Talk | MCT 722.9 TCU TQ limiters.
The only problem for some people now, myself included is I really don’t know if the tune is underrporting tq values or not. It’s quite an aggressive tune so there is a big chance it is, but maybe even so it will still work as it’s tuning a separate control unit.
The only problem for some people now, myself included is I really don’t know if the tune is underrporting tq values or not. It’s quite an aggressive tune so there is a big chance it is, but maybe even so it will still work as it’s tuning a separate control unit.
If you get the TCU tune and it doesn't work they will refund you the entire amount. During the test drive following the tune it will be readily apparent if there are issues.
Most of the tuners in the AMG world, or at least the ones I've dealt with, have been correctly reporting torque so it hasn't been an issue. Quite a few of us are running pretty aggressive ECU tunes with zero issues.
i was under the impression before that the same company has to make both tunes in order for the TCU and ECU to properly communicate in harmony.
The only problem for some people now, myself included is I really don’t know if the tune is underrporting tq values or not. It’s quite an aggressive tune so there is a big chance it is, but maybe even so it will still work as it’s tuning a separate control unit.
The TCU tune will still show great gains, but to be as efficient and get the most out of it, the ecu tq reporting should be 100% accurate like oem, so the ecu and tcu can work together now, again, like oem

Some tuners under report more than others, and of course there is a limit to how much you can under report..
Slight under reporting is fine for stock turbo low HP, the higher the HP and more the lying, can cause issues like premature wear of the clutches and drivability concerns etc over the course if thousands of miles.
I am working on a few ways us customers can come to the conclusion of what are tunes are doing in this regard.. stay tuned

Boost is not an absolute with these engines. The ECU will use as much boost, or as little, as needed to meet power requirements. My knowledge stops there. Maybe one of the tuners can step in to add more back story on the mechanics of a tune.
While my boost was lower on this run, my trap speed was identical to previous runs... telling me the power levels are consistent.
My apologies, I know that was as clear as mud probably.
Boost is not an absolute with these engines. The ECU will use as much boost, or as little, as needed to meet power requirements. My knowledge stops there. Maybe one of the tuners can step in to add more back story on the mechanics of a tune.
While my boost was lower on this run, my trap speed was identical to previous runs... telling me the power levels are consistent.
My apologies, I know that was as clear as mud probably.
My best post TCU 60' time is 2 seconds due to tire spin. I'm still making an 11.1 @ 129 with a suck *** 60ft. If I can get my launch down and improve my 60ft my quarter mile time will follow.
The extra torque I have with my E50 tune may be working against me here.
I have three options it appears...
1. Have the TCU restrict boost in the first gear to reduce the amount of available torque...
2. Have Jerry redo my tune from the ECU side of the equation to make less torque
3. Buy a better set of tires....
.I think I'm going to try option 3 first, followed by option 1 if its still needed.
This 4 door executive saloon that I use for business may be rocking some MT Streets here before long...
1st gear aside... 2nd and 3rd gears are an absolute day and night difference now. Having full access to all the power really changes the driving dynamic.
Last edited by brutus_tx; May 18, 2020 at 11:40 AM.
And lastly Here are some videos from Efrain car last night to end it here, where he ran a 1/4 mile time of 10.6! Beast of car!
For anyone who is interested in a Stage 1 TCU tune, I can help in my Northeast region of the country with any member who needs it, and outside of this region, please contact David, our member here @DavesMeanE's specifically for this Stage 1 TCU tune and he can help you out

https://youtu.be/Idf5DdiBS3k
The Best of Mercedes & AMG
I assume this is what you are referring to..
My data set above covers a span of approximately 12 seconds... the throttle closure is in the tenths of a second over that period.
In the data record the throttle starts to close almost exactly after the start of drop in RPM's at the allotted gear change. They are in sync.
Last edited by billvp218; May 18, 2020 at 02:57 PM.
The TCU does have the capability to modify torque in every gear. It may be worth experimenting with a RWD platform to modify the torque limits of each gear to optimize the tune for the RWD platform. Hell, with the tire spin I'm having in first I may see about modifying mine.
The TCU does have the capability to modify torque in every gear. It may be worth experimenting with a RWD platform to modify the torque limits of each gear to optimize the tune for the RWD platform. Hell, with the tire spin I'm having in first I may see about modifying mine.
The engine of course closes throttle, and sometimes, drops fuel and timing during shifts aswell, and since we dont have a diverter valve or blow off valve, this needs to be completed and is limited in physical speed.
Last edited by 5soko; May 19, 2020 at 05:42 AM.
Boost is not an absolute with these engines. The ECU will use as much boost, or as little, as needed to meet power requirements. My knowledge stops there. Maybe one of the tuners can step in to add more back story on the mechanics of a tune.
While my boost was lower on this run, my trap speed was identical to previous runs... telling me the power levels are consistent.
My apologies, I know that was as clear as mud probably.
Our cars as you probably know use a Boost by load system, so depending on numerous factors including ambient temperature, density altitude, iat, etc. Boost is increased or decreased, more along the lines of, hotter weather, more boost to hit a givin target load, colder weather, more dense air, less boost needed to hit the target load.




BEST MOD IVE DONE SINCE ECU TUNE!!!
As we dig deeper into these cars we are starting to quantify what these aftermarket parts mean in the real world.
One of the things that separate my car from others is the addition of an anti-surge valve which dumps boost pressure during shifts... allowing for smoother gear changes.
With the quicker shift times being afforded by the TCU tune, it looks like we are coming up against mechanical reaction times of the hardware.
Does this affect performance? That's not for me to say, as everyone seems to be making quantifiable improvements in performance.
Of all the aftermarket hardware I have purchased... the water meth kit had the least ROI of any of it. One of the fringe benefits of the kit was the addition of an anti-surge valve though, so it wasn't a complete waste of money looking back on it. I just needed the TCU tune to see it.




As we dig deeper into these cars we are starting to quantify what these aftermarket parts mean in the real world.
One of the things that separate my car from others is the addition of an anti-surge valve which dumps boost pressure during shifts... allowing for smoother gear changes.
With the quicker shift times being afforded by the TCU tune, it looks like we are coming up against mechanical reaction times of the hardware.
Does this affect performance? That's not for me to say, as everyone seems to be making quantifiable improvements in performance.
Of all the aftermarket hardware I have purchased... the water meth kit had the least ROI of any of it. One of the fringe benefits of the kit was the addition of an anti-surge valve though, so it wasn't a complete waste of money looking back on it. I just needed the TCU tune to see it.
must now more then before because of the quicker shifts from the tcu tune.
I feel it was a convenient place for the developers to put the nozzles... nothing more. On the dyno we tried different start pressures, different nozzle sizes etc and didn't see a net benefit.
I run it because I have it, but looking back on the purchase I could have just opted for the ASV that came with the kit. That has shown a tangible benefit and I feel was worth the price.
On the list of "Best Bang for Buck" and ROI... the water meth is pretty low on my list.. as configured on my car.
My best post TCU 60' time is 2 seconds due to tire spin. I'm still making an 11.1 @ 129 with a suck *** 60ft. If I can get my launch down and improve my 60ft my quarter mile time will follow.
The extra torque I have with my E50 tune may be working against me here.
I have three options it appears...
1. Have the TCU restrict boost in the first gear to reduce the amount of available torque...
2. Have Jerry redo my tune from the ECU side of the equation to make less torque
3. Buy a better set of tires....
.I think I'm going to try option 3 first, followed by option 1 if its still needed.
This 4 door executive saloon that I use for business may be rocking some MT Streets here before long...
1st gear aside... 2nd and 3rd gears are an absolute day and night difference now. Having full access to all the power really changes the driving dynamic.
also, does it make all 7 gears have faster shifts than stock or is it only messing with gears 1-2-3?
Last edited by Amg63-; Jun 4, 2020 at 04:31 AM.





