Short 930 Box in Carrera

MotoSook · 01:14 PM

Who's done it?

I received what were suppose to be all the right parts for the install, but nope...they sent all 915 parts. I've been trying to work it out with the clutch company (I don't have faith that they ever sold parts for such a conversion), but I also want to make sure they don't send me any wrong parts again! It's been killing me!

Anyhow, I have a 930 short bell housing tranny that I'm mating to a 3.2 that had a 915 in it.

I'm certain I will need a 930 pressure plate to work with the 930 TOB and TOB fork on the tranny, but will a 930 pressure plate allow me to use the 3.2 ring gear and flywheel? If so, will the PP be the right thickness so the starter will engage?

Is the early 930 pressure plate the right diameter?!

I need to retain the 3.2 flywheel for the reference sensors to work, or do I have to go to Patrick Motorsport and buy a custome flywheel?

OR!

Has anyone used the 915 clutch package with a 930 tranny, but changed out the 930 TOB fork for a 915 TOB fork. I need to make some comaprisons, but it looks like I that might be the easiest part to do the conversion...if the forks have the same shaft contact dimensions.

The 915 that was on the car is long gone, so I can't make measurement comparison...so HELP! PLEASE...

MotoSook · 07-30-2005, 01:24 PM

Com'on guys, I need this sorted this weekend, or I'm going for a long walk and never turning back....argh! Someone must have done this before. Yep, I ran a search, but I didn't turn up anything. I don't want to have to buy parts for trial and error.

Grady? John Walker? Ramsey?

YermanCars · 07-30-2005, 06:27 PM

No Help

MotoSook · 07-31-2005, 05:39 AM

Bump for the "easy like Sunday morning" crowd!

beepbeep · 07:48 AM

Hello!

We have some limited expirience with mating of different transmission to engine. Until Hayden chimes in, I'll try to do my best.

930 short tranny is good beacuse you don't have to cut torsion tube or move engine mounts further back. 915 clutch has smaller diameter than 930 clutch (225mm compared to 240mm I think) and should thus not be used.

Long bellhousing 930 transmission use rubber-damped clutch plate and short bellhousing use spring-damped plate. also, long bellhousing pressure-plate is thicker and thus heavier than it's short counterpart.

This is lightweight aluminium short-bellhouse pressure plate:

This is heavy cast-iron long-bellhousing pressure plate with start motor ring gear installed (it's bolted to another motor, but everything else is the same).

As far as I know, 930 and 911 starter are the same, so your only concern is bolting together right clutch package so starter ring is at same distance from transmission as usual. I believe you should be able to use early "short-bellhousing" 930 clutch package alltogether and mate it to your 3.2 engine.

That way, clutch assembly won't know "who's spinning the flywheel".

Unfortunately, early 930 OEM clutch parts are hideously expensive for some reason so you should check out aftermarket parts.

So to round it off:

Use 930-parts troughout (clutch, pressure plate, TO-bearing, TO-fork etc.) and check if you can bolt it to your Carrera flywheel. If not, try to machine your exisiting flywheel or find used 930 75-77 flywheel.

Luckily, you can use OEM Carrera shafts as they have same CV diameter as 930.

YermanCars · 07-31-2005, 12:59 PM

he early 930 stuff should work, just use your 3.2 Flywheel. The 3.2 and the early 930 were all 240mm clutches. Juan burnt his clutch out at one raceand in the middle of the night we decided that we were gonna throw my early 930 PP on his car, we had it already to go on then found a better replacement at the last minute. You would use the 3.2 ring gear on the 930 PP. I'm not 100% positive how yoru stuff is setup exactly, i just know how it would have worked on juans car.

MotoSook · 07-31-2005, 02:09 PM

Does Juan have a 930 4-speed?!

Who posted that above?

MotoSook · 07-31-2005, 02:26 PM

Quote:

As far as I know, 930 and 911 starter are the same, so your only concern is bolting together right clutch package so starter ring is at same distance from transmission as usual. I believe you should be able to use early "short-bellhousing" 930 clutch package alltogether and mate it to your 3.2 engine.

Thanks for posting Goran. I'm hoping that is the case.

ChrisBennet · ChrisBennet's Garage

Quote:

Originally posted by beepbeep

Luckily, you can use OEM Carrera shafts as they have same CV diameter as 930.

Sometime in 1985 the Carrera went to the larger diameter CV's with the 10mm bolts - same size CV's as 930.
-Chris

MotoSook · 09:28 PM

We workout out the output flange and CV issue, now I just need to get the right clutch parts. We had to use fine spline output shafts for the smaller CVs.

KTL · 07-31-2005, 09:24 PM

So, it sounds like the solution is to use a 87-89 3.2 flywheel and then bolt the early 930 clutch housing to it?

I got a couple of 87-89 3.2 flywheels Souk. Let me know if you need one.

MotoSook · 07-31-2005, 09:31 PM

Still don't know yet Kevin. I was busy wrenching all day to research it further..then I get a visit from Dad (bad family news) then I get a call to go help my sister with her garage door (broken spring!), then I had to kill a raccoon, them I run out of beer....OH! I'ts just too much! I'm going to go take a bath and let Calgon take me away

Thanks for the offer. I'm going to make some calls in the AM and see if I can get it sorted...adn I might need to take you up on one of those flywheels. Thanks bud!

beepbeep · 07-31-2005, 11:02 PM

Quote:

Originally posted by ChrisBennet
Sometime in 1985 the Carrera went to the larger diameter CV's with the 10mm bolts - same size CV's as 930.
-Chris

Yeah, halfshafts needed to bolt 930 flange to Carrera hubs are of 108mm diameter. Luckily, those halfshafts are pre-assembled. pre-lubed, sturdier and much cheaper than it's SC counterparts. Outer CV's don't have any CV bolts to care about either.

YermanCars · 08-06-2005, 11:04 AM

Souk, it looks like we may have found are answer In another thread.

What do you guys think?

MotoSook · 08-10-2005, 01:05 PM

OK Gang...I need to resolve this, and there is little information out there. So lets put our heads together..

Patrick Motorsport has a solution, but in another thread it was mentioned that a Pelican had problems with Patrick Motorsport's package on a high power application. In Patrick MS's defense it was also mentioned that the package was their first such thing. Protomotive has also done it, but I haven’t talked to Todd yet (I will tonight or tomorrow).

So! Some have said that the 935 pre$$ure plate can be used or the 930 pressure plate (less pressure applied to the clutch disk, but same as the 935 PP). Some machining is needed on both the 930/935 pressure plate. Machining is also necessary on the G50 flywheel.

The sensors are reversed (speed sensor now on the inside and TDC sensor on the outside), with a new indicator pin installed on the pressure plate for the TDC sensor to work.

The 240 mm 930/935 pressure plate should fit inside the 240 mm flywheel of the G50, but with holes drilled in the pressure plate so it can be bolted to the G50 flywheel. So it appears that the flywheel is machined down to allow for greater TOB travel, and allow the clutch disk and flywheel to disengage. (RIGHT?)

A 930 ring gear is then used, but it needs to be drilled so that it too can be bolted to the flywheel.

But are spacers used to space the ring gear forward so that the starter can engage it?

Did I understand the machining of the flywheel and PP correctly?

OK….some of you might just say “Why not just buy something that works?” Well, something that “works” seems to be the issue. There is no clear solution..YET! And it’s not as clean cut as you might think…..I just can’t post it.

MotoSook · 08-10-2005, 01:08 PM

Anyone have the dimensions for a 930 ring gear and pressure plate?

Better yet! Anyone have those parts laying around that they can send me? I'll sent then back if they are useable.

I might as well engineer that dang package myself!

MotoSook · 08-10-2005, 01:21 PM

Here is a thread on a G50 install on to a 3.2. Relavent? Depends on whether the G50 and Short-bell 930 boxes have the same dimensions inside the bell.

Seems that thread has been abandon:

g50 into 84 carrera?

MotoSook · 08-10-2005, 01:44 PM

Com'on gang....we can't only be interested in the color of our car and the different Fuchs finishes

This is a technical forum

SC-targa · 08-10-2005, 02:19 PM

I feel for you Souk, but I have no info to share. Sorry

Jerry Kroeger

MotoSook · 08-10-2005, 02:22 PM

Thanks Jerry. That helped the soul.