Gear detection glitch

[Pete_89t2]

After a drive yesterday with my laptop and PCLink logging data, I noticed something odd in my logs. This is with a G4+ Fury in an S6 RX7. For some time now I've been using the OEM vehicle speed sensor (VSS) as an input to DI1 to provide driven wheel speed, and I've done the gear detection calibration procedure so the G4+ can compute which gear I'm in. When testing that function out months ago, it always seemed to work - gear reported in live/real time data matched what was going in. I haven't used the gear detection functionality yet for anything in my tune, but now that I'm working on boost control, I may want to apply a gear trim, so I've been taking a closer look at that gear data in my logs.

What I noticed in the PCLink log yesterday while looking at a time plot that shows gear, Engine RPMs, DI1 frequency and Driven Wheel Speed was that sometimes the gear position will randomly drops from whatever gear I'm in to 0 on the plot while the car is actually running at speed in any one of the gears (1st thru 5th). At the same time on the plot, the DI1 frequency, driven wheel speed and engine RPMs are all showing correct data, consistent with the speed I'm driving & engine RPMs.

I can post up a log later for review, but the log data indicates to me that there's no hardware/wiring issues, as I'm getting consistent input on DI1, no RPM/trigger issues and there are no issues with the G4+ calculation of driven wheel speed from the VSS. Is this perhaps a glitch in PCLink logging?

[Adamw]

Will need to see the log and tune.

[Pete_89t2]

Adam,

Here's a link to the log & current tune file. https://drive.google.com/drive/folders/1mxt-Y19KZ0yTBcaL444ulelE5zL0UmuU?usp=sharing

You can see the gear glitch happening right around time indexes 5:46~5:47; 6:51~652; 9:30~9:31 and a few more places later in the log. Thanks in advance!

[Adamw]

Your gear ratios are set wrong.  Possibly you have changed the speed calibration after it was originally set up or something. 

From your log 1st ratio should be 120, 2=68, 3=47, 4= 33.6, 5=24.1.

[Pete_89t2]

49 minutes ago, Adamw said:

Your gear ratios are set wrong.  Possibly you have changed the speed calibration after it was originally set up or something. 

From your log 1st ratio should be 120, 2=68, 3=47, 4= 33.6, 5=24.1.

 

Now that you mention it, I did do a small adjustment to the speed calibration about a month ago so the speed displayed would match closer to actual/GPS speed measurement. Didn't realize I'd have to do the gear calibration again after that - assumed those gear cal #'s are just fixed constants based on your gear ratios.

On a semi-related question, on the series 6 FD there's 2 options for tapping a speed input. One is doing what I am now, which is taking a parallel wired connection to the analog VSS sensor, and sharing the VSS sensor input with the OEM dash speedo. The VSS is a VR/magnetic sensor that puts out a sine wave signal, 8 pulses per shaft rotation. The other option available is to tap the digital speedo output from the OEM dash cluster that would normally goes to the OEM ECU - that is a digital square wave 4 pulse/VSS sensor rev signal. I think both will work with the Link's DI1 input, but is there any advantage in using one over the other?