updated transaxle research, & question, high power 71-89 911

[ramey]

I have done a whole lot of surfing, on a whole lot of sites, and talked to a whole lot of people, and so far I don’t have a great solution for a problem that I would think would be a problem for a whole lot of people. 600+ hp in a 2000 lb car is nothing spectacular these days. So why such a hard time finding transaxle options?

I am looking for tall, wide ratio gears in streetable (preferably not straight cut race gears) in a compact transaxle that can take 700 hp all day long. i really dont want to cut the torque tube housing or firewall of a nice 911 to fit some big transaxle.

Options so far seem to boil down to a stock short 930 unit, or a shortened G50.

The 996 and other options are physically too long, and still way, way too short geared and narrow ratios, even with tall upper gear swaps. They were made for low horsepower high revving motors in heavy cars.

Some of the 997 had slightly better ratios, but they seem to be unobtanium, and still physically very big. Small light cars don’t need 6 gears anyway.

A tall ring and pinion short bellhousing 930 would be optimal, but no one seems to have a 4.0 or taller ring and pinion for the 930. The available taller cut 3rd and 4th gears are ok, but not a huge improvement from stock. (.893 to .828 3rd, and .654 to .593 4th). There are slightly taller gears but they are race cut only.

The 828 and 593 would work pretty well if I could find a 3.7-8 or so final drive, even the 4.0 would be pretty good… but the stock 4.22 is just too low for a street car.

With my power to weight, a 3.7-4.0 geared 930 with tall 3rd and 4th would be ideal. If anyone knows where to get such a ring and pinion let me know. Already hit albins, and their us distributors (retrosport, carquip, etc).

Anybody know where to go to get a tall ring and pinion shortened bellhousing 930 with a tall 3rd and 4th? If so, i am ready to go!


All of the high dollar units are geared for sandracing, WAAAAY too low and narrow spacing (mendeola, albins, rancho, rbt, etc.)

I have even looked into automatics, but don’t see anyone online offering solutions. A modern paddle shifted auto would actually be kind of interesting. There seems to be an audi unit that will take 1000 hp from level10, but they don’t have any stand alone solutions for swaps.

The old transverse solutions are not ideal (th425, etc.) and the modern ones (6t75 etc) are not really ideal as they are transverse, really heavy, and not very strong.

Back to the G50, can you get one short enough to fit in a 911 withtout cutting, and s there any real answer for whether a G50 is strong enough?

What I am looking for obviously wont be cheap, so I damned sure don’t want it to break.

Albins seems to make a tall 3.1 ring and pinions for G50, which with the G50/50 or 52 ratios would be pretty good, but I cant seem to find anyone to put all that together.

3.154
1.789
1.269
.967
.756

Even that would still beg for a different 5th gear.

Albins makes .688 and .645 5th gears, that would be pretty ideal, hauling ass to 170, and also 2500 cruising at 90

7000 52 92 130 170 255

Anybody know where to go for a shortened bellhousing G50 with a 3.1 ratio, a nice limited slip, and a .645 4th gear?

Or anyone have a better idea?

many thanks!

[Flieger]

You are saying 930 gearing is too tall? The usual complaint is it is too long- i.e. you only ever need first or second gear on the street.

I'd talk to Matt Monson at Guard to see if they can get you what you need.

[ramey]

Yeah, motor needs taller gears for sure.

At 2000 lbs, you just cant use the stock 930 gears with big power on the street.


I would think this would be more and more common with todays power levels.

Thx. I will call him, i havent talked to guard yet. I appreciate it.

Any more ideas are much Appreciated!

[Tremelune]

Some people have put Subaru transmissions in these cars:

Subaru transmission in place of a 915

You would need a custom adapter to mate it to a Porsche motor, and handling 700hp all day would probably not be possible with a stock box, but for the money you're willing to spend, the aftermarket on WRX/STi transmissions is huge.

[ramey]

Great suggestion, looked into subie stuff. Still geared way too low, same problem. All designed for 250 horse 3200 lb cars with high rev limits. No luck so far.

I guess I'm stuck with a 930, if anyone knows where to find an 8:32 gear for one let me know, or who could put together a strong enough g50 with. 3:1 ring gear and a tall 5th.

[Tremelune]

Originally Posted by ramey

Still geared way too low, same problem.

For the cost of a 930, I suspect you could get any gears you want in a Subaru transmission...The racing scene is huge:

RalliSpec 6MT Long Ratio Kit