Im really confused about the whole dyno testing/tuning. What is it exacly what is it use for what are the gains/lossed pluses/minuses. Please explain.

 

Dyno tuning is a great way to dial in your ignition timing and air/fuel mixture for the best performance. You start with a base pull then make changes to see what effects it has on your output. My engine was tuned on the engine dyno before I put it in my car so I didn't have to fool with a thing.

 

The tuning part is in the computer system is just you telling the computer "if you see (X) from the sensors then do (Y)"

Dyno tuning on a modern car in its stock form will not get you much. The tuner does not have his hands tie by the goverment so he can get a little more out of the motor. Most tuning on modern car is done after you have changed the engine in some way. Let say a tune gain you 12 HP stock and a you install headers afterwards and get another 12 for a total of 24 HP. If you install the headers first and take to get tuned now the motor is tuned for the header and the result could be 30 HP.

I think Pablo63 is talking about tuning an old school car. That tune is getting the carb setup right and the timing advance correct. In both cases "Tuning" a car on the dyno is always the best case cause you can check true results of what you just tuned.

 

so what are the costs of a dyno test/tune?

 

That will depend a lot of the year of the car but I have seen it for $250 to $400 for a basic tune. You can also buy a tune online. That is when you fill out a form that lists all your mods and a tuning company makes a educated guess at what tune you should have. Some of the guys here have used PCM for less and have been happy with the results.

http://www.pcmforless.com/