Hello ECUmaster community,
i have following set-up:
VW EA888 engine (2.0 TSI) changed to suction pipe injection
Holinger SF sequential gearbox
EMU Pro
I have already programmed that shifting is possible, but I am struggling now to find the right strategy within Pre-Shift, Shift and Post shift that its working properly.
Can someone send me a proposal with some explanations how to set this up and what times / figures / torque reduction i should use as a starting point?
Hi,
Unless someone has the same engine and gearbox, settings from other projects wonât be very useful.
Please provide the files with what you already have. The project file with your current settings and the log file with some gear changes.
Some basic ideas about tuning:
Pre-shift - phase used to remove the current gear. You want minimum torque reduction that allows you to take the gear out.
Shift - phase used to put the new gear in. You need appropriate torque reduction/blip to match the engine and gearbox speed, allowing you to put the new gear in.
Post-shift - phase used to ensure the gear is fully in before finishing the shift process and restoring the torque. You can start with a high duration and optimize it by lowering it until you can see negative effects on the shift process.
Torque reduction - the easiest way to configure torque reduction is to map the 0-100% reduction into 0-100% cylinder cut. The smoother option is to use ignition retard for small reduction and cylinder cut for higher reductions.
I have attached the data I have now, this was adjusted by a Ecumaster distributor, who told me that this is gear shifting is new with the pro and he is not experienced at all.
It seems some of this strategy would be better suited to a DSG transmission, and to me seems a little to complex for a Dog Box sequential transmission like the Holinger SF. I am assuming you are also using their pneumatic air shifter with integral solenoids to control the up/down shifting?
I would set all pre shifting to 0,
Upshifting to have PWM to 100%, hard cut of 30 to 50ms, lots of air pressure (100PSI plus)
Dog boxes are brutal objects, and you need to shift them as hard and as fast as possible to ensure best wear.
Take care to test and log the shifts when you set this up for the first time. Compare the shift drum position output to shift progress timing for each gear, and adjust the shift cut time to suit, untill you get the timing correct.
Out of time up and down shifts will destroy the transmission quickly, get it correct and it will last you many years without issue. The SF is a great transmission if treated well.
Thank you for your answer, I also use their pneumatic shifter, but it hastn the solenoid inside, I have an additonal one to control upsihft and downshift.
Also I have approx 7 bar air pressure (Holinger recommend 6-8 bar shifting pressure).
Thank you for your advice, 30 to 50 ms seems very low for me.
My problem with my configuration is, the shifting is very slow, I can feel that the pulling gets down and then kicks in again.
And sometimes if I push the paddle up, the gear does not get in. (Especially 1-2 and 2-3)
ensure the shifting solenoids are as close to the transmission as possible.
These are the best. Removes the shift lag time.
If the solenoids are mounted away from the transmission, ie vehicle cabin or boot connected via long hoses, this will be very bad for your transmission, and will result in slow shift times (due to lag and pressure drops), and significant gear dog damage.
If the vehicle is stationary, it will have difficulty shifting into shift gears.
1-2 and 2-3 shifts result in the most drive train shaft âwindupâ', therefore require longer shift cut times, to allow the gear dog to unload to allow for smooth shifting.
Hi
Pro has very sophisticated startegy all pre load and pre shift allows all compesantions for play and hose lengths. But actuator woth inbuld valves is definitely best solution especially when you run DBW.
In your setup you goingn stright to cut for shift so you missing parts preloading âdogsâ and is easy to damage gearbox . Ive done several different systems on pro hydraulic and pneumatic and all works perfectly especially with torque estimation allows smooth shift and on the trhottle downshift and off the throttle up shiftâŚ
I will create soon some video trying to explain strategy. Once you understand is easy like everything.
Hello, this is the set-up from the gearbox, hoses are 50cm away inside the cabin on the spray wall.
I understood from Greg, thank you therefore, that this can be compensated with the preload and preshift. I will try to shorten as much as possible.
Fix the logging first. You need logging for the gearboxâs tuning process, and there is no way around it. You need a flash drive from a reputable brand (we recommend SanDisk). Also, a common mistake is swapping data wires. You can just swap them around and try again.
If there was a shift that wasnât accepted, you can see why with the âGear shift Stateâ channel. It will tell you the exact reason why it was rejected.
You can observe the barrel position to decide how long each shift stage should be.
The pre-load stage is used to apply load on the shifting mechanism before any torque reduction takes place.
I will describe how an upshift with a paddle should look like:
Pre-load: Apply a load to the shifting mechanism. The barrel might move slightly or not at all, depending on the mechanical setup. The duration should be as short as possible but long enough to apply a steady load. Too much force from the actuator can take the gear out before torque reduction, which you do not want to do. You might need to use PWM with a lower DC to limit the force of the actuator.
Pre-shift: Reduce torque to pull out current gear. If the torque reduction is not enough, the dogs will not loosen up, and you canât pull the gear out. You can see if the gear is out with the barrel position. You can also measure on the log how long it took to pull the gear out from when the pre-shift stage started.
Shift: Reduce torque to put the new gear in. Usually, the reduction in the shift stage is 100%. You want to lower the engine RPM as fast as possible to match the gearbox speed. When the speeds are matched, the new gear will go in. Again, how the gear goes in and how long it takes can be seen on the log.
Post-shift: This is a constant-duration phase used to wait a bit after the shift to ensure the gear is fully in. In open-loop mode, this stage is often not needed since the shift stage will have a duration with some additional margin to take shift variation into consideration. In closed-loop mode, the shift stage will finish when the barrel position reports that the new gear is in. In this situation, waiting a short time after each shift is a good practice.
Recovery: After a successful shift, we want to gradually recover the torque to minimize stress on mechanical components and tires that try to accelerate.
Thank you for your help, I will fix the logging (just bought a new Sandisk USB) and test how you described.
Is closed loop mode possible in Shift stage for up-shifting?
In my understanding, the ECU reduces torque as long as the next gear is inserted. This would be the perfect solution.
torque reduction is user configurable for each stage and they are in closed loop . stages with time out setting working in closed loop stage with duration is time based not closed loop.
cutting at the same level thru all process is massive simplifying whole shift strategy you need higher cut for disengage than shift stage and all depend of the gearbox, system you are using , engine inertia, engine respond for torque reduction âŚ
Thank you so much for all your answers, all of them help me understand this topic better.
Can anybody tell me, regarding my set-up and programming, at what time does the solenoid open to push the pneumatic piston?
And what does in Pre-Load and Pre-Shift the âActuator PWM duty cycle in %â mean?
Am I right that when this value is zero, there is no activation of the solenoid and at my set-up the first time the solenoid starts is ans Shift time?
Thanks for your help and sorry for the maybe stupid questions
pwm is solenoid control with for example hydraulic system you can pwm solenoid to adjust force of solenoid shifting and now depend what solenoid are you using for pneumatic system if they opening with âpilotâ air control you cant really do pwm to them so you just set close to 100% if this is not proper motorsport solenoid ( some using mac industrial solenoids) you will be able to use pwm setting. if you ahve 100% duty solenoid is not activated at all
Hello Greg,
the solenoid I use is as you mentioned with âpilotâ air, so therefore I can´t really do PWM, its only open/close.
Ok, then when i Have now 100% an Shift stage, the solenoid ist not open at all?
What figure to set that the solenoid is open? 90%?
Hello everybody,
just tried everything, but I didn´t got the logging to work.
All USB drives I tested (also Sandisk) with FAT32, there was always this âUSB disconnectedâ sign.
Can there be a failure in the wiring?
like everything.