Talk | MCT 722.9 TCU TQ limiters.
We have a huge mercedes/amg club so I am sure we would have a lot of interest, but let me reach out to the group and see what I can gather.
For an ML you're gonna see a better/faster start-off, along with all the shift-speed advantages any other car would see. Some of the SUV's have a slightly weaker trans though (just PM me your VIN and I can check it). So if your variant is the less-beastly one, we can just tailor those first two gears to a slightly less aggressive level.
Thanks!
Dave
Thanks!
Dave
Thanks!
Dave
That is basically what I would want with my RWD car, and I've heard some others with RWD on the forum speak similarly.
The Best of Mercedes & AMG
What will change with different ECU tunes and TQ values, is things like like pressure, clutch clamping force, etc
These are adjusted in force and aggressiveness as due fit, for the given TQ the motor is making at the time. Of course with more TQ you make, higher line pressure, hold pressure and clamp force is what you want, just like complete oem fashion, and the TCU tune appropriately raises and sets this accordingly
Last edited by 5soko; Jun 19, 2020 at 07:43 AM.
If so, I'm sure they'd like that clarified ahead of time. If it's not the case, then I'd also like that clarified, because I'd be more interested

What will change with different ECU tunes and TQ values, is things like like pressure, clutch clamping force, etc
These are adjusted in force and aggressiveness as due fit, for the given TQ the motor is making at the time. Of course with more TQ you make, higher line pressure, hold pressure and clamp force is what you want, just like complete oem fashion, and the TCU tune appropriately raises and sets this accordingly

So if I understand it correctly, a guy can still drive on the stock ECU with the stock TQ at 500+ (if you needed to use stock ECU) even though you have an TCU tune set up for the higher TQ value 700+ from the E50 tune for example?
Is there a MAX torque value for the w212 / 722.9 trans does anyone know?? Thought I read on the boards somewhere that it was upto 1000 TQ it could handle safely so seems this TCU tune would be playing well within the safe limits at 700-800 TQ
thanks for all the great info 5soko!
If so, I'm sure they'd like that clarified ahead of time. If it's not the case, then I'd also like that clarified, because I'd be more interested

Thanks!
Dave
Thanks!
Dave
So if I understand it correctly, a guy can still drive on the stock ECU with the stock TQ at 500+ (if you needed to use stock ECU) even though you have an TCU tune set up for the higher TQ value 700+ from the E50 tune for example?
Yes, Stock ECU can be paired with a TCU tune, and it will still benefit a completely stock car as even first gear Tq limited below what a stock engine can make in TQ.
So the TQ limit is a static number and max cap, but what your engine makes between 0ft lbs and to the TQ limit, is the engines business
IT can be stock tq, tune only tq, or FBO tq, until it reaches the TQ limit. Is there a MAX torque value for the w212 / 722.9 trans does anyone know?? Thought I read on the boards somewhere that it was upto 1000 TQ it could handle safely so seems this TCU tune would be playing well within the safe limits at 700-800 TQ
This value is gonna be pretty wide spread depending on miles, mods, type of ECU tune, type of driving that was and is done. We have seen Healthy W212 4matics take massive amounts of tq with high miles and FBO. As I tell most I flash, warm up the drivetrain properly before agressive use, and change trans filter and oil more often.
thanks for all the great info 5soko!
Not trying to stir up controversy at all....just super curious to understand what truly is the MB stock torque limits relative to what these new TCU tunes are raising the limits to.
thank you again for all your amazing sharing and collaboration. Let me know If you can clarify.
Not trying to stir up controversy at all....just super curious to understand what truly is the MB stock torque limits relative to what these new TCU tunes are raising the limits to.
thank you again for all your amazing sharing and collaboration. Let me know If you can clarify.
So, yes, even in first gear, MB does not allow the full STOCK tq to be applied.
Let me know if that makes sense.
So, yes, even in first gear, MB does not allow the full STOCK tq to be applied.
Let me know if that makes sense.
It's strange to me that there aren't better gains in trap speed (after TCU tune) on ECU tune cars if the 3rd gear+ actually have such a limit though.
It's strange to me that there aren't better gains in trap speed (after TCU tune) on ECU tune cars if the 3rd gear+ actually have such a limit though.
And yes, most of the time there is "underrating", most forced induction engines rated HP is at harsh conditions, high elevation or heat soaked or low octane, so no matter where they go in the world, they meet this target HP. People living in areas from cold weather, at sea level, with high octane levels, get the benefit of the extra hp

I think what were are seeing with trap speeds is the years of ECU tuners who have had to under report their TQ values to get impressive gains for customers, this is why you wont see some members with trap speed gains after a tcu tune. Some do it more, some do it less, but just about every tuner in the market for the M157 does underreport tq to a degree as they had no choice before with no tcu tune, some is acceptable, some is a bit aggressive. You can check engine tq in xentry
If it says your tuned M157 is making 600 FT LBS, than we know someone is under reporting alot.Under reporting might get you by with letting more power under the table of the tcu, but your trans is also operating at this reported low TQ, which causes premature wear, less crisp shifting, slower response, etc etc. Most don't realize how bad it gets until they got back to a stock ecu tune and are amazed how smooth everything suddenly becomes.
Last edited by 5soko; Jul 27, 2020 at 11:11 PM.
It's strange to me that there aren't better gains in trap speed (after TCU tune) on ECU tune cars if the 3rd gear+ actually have such a limit though.
And yes, most of the time there is "underrating", most forced induction engines rated HP is at harsh conditions, high elevation or heat soaked or low octane, so no matter where they go in the world, they meet this target HP. People living in areas from cold weather, at sea level, with high octane levels, get the benefit of the extra hp

I think what were are seeing with trap speeds is the years of ECU tuners who have had to under report their TQ values to get impressive gains for customers, this is why you wont see some members with trap speed gains after a tcu tune. Some do it more, some do it less, but just about every tuner in the market for the M157 does underreport tq to a degree as they had no choice before with no tcu tune, some is acceptable, some is a bit aggressive. You can check engine tq in xentry
If it says your tuned M157 is making 600 FT LBS, than we know someone is under reporting alot.Under reporting might get you by with letting more power under the table of the tcu, but your trans is also operating at this reported low TQ, which causes premature wear, less crisp shifting, slower response, etc etc. Most don't realize how bad it gets until they got back to a stock ecu tune and are amazed how smooth everything suddenly becomes.
And yes, most of the time there is "underrating", most forced induction engines rated HP is at harsh conditions, high elevation or heat soaked or low octane, so no matter where they go in the world, they meet this target HP. People living in areas from cold weather, at sea level, with high octane levels, get the benefit of the extra hp

I think what were are seeing with trap speeds is the years of ECU tuners who have had to under report their TQ values to get impressive gains for customers, this is why you wont see some members with trap speed gains after a tcu tune. Some do it more, some do it less, but just about every tuner in the market for the M157 does underreport tq to a degree as they had no choice before with no tcu tune, some is acceptable, some is a bit aggressive. You can check engine tq in xentry
If it says your tuned M157 is making 600 FT LBS, than we know someone is under reporting alot.Under reporting might get you by with letting more power under the table of the tcu, but your trans is also operating at this reported low TQ, which causes premature wear, less crisp shifting, slower response, etc etc. Most don't realize how bad it gets until they got back to a stock ecu tune and are amazed how smooth everything suddenly becomes.
my only question regarding how the underported tq values work in m157 ecu tunes, is that why won’t it work when trying to use this trick in first gear? Seems like no matter which tune we get, it only starts making more power than stock starting from gears 2+ and that’s why the 0-60 times without a TCU tune is normally never able to get below 3.1-2s. So does this trick not work when trying to trick the ecu in first gear?
my only question regarding how the underported tq values work in m157 ecu tunes, is that why won’t it work when trying to use this trick in first gear? Seems like no matter which tune we get, it only starts making more power than stock starting from gears 2+ and that’s why the 0-60 times without a TCU tune is normally never able to get below 3.1-2s. So does this trick not work when trying to trick the ecu in first gear?








