What Is A Tune?

[newguy07]

Hey all. Going to be picking up the new truck tomorrow. 2007 NBS sierra 1500 with max trailering package (6L). I have picked up a lot of good info on here since joining the site last week but what the heck is a tune that I keep seeing mentioned? What do they do and how do they work etc. Thanks, I guess I am totally clueless.

[grimmysnr]

Basically, every new car has a computer that controls every aspect of the vehicle. When i say everything i mean if this brain fails the vehicle will not operate. It controls timing, fuel trims, injector firing, spark, and hell it even controls your radio.

 

GM programs these computers to mix fuel and air to run the motor. But they program them for a happy medium of fuel economy, emissions, and power. Well some folks on here do different things with their truck. Some people want better fuel economy so therefore you take away horsepower to gain gas mileage. Some folks want more power (who doesnt?) so they program the computer to add more fuel to make more power. You can program the computer to change shift points for better shifting or take away the speed limiter (governor).

 

Essentially, the computer dictates how the vehicle operates. The programming GM uses is generic and doesnt take into account the different elements that these vehicles are subjected to. For example, you get the same programming if you live 10k feet above sea level as the guy who lives in Gulf and is below sea level. When you increase altitude the air is thinner therefor it takes more air to mix with the fuel. So people get these tunes that suit them and their application.

 

Hope this makes sense. All that happens is somebody will hook up to your computer and change the code to what you want yout vehicle to do. More power, better gas, and better drivability.

[newguy07]

anyone else? Does this void your warranty? Do you do it yourself, go to a dealer, or take it to some other mechanic somewhere? Is there any possiblity of it screwing up your vehicle?

[svensk]

anyone else? Does this void your warranty? Do you do it yourself, go to a dealer, or take it to some other mechanic somewhere? Is there any possiblity of it screwing up your vehicle?

Under no circumstances do you let your dealer know your getting one or have one. if you go to the dealer for whatever reason, just swap the old PCM (computer control module) out with the old stock one so they don't accidentally flash it back. Most dealers will tell you that they will void your warranty for anything that goes wrong if you have the tune. They will poo-poo tunes and say they don't do anything to discourage you from getting one. But, if you know the tech doing the work on your truck he might not care what you've done, but it's safe just to keep your mouth shut about if your under warranty.

The most common tunes on this forum are westers, wait4me, and wheatley's. You can also get a hand held scan tool that can load custom tunes yourself such has a predator or something.

If you really want your truck to come alive I might suggest a dyno tune at a performance/speed shop. However, the costs don't always justify it unless you do something drastic like forced induction or a new cam.