5th gear not showing up on HUD after 4.3 diff swap - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

norcalpb · 08-27-2019, 07:57 PM

Hello all,

I should’ve seen this coming but the onboard computer that measures the speed and rpm of the car to calculate/indicate what gear you’re in doesn’t work too nicely with a higher FD. Every gear is fine except for 5th. I shift the car into 5th and nothing shows up on the hud for about 10 seconds and then it’ll give up and show 4th again.

Is there any way via OBDII to recalibrate the gear indicator sensors?

Turdinator · 08-27-2019, 10:20 PM

I am 90% sure you can fix this with OFT and presumably ecutek also.

mabviper · 08-28-2019, 10:28 AM

You have to recalibrate the gear calculation table. That's what I did. New value = old value / 4.1 * 4.3

elBarto · 08-28-2019, 11:01 AM

Quote:

Originally Posted by norcalpb

Hello all,

I should’ve seen this coming but the onboard computer that measures the speed and rpm of the car to calculate/indicate what gear you’re in doesn’t work too nicely with a higher FD. Every gear is fine except for 5th. I shift the car into 5th and nothing shows up on the hud for about 10 seconds and then it’ll give up and show 4th again.

Is there any way via OBDII to recalibrate the gear indicator sensors?

You need to change the Gear determination tables. Only possible if you are tuned (OpenFlash or ECUtek).
In RomRaider you can find those tables in the "Miscellaneous - Thresholds" folder (probably it's going to have a similar name in ECUtek).
Then change the tables accordingly.
I think you can use the values of a 2017 model since those use an 4.3 FD.

Th above example is for a 4.556 Final Drive.

norcalpb · 08-28-2019, 12:04 PM

Thanks guys

norcalpb · 08-28-2019, 07:28 PM

In case any one stumbles across this thread:

4.3FD
1. 9403.05
2. 6232.05
3. 4677.63
4. 3777.35
5. 2990.87
6. No input needed

08-27-2019, 07:57 PM	#1
norcalpb Senior Member Join Date: Oct 2013 Drives: 2013 BRZ, 2023 Model 3 Location: SF Bay Area Posts: 2,296 Thanks: 1,212 Thanked 861 Times in 570 Posts Mentioned: 15 Post(s) Tagged: 0 Thread(s)	5th gear not showing up on HUD after 4.3 diff swap Hello all, I should’ve seen this coming but the onboard computer that measures the speed and rpm of the car to calculate/indicate what gear you’re in doesn’t work too nicely with a higher FD. Every gear is fine except for 5th. I shift the car into 5th and nothing shows up on the hud for about 10 seconds and then it’ll give up and show 4th again. Is there any way via OBDII to recalibrate the gear indicator sensors?

08-28-2019, 10:28 AM	#3
mabviper Senior Member Join Date: Jul 2013 Drives: WRB BRZ Location: Toronto, Canada Posts: 286 Thanks: 21 Thanked 161 Times in 97 Posts Mentioned: 5 Post(s) Tagged: 2 Thread(s)	You have to recalibrate the gear calculation table. That's what I did. New value = old value / 4.1 * 4.3 __________________ Custom datalogger with GPS Support

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08-28-2019, 12:04 PM	#5
norcalpb Senior Member Join Date: Oct 2013 Drives: 2013 BRZ, 2023 Model 3 Location: SF Bay Area Posts: 2,296 Thanks: 1,212 Thanked 861 Times in 570 Posts Mentioned: 15 Post(s) Tagged: 0 Thread(s)	Thanks guys

08-28-2019, 07:28 PM	#6
norcalpb Senior Member Join Date: Oct 2013 Drives: 2013 BRZ, 2023 Model 3 Location: SF Bay Area Posts: 2,296 Thanks: 1,212 Thanked 861 Times in 570 Posts Mentioned: 15 Post(s) Tagged: 0 Thread(s)	In case any one stumbles across this thread: 4.3FD 1. 9403.05 2. 6232.05 3. 4677.63 4. 3777.35 5. 2990.87 6. No input needed

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