| View previous topic :: View next topic |
| Author |
Message |
Han Solo
Joined: 11 Jul 2015
Posts: 249
Location: Lebanon TN
|
 Posted: Thu Dec 22, 2016 1:43 am Post subject: Extra sensor trigger screws on 924S/944 flywheel? |
 |
|
So last night I'm about to install a new SPEC aluminum flywheel on my 924S race car and I noticed that two of the sensor trigger screws are missing when compared to the OE flywheel. This made me think that SPEC had forgot to manufacturer those in the part and those two were needed for the speed sensor. However, Clark's describes the speed sensor as counting the teeth on the flywheel so apparently those two screws serve no purpose. So is that a hold-over from earlier 924/931 ignition systems?
_________________
-----HAIRY ANT NEST RACING-----
Collecting, racing and restoring Porsches for fun and negative cash flow.
-----Epic 914 race car build----- http://forums.pelicanparts.com/porsche-914-914-6-technical-forum/767721-yet-another-rescue-porsche.html |
|
| Back to top |
|
 |
Rasta Monsta
Joined: 12 Jul 2006
Posts: 11732
Location: PacNW
|
| Posted: Thu Dec 22, 2016 2:02 am Post subject: |
|
|
Diagnostic sensor?
_________________
Toofah King Bad
- WeiBe (1987 924S 2.5t) - 931 S3
|
|
| Back to top |
|
|
Han Solo
Joined: 11 Jul 2015
Posts: 249
Location: Lebanon TN
|
| Posted: Thu Dec 22, 2016 2:16 am Post subject: |
|
|
| Rasta Monsta wrote: | | Diagnostic sensor? |
Unknown. Just searched threads and I'm not finding any reference.
The 931 flywheel is different however 93110220604 to the 924S/944 94410205101.
And the there's only one screw shown in the parts diagram 94410313302.
Is there another port in the bell housing for said diagnostic sensor Rasta? I've got another item dangling near the bell housing that I thought was related to O2 mixture and it has a bracket attached. You can see it next to the flywheel in this photo...
 [/url]
_________________
-----HAIRY ANT NEST RACING-----
Collecting, racing and restoring Porsches for fun and negative cash flow.
-----Epic 914 race car build----- http://forums.pelicanparts.com/porsche-914-914-6-technical-forum/767721-yet-another-rescue-porsche.html |
|
| Back to top |
|
|
KDJones2000
Joined: 14 Sep 2010
Posts: 322
Location: Phoenix, AZ
|
| Posted: Thu Dec 22, 2016 4:04 am Post subject: |
|
|
Those are for the TDC for the Por$che dealer diagnostics.
Not needed for a race car.
You can see the sensor in your picture, the one with the light grey wire that is in the hole on the left of your picture in that bracket.
_________________
1987 924S SPEC car
Team Toofah Racing
1988 944 Turbo S |
|
| Back to top |
|
|
Han Solo
Joined: 11 Jul 2015
Posts: 249
Location: Lebanon TN
|
| Posted: Thu Dec 22, 2016 4:45 am Post subject: |
|
|
| KDJones2000 wrote: | Those are for the TDC for the Por$che dealer diagnostics.
Not needed for a race car.
You can see the sensor in your picture, the one with the light grey wire that is in the hole on the left of your picture in that bracket. |
Mystery solved! Thanks for your help gentlemen. Now I can install the SPEC flywheel with some degree of confidence.
_________________
-----HAIRY ANT NEST RACING-----
Collecting, racing and restoring Porsches for fun and negative cash flow.
-----Epic 914 race car build----- http://forums.pelicanparts.com/porsche-914-914-6-technical-forum/767721-yet-another-rescue-porsche.html |
|
| Back to top |
|
|
Han Solo
Joined: 11 Jul 2015
Posts: 249
Location: Lebanon TN
|
|
| Back to top |
|
|
Han Solo
Joined: 11 Jul 2015
Posts: 249
Location: Lebanon TN
|
| Posted: Fri Dec 23, 2016 6:00 am Post subject: |
|
|
So I figured out why my new SPEC aluminum flywheel was missing two of the trigger screws present on the OE flywheel yesterday through this thread and more research...
And I installed the SPEC flywheel last night. But it appears the spacing on the sensors is going to need to be adjusted. I'm thinking that doing that now with great access to the sensor bracket in the bell housing tunnel, from below. I can adjust the bracket with the reference sensor temporarily installed by measuring from the trigger screw on the new flywheel. However, everything I've read says to measure .8 mm on the speed sensor and that, in turn, sets your reference sensor. So does anyone know what the reference sensor ends up at you you follow that procedure? Another reason I need to know is because the trigger screw on the SPEC flywheel is much shorter than OE. I suspect I'm going to have to back that out a ways to get the correct gap.
_________________
-----HAIRY ANT NEST RACING-----
Collecting, racing and restoring Porsches for fun and negative cash flow.
-----Epic 914 race car build----- http://forums.pelicanparts.com/porsche-914-914-6-technical-forum/767721-yet-another-rescue-porsche.html |
|
| Back to top |
|
|
KDJones2000
Joined: 14 Sep 2010
Posts: 322
Location: Phoenix, AZ
|
| Posted: Fri Dec 23, 2016 9:30 am Post subject: |
|
|
Look in the factory manual. There is a specification height for that trigger.
It should be red-Loctited into the flywheel, once set.
_________________
1987 924S SPEC car
Team Toofah Racing
1988 944 Turbo S |
|
| Back to top |
|
|
Han Solo
Joined: 11 Jul 2015
Posts: 249
Location: Lebanon TN
|
| Posted: Sat Dec 24, 2016 6:06 am Post subject: |
|
|
So here's what I'm looking at. Speed sensor set at .8 mm from the ring gear with no space. The reference sensor is off the pin considerably more. I set the pin height at 6 mm off the flywheel. That just looks really far away to me.
_________________
-----HAIRY ANT NEST RACING-----
Collecting, racing and restoring Porsches for fun and negative cash flow.
-----Epic 914 race car build----- http://forums.pelicanparts.com/porsche-914-914-6-technical-forum/767721-yet-another-rescue-porsche.html |
|
| Back to top |
|
|
hdrider19
Joined: 03 May 2016
Posts: 193
Location: Catawissa Missouri(40 mi sw of St Louis)
|
| Posted: Sat Dec 24, 2016 9:27 am Post subject: |
|
|
You could put a shim under the long sensor. Take a look at page 243 in the pet. Part 29 appears to be a shim for this purpose. By raising that sensor it will bring the other one closer when you readjust the bracket.
_________________
87 924S |
|
| Back to top |
|
|
Han Solo
Joined: 11 Jul 2015
Posts: 249
Location: Lebanon TN
|
| Posted: Sat Dec 24, 2016 1:25 pm Post subject: |
|
|
| hdrider19 wrote: | | You could put a shim under the long sensor. Take a look at page 243 in the pet. Part 29 appears to be a shim for this purpose. By raising that sensor it will bring the other one closer when you readjust the bracket. |
And that's exactly what I did. I didn't have the OE spacer so I fabricated one out of a large washer. That raised the speed sensor and I then re-adjusted the bracket. I suspect Porsche added that spacer when the sleeve was added to the reference sensor. The early cars didn't have the sleeve and the starter was causing EMF to interfere with the signal. So the sleeve added about .5 mm to the reference sensor and the speed sensor had to be raised to keep the same relationship. Anyway, it's as close as I can get it and we'll see soon if there's issues.
_________________
-----HAIRY ANT NEST RACING-----
Collecting, racing and restoring Porsches for fun and negative cash flow.
-----Epic 914 race car build----- http://forums.pelicanparts.com/porsche-914-914-6-technical-forum/767721-yet-another-rescue-porsche.html |
|
| Back to top |
|
|
Han Solo
Joined: 11 Jul 2015
Posts: 249
Location: Lebanon TN
|
| Posted: Wed Dec 28, 2016 11:52 pm Post subject: |
|
|
Update - I finished installing the pressure plate, bell housing, clutch slave cylinder, starter, torque tube, header, new speed and reference sensors. The fuel tank is out but I wanted to confirm ignition before getting much further. So I shot a bit of ether into the MAF and cranked the engine. The tach bounced and the engine fired up. So that spacing on the reference sensor is correct as far as I can tell that this time.
_________________
-----HAIRY ANT NEST RACING-----
Collecting, racing and restoring Porsches for fun and negative cash flow.
-----Epic 914 race car build----- http://forums.pelicanparts.com/porsche-914-914-6-technical-forum/767721-yet-another-rescue-porsche.html |
|
| Back to top |
|
|
|
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
924 FAQ (Technical)
