Jump to content

4l65e tuning question


Recommended Posts

ive been playing with hp tuners for a months now and wanted to play with my trans tune a bit.. ive already adjusted my torque management a bit ,but wanted to know what tables needed to adjusted for shift speed and firmness ,wanted to ask before adjusting anything without knowing...sorry for the newb questions,

thanks for any info

Link to comment
Share on other sites

Transmission tuning requires 2 parameters to be met before it shifts. The 2 parameters are the speed (MPH) at which you want it to shift and the rpm. First time adjustments just try little steps at a time. Here is a good instruction to give you a basic idea to use when doing so that I have used in the past when learning. Otherwise go to the HPtuners forum and they have lots of good info and how to's... This is not my write up but will give you a general idea...Keep in mind this is not for our trucks or transmission so the rpms and speed they use wont be the same and some of the options will be different. A lot of trial and error just do small increments. Do so at your own risk... Baby steps I repeat small baby steps

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.
Shift Point Tuning:
In this section we will deal with shift point tuning. This can be very hit and miss. Just because you set a certain value does not guarantee that the trans will shift at those EXACT values. It usually varies a hundred or so RPM and a MPH or two. The goal here is trial and error (without going to jail trying to dial it in!). Set it, test it. If its fine then great. If not, adjust accordingly to your taste. First off the A4 needs to satisfy TWO variables before the shift is made. 1) RPM 2) MPH. Lets say you have a 1>2 (meaning 1st to 2nd gear shift) set at 6,400 RPM and 40MPH. When the engine gets to 6,400 RPM then trans will generally wait until it hits 40MPH before commanding the shift and vise versa. You'll want to give yourself a smidgen of room here since it takes time for solenoids to activate, springs to move, fluid to flow...etc. I.E If you want out at 6,500 at 40MPH try setting it at 6,350 and 37MPH, it might just bang out right where you need it. If not, readjust. A common mistake people make in this area is just addressing the WOT shift points. It is important to increase/decrease the part throttle values by the same % as the WOT values
. Computers can be finicky and if everything isn't set up right you may just find yourself banging the limiter searching for that perfect shift and all the while the problem is in the part throttle tables. Something to use that usually gives good luck on predicting where to set shift RPM so it correlates with MPH is the VCM scanner. First do a few log runs with the car with the VCM Scanner. Full pulls into 3rd (don't go to jail! legal areas only! Mexico seems to be a nice place to get away with this stuff secret.gif ). Notate where your trans is shifting out at: (This pic is from a modified tune with built trans and DRs, not stock)

Now lets apply our new found info to the tune. Click on the "Trans" tab on the toolbar and under the "Auto Shift Speed" tab find "Full Throttle Shift Speed Normal" and click the "Normal" tab and you'll see something like this (stock file in this pic):

I like to set the MPH low, and let the RPM be the trigger spot for the shift and you'll see this in my tune. Meaning, I like to get the MPH variable satisfied so that the TCM just waits for the RPM to hit and then bang (remember, 2 variables needed, RPM and MPH) A good 4-5 or so below actual MPH is a good buffer for MPH variables. Don't set it too far off though. If its too far off it may miss the shift. I.E. if you have the MPH set at 70 and the shift should occur at 86 its too much of a discrepancy for the TCM to decipher. Try to keep it close +/- 4 or 5MPH max. Remember it probably wont hit dead nuts spot on either RPM or MPH due to the things I mentioned before (internal part actuation...etc). Now lets change that variable to reflect what we need. We will need to do this in "Normal" and "Performance" or "Pattern B" (if using 2.23 Beta).

Also, we need to adjust the downshift MPH by the same percentage that we adjusted the upshift MPH. Although, the uphift MPH has to remain higher than the downshift MPH. You'll see how I modified those variables as well. Notice I added about 2-3MPH to each upshift point except for the 3>2 downshift. This is where further custom tweaking comes in. For me, I dont want my trans downshifting into 2nd gear at 79 MPH if I go WOT or manually pull down because I feel it is too close to the shift out point and dont want the engine screaming for a second before it shifts. It generally feels like its holding back and slower when the downshift is really close to where the upshift is. Id rather just stay in the gear Im in (this case 3rd) and continue to climb. Adjust to your tastes.

Now we need to go into "Part Throttle Shift Normal" to adjust a few things:

Now we need to copy over the 100 (WOT) values from the Full Throttle Shift Speed area to the Part Throttle Shift Normal. In my readings, this isnt 100% mandatory, but many good tuners like to make them match up so the TCM doesnt have any variance issues and I like to follow suit with that idea so here goes:

Now that we have that squared away its time to tackle RPM. This one is pretty straight forward and if you've set up your MPH correctly and have given it a 4-5MPH buffer before actual you should be able to get your RPMs to hit pretty close. If not, like anything else, adjust accordingly. Lets start off by opening the "Full Throttle Shift RPM Normal", "Normal" tab and the "Performance" or "Pattern B" (if using 2.23 Beta) tab as well:

Now adjust the values to your liking:
Now I usually punch out of first around 6,300 and 2nd and 3rd at around 6,450-6,500. This is where that variance stuff comes in. Since I know I'll have a small but of time before actual shift, since I want the 2nd and 3rd out at 6,500 I've set them to punch in the tune at 6,300. This mixed with my MPH settings have worked for me. You will need to test and tune them to your flavor. That pretty much wraps it up as far as shift point tuning. If I've left anything out of this section feel free to comment and I will add it in.

Shift Pressures:
As far as shift pressures go I leave them at stock levels and so do many of the major builders/tuners out there. The stock levels in the GTO are max @ 90psi and are plenty fine for quick shifts. The correct way to increase shift pressures is mechanically with a shift kit. The kit will include pieces that are built to handle the increased pressure such as different springs and metal parts that replace plastic parts I.E. the boost valve. Beyond this people who boost up the pressure through the tune are risking mechanical failure for no great reason. If torque management is gone 90psi is plenty of pressure even in a stock trans to make a quick shift. Remember: its not about how HARD the trans shifts, its about how QUICK it does it. That old school nonsense about a trans that slams the tires in every gear and hits hard on shifts is just that. Nonsense. My trans is very smooth and while it definitely hits and lets you know its there, its emphasis is on speed rather than force.

Edited by 2003_SuperSport
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...