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Title: DQ250 max torque 630nm due to CAN-BUS limits Post by: Alexander24 on October 29, 2024, 05:43:34 AM I got an Audi TT 2007 VR6 8J (PQ35) running on EcuMaster Black and DQ250.
The car is still being built. I want to go around 800nm. While reading the forum I found out about CAN-BUS limitations on PQ35: Quote Your problem is, 630Nm is maximum value for MO2_max_Mo, signal is only 6bit and factor 10. So, if you change Com_trqMaxNorm_C in EDC higher than 630Nm, CAN bus is limited and will still send 630Nm (FF FF FF). TCU will calculate torque on 630Nm and torque modell is bended .. (I never need to chance this value in this range in my projects so fare, so did not have in mind the maximum of MO2_max_Mo Undecided ) So, no chance send higher value in CAN doesn´t care if Diesel or Pentrol.. What I don't understand is whether it applies to my case (EcuMaster Black instead of ME7.1) or not? In EcuMaster settings there is a setting called "VAG MDI torque". I found this explanation on EcuMaster's forum: Quote MDI torque is a prameter from VW CAN stream that tells the gerbox how to intepret the torque percent sent from the ECU. As I wrote above the ECU sends torque percent, not an absolute value. So here it says EcuMaster sends a percentage of torque, not an absolute number. Thus, a CAN-BUS limit of 630nm should not apply in my case? Here's my guess how things might work:
Title: Re: DQ250 max torque 630nm due to CAN-BUS limits Post by: prj on October 29, 2024, 07:33:34 AM Your guess is completely wrong, it will work nothing like that.
Also you will snap the input shaft on the gearbox over 600nm. And the gearbox needs code patches to even calculate clutch torque over 500nm. Anyway no matter what you do the gearbox will never see over 630nm on CAN, nor is that important because the hardware can't handle more than that anyway. If you need to run that much torque you need a DQ500. Title: Re: DQ250 max torque 630nm due to CAN-BUS limits Post by: Alexander24 on October 29, 2024, 11:42:58 AM Your guess is completely wrong, it will work nothing like that. Thank you for your answer. Also you will snap the input shaft on the gearbox over 600nm. And the gearbox needs code patches to even calculate clutch torque over 500nm. Anyway no matter what you do the gearbox will never see over 630nm on CAN, nor is that important because the hardware can't handle more than that anyway. If you need to run that much torque you need a DQ500. I currently have a TVS Stage2+ tune which has max torque at 500nm. My engine is gonna be tuned by an experienced EcuMaster engine tuner but since he specialises on Japanese cars, he's never set up a car with a DSG. So I'm researching the way Ecumaster talks to DQ250 and what needs to be done. Do I need to set VAG MDI torque to 500nm (current max torque in the TCU)? Title: Re: DQ250 max torque 630nm due to CAN-BUS limits Post by: prj on October 30, 2024, 04:02:28 AM You just said you want 800nm.
In this case get a DQ500, it will do 800nm by only changing the torque limiter. How to setup ecumaster - ask whoever sold it to you how to do it. Dealer is obligated to provide support. Torque gets sent as 6 bit value in Motor 2 in the multiplex byte. The multiplex is 2 bits, the torque is 6 bits, so 63 is the maximum value that it can carry, that is why 630nm is a hard limit. You might as well use that. It is possible to double this value using an additional flag, but the DQ250 firmware does not support this. DQ500 does. Title: Re: DQ250 max torque 630nm due to CAN-BUS limits Post by: James1 on November 12, 2024, 02:36:51 PM DQ250 will shit itself at 630Nm
Title: Re: DQ250 max torque 630nm due to CAN-BUS limits Post by: IamwhoIam on November 13, 2024, 05:09:13 AM DQ250 will shit itself at 630Nm Which is why dozens of people run them at 600+ and even 700Nm and none of them has shit itself yet lol |