Hu well thats promising. Better start saving for a new transmission. lol

 

 

Looks like it works with any tune..$2.480. I wonder if its a flash? IIRC the tcu is inside the transmission.

 

 

Yea, that is shocking! Next question is it flashed through the OBD?

 

The TCU Upgrade is a flash through the OBD2 port. Due to the fact that special tools/interfaces are required, the upgrade was for the first year only available at our HQ in Stuart, FL. That's the reason why there are not too many reviews out there.
Since then we extended the availability to selected RENNtech dealers.

If someone is interested in the upgrade, we can work with a dealer close to get the tools there.

 

Honestly that makes sense. From what I gathered from another site, GAD has been doing TCU reprogramming from the onset with no issues breaking into the actual unit. One guy even insinuated it was not much different from the TCUs of old (hacking and reprogramming). The problem was the location and access to the actual unit. MB simply made it where reprogramming was to be done via OBD (like they do the the current ECUs) and this effectively stumped the aftermarket with no way to bypass whatever security protocols MB has.
I bet if you are willing to drop your trans and remove the unit, most tuners will be able to reprogram your TCU for you. But if you want to program via OBD port, well seems Renntech is the only game in town

 

It’s hard to believe Renntech or GAD when none of their cars can prove themselves in the 1/4mile...

 

It is not done via OBD.
A few years ago this tuner from Germany was in Houston and I watched him flash a few TCU for the 722.6. The car goes on the lift and the electrical connector going to transmission is disconnected and the flashing hardware is connected to re program the TCU.

 

VGS3 TCU's could always be read and flashed by Vediamo if you had and SDS. In fact that was a feature of the VGS3 by design. I would say the delay in having something for performance tuning was on the SW editing side by getting the DAMOS or definitions for the tables fully defined from the ROM. There have been a few vendors who offered the ability tune the TCU shift characteristics for some time. Specifically clutch fill rates, volumes, and pressures by shift transitions and TCC lockup control. These were marketed to transmission rebuilders, mostly in Europe, to tweak the the "comfort" characteristics of the non AMG 722.9s. What they didn't have was overall line pressure control, torque management tables, shift speed/rpm and AMG specific mode settings included in the editors.

This type of control is common in GM/dodge/ford world through SW like HP tuners. All modern clutch to clutch style transmission operate the same way. Apply pressure and volume of fluid to a clutch or brake basket at a certain time to switch gears, with torque mgt acting like a nanny to keep things from breaking. Even a moderately powered car can break transmission parts without some TM in place. The balance is in tuning the shift timing, pressures and volumes, shift points, against hard parts in your trans. Even if we could remove all TM, the problem just moves down the line to hard parts.

That diversion from the thread topic aside, If RT has the editor capability, and the access to the correct tables, there is no technical reason they can;t do what the say. RT has lots of connections via Hartmut, so if anybody can get access to the information needed they can. I Think the price is a little high for the target market since most people entertaining this upgrade are people tuning older models now, not new 200K S classes, so if this was like $1500, and we could customize shift points and overall line pressure, I'd be down in a heartbeat. RT if you're looking for testimonials, happy to try it out... ;-)

 

Is there a dealer close to Chicago?

I know the TCU is inside the transmission. Is there a reason that it can not be done via OBD?

 

The TCU can 100 prevent be flashed via OBD2. The move to embed the TCU on the mechatronics of the valve body assembly was to limit the physical distance between the controller to the solenoids on the VB. This decreased the time for Signal to reach them and improve shift times. There are bench flashing adapters that you can connect to the trans VB plate to directly flash as well, but because of the design move to put the TCU on the VB, OBD flashing was also a major design consideration. I have no doubt RT can Flash this. How will it works on the average car is tbd.

 

Hopefully RennTech can step in and add more comments. I have looked through their website a few times, there is no mention of the TCU work. It would be nice to have a couple of bullet points. What parameters are changed? Shift points? How much change is there in the TQ management system? Daily drivability? Are the parameters changed in C, S, and S+ ? Is this dealer detectable?

It's good news regardless, nice to see a little development for the platform. I am sure there is not a ton of AMG owners that even consider "modding"

 

Let's keep this thread going. This has to be the #1 (or close to it) performance issue on this forum. It would be great if someone would contact RENNTECH directly and get a full overview of this. As far as dealer awarness of this , my dealer in Eldorado Hills CA is a RENNTECH authorized provider ( I believe ) but would rather hear it from RENNTECH directly. Obviously trans life would the most important issue, along with any change in driving characteristics. This would/should be a gold mine for RENNTECH just from this forum alone. Anyway let's keep this going until we get to the bottom of it. Be safe.

 

 

So...the issue that you guys have with the M157 platform is that the tranny doesn't allow you to launch hard enough to get a solid ET to match the power at the engine, or the tranny generally limits overall torque to the wheels when in gear, regardless of what the engine can make on a dyno?

Therefore...you guys are keen to have the TCU programmed so that torque limiters stop spoiling the fun either from a launch, or when in gear?

Apologies for sounding like a noob. I'm just trying to understand the issue here. I'm also interesting in tuning my TCU, but with M156 engine - I want to alter the gearing of the ring/pinion ratio, but it's the software which I need that's hampering my progress.

Also...is it unusual for a tuned M157 to hit low 11s (like an 11.1 or 11.2) or high tens in the standing quarter?

 

 

First of all, the TCU Upgrade promoted by us is for the 722.9 Seven Speed Transmission. On the 722.6 Five Speed TCU, it is physically removed and programmed on the bench.

--> Axel's Automotive, details via DM


As mentioned above by @KLR CLS, the TCU is flashed through OBD2 with a special interface/tools. Our upgraded TCU Software includes removal of the lower gear limits, increase of the torque tables and increased line pressures. Shift points remain stock (since the power drops off before redline anyway, there would be no gain in increasing shift points). The Upgrade does not effect daily drivabilty, but the improvements are noticeable in all driving modes. We've been upgrading 722.9 TCUs for 2+ years with great success and zero issues...these transmissions are incredibly sturdy!

If someone wants to come to our HQ in South Florida and wants to do the upgrade, we're happy to take them with us on our next track day in order to get their own before and after results.
As most of you know, we've been in business for over 28 years and always published before and after results - either from VBox or track testing. These results are always averaged and not based on one time extreme results.

 

wait.. so there's finally a Trans tune for the 2012+ E63 models?

 

Thanks Mike,

Yeah I tend to see a lot of stock M157s over here making 480rw and then gaining around 100 from a tune, so they're certainly capable cars. The 2.65 rear end kinda sucks though, but then it's probably what keeps the majority happier and safer with traction.

I'll keep an eye on this thread and see what comes of it. Finally....looks like you guys are about to get your wish...fingers crossed for you all.

 

Thanks a bunch for stepping in and answering questions!

 

 

The solutions to most things MB/MB tuning.....buy it, try it, answer your own questions, repeat your findings on a forum, get accused of not knowing what you are doing/saying on said forum, eventually get vindicated a year later when everyone else who bought it also says similar things....

 

lol....that actually does tend to happen around here. I've seen it myself over the years.