Board logo

Dash2 Gear Indicator Issue (Hayabusa)
Parkstar - 24/11/25 at 03:47 PM

Hi everyone,
I have a RaceTechnology Dash2 display fitted to my gen2 hayabusa car, and I'm having an issue where the gear indicator flickers between several gears so I don't have any confidence in which gear I'm in!

At the moment the dash is set up to base the gear indicator on the voltages from the gear position indicator as follows:

1st gear = 1.782v
2nd gear = 2.242v
3rd gear = 2.960v
4th gear = 3.630v
5th gear = 4.310v
6th gear = 4.660v
Neutral = 5.000v

The problem I think is that the voltages are very close together so any small variance causes the dash to misread the gear, combined with the dash itself rounding the voltage up or down to identify the gear. The dash flickers between a lot of gears but the most common is 6th and Neutral where the voltages are very close, but out of all of them this is the least troubling as its pretty obvious whether I'm in 6th or N!

Has anyone had any success with this dash and engine? Any set up values etc you can share?

The dash can also be set up to use the gear ratios and final drive to calculate the gear on road speed. I've not tried this method as I couldn't get my head around how to take account of the primary drive ratio as well as the final drive. Similarly if anyone has had success in a BEC please help!

Thanks!


Sanzomat - 24/11/25 at 04:16 PM

Not sure how it works on the Race Tech one but on my Acumen gear indicator it can take a pulse feed from the rev counter and the speedo and you run through a learning procedure where it works out what the gears are from the ratios of the pulse counts. I did mine with the car on axle stands and run it up through the gears and it sorted itself out.


Slimy38 - 24/11/25 at 04:18 PM

They're not that close together? It should be able to read them without too much difficulty. My first thought is the reference though, IE ground connection. Are there some nice thick ground wires going between everywhere? If you have a multimeter could you see whether there are any stray volts going around that could interfere with the readings? Does it make you feel like you've changed gear when you put your lights on, or can you seemingly change gear in time with the indicators?


Parkstar - 24/11/25 at 04:19 PM

quote:
Originally posted by Sanzomat
Not sure how it works on the Race Tech one but on my Acumen gear indicator it can take a pulse feed from the rev counter and the speedo and you run through a learning procedure where it works out what the gears are from the ratios of the pulse counts. I did mine with the car on axle stands and run it up through the gears and it sorted itself out.


Thank you! I'll look into it, hopefully it has a similar feature on my dash


Parkstar - 24/11/25 at 04:22 PM

quote:
Originally posted by Slimy38
They're not that close together? It should be able to read them without too much difficulty. My first thought is the reference though, IE ground connection. Are there some nice thick ground wires going between everywhere? If you have a multimeter could you see whether there are any stray volts going around that could interfere with the readings? Does it make you feel like you've changed gear when you put your lights on, or can you seemingly change gear in time with the indicators?


Hadn't thought of that. From memory it could be pretty close to the engine case ground connection, then it all goes past the fusebox etc to get to the dash.

I'll have a play and see if the gear number changes with lights etc. Whats the solution if this is the problem? Any way to shield the gear position sensor wire from interference?


Slimy38 - 24/11/25 at 05:37 PM

quote:
Originally posted by Parkstar
quote:
Originally posted by Slimy38
They're not that close together? It should be able to read them without too much difficulty. My first thought is the reference though, IE ground connection. Are there some nice thick ground wires going between everywhere? If you have a multimeter could you see whether there are any stray volts going around that could interfere with the readings? Does it make you feel like you've changed gear when you put your lights on, or can you seemingly change gear in time with the indicators?


Hadn't thought of that. From memory it could be pretty close to the engine case ground connection, then it all goes past the fusebox etc to get to the dash.

I'll have a play and see if the gear number changes with lights etc. Whats the solution if this is the problem? Any way to shield the gear position sensor wire from interference?


Personally I'd take inspiration from O2 sensor wiring, the way it's shielded and protected due to the voltages involved. If possible go direct from the sensor to the indicator, something like that?