Jump to content
SAU Community

Recommended Posts

Has anybody successfully worked out how to have an aftermarket gear position indicator for an auto in a stagea?

With the Link dash installation almost complete were having issues getting the gear position to show on dash unit, as the factory dash uses 2 seperate signal types between the box and the ECU, as in it receives a square wave signal and transmits a sine wave or vice versa, so it's not reading and allowing the dash panel to show .

It will also be making it potentially worse being that the trans is a manualised valve body and being Jatco 4th gear is electrically selected as well as the lock-up for converter, so they are switched seperate 

Link to comment
https://www.sau.com.au/forums/topic/483731-gear-indicator-display/
Share on other sites

On 6/6/2022 at 8:05 PM, GTSBoy said:

Just do it calculated off of vehicle speed vs RPM.

We can potentially do that, but what about indication for neutral, reverse,park and converter lock up? And would also like to avoid any more thousands in labour costs for calculating and calibration, am reaching out to Link and Aim(dash manufacturers) to see if they have a work around,but thought there may have been someone that's seen it done in a track,drift or drag car that has a Jatco box???

On 6/6/2022 at 5:48 PM, oxford1327 said:

Has anybody successfully worked out how to have an aftermarket gear position indicator for an auto in a stagea?

With the Link dash installation almost complete were having issues getting the gear position to show on dash unit, as the factory dash uses 2 seperate signal types between the box and the ECU, as in it receives a square wave signal and transmits a sine wave or vice versa, so it's not reading and allowing the dash panel to show .

It will also be making it potentially worse being that the trans is a manualised valve body and being Jatco 4th gear is electrically selected as well as the lock-up for converter, so they are switched seperate 

I can look into the wiring tomorrow and see where it picks up the signal if you want

  • Thanks 1
On 6/6/2022 at 6:58 PM, oxford1327 said:

neutral, reverse,park

There are switches for those, no?

TC lockup could possibly be inferred from rpm vs speed also. If it sits dead bang on the relationship given by the gearing, then TC is locked up. If it is in the "band" available from TC slip around the gear ratio, then it is unlocked.

On 6/6/2022 at 11:44 PM, GTSBoy said:

There are switches for those, no?

TC lockup could possibly be inferred from rpm vs speed also. If it sits dead bang on the relationship given by the gearing, then TC is locked up. If it is in the "band" available from TC slip around the gear ratio, then it is unlocked.

Yep there are 2 manual switches for 4th gear and lock up, so they're the easiest to solve I spose in comparison, just a bugger that the Link ecu and the Link dash can't bloody read the gear position by themselves, and seems that I'm always the damn guinea pig too, but that's my fault for wanting pretty /shiny things and jumping first....

I have replied in other thread, this is so easy to do and isn't thousands to setup by a competent workshop/tuner.
Its all in what is wired to ecu and in its setup so many people have no idea how to do it right.

On 6/6/2022 at 6:44 AM, GTSBoy said:

There are switches for those, no?

TC lockup could possibly be inferred from rpm vs speed also. If it sits dead bang on the relationship given by the gearing, then TC is locked up. If it is in the "band" available from TC slip around the gear ratio, then it is unlocked.

Can't you snoop the TC lockup solenoid to determine this too?

On 6/8/2022 at 7:57 AM, joshuaho96 said:

Can't you snoop the TC lockup solenoid to determine this too?

Honestly have no idea with anything that has wires cos I tend to let the smoke out of them, so I leave that stuff to others and stick to mechanical things that I can see what they do and how.....

The 2 shift solenoids form a 2-bit number which describe the forward gears. But don't assume, 0 is first first gear, and 3 is 4th gear. I think from memory b00 is actually 3rd.  The ECU loom also has wires which are digital states for when central shifter is in reverse, neutral or the forward gears.

Coupled with some microcontroller logic (or lucky you if your ECU is modern and has some flexible inbuilt programmable logic), you could determine what gear is currently active, and drive an LED digit display.

Forget the speed vs rpm method for an auto.

P.S.

From one of my micro programs the solenoid combos are as follow (LSB being solenoid 1)

b00 : 3rd gear
b10 : 2nd
b01 : 4th
b11 : 1st

On 6/9/2022 at 2:47 PM, zoomzoom said:

The 2 shift solenoids form a 2-bit number which describe the forward gears. But don't assume, 0 is first first gear, and 3 is 4th gear. I think from memory b00 is actually 3rd.  The ECU loom also has wires which are digital states for when central shifter is in reverse, neutral or the forward gears.

Coupled with some microcontroller logic (or lucky you if your ECU is modern and has some flexible inbuilt programmable logic), you could determine what gear is currently active, and drive an LED digit display.

Forget the speed vs rpm method for an auto.

P.S.

From one of my micro programs the solenoid combos are as follow (LSB being solenoid 1)

b00 : 3rd gear
b10 : 2nd
b01 : 4th
b11 : 1st

Cheers, will look into this 

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Hello! Long time lurker, been using the forums to address concerns and questions from afar for a while but I've struggled to find some answers so I guess its about time I made an account and formally asked some more knowledgeable people, since finding local skyline owners is hard (and shops that are knowledgeable or trustworthy to work on 'rare' cars are non existent out where im at, as skylines are quite uncommon to find in the wild around here). So the main 3 questions I have, 1: Steering rack has blown seals, well.. they kind of hold but they are not sealed properly anymore and as my R33 is my DD, i cant exactly rip the rack out and send it off or attempt to fix myself. As most refurb ones are around $1,100 or more shipped, and I have other things I need to work on around the car, I was seeking clarification on whether an S15 rack will more or less bolt right in, and whether a common mechanic could do any other required work to get it to fit. I ask, as I've found a supplier than can sell a manufactured as oem one for around 400, if not I'll likely order a used one from Jacks JDM, and take a risk on the seals there. The second question i have is that im replacing the front wiper cowl and have planned to buy 4 new clips and a new center clip but wasnt sure if there were any other clips that would also need to get replaced while I was at it. Given im sure any that are there now will simply break when I remove the old cowl... Last thing would be a fairly straight forward question, i think. If I manage (strong if, finding one has proven to be a pain) to find a R33 GTR spoiler/wing will it require much modification to bolt to a S2 R33 GTST? I've read the bolt patterns dont match but otherwise would bolt in, only options I have found with much luck is China stuff on ebay and carbonetics, which has a nice $650 shipping fee... so if anyone has any pointers where a US chap could locate one that would be great Random side question as well, the mirrors as I understand are mirror glass, and as im planning to polish my windows from water spots and surface scratches, i was hopeful cerium oxide would be fine for them too, as my research points to, but clarification is always nice. Any pointers would be appreciated, and while I have scoured the internet for answers if I missed a prior post somewhere that may answer these directly please point me towards it, as i must have simply missed it. I have seen a post here or there that has mentioned it, but I usually get 50-50 answers, or half answers... I dont have a lot of fab experience or mechanic experience, outside of hydraulic and pneumatic stuff I did in the military and with how hard it is to source stuff in the US, id rather not wing it and hemmoraghe money lol. Thanks guys! Sorry for the monumental first post haha
    • Yep, there's a very minor drift left that happens a few seconds after letting go of the steering wheel, but not enough to bother me. Enjoying the car still!
    • Got you mate. Check your email!
    • I see you've never had to push start your own car... You could save some weight right now...
×
×
  • Create New...