marchewa
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« Reply #270 on: June 09, 2022, 03:15:40 AM »
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There are hard limitations such as 500nm calculated clutch torque, which need a patch or fudging stuff in the cal, but you probably won't hit them.
I have a problem with r32 turbo and some weird torque interventions (probably?) when reaching over ~550Nm on the flywheel. With low boost (up to about 0.8bar I think) it behaves properly. With target boost ~1.1bar and some overboost to 1.2-1.3bar gear shifting is hard and some kind of power hesistation are feelable. In dsg logs in both cases I'm reaching 500Nm (or 497 or whatever is vcds showing). Described problem is clearly visible on the highlighted area of the screen. Boost is stable and about 10deg of ignition is "missing". Cutch pressure is 16-17bar, no slippage noticed. Am I hitting this hard limit in this case? me7l logs attached |
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fknbrkn
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mk4 1.8T AUM
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« Reply #271 on: June 09, 2022, 03:31:38 AM »
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Log migs / miges
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marchewa
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« Reply #272 on: June 09, 2022, 06:15:00 AM »
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Log migs / miges
thanks for reply- new logs attached |
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Tezotto01
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« Reply #273 on: June 15, 2022, 06:37:22 AM »
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What problem are you trying to solve?
What do you think adding more pressure will do?
I am tuning an A3 8V with 460whp and 580Nm, the ECU tuning was not done by me, the engine torque shown in the logs is 389Nm, there is skidding occurring when driving on the highway, I have been trying for days to solve it but without success, the solenoid current does not exceed 1100mA and the clutch pressure does not exceed 13.22Bar. Any suggestions how I can solve this problem? |
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prj
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« Reply #274 on: June 15, 2022, 09:10:18 AM »
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Proper ECU tune which reports torque to the gearbox in a linear fashion.
It doesn't even matter what the absolute numbers are, it's just important that it is linear.
Or destroy the microslip control and make the gearbox drive like shit with excessive pressure all the time.
But I'm not going to tell you how to do it.
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curamrdan
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« Reply #275 on: June 15, 2022, 04:59:45 PM »
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Proper ECU tune which reports torque to the gearbox in a linear fashion.
It doesn't even matter what the absolute numbers are, it's just important that it is linear.
Or destroy the microslip control and make the gearbox drive like shit with excessive pressure all the time.
But I'm not going to tell you how to do it.
Linear you mean to have KFMIRL and FMIOP linear, not bend due modified only last 1-2 rows? Absolute numbers, you mean reported torque or pressures(as you previously noted its closed loop...)? Can i rise a bit the MDNORM to rise reported torque closer to real values or it will result by sideeffects? |
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prj
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« Reply #276 on: June 15, 2022, 11:48:56 PM »
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MDNORM has almost zero effect on DSG. The absolute numbers matter very little.
The important part is that kfmirl and kfmiop are completely linear with actual torque.
If they are not you will have slip.
This works until 500nm calculated clutch torque. Which again, is calculated internally based on clutch parameters and the torque output from the ECU means very little. After you hit 500, you either make a 5120 style patch for the TCU or you do the microslip controller destruction.
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armada
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« Reply #277 on: June 16, 2022, 03:13:32 AM »
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I am tuning an A3 8V with 460whp and 580Nm, the ECU tuning was not done by me, the engine torque shown in the logs is 389Nm, there is skidding occurring when driving on the highway, I have been trying for days to solve it but without success, the solenoid current does not exceed 1100mA and the clutch pressure does not exceed 13.22Bar.
Any suggestions how I can solve this problem?
I'm driving A3 8V as well and I had exact same problem on some reputable, but actually shitty custom tune. It was driving me nuts and no matter what I reported to the tuner it wasn't fixed properly. They just retarded boost\ignition in the area of slippage to make less torque, which is very stupid fix. So, I was forced to tune my car myself (had an experience with tuning of high performance drift cars on standalone ECUs, but never touched SIMOS18). It was night and day difference when tuned correctly. Now, it is just a stock feeling gearbox all the way. TL;DR: it is not a gearbox issue, but engine torque model is broken as mentioned by prj. |
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curamrdan
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« Reply #278 on: June 16, 2022, 04:14:27 AM »
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MDNORM has almost zero effect on DSG. The absolute numbers matter very little.
The important part is that kfmirl and kfmiop are completely linear with actual torque.
If they are not you will have slip.
This works until 500nm calculated clutch torque. Which again, is calculated internally based on clutch parameters and the torque output from the ECU means very little. After you hit 500, you either make a 5120 style patch for the TCU or you do the microslip controller destruction.
But i as you know, there are some forum tips to reduce MDNORM = to reduce reported torque under DSG limiter(to avoid modifing it). You already answered there, that is stupid idea undereporting torque. MDNORM has direct influence on it, so why on other direction (rising) it has marginal effect? My noob experience, on MED17 2.0 tsi dsg K04 conversion , when i tried to do linear kfmirl/kfmiop (same % increase of kmirl and axis of kfmiop, ideal inverse), i gets torque monitors code on part throttle accel(no matter what limiters ect i FFed ect then). So i must reverted back to "bend" style, only last 2-3 rows edited and as bandaid rised MDNORM to roughtly bit over real tq to compensate low the report on that "bend" iop maps. No problem with driving on Sport, but on D owner claims slippage occasionaly... |
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prj
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« Reply #279 on: June 16, 2022, 04:39:20 AM »
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But i as you know, there are some forum tips to reduce MDNORM = to reduce reported torque under DSG limiter(to avoid modifing it). You already answered there, that is stupid idea undereporting torque. MDNORM has direct influence on it, so why on other direction (rising) it has marginal effect? Reducing MDNORM is a bad idea because all other control units that use torque, for example ESP etc start to work incorrectly. DSG actually does not care a great deal about MDNORM, it only cares that reported torque is linear - if you reduce MDNORM you can bypass limiter, but the control will not change much as long as IRL/IOP are correctly extrapolated. Usually it's enough to change only last row of IRL/IOP, but the map must remain linear, you can not "bend" it. For example if real torque rises 20% then reported torque must also rise 20%, and this must be true throughout the entire torque range. If real torque rises 30% in some area but reported torque only 20% then you will have slip instantly pretty much. It's due to the way they did the torque calculation inside the transmission. ZF transmissions are much simpler in the way that there's simply RPM x Torque maps with pressures and ramp rates, but no such thing exists in DSG. My noob experience, on MED17 2.0 tsi dsg K04 conversion , when i tried to do linear kfmirl/kfmiop (same % increase of kmirl and axis of kfmiop, ideal inverse), i gets torque monitors code on part throttle accel(no matter what limiters ect i FFed ect then). So i must reverted back to "bend" style, only last 2-3 rows edited and as bandaid rised MDNORM to roughtly bit over real tq to compensate low the report on that "bend" iop maps. No problem with driving on Sport, but on D owner claims slippage occasionaly... Yes, you did it wrong. Your MDNORM change does not do anything for the DSG. As said before, it only cares that torque is linear. If it's not -> slip. If you need more torque than 100% allows in linear form you must change entire map, also friction map, and of course relax torque monitoring a little or modify it as well (only applicable to MED17). If you do a small change, e.g. 20% more, then you can get away with just changing IRL/IOP and friction torque. However, if you need more, you will have to start rescaling things like idle control and so on. Basically all maps that are in torque % must be rescaled by the same amount if you want the transmission and engine to work correctly after some point. E.g. if MDNORM is 400 and you want to go to 600, there will be a lot of work to be done. But if it's 400 and you want to go 500, you can probably get away with very little without hurting idle control and LSD/DASHPOT/ARMD too much. |
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« Last Edit: June 16, 2022, 04:43:05 AM by prj »
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ktm733
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« Reply #280 on: June 21, 2022, 10:27:49 AM »
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Reducing MDNORM is a bad idea because all other control units that use torque, for example ESP etc start to work incorrectly.
DSG actually does not care a great deal about MDNORM, it only cares that reported torque is linear - if you reduce MDNORM you can bypass limiter, but the control will not change much as long as IRL/IOP are correctly extrapolated. Usually it's enough to change only last row of IRL/IOP, but the map must remain linear, you can not "bend" it. For example if real torque rises 20% then reported torque must also rise 20%, and this must be true throughout the entire torque range. If real torque rises 30% in some area but reported torque only 20% then you will have slip instantly pretty much. It's due to the way they did the torque calculation inside the transmission. ZF transmissions are much simpler in the way that there's simply RPM x Torque maps with pressures and ramp rates, but no such thing exists in DSG.
Yes, you did it wrong. Your MDNORM change does not do anything for the DSG. As said before, it only cares that torque is linear. If it's not -> slip.
If you need more torque than 100% allows in linear form you must change entire map, also friction map, and of course relax torque monitoring a little or modify it as well (only applicable to MED17). If you do a small change, e.g. 20% more, then you can get away with just changing IRL/IOP and friction torque. However, if you need more, you will have to start rescaling things like idle control and so on. Basically all maps that are in torque % must be rescaled by the same amount if you want the transmission and engine to work correctly after some point. E.g. if MDNORM is 400 and you want to go to 600, there will be a lot of work to be done. But if it's 400 and you want to go 500, you can probably get away with very little without hurting idle control and LSD/DASHPOT/ARMD too much.
I grasped the whole tuning torque correctly but I have a question that's on topic but on a different tcu ecu. mg1 ecu, zf trans 2019 Audi s5... I can mess with torque and make it say 600nm car shifts fine, or make it 1000nm and car shifts fine, but feel mopre torque reduction. So the question is, how do you know where to put torque? Someone stated raise torque if you have clutch slip. My thoughts are with seeing 900nm of torque it's going to try and reduce a lot of torque making shifts pull power and harsh shift. What is your take? I have a dyno to record actual torque. |
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prj
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« Reply #281 on: June 29, 2022, 01:56:40 AM »
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Report the correct torque of course!
And the rest you do in the TCU!
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ktm733
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« Reply #282 on: June 29, 2022, 09:43:34 PM »
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Report the correct torque of course!
And the rest you do in the TCU!
How do you know what reporting the right torque is? For example, simos 18 ecu. You can raise boost by raising max torque limiters, but I feel like torque readings are over scaled... simos 18.1 2015 Audi A3, ecu reports 500-550nm running stage 1 full e85 25psi 20 degrees of timing. This seems overscaled, but I listen to your strategy. (tuning is simply scaling up.) Well I keep scaling up and just feel torque readings are just high. Car drivers fine but my scaling being so high I lose resolution in certain loads. Hints why I feel people under scale the car to have more resolution and driveability. Maybe I'm way off, shed some light lol I over scaled my Mg1 2019 S5 ecu not knowing because I was listening to your strategy. This led to very torquy driving as it went from 200nm to 900nm in a couple second. So I'm lost, do I only raise torque scaling if I'm experiencing clutch slip in mech unit? Or do I keep looking for the million torque limiters till I don't hit any torque limiter but results show extremely high readings? |
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prj
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« Reply #283 on: June 30, 2022, 01:24:01 AM »
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You report the correct torque.
And you learn the difference between indicated torque. Inner torque, friction torque and clutch torque.
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Sagishm
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« Reply #284 on: July 05, 2022, 09:10:59 AM »
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Hi,
After tune dq250 fxx to 16bar pressure i had an issue with start driving, when i leave the brake the car not start to surfing and if i tap on throttle there is bomb from gearbox, someone have any idea or details about that?
Maybe is related to micro-slip?
Thanks
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