Author Topic: WTB electronic speed sensor for 5 speed L series gearbox  (Read 913 times)

Offline RLY240

  • Donating Member
  • Registered User
  • ***
  • Posts: 122
  • Location: Adelaide Hills, SA
WTB electronic speed sensor for 5 speed L series gearbox
« on: April 06, 2012, 04:34:06 PM »
I'm looking for an electronic speedo sender for an L series gearbox to drive my electronic speedo.
Anyone have something that is a direct replacement for the standard cable drive unit?
Roger
1972 240z tarmac rally car.
Roger

Offline dat2kman

  • Registered User
  • *
  • Posts: 1969
  • Location: The Gap Brisbane
  • comin' down the mountain!
Re: WTB electronic speed sensor for 5 speed L series gearbox
« Reply #1 on: April 06, 2012, 07:35:34 PM »
Grab one at a wreckers out of a S14 Sylvia, or an rb20 det engined something, it will fit into the existing hole in the ext housing of the B or C type box, your electronic speedo ( terratrip/brantz ?) should be able to be calibrated.
I just race old datsuns:
Group S Historic 280Z ( not a zx but a USA 280z)
Group O/T Historic Datsun Sports 2000
Group G Datsun 120y  with FJ24 fitted( ex G. Fury)
Marque Sports Datsun Fairlady 1966 -SR20DET

Offline RLY240

  • Donating Member
  • Registered User
  • ***
  • Posts: 122
  • Location: Adelaide Hills, SA
Re: WTB electronic speed sensor for 5 speed L series gearbox
« Reply #2 on: May 24, 2012, 06:07:22 PM »
Grab one at a wreckers out of a S14 Sylvia, or an rb20 det engined something, it will fit into the existing hole in the ext housing of the B or C type box, your electronic speedo ( terratrip/brantz ?) should be able to be calibrated.

OK, so I took the advice and sourced an S14 Sylvia sensor and sure enough it fits right into the L gearbox.  Problem is that the S14 sendor is a 2 wire job and the speedo I have requires only a single signal wire (presumably from a 3 wire sensor).
Can anyone shed some light on how I can convert the 2 wire signal into a single wire output?
Thanks,
Roger
1972 240z tarmac rally car.
Roger

Offline nat0_240_chevZ

  • Donating Member
  • Registered User
  • ***
  • Posts: 744
  • Location: Adelaide
Re: WTB electronic speed sensor for 5 speed L series gearbox
« Reply #3 on: May 24, 2012, 08:32:57 PM »
hi roger,
your signal is a ground/earth pulse,
earth the other side of the sensor.
is your speedo calibat'able to use either a 2, 4 or 8 pole sender, ie you can scale your speedo to any input frequency?
as i believe the S series sender is a 4 or 8 pole and the rb types are only 2 so ther are twice as many pulses per rev.
this is digging info out of the dead brain cell area of my brain,
so may not be 100% correct but at least 98% for the flamers.....
What speedo are you using? what type of input is it looking for? Earth pulse or voltage pulsed? depending on you unit, but some of the after market or upper quality units can use either.

let me know if this helps,
cheers Nathan

Offline RLY240

  • Donating Member
  • Registered User
  • ***
  • Posts: 122
  • Location: Adelaide Hills, SA
Re: WTB electronic speed sensor for 5 speed L series gearbox
« Reply #4 on: May 25, 2012, 09:06:00 AM »
Hi Nathan, thanks for the info.
The speedo is actually a head up display (HUD) unit that has only three inputs, power, ground and signal.  The documentation is very thin and I understand that it is expecting a pulse or digital signal.  I also thought that 2 wire senders were a wave or analogue signal that wouldn't work on the HUD.
I'll try your suggestions and see what happens.
Thanks,
Roger
1972 240z tarmac rally car.
Roger

Offline dat2kman

  • Registered User
  • *
  • Posts: 1969
  • Location: The Gap Brisbane
  • comin' down the mountain!
Re: WTB electronic speed sensor for 5 speed L series gearbox
« Reply #5 on: May 25, 2012, 11:47:39 AM »
Just a thought, goigle up the VDO electronic speedo, and how it is wired in, i know of a few who have gone S14 elect speedo box output, into the VDO dash gauge, maybe there is a dongle/interface, they supply as a "multifit" , or a pulse count reducer/increaser dongle.

The back of the VDO has calibration covering all types.
Re the HUD, maybe ask around some of the circuit guys that use them.

Be interested to see what you discover, please post results!
I just race old datsuns:
Group S Historic 280Z ( not a zx but a USA 280z)
Group O/T Historic Datsun Sports 2000
Group G Datsun 120y  with FJ24 fitted( ex G. Fury)
Marque Sports Datsun Fairlady 1966 -SR20DET

Offline RBZ 260

  • Donating Member
  • Registered User
  • ***
  • Posts: 1173
  • Location: Adelaide
  • S chassis Nutter
Re: WTB electronic speed sensor for 5 speed L series gearbox
« Reply #6 on: May 25, 2012, 12:25:10 PM »
Hi Roger,

yes S13 or S14 silvia 200sx 180sx.

Rb20 on R32 is cable driven so don't waste your time.

R33 or R34 maybe, but not sure or physical dimension.

yes Nathan is correct one is signal and other is signal ground. just run the two wires back to HUD. As for number of poles no idea but I'm sure you can select it through setting of your HUD.

Keep changing the settings till you get the correct speed readout. 

You may need to play with different drive gears if its not giving correct speed. S13-S14 gear ratios are differnet. Diff ratio will play a part in it too.
« Last Edit: May 25, 2012, 12:28:14 PM by RBZ 260 »
Nissan just wait till you drive it!

Auszcar 240z, 260z, 280zx Forums

Re: WTB electronic speed sensor for 5 speed L series gearbox
« Reply #6 on: May 25, 2012, 12:25:10 PM »