Bill Verburg

the /32 was used in the 993RS/CS not Cup cars. /30 was the Cup car trans. See above, it is geared much lower and closer. Both come w/ all steel syncros and motorsports lsd

And I agree, the later 40/65 motorsport lsd is better for most of us.

Tom W

I'm having enough trouble just trying to find a simple used G50/01 or /03 to use as a donor. How long did it take to find a /30, /32 or /34?

Chance: Tom van Overbeek runs 2:03ish at TH. Your car should be capable of 2:00. It took me 2 years of driving mine to get there. I had a hell of a time in the first few races staying ahead of the pesky Toyo spec cars (I think my first outing in the car was a 2:08 or something like that). I'm hoping that by dropping the 350 lbs to get to class weight, it will be enough to be competitive with the newly built GTL cars and should help make me competitive with the 996 cup cars.

Bill Verburg

/31(RS), /32(RS/CS) are still available as factory rebuilds through the dealer net.

N51

David

You may be better off to sell your box and go to another box that suits your needs. They come with steel syncros and two year unlimited mileage. Bill and Jean have been my mentors and benefactors.

Ritter v4.0

I'm coming round to that idea. I like the look of the 30 on paper at least.
Whats a G50 03 with 140k miles on it worth? Will they take it as a core trade-in on a 30/31/32?
I thought not : (

Cupcar

Interesting on the G50/30 gearbox, I never had heard of one before.

I looked at the ratios listed in the chart and came up with the following gear progressions. I define a "split" as the percentage a given gear is of the gear below it. The higher the percentage the "closer" the gear is to the preceding gear. The progressions below go in order of Gear 1 to Gear 2, Gear 2 to Gear 3, etc.

******* G1 > G2 * G2>G3 * G3>G4 * G4>G5 * G5>G6
G50/31 is: 63.4% > 76.1% > 81.6% > 82.4% > 80.2 %
G50/32 is: 63.4% > 76.1% > 81.5% > 83.1% > 80.4%
G50/30 is: 63.4% > 76.0% > 79.7% > 84.7% > 86.3%

Looking at it this way, the G50/31 & 32 are almost identical with the /32 having very slightly closer 4 to 5 and 5 to 6 shifts.

The G50/30 has a wider split from 3 to 4 than any of the gearboxes, but is much closer in the 4 to 5 and 5 to 6 shifts. The G50/30 is more geared to high speed track use where gears 4,5 and 6 are used most frequently. The other two gearboxes are more geared to street use and progressive acceleration.

In a drag race, all other things being equal, the G50/30 would come up a loser on the G2 > G3 and G3 > G4 shift that may be significant, allowing the G50/31 & 32 car to get ahead a bit, but the higher speed gear changes from G4 to G5 and G5 to G6 would be much better and the G50/30 would start to catch up.

Mark in Baltimore

I have a 993 6 speed gearbox that I'm willing to sell for $1,200 obo. It came out of a 57,xxx mile street cab that rolled. The catch? Center case is cracked. PM me if you're interested.

Cupcar

When I asked about this I was told no, "we only rebuild the gearbox to its original type specification". Porsche just puts in new syncros and bearings of the type already in the box. Replacing gears en masse is not part of the deal.

It requires all new gears, all new syncros and other parts that tally up to a big bill pretty fast. to convert an /03 to a 30 series box.

Bill Verburg

I did the splits the other way, it's more intuitive(JMO) as the closer the gears are the lower the split %. But even the splits don't tell the whole story, they are certainly an indicator but the important things are the drops and speed in gear. /30, /31 and /32 all have the same 1, 2 after that they start to deviate, the /30 has progressively smaller drops, lower split % and the lowest top in 6. It is by far the most track oriented box.

the /31 and /32 have slightly lower 4, slightly taller 5 and much taller 6. The taller the 6 the more relaxed freeway driving will be.

I'll organize and post a comparison later if anyone is interested.

N51

Tom,
I may be selling my G50/05. Has LSD and shifts perfectly. But unless you need custom gears, I think you'll find it less expensive to go with one of the PMS boxes.

Bill Verburg

Comparison of 993 RS/Cup gearboxes including rpm drops and cruise rpms

edited to ammend a few errors in the data

Cupcar

I can see why you look at it the way you do, one thing I like to do with my method is multiply my "split percentage" by the RPM at the time of the shift to get the RPM in the next gear up in the acceleration sequence.

Doing this with a 6800 RPM shift I get:

*******G1>G2*G2>G3*G3>G4*G4>G5*G5>G6

G50/31 = 4312 > 5175 > 5549 > 5606 > 5452

G50/32 = 4312 > 5175 > 5545 > 5649 > 5468

G50/30 = 4312 > 5168 > 5422 > 5762 > 5866

Edit Note: Bill posted his chart while I was typing mine, I suspect we used different RPM at the time of shift. The point is the same.

G50/20 = 3648 > 4672 > 5403 > 5602 > 5722

Note the big difference in RPM after the G1>G2 and G2>G3 shifts comparing the stock G50/20 and the sport gearboxes. Not only is there a big difference in torque mupltiplication because of the lower ratio, but the flywheel torque has gone from around 260 Nm to over 300 Nm because of the shape of the engine torque curve.

This is what makes the sport gearbox so much fun on the street- and faster.

Bill Verburg

yes, I forgot to include rpm didn't I.

For comparison purposes only I used 25" drive tire which is going to be a bit taller than reality and 6500rpm shift points which is a bit conservative

Tom W

Noah: PM sent. (and what's an /05? My service manual does not list it and it's not in any chart I've seen.)

The G50/32 is pretty darn close to what I'd want ideally. I considering gears a little shorter than the /32 with 2nd at 2.000, 3rd at 1.560, 4th at 1.286, 5th at 1.083 (4th and 5th the same as my existing 6-speed) and 6th at 0.973. These gears fit the tracks out here and my car a bit better than the /32.

I've looked at my engines power output (max hp at 6000-6500, rev limiter set at 7400 and normal shift point at about 7000), tire diameter (24.5" for the slicks my class requires), and my speeds at the start of braking zones, corner entry, apex and exit at the tracks I run most frequently. Most tracks I run will only use 2-5, but adding a 6th with a reasonable top end means that if I go up to Portland for a race, I'll have the top gear I need.

N51

Tom,

Adrian's book lists it for USA '92 on. Same gears as the G50/03.