[Rainfarer]

Hi, everyone

As I'm waiting for my MPVI3 to arrive I've been gathering info on how to tune the transmission on my 2016 V6 and so far I found a lot and nothing at the same time. My goal is to understand what parameters are responsible for what aspects of the trans behavior and to tune the trans for quicker and firmer downshifts. I have dug through the WeberAuto youtube channel as I was tuning my BMW X5 with 8HP45 so I have an acceptable level of understanding of how a transmission operates hardware-wise. But I have an XHP tune for X5 so I had only played around with a dumbed-down version of the tune via the XHP's iOS app.

Can anyone point me in the right direction on where to start with trans tuning specifically for 8L45? Thank you

[Rainfarer]

Originally Posted by david grayson

When it comes to tuning the transmission on your 2016 V6 with the 8L45 transmission, there are several aspects to consider. While I can provide some general guidance, it's important to note that specific tuning parameters and procedures can vary depending on the tuning software or device you are using.
Here are some steps to get started:
Research-Supported Tuning Software: Identify the tuning software or device that is compatible with your vehicle's transmission. Check if there are specific resources, guides, or forums dedicated to tuning the 8L45 transmission with that particular software.
Understand the Stock Parameters: Familiarize yourself with the stock parameters and settings of the transmission. This will help you understand how the transmission currently operates and identify areas you want to modify or improve.
Identify Tunable Parameters: Determine which parameters are available for tuning with the software you are using. These parameters can include shift points, shift firmness, torque converter lockup, shift duration, and more. The specific names and options may vary depending on the tuning software.
Determine Your Desired Changes: Decide on the changes you want to make to the transmission behavior. In your case, you mentioned wanting quicker and firmer downshifts. You may need to adjust parameters related to downshift timing, shift pressure, and torque converter behavior to achieve your desired outcome.
Take Incremental Steps: When making adjustments, it's generally recommended to make small incremental changes and test the results. This allows you to evaluate the impact of each adjustment and avoid making drastic changes that may negatively affect the transmission's performance or durability.
Data Logging and Analysis: Utilize data logging tools and features provided by your tuning software to capture and analyze transmission performance. (BMW M114d) This can help you assess the effectiveness of your tuning changes and make further adjustments if necessary.

Thanks, but I'm already familiar with this generic info. What I'm looking for is info on the exact case - tuning 8L45 with HPTuners VCM editor with detail breakdown of parameters description, etc.

[arpad_m]

Originally Posted by Rainfarer

Thanks, but I'm already familiar with this generic info. What I'm looking for is info on the exact case - tuning 8L45 with HPTuners VCM editor with detail breakdown of parameters description, etc.

No point in reasoning with a bot.

I'm not aware of any free database of detailed tuning information on the 8L45/8L90. Tuners, understandably, will not create one, and GM even less so.

If you don't want someone else to tune your trans, I'd just download samples from HP Tuners' repository (it's under your account) and compare it to stock, read their scant parameter descriptions or documentation where exists, and figure it out via trial and error. For example, the first tune in the screenshot below is a complete one for the 8L45, that is, it has a TCM component as well, so that's a good candidate.

[Rainfarer]

Originally Posted by arpad_m

No point in reasoning with a bot.

I'm not aware of any free database of detailed tuning information on the 8L45/8L90. Tuners, understandably, will not create one, and GM even less so.

If you don't want someone else to tune your trans, I'd just download samples from HP Tuners' repository (it's under your account) and compare it to stock, read their scant parameter descriptions or documentation where exists, and figure it out via trial and error. For example, the first tune in the screenshot below is a complete one for the 8L45, that is, it has a TCM component as well, so that's a good candidate.

Yeah, I kinda figured it out, but it never hurts to be polite and answer.

As for the HPTuners stuff - thanks. It was my first guess to run through the examples and stock tunes, but it will be ~3-4 weeks till I get my MPVI, meanwhile "The Tune Repository is available to users that have 1 or more devices in their My Devices list." Is there anything, in particular, you would recommend to school me with while I'm waiting?

[arpad_m]

Originally Posted by Rainfarer

Yeah, I kinda figured it out, but it never hurts to be polite and answer.

As for the HPTuners stuff - thanks. It was my first guess to run through the examples and stock tunes, but it will be ~3-4 weeks till I get my MPVI, meanwhile "The Tune Repository is available to users that have 1 or more devices in their My Devices list." Is there anything, in particular, you would recommend to school me with while I'm waiting?

That would be pretentious, I have only a basic understanding of the implications of line pressure, slip, timing etc. parameters, so I'd leave it to the pros in this forum.

The one thing I certainly know works well for the 8L45/8L90 across trims and power levels is setting the TTC slip tables to 0 to prevent the trans from shuddering, you'll find them under Trans > Torque Converter > TCC Desired Slip > AC Off xxx > set all values to 0; if you use DoD (AFM), set the DoD tables here up the same way as well (or you can just set them regardless of AFM state for good measure).

[Rainfarer]

Originally Posted by arpad_m

That would be pretentious, I have only a basic understanding of the implications of line pressure, slip, timing etc. parameters, so I'd leave it to the pros in this forum.

The one thing I certainly know works well for the 8L45/8L90 across trims and power levels is setting the TTC slip tables to 0 to prevent the trans from shuddering, you'll find them under Trans > Torque Converter > TCC Desired Slip > AC Off xxx > set all values to 0; if you use DoD (AFM), set the DoD tables here up the same way as well (or you can just set them regardless of AFM state for good measure).

Thanks, that's a good starting point. As for the DoD/AFM - I actually wanted to make it more agressive on Snow/Ice program so I could have a some kind of Eco mode. Does it make sense? Could AFM be tuned for Snow/Ice at all?

[arpad_m]

Originally Posted by Rainfarer

Thanks, that's a good starting point. As for the DoD/AFM - I actually wanted to make it more agressive on Snow/Ice program so I could have a some kind of Eco mode. Does it make sense? Could AFM be tuned for Snow/Ice at all?

That would be a no unfortunately, DoD/AFM is a global feature and has no mode-specific on/off switch. (As you can see from the screenshot, it's turned off on my car.)

However, the transmission has many features you can tune separately for each drive mode, and from what I see, the engine torque model also has DoD+mode specific settings. You need to talk to a real tuner at this point, or be willing to experiment on your car

[Rainfarer]

Originally Posted by arpad_m

That would be a no, unfortunately, DoD/AFM is a global feature and has no mode-specific on/off switch. (As you can see from the screenshot, it's turned off on my car.)

However, the transmission has many features you can tune separately for each drive mode, and from what I see, the engine torque model also has DoD+mode specific settings. You need to talk to a real tuner at this point, or be willing to experiment on your car

Thanks. I'd like to talk to an actual tuner, but that would be complicated - I'm from Kyiv, Ukraine, and our local tuners' level is way behind yours (we're talking astrology, Taro reading, and voodoo magic level). I know only a couple of guys who really know what they are doing in terms of scientific explanations of the consequences of their actions, and none of them are doing GM. We have a couple of guys that tune GM/Dodge/Ford but I'm yet to meet them and meanwhile I'll be learning stuff on my own

[arpad_m]

Originally Posted by Rainfarer

Thanks. I'd like to talk to an actual tuner, but that would be complicated - I'm from Kyiv, Ukraine, and our local tuners' level is way behind yours (we're talking astrology, Taro reading, and voodoo magic level). I know only a couple of guys who really know what they are doing in terms of scientific explanations of the consequences of their actions, and none of them are doing GM. We have a couple of guys that tune GM/Dodge/Ford but I'm yet to meet them and meanwhile I'll be learning stuff on my own

Goat Rope Garage on youtube has a tuning 101 series, that'd be a good start. The LGX isn't as widely supported as the LT1 and LT4, but I'm sure there are tips you can use even from his Gen V engine tuning tutorials, especially transmission related ones. Hopefully others can chime in with similar resources to help you get started.

Honestly, not sure about your financial situation, but likely the fastest way to get a working tune would be to contact a professional shop that does remote tuning without locking their tunes, you'll find plenty of references here in the forum. As an example, my car was tuned by Ted Jannetty from Jannetty Racing, I'm not sure whether or not he works with the LGX, but he does offer remote tuning, so it's worth an email or a call.

[Rainfarer]

Originally Posted by arpad_m

Goat Rope Garage on youtube has a tuning 101 series, that'd be a good start. The LGX isn't as widely supported as the LT1 and LT4, but I'm sure there are tips you can use even from his Gen V engine tuning tutorials, especially transmission related ones. Hopefully others can chime in with similar resources to help you get started.

Honestly, not sure about your financial situation, but likely the fastest way to get a working tune would be to contact a professional shop that does remote tuning without locking their tunes, you'll find plenty of references here in the forum. As an example, my car was tuned by Ted Jannetty from Jannetty Racing, I'm not sure whether or not he works with the LGX, but he does offer remote tuning, so it's worth an email or a call.

Yep, I'm already half through GRG videos and I like the guy's attitude towards tuning and the way he explains stuff.

As for the Jannetty Racing - thanks, I've heard of them on this forum. I'll dig around a bit on what they do and examples of their work