Base tune, what does it do?

[Kor3y101]

So before I get flamed for posting this;

I understand the point of a Base tune after a Big Turbo upgrade is to protect the engine from damage. But I just don't understand HOW it does this. From all the searching I have done, it just seems to be a matter of "get a base tune; Okay" and that's all that's said.

Now I'm going BNRS3 in a month once it finally arrives, and I am currently E-Tuned by a local so I will obviously get tuned again, but I want to understand how and what it does. I have been told/read to NOT start the car at all until a base tune is made. What damage can occur if it is started without a tune? Not that I'm going to do it. But once again, I just want to understand and know what is being done to my car for performance/to protect it.

If this is just a obviously stupid question and someone has a thread for me to read, by all means go ahead an destroy my couch.

Thanks Guys.

[SarcasticOne]

Calibrated for your intake/map sensor
Set to base spring pressure so that you don't get too much boost
Timing reduced so it's nothing bad

[Kor3y101]

Awesome! Thanks for that. So it really is just the simple reasons. Makes things easier.

[mituc]

A base tune will have lower limits as well as targets. It also comes with tables populated with values that are generally known to work such as the MAF calibration vectors and the WGDC tables, so that after a few WOT pulls a tuner will understand the deviations and the potential of your setup even if because of the tune the engine will not make big power.

So this is how you can make yourself a base tune:
1. start from a stock tune;
2. change the MAF calibration table(s) to match your current intake;
3. zero the WGDC tables so that the turbo will boost up to the spring rate of the wastegate;
4. put in some conservative timing tables such as the factory timing tables or taken from a 91/93 octane stage1 OTS map or better from a factory map;
5. leave all other limits (rev limit, throttle reduction and fuel cut boost, load and speed limits) as they are just in case something is hooked up incorrectly, leaks or gets loose.

If you can change yourself your current tune you can run that no problem with zeroed WGDC tables. If you can't change your tune or flash yourself one then you will have to baby the car until you get tuned again, because the factory turbo WGDC tables applied to a BNR can result in unpleasant situations, and even though in the end you will probably end up with about the same tables some other things may get changed in the tune after changing the turbo.

So this is how a base tune protects your engine: by implementing the factory stress limits for your engine and limiting the torque ramping as much as possible by not actively upping boost or timing, and by giving you time to observe any potential issues which may be caused by overlooking things after working on the engine bay or simply issues that you've had and were not visible prior to the latest work done on the car.

After you run the base map for a few tens of miles (or 150-200) and you feel like everything is good you can start doing some pulls and taking some logs to understand the MAF cal deviation, how much WGDC is needed to reach some certain load or boost values, to make sure there are no leaks or other issues (fuel pressure, sensors problems, engine bay rattling, overhearing or any other problems because there can be many).

[Kor3y101]

Originally Posted by mituc A base tune will have lower limits as well as targets. It also comes with tables populated with values that are generally known to work such as the MAF calibration vectors and the WGDC tables, so that after a few WOT pulls a tuner will understand the deviations and the potential of your setup even if because of the tune the engine will not make big power. So this is how you can make yourself a base tune: 1. start from a stock tune; 2. change the MAF calibration table(s) to match your current intake; 3. zero the WGDC tables so that the turbo will boost up to the spring rate of the wastegate; 4. put in some conservative timing tables such as the factory timing tables or taken from a 91/93 octane stage1 OTS map or better from a factory map; 5. leave all other limits (rev limit, throttle reduction and fuel cut boost, load and speed limits) as they are just in case something is hooked up incorrectly, leaks or gets loose. If you can change yourself your current tune you can run that no problem with zeroed WGDC tables. If you can't change your tune or flash yourself one then you will have to baby the car until you get tuned again, because the factory turbo WGDC tables applied to a BNR can result in unpleasant situations, and even though in the end you will probably end up with about the same tables some other things may get changed in the tune after changing the turbo. So this is how a base tune protects your engine: by implementing the factory stress limits for your engine and limiting the torque ramping as much as possible by not actively upping boost or timing, and by giving you time to observe any potential issues which may be caused by overlooking things after working on the engine bay or simply issues that you've had and were not visible prior to the latest work done on the car. After you run the base map for a few tens of miles (or 150-200) and you feel like everything is good you can start doing some pulls and taking some logs to understand the MAF cal deviation, how much WGDC is needed to reach some certain load or boost values, to make sure there are no leaks or other issues (fuel pressure, sensors problems, engine bay rattling, overhearing or any other problems because there can be many).

Wow. Thanks for that! I appreciate it. I figured it would be the more obvious reasons. Now this just makes me more anxious for my Beaner to arrive haha.