What are the advantages and disadvantages of chip-tuning a car?

That's a piggyback chip.
Not worth it, a decent retune would do better and more reliably.

is it hard to burn your own chip?
does retuning factory ecus make standalones pointless?

Depending on the car, making the engine race harder than it was designed to could be hard on the entire drive train including the transmission

>>16787894
If there's the ability to retune a factory ecu then there's no need of a standalone. Most ecu's haven't been cracked because there's no point but a lot of the performance car ones have.

>>16787884
Don't use piggyback systems that send fake signals. The ECU will just compensate for the changes.

Generally speaking remapping the factory ECU is best. Standalone is only if there's something that you need that factory ECU can't do. Almost never the case.

>>16787891

>>16787884
The build quality and reliability and specs of a factory ecu are far better than standalones unless you're fitting a proper motorsport spec one.

>>16788313
this is the most valuable piece of knowledge i've gotten from this place

thoughts on doing it yourself?

>>16789967
You'll need to know exactly what you're doing before you go moving numbers around

>>16787884
Standalone is superior 100% of the time.

>>16789967
Unless you have a dyno you won't really know what timing is needed. Don't tune for knock by ear, light knock is basically not audible. Ideally you would use a pressure sensor in the cylinder to detect knock but you can use a knock sensor with frequency filtering and crank angle filtering along with noise filtering to get close. As a general rule back off 1% of torque from the knock threshold for safety.

For a street car stick to MAF based fueling to improve open loop steady state performance. For transients MAP is better. Some stock ECUs use both. If they do, don't delete either sensor.

There is a ton of stuff to know about how to map an engine. EFI University has some documentation. You can do it yourself if you're dedicated. Start conservative with rich mixture and retarded ignition timing. Even if you let someone else tune it knowing what to look for will only help with due diligence.