996 trans

[justanut]

Hoping to do an ls swap in the near future. Lots of info here. My question is how much modification if I wanted to use a 996 transaxle in a late 70’s 911. G50’s are terribly expensive and thought the 996 would be a cheaper alternative as long as I don’t have to cut my car to pieces. Thanks for any help with this

[VacantSky]

I looked into it, wayyyy more involved and you would still have to cut the car and figure out the hydraulic clutch, you’d be in just as much money with fabrication. The nose cone on the 996 transmissions are very long, as is the bellhousing. I’d say if you have a 915 trans car your best bet would be either to build the 915 and run maybe an aluminum block 5.3, or maybe destroke a 5.7 or 6.0 using a 4.8 crank to reduce torque making it a little more forgiving (and increase the rev range..!), or get yourself a shortened 930 4 speed. Don’t let the 4 speed fool you either, it’s geared very tall so not a highway screamer 2250~ rpm @70mph, And it can handle 6-700 ft lbs - 300ft lbs continuous.

[justanut]

Thanks for the reply. Kinda what I figured. Just finished reading ur thread. Hopefully the build is nearing the end. An L33 5.3 is exactly what I was thinking because as much as I want 500hp 350ish will be more than enough as my sometimes daily driver. Thanks again and hope to pick ur brain in the future as my build gets under way.

[Yan2947]

I have a 383 stroker with a 915 tranny that was modified and has really tall gears from Calif Motor Sport. I am willing to sell because I came across a 930 tranny that I had shortened and plan on doing a ls7. The 383 has approx 450 hp and is complete with everything and exhaust/turn key to put in a car that excepts the 915. It came out of an 80sc... $9723 in tranny work alone from CSM. Will sell the whole setup with motor/tranny. Just needs a car and I have an 80 slant nose if you are looking...

[justanut]

So I was looking at a project that a guy had but never really got started. His also had a shortened tranny. I know this affects engine mounts/placement but does it then require firewall work. I know the power of 383 will offset weight gain from iron block but how does the weight affect the dynamics so to speak?

[Yan2947]

This engine bolts right into any porsche without any modification. If you add a radiator in the front you will need to cut the tub up there. Other then the radiator there is no additional cutting. My 89 911 ls1 has a radiator in the rear tail. Not many people do this because having ram air on the radiator is a good thing. Does his project have a shortened 915 or 930? This 915 is not shortened but has all the bells and whistles. Feel free to give a call if interested. Just PM me and I will send my phone. I'm in NY where are u?

[Yan2947]

By the way, here is the 80 sc. I ended up getting an 86 911 with fire damage and its getting painted now so I don't need the 80 or the motor/tranny. I was going to put in the motor/tranny in the 86 just to get everything on the car sorted and if I don't sell the motor too quickly I will still do that because it is easy to do.

1980 911 SC Slantnose 383 Stroker Conversion

[justanut]

Yan
Yes his was a shortened g50. Also said some other modification to torsion tube to move tranny even further forward with custom tranny mount. I read in another post of yours that you were using a shortened case. I just assumed this one.

[Yan2947]

Not this one. Sounds like that 70's project needed a lot of fabrication. The g50 doesn't fit easily into a pre 87 car. The 915 that I have fits nicely into a pre 87 car but I don't know how far back it goes. If you are looking at purchasing that car then it is what it is. Any photos? Any photos of the torsion tube motification? The shortened tranny if for the 86 not the 80. The 80 was a race car for a short period of time until the guy bought a Cayman to race.

[VacantSky]

Originally Posted by justanut

Thanks for the reply. Kinda what I figured. Just finished reading ur thread. Hopefully the build is nearing the end. An L33 5.3 is exactly what I was thinking because as much as I want 500hp 350ish will be more than enough as my sometimes daily driver. Thanks again and hope to pick ur brain in the future as my build gets under way.

No problem! Feel free to PM me any time, my project has become a “as I get the time” lately due to work and my 2 year old son, and a “while I’m in there” (currently rebuilding the entire suspension). But I hope to have it running this year! There’s a lot of good info here in the conversion forum, sometimes you have to use the search function to pull up non active threads. A lot of folk do a lot of things differently so it’s nice to read through everything and come out with inspiration. L33 is a great engine, if i ever get a second block to build it’ll be that one. I’ve read it’s earned “baby LS6” as the nickname due to the 799 heads and flat top pistons.