Amg63-

Thanks for clarifying that. I understand what your saying, that it’s a totally 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.

brutus_tx

Ask your ECU tuner. They should come clean.
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.

5soko

Talking your tuner to clarify is the only certain way to know. Let them know you are gonna be tuning your TCU and IF ( IF of course) they are under reporting, to not do so anymore for your tune.
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

c3004wife

Are you on the low boost, E85 tune? I thought you were on the E50, 18psi tune? Do those two variations of the corn tune still exist?

brutus_tx

I am on the 18psi tune.... I haven't changed it or tweaked it since we buttoned it up 7 months ago. Prior to my TCU tune, the most I had seen was in the 18 psi range. I had also seen many multiple 15 to 17 psi runs.
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.

c3004wife

No, that makes sense. I see different boost levels depending on IAT, knock, etc. also. Mainly wondering if the TCU tune somehow negatively impacted your overall boost levels. Seems most people with the new TCU tune are picking up a mph or two in the 1/8 and at the end of the quarter but that doesn't seem to be the case with your car.

brutus_tx

My issue is traction. I'm the AWD burn out king now. I'm struggling with my Pirelli P Zero tires to get traction out of the hole. Every launch has tire spin in first.

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.

Sugar_Mouth

What is happening after the shift on the first couple shifts?

brutus_tx

Are you referring to the dips? That's the ECU closing the throttle body on gear change to reduce boost (and torque) so as not to overboost. That is standard on all tunes.

I assume this is what you are referring to..

Sugar_Mouth

Yes sounds like it shifts then rpms dip unrelated to the shift.

brutus_tx

Nope... the throttle closure is directly related to the drop in rpm caused by the gear change.
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.

c3004wife

I hear it too. On the 1-2 and 2-3 shift. Sounds almost like the clutch is slipping.

brutus_tx

I get it now... the video not the graph... lol

Sugar_Mouth

Yep

billvp218

3rd gear is affected? I thought 3rd gear didn't have the restriction previously. If it does, then maybe a variation of the TCU tune where only 3rd gear is updated may work for us RWD street-focused individuals.

brutus_tx

I can only speak to the results of the logs pre and post tune for the AWD platform. I saw max boost available in all gears.post TCU... whereas prior to the tune, 1st, 2nd and 3rd have some degree of intervention with respect to throttle closure.
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.

billvp218

Do you have the values handy for 1st - 3rd before?

5soko

I think that is the physical change of the MCT switching and engaging you may be hearing and not slip, as CIFDIG can confirm.
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.

Every gear in the MCT trans has TQ limits. And yes, any Tq limits values in any gear can be done to the end users request

5soko

The TCU only really cares about mainly the TQ value the ECU is calculating and giving it. Remember, there is still TQ limits in place, just alot higher than stock.

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.

Cifdig

it does sound like slip , but I’m gonna say it’s more of the engagement and the motor dumping over boost between the small gap in shifts. I log consistently and draggy at the same time. Slip is inconsistent it can’t be controlled and in that, my times would be all over the place. So far my time are 10.71- 10.73 my best so far being 10.69 and that’s extremely consistent so I ruled out clutch slip. And I’m running a pretty aggressive leaded mix fuel tune. I definitely want to get the blow off valve to see if I can help the motor rid of unwanted boost that much faster.

BEST MOD IVE DONE SINCE ECU TUNE!!!

brutus_tx

@5soko Can you post the logs of my run showing my Anti Surge Valve at work, versus Cifdig's log?
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.

billvp218

You didn't tune for the meth kit though, right? So you wouldn't see any results. It's like insurance ... people say it's a waste of money when they didn't die or have a wreck, but that misses the point - it doesn't pay off financially for most people, but it's a safeguard against disaster just in case. Beyond insurance, a better comparison for the meth kit may be a private security firm that doesn't tell you when it saved you.

Cifdig

im definitely getting boost spikes . Bov is a
must now more then before because of the quicker shifts from the tcu tune.

brutus_tx

Not in this case with this nozzle placement, for me at least. I can see the argument post turbo for sure, as I've seen very positive results from cars configured that way.
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.

Amg63-

So the TCU tune raises power in all gears and not just gears 1-2?

also, does it make all 7 gears have faster shifts than stock or is it only messing with gears 1-2-3?