Convert 915 to a push-style throw-out bearing/pressure plate...

[DieLucas!]

...looking for info on the possibility of converting my 915 transaxle to a push-style clutch. It is being used in a rear-engined Fiat project. My options are to modify the flywheel for the Porsche pressure plate, or to convert the transmission over to a push-style throw-out bearing and use the Fiat pressure plate on the stock flywheel.

Can it be done, without venturing into the uber-expensive Tilton hydraulic set-up? If so, what does it require? I'd imagine a different throw-out mechanism...and actuation is no large concern; at worst I can solve the problem by using a hydraulic piston to actuate the mechanism.

Thanks!

[john walker's workshop]

get a 915 out of a 76 912E. they're setup with a vw sized mainshaft spline and a push release fork.

[DieLucas!]

Can I just get the release fork?

Seriously...this is for a Fiat project; I honestly cannot afford to purchase another Porsche transaxle

[doozer]

Tilton makes a hydraulic push type throw out bearing for 915 and 930, I will be using one with my tilton clutch on a 930 box

http://www.tiltonracing.com/content.php?page=list2&id=207&m=d


OR you could try one of these universal ones: $147



http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=howe&N=400309+4294848712&D=400309&part=HRE%2D82870&autoview=sku&Ntk=KeywordSearch

[wevoid]

You can install the whole 912E release mechanism in any 1976 or later 915 final drive housing. If you have a pre 1976 915, you can still do it, but you will have to make a cable-outer-abuttment, for the clutch cable, as this feature was integral with the casting from 1976 onwards. For your Fiat install, you might need to do something different for the cable anyway.
I assume you need to have a TOB contact ring to suit the Fiat clutch package? that might need something custom, perhaps not.
None of the off-the-shelf annular hydraulic units are compact enough for the tight packaging in the 915 bellhousing, that's why we had to do both custom cable and hydraulic release mechanisms for the 5.5" push style clutch packages.

Regards

Hayden

[DieLucas!]

Originally posted by doozer
Tilton makes a hydraulic push type throw out bearing for 915 and 930, I will be using one with my tilton clutch on a 930 box

Does that Tilton unit bolt right into the 915 (or 930) or is there an adapter that has to be used to mount the throw-out bearing? Sounds promising...


...either way, I'm in for some work. Stock 915 pressure plate: I just need to modify my flywheel. Fiat pressure plate: I need to rework the release mechanism (hydraulic or mechanical), but I would then need to modify the Porsche ring gear...unless my wife would agree to pushing the car to start it :laughing:

:sigh:

Thanks for the info, guys!

[doozer]

Check out :

KENNEDY ENGINEERED PRODUCTS
38830 17th St. East, Palmdale, California 93550
35 year old company
specializing in engine adapters
and high performance clutches
for the Volkswagen bug, bus
and Porsche style transaxles.
kennedy@antelecom.net
postal address, or
Phone# (661) 272-1147
FAX # (661) 272-1575

http://www.kennedyeng.com/


You could probably mount the 915 ring gear to the fiat flywheel and then use the tilton to push the clutch.

I know they have tiltons for the long bell housing 930 that mount with a shim adaptor. I would think that it would also fit a long bell 915. Call tilton - their tech department is great.

[DieLucas!]

Did I miss it...or is there no Tilton info at Kennedy's website? Kennedy does not do anything with the Fiat engine...even approached them about a custom adapter plate and they were not to enthusiastic about helping; I already have an adapter plate, so now I'm just dealing with the other details.

I'm under the assumption that the 915 ring gear mounts onto the front of the pressure plate...that's the way it appears to me based on the pressure plate and ring gear I've got. Is this correct?

I'll give Tilton a call on the TO bearing.

[doozer]

Sorry, I did not know you had the flywheel -- that is why I was saying check out Kennedy.

The 915 ring gear actually mounts to the front of the clutch pressure plate

flywheel > disc (floating ) > pressure plate > ring gear

[doozer]

FROM: BeepBeep's ( Goran B. http://project911.luminasweden.com/ )
custom flywheel, pressure plate, and ring gear to SAAB engine

[beepbeep]

Actually, only thing that's custom on that pic is the adapter plate

Everything else is stock, bar machined SAAB flywheel.

Ring gear is stock 930, pressure plate is stock 930 and clutch disk is stock 930.

We wanted to keep it simple, so we just "adjusted" the flywheel until clutch came to same distance as OEM 930...that way, clutch fork never knows what's on the other side.

[DieLucas!]

Very cool; thank you both. Yeah, it does appear having my Fiat flywheel modified for the Porsche pressure plate would be the easiest and most straight-forward solution...

...however, now I have been entertaining the idea of replacing the entire pedal set...hmmm; we'll see what info Tilton may provide. Maybe I'll still have the flywheel redrilled (as I still need to use the ring gear) but convert to a push-style pressure plate with the hydraulic TO bearing. Good grief, this will be interesting.

And even more interesting is digging a Saab enthusiast out of the woodwork. I'm going to try to adapt a Saab EZK ignition box and knock sensor to my Fiat engine...any cheerful advice other than "don't do it"?

[beepbeep]

Huh? Are you sure it's "EZK" box and not "APC" box you're talking about?

I cannot remember that SAAB ever used EZK ignition...maybe old K-Jet models? Anyway, I don't find EZK ignition too user-friendly...they are hard to re-program etc.

I know they can be found in K-Jet equipped volvos though.

On of SAAB grommets that is quite usable (at least on watercooled cars) is so called APC-box. It's basically an analog knock-sensitive electronic boost controller. It has a knock sensor and operates a solenoid to achieve certain boost, unless knock is sensed.

[DieLucas!]

If my understanding and info is correct...


...the EZK came on the N/A Saabs clear through the 90's on LH-jetronic equipped cars (at least in the US), while the APC was equipped on the turbo'd Saabs. The EZK had a greater range of knock retard and was used with a centrifigal dizzy.

The APC had a lesser range of electronic knock retard, but boost also affected retard at the dizzy (boost retarding the dizzy's centrifugal advance), so APC did not need the range of spark retard that the EZK system offerred.

This is what I've figured out from info on the two systems...EZK was capable of 20+ degrees of retard while APC was around 15 degrees (or less).


Back to the TO bearing...I've been talking with Tilton this morning. The hydraulic TO bearing they sell for the 915 is only compatible with their racing clutch set-up. However, they use an adapter mount for this TO bearing, so I may be able to purchase the mount and modify it for a hydraulic TO set up for a conventional clutch. Progress...

[beepbeep]

Sorry for going off-topic but APC has nothing to do with ingition. It just controls the boost, trough solenoid. It takes in RPM, boost and knock signal and outputs PWD signal for solenoid.

With other words, It's fully possible to use EZK together with APC.

As far as I know, no SAAB 9000 used EZK, ever. Dunno about 900.

9000 used Hall-sensor triggered ignition integrated in Bosch LH from 1984 to 1989. After that came SAAB DI + Bosch LH (coil-on-plug with integrated knock detection) up to 1993. From 1994 and onwards it was SAAB Trionic all the way.

[DieLucas!]

It looks like my distinction between EZK and APC is still murky. I think some of it may be confusion between EZK ignition on turbo'd Volvos and Puegeots having different max retard than on N/A's Saabs...but I'm not even sure about that.

Anyway, EZK was used on pretty much all US N/A Saabs, 900's and on 9000's from the early 80's to '89.

http://www.thesaabsite.com/900old/c900ignition.htm
http://www.saabnet.com/tsn/faq/bu9000.html

You can google Saab and EZK and spend all day sifting through the info...