[Sequential gear shift control issue]

Thanks for the quick reply.

 

So essentially do a physical clock of the sensor so all line up in a sequential voltage drop?

 

Ps. I believe that AN4 was logging at 1000hz

[Sequential gear shift control issue]

I have a R32 GTR with Albins sequential, set up with a G4X and using a gear lever force to start cut and gear barrel position sensor to end the cut. Everything seems to working very well in logs for all gears apart from the 4th to 5th shift where the ECU is introducing torque too early and seemingly ignoring its settings.

Basic settings for the barrel are 0-5V analog sensor, voltage tolerance of 0.26V and next gear reached voltage margin is 0.15V.

4th gear is 0.34V and 5th gear is 4.5V

When under power in 4th gear is around 0.34V, when the shifter is pulled this drops to around 0.2V, before the gear starts to change and it shoots up to 4.5V. By the software logic, the driven upshift should cease and the torque introduction should engage when the voltage is 4.5V +/- 0.15, in this case therefore at 4.35V

But for some reason, it's engaging the torque introduction much earlier, see example below

It actually appears to be using the minimum shift time (which is set to 30ms) rather than waiting for the waiting for the next gear voltage margin window. 

It only has the issue in 4th to 5th, which coincidentally and I'm unsure if related is the only gear that when upshifted goes from a lower voltage to a higher voltage.

It also frustratingly doesn't appear to always happen. Example below when it appears to work fine.

No issues in any of the other gears... Help?!?

 

 

[R32 GTR issues]

8 hours ago, Adamw said:

 

Have you both already tried setting the DI to use the opposite edge?    

In the R32 it is common for the reed switch at the back of the speedo to get sticky, sometimes swapping the edge can give you a better signal.  If not you will have to connect a scope to the DI so we can see why the ECU is not happy with the signal.

 

29 minutes ago, Stu UK said:

Yes, I tried the opposite edge but it didn't really make any difference. Must have a log file somewhere. I'll have a look.

Also tried both edges with no luck. As I mentioned before, it was perfect with my old plug in Vipec but as soon as I changed to Link it became an issue so I'm assuming it's a software issue with how it interprets the signal

[Gear Detection]

1 hour ago, Adamw said:

You are correct, the tolerance setting will affect the point at which torque reintroduction occurs.  Which option is correct will depend on how fussy the gearbox is but you may have to put up with a short period of "gear zero" in between gears if reintroducing torque while it is still shifting causes a problem.  My gut feeling is since you have six gears + R & N, the spacing between each barrel position is close enough that it will be perfectly happy with a fairly big volt tolerance there.

I have tuned a couple of cars with closed loop gear cut systems and in those I have a big enough tolerance that we dont really see gear zero at all during a shift.

 

Thanks for the reply. Is there any issue with seeing gear zero during changes or just ?

Another option would be to lower the voltages of each driven gear by say 0.2V so there is still a big enough window to see the gear correctly but effectively will delay the torque introduction until 0.07V before the gear is full engaged (rather than 0.27V)

or am I totally overthinking it? I just want the dogs (and gears) to be as safe and long lasting as possible

[R32 GTR issues]

15 hours ago, AbbeyMS said:

It will say wheel speed but it will be picked up from the speedo output.

 

All the Skylines take the speedo input from the gearbox but list as wheel speed

 

 

Correct, comes as wheel speed but it's picked up by the gearbox drive

[R32 GTR issues]

35 minutes ago, AbbeyMS said:

presume you guys are talking about the Speed (MPH/KMH) reading not RPM?  The Power FC logs so slow you never see the in consistence figures like you see from a Datlog on a Link ECU,  The speed signal comes from the speedo as the speedo drive is via a cable to the speedo then as a electrical signal from the speedo to the ECU

Yes speed (km/hr) reading zero at random times. I had a Vipec plug in and no issues at all, straight after swapping to Link G4+ plug in it's had issues, like the other 2. I assume it's something to do with filtering, I just want a fix because it's stopping me being able to run anything dependant on a semi reliable speed source (launch control, boost control etc)

[R32 GTR issues]

Bump, this is now 3 users with issues with the speed reading that have posted on here. Is there anything that can be done? 

I'm going to guess it's even more common, just not a lot of people look at speed in logs

 

[Gear Detection]

Just want to confirm something with gear detection and voltage tolerances. It's for a PPG sequential with a rotary position sensor, so when in gear the voltages are fairly accurate, usually +/- 0.02V. 

Originally I had the voltage tolerance much lower, +/- 0.05V but the ECU and dash were registering neutral so I've raised to +/-0.27V which is basically half the difference between the smallest gap in driven gears. I can actually increase it to +/-0.29V if needed as it still sees neutral between some gears for a very short time.

This tolerance fixes the neutral readings between gears but it concerns me that the ECU will register the next gear during a driven up shift too early (0.27V before it's fully in gear) and engage torque too early causing premature dog wear and or mis-shifts.

I guess my question, is it better to have a large window so the ECU doesn't register neutrals or small window so the ECU knows exactly when the gear has made it fully into the next gear?

[R32 GTR plugin issues]

5V out is rock solid on 4.99V

12V internal does occasionally drop to 11.7V from 12.01 but nothing to correlate to the rpm or speed jumping around, same with the battery.

Redid some more testing and it doesn't appear that the speed and rpm wobble are related, just seems to happen more often together but not all the time. Wierd

[R32 GTR plugin issues]

On 10/03/2018 at 6:16 PM, Adamw said:

 

Higher resistance is less pull-up effect, the sensor needs a stronger pull-up (lower resistance) to switch cleanly.

The ecu pull up (when turned on) is 4.7k ohm to 5v. ZF recommends 1kohm if connected to 5v, that is approx 5 times “stronger” than what the ecu can provide.

Their recommended values would be based on the interface circuit having no pull-up.

In this case, assuming the user is powering from 12V, it would be easiest to turn off the ecu pull-up and just add a 2.4K external between the 12v and signal wires

Is it just my imagination or could these be correlated?

[R32 GTR plugin issues]

Thanks for the reply, speed seems to have fixed with the pull up resistor on (although does still have some random low spikes) but I may try and switch the falling edge tonight but it's a massive improvement.

I'll look into wiring a resistor into the sensor and see how I go, sounds like a bigger job but may be worth it

 

[R32 GTR plugin issues]

Hi guys,

Got a few little niggling issues, first is the speed sensor. Have set at rising and falling and tried to calibrate but it seems to jump around all over the place. I did have a Vipec plug in before this and it worked perfectly and then started playing up after the swap and appears to get worse and worse. Had a few different gearboxes in as well so I don't think it's the sensor. Settings and logs in images.

I also have a little issue with the high octane crank trigger kit. The signal appears to "bounce" a little when the throttle is released, probably not the biggest issue but it does make the data for the flat shift cuts for the sequential box tuning a lot harder. Example highlighted in red circles