Will a stock 3.3 flywheel bolt to a 915?

[laughac]

I'm having an '87 3.3 installed into my '77 911s and the mechanic does not know which flywheel to order. The 930 did not come with one.

[sundevil64]

Not sure what the part number is, but I have an 84 Carrera with a 79 930 motor bolted to a 915 tranny. I would say yes.

[triguy]

I am starting to put a 3.3 into my 1974 911. I just had my 2.7 flywheel beside the one on the 3.3 I believe the turbo is 240mm for the 930 trans and the other one is 225mm for the 915 transmission. I am not 100% sure.

[quattrorunner]

Just use one for your car. Needs to be the 9 bolt. Toys should be fine. Order the sachs sport though. You'll need some extra clamping force. It should fit your 225mm flywheel.

[quattrorunner]

Toys meant to say yours. iPhone thinks it knows best when spelling.

[RarlyL8]

I used the (225mm) 915 flywheel and a Sachs Sport Clutch on mine.

[triguy]

Brian how does the 915 hold up with that power. I am planning to get rid of my 915 and put in the 930 four speed but they cost a bit more and along with the change of the shifter etc.

Thnaks Neil

[RarlyL8]

I ran a stock 915/61 for 10 years in front of a 300WHP 930 engine. No issues until I took it to the drag strip. While the tranny was apart I added the WEVO bearing retainer and a Carrera side cover. I put that tranny back in and built a Euro Carrera 915 with the same style bearing retainer and custom gears to facilitate more power that was anticipated with the addition of my headers.
The headers added 50WHP and 60ft/lb torque for a total of 350WHP. So far the tranny is doing fine. You will note that no trips to the drag races will be in this tranny's future.

[laughac]

Originally Posted by triguy

I am starting to put a 3.3 into my 1974 911. I just had my 2.7 flywheel beside the one on the 3.3 I believe the turbo is 240mm for the 930 trans and the other one is 225mm for the 915 transmission. I am not 100% sure.

I'm not home to look, but I think my 2.7 flywheel is 6 bolt and the 3.3 seems to need a 9 bolt.

Patrick Motorsports just sold me a $400 RSR 225 mm 9 bolt saying that I'd need it.

[turbo nut]

A SC 3.0 flywheel should work.

[RarlyL8]

Send it back you don't need it. All the 915 parts will work and will bolt right onto the 930 engine case as it is the same as the SC.

[quattrorunner]

If your flywheel is 6 bolts, you need one with 9 bolts. The 3.3 only accepts the newer flywheel. An sc would work for sure. I'm not sure but maybe the 77' is new enough that it got the newer flywheel. That year is right at the cutoff if I remember right. Maybe 76 was the last 6 bolt?

[spuggy]

Originally Posted by quattrorunner

If your flywheel is 6 bolts, you need one with 9 bolts. The 3.3 only accepts the newer flywheel. An sc would work for sure. I'm not sure but maybe the 77' is new enough that it got the newer flywheel. That year is right at the cutoff if I remember right. Maybe 76 was the last 6 bolt?

Pretty sure my flywheel is 9 bolt, and from the '77.

My Sachs Power Clutch was down to the rivets after 15,000 miles, and had probably never held the stock torque. Use a Sport pressure plate or better, like others have said. That seems to be holding up well (although I think I'm pushing my luck and am plotting for a G50.,.). Make sure everything is in good shape, so it'll stand up to the higher pedal pressures (I've broken/replaced about every external doo-hickey & bracket attached to the clutch in the last 5,000 miles).

My mag case 915 looked pretty sad inside after 15,000 miles behind a 930. Whatever you use, you should make sure it's in as good shape as you can - and the later the 915, the stronger it is. If it breaks, it'll be bad.

WEVO bearing retainer and an LSD are really good investments, as is the later side cover or a WEVO billet replacement. Internal spray bar kit on the gear faces is also useful (factory did that for all the racing boxes, as well as a cooler). If I were doing it over again, I'd use the exchange WEVO cases with the steel bearing inserts as well.

No matter what you do, the 915 is the limiting factor with a 930. You get easily get to a point where you make more power than you can reasonably expect the 915 & axles to handle/stand up to for long and you get tired of babying it. But it's tough to give up the 5-speed and the short gears...

[quattrorunner]

Here is a good thread on the difference of all 915 models. I believe that the 76-77 mag case model to be the best one of all but it's the one I have so I choose to believe that. Read the graphs. Mag is lighter and doesn't deform the way aluminum does, still the typical upgrades are pretty much required for 930 torque. I have this mag trans axle and I still think it's wise to "baby" it. As Brian said, it's a good 915 (915/61) but they are meant for 200lb ft. torque. Look at what renegade hybrid has as upgrades, they typically run a lot of torque.

http://forums.pelicanparts.com/Porsche-911-technical-forum/332597-best-year-915-transmission.html?highlight=915

[quattrorunner]

triguy, your car deffinately needs the newer flywheel. Yours won't bolt to the crank of the 3.3.
You could use any sc or carerra up to 87 flywheel.

[triguy]

I knew about the flywheel being different. I have a 74 915 with the small ring and pinion in it. I think it will be weaker under load. I am going to have to buy something so I am leaning toward the 930 tran.

One other question is the sach power clutch the same as the sport clutch?

Thanks Neil

[spuggy]

Originally Posted by triguy

One other question is the sach power clutch the same as the sport clutch?

Not even close. The Power Clutch is a cherry-picked stock clutch - guaranteed to be in the top 10% of spec. You could buy a stock clutch and get precisely the same thing. Mine was all worn out (down to the rivets) after 15,000 miles with a 930/60 with SC cams. I put in a brand new Power Clutch in after the intercooler/K27 upgrade - as soon as I stopped babying the rebuilt motor it would brake loose over 3,000 on anything more than 1/2 throttle. And it got rapidly worse from there.

The Sport clutch is the closest thing you can buy to an RSR pressure plate, I'm told. Mine holds 350 ft/lbs to the rear wheels, but the pedal pressure is at least 50% higher, maybe double. Just in the last month or two (after 15,000+ miles) I've had the splined hub crack on the adjustment lever ("never seen one fail like that before", quoth my wrench) and the cable bracket ("seen one fail before, but it's quite rare").

[laughac]

I ordered the RSR flywheel