|
|
|
|
| Author |
|
|
Registered
Join Date: Sep 2020
Posts: 408
|
911 speedo in a 930
Hi,
I wonder if a 911 SC speedometer will work correct in a 911 Turbo (930) ? Cheers Sent from my iPhone using Tapatalk |
||
03-27-2023, 03:00 PM
|
|
|
Registered
Join Date: May 2004
Location: Boulder, Colorado
Posts: 7,275
|
Should work. In 1976 the 911 shifted from a cable speedometer to an electronic speedometer. Seems the Turbo had that from the get-go. But you might need to have it "tuned." The speedo has to be matched with the tire circumference. Some SC speedos only go to 85mph!
|
||
|
03-27-2023, 03:18 PM
|
|
|
Registered
Join Date: Jul 2003
Location: Glorious Pac NW
Posts: 4,184
|
As Walt says, all the electronic speedometers interchange, up to the G50 - they all use a reed switch with a disc of magnets (8, I think) in the transmission to drive the speedo. It just generates an analog square wave signal that the speedo "counts".
I thought the changeover to electronic was earlier than '76 - but some show still listed in 1976 for base (eg non-S, non-Carrera) 911s. Heh. Those have gotta be pretty rare... I've had the original, 930 & 3.2 speedos in my '77, and am currently driving mine from a G50. They Just Work - however, calibration is a real issue, if not running the exact wheel size & tire profile (and hence rolling diameter) speedo was originally designed for. You can end up 11-15% out, or even more. Mine were useless with low-profile 17" tires... I fitted a Yellow Dog in 2012 and keep forgetting it's there... Calibrate until it's as accurate as you need (I prefer mine to show the "real" speed) and forget it. https://forums.pelicanparts.com/porsche-911-technical-forum/951077-speedometer-correction.html
__________________
'77 S with '78 930 power and a few other things. |
||
|
03-28-2023, 02:46 PM
|
|
|
Registered
Join Date: May 2004
Location: Boulder, Colorado
Posts: 7,275
|
Right - it is 8 magnets, glued radially in an aluminum disk.
 What sends a signal to a G50 era speedometer? |
||
|
03-28-2023, 03:25 PM
|
|
|
Registered
Join Date: Jul 2003
Location: Glorious Pac NW
Posts: 4,184
|
Quote:
  So the factory didn't need to change speedometers for either the 911 or the 930 when they went G50.
__________________
'77 S with '78 930 power and a few other things. |
||
|
03-29-2023, 08:30 AM
|
|
