I have outputs on it that I can assign to do different things in different conditions. I can adjust my traction control and how it behaves. Boost pressure and how much fuel pressure it needs per the rpm level. So very much you can do with it. I can even do a “Boost by gear” where on lower gears I’ll have lower boost and eventually it ramps up with higher gears so the movement of your car combined with traction control is so much more efficient
This is most common with turbocharged or supercharged engines.
Basically, a turbo or supercharger is like an air compressor that injects highly compressed air into your engine so that you can burn more fuel, and therefore, create more power.
A tune is usually adjusting the levels of air compression (boost), the amount of fuel (over various RPMs) and the timing of a few other things to make the engine produce more power.
Tune up? You can tune a lot of different parts and most places let you pick and choose. You can also get your pedal bike tuned. This helped me understand tune ups.
Car manufacturers have to deal with the EPA and emissions. So they tend to mess with the fuel to air mixture such that it passes all the EPA tests, but tends to rob the engine of power…. Think “efficiency over power”. When you tune the car, you adjust how much fuel and air the engine is getting, at what exact moment the sparkplug fires, and even b the maximum turbo boost such as to maximize it’s power output, instead of the efficiency settings that the manufacturer set it to.
When you tune a piano, you are adjusting screws that tighten and loosen the piano wire. Engines are exactly like this, except not. They are full of little mechanical components (and an electrical one, the computer, I will mention later) that can be adjusted and cleaned, replaced and removed. Engines are also incredibly intricate machines, where the exact amount (down to number of molecules) of reactants matters, as well as the timing of the various cycles down to microseconds can affect performance. So when you tune, you are effectively doing exactly what you do to a piano. You are adjusting the parts so that the perfect amount of air, gas, timing, etc are in each cylinder at the perfect time so that the engine runs as efficiently as possible. No it doesn’t have to do with power, you don’t tune to get more power, you tune to make it work better. This will increase power as you are getting more complete burns and extracting as much energy out of the burn as the engine will allow, but that is not the point of a tuning.
Now, some things are obviously not possible with current tech in any practical sense. So really it’s just about getting it good enough. Additionally, most easily controllable things on your modern car is run by the CPU, so timing is usually adjusted in there. You often aren’t replacing or modifying physical components when doing the tuning, just adjusting the timing on things the CPU controls, electronically. You do still need to adjust some things physically, so it’s not entirely electronic now as some here have been implying. The computer can’t tighten a screw for you after all.
The point of a tuning is to make the engine parts you have work at their best level, so if you get a new air filter or compressor or spark plug or something, you will need to tune the engine after it is installed so the new part works properly. Imagine having a piano and you get the new and improved titanium wire, guaranteed to blast your enemies ear drums with a small key press ™!!1!!1!. You now still need to tune that wire so it is, wait for it, in tune. Sure the power could be better on its own, but it will sound awful unless you tune it!
The tldr, you can’t tune for power, you tune for efficiency. Adjust those screws and nozzles and such until the engine runs nicely and efficiently.
Latest Answers