I made this guide back in March 2010 and posted it on my "home" site. You'll notice that the guide has been designed around the 2004-2006 GTO but the principals remain the same for other vehicles with the 4L6x series. The response has been positive. Time to post it where I learned all the information in the first place and see what the pros think. Thanks!
Disclaimer: Myself (CoolAid) as well as hptuners.com will NOT be held responsible for nor claim responsibility for damage to a vehicle or loss of any warranty coverage from members or guests that use this GUIDE. Use this How To as a guide and reference ONLY. Do not directly copy numbers or values into your tune from this write up without knowing what you are changing first! That being said, every vehicle is different. As such, every driver is also different. Expectations of driveability or performance will VARY so once again, use this write up as a GUIDE and adjust your tables and tune to suit YOU and your goals/expectations.
I'll be using 2.23 BETA for this write up which isn't generally available for the mass public yet.
The current stable release listed on the site is 2.22, so you may see some tables or variables in my pics that don't completely match up with yours if you using 2.22. The general idea remains the same however. TCC apply/release speed is TCC apply/release speed across all platforms. The tunes I will be comparing in this guide are my bone stock 2006 GTO A4 file and my former bolt-on modified file.
My trans specs:
-4L65E fully built by Top Gear Motorsports.
-Stall: 4,200 billet 254mm (9 3/4'') single disk built by Circle D Specialties.
A little info to set the pace of this thread: My car is not a DD. I am going to use my tune/car as a reference in this thread and you may see some settings that are too harsh for a DD or "occasional" fun car. With me performance and reliability comes first, ride/shift comfort is a very distance after thought. That's what crappy beaters with good MPG are for. Anyway, lets continue.
First and foremost:
SAVE A COPY OF YOUR STOCK/CURRENT TUNE!. Lets make sure we have a back up tune if need be. I recommend emailing it to yourself just in case your laptop hard drive crashes you'll be able to access the file. I email all important tunes to my various emails for backup. The files are small and its easy and free insurance. Always name your tunes something different so you can differentiate them. I also like to create txt files containing any changes I've made to the tunes naming the txt file the same as the tune. I.E. Stock1.0.hpt for the tune and Stock1.0.txt for the notepad txt file that you mark down what you've changed. HPT has a history, but nothing is more detailed than your own personal account of things.
Speedometer Check:
In this section we make sure the speedo is in check. Most of the trans settings rely on MPH input in order to function so we need to make sure your current rear tire height is in on par with reality. First go to your tire manufactures website and notate the exact height of the tire you use. For me this is a Nitto 555R 275/45/17 DR that is 25.63''. So we need to click the "Speedo" button on the toolbar and enter the correct tire size into the box, correct rear end gear ratio into the box (stock is 3.46) and click "Commit". This will help to dial in your speedo correctly so that your MPH values reflect real world numbers.