nothingbutgt3

I am going to regear my 993 and I am more for the G50.32 gear ratios, because they have a longer 1st gear, which probably would be usable in very slow harpins, while the 1st gear of the g50.20 and 21 is too short for such a purpose...the result is you use the 1st gear only for rolling the car from the stops.

Tlaloc75

I feel kind of dumb asking this, but why is it so transformative? With stock gearing, my 2->3 shift puts me at 4.7k rpm and 3-4> puts me at 5k rpm. That’s smack in the middle of the power band. What RPM do you see on these shifts?

Bill Verburg

Here's mine w/ the current g50/30 from a 993 Cup/RSR vs same engine w/ the original g50/20, the /20 is too short in the lower gears too tall in the upper gears and the drops are awkward

pp000830

I suspect somewhere deep in the bowels of the Porsche Motorsport department there is a file on every major track in the world with

• gear ratios and
• shift points worked out for a given
• maximum sustainable rpm,
• torque and
• horsepower for a given 911
• to maximize performance and
• durability for the given
• maximum speed and
• distance profiles obtained for the various sections of the track.

My point being, yes change your gears, shorten them up, could be fun, may even improve performance under specific conditions but recognize the real result will largely be subjective due to the many variables under which a car actually runs. Spend the money but recognize you are doing it for FUN and be comfortable with the value proposition.
Andy

nothingbutgt3

I am regearing only because the orginal gears have lost cementation, otherwise I would be happy enough with a G50.21: some people here In italy say the 272 hp with G50.21 is slightly quicker than 286 hp with G50.20.
On my other 993 I saw 212km/h of GPS speed in 4th gear and 255km/h in 5th gear, so yes, the last tree gears are too long, since I don't think there is a straight long enough in any of the international circuits to allpw the car to reach the top speed in 6th gear.
basically it is a 4 gears gearbox...the first is way too short, the 5th and 6th way too long, but those were the years when the factories need to show higher ttop speed than the others, that's why the did such a ****ty gear ratios gearbox.

Tlaloc75

I don’t know how to read these for RPM. What’s the 2–>3 and 3->4 RPM drop?

Thanks!

Bill Verburg

I ind the thrust curves more informative than just looking at the trans
here's the trans

g550/20

g50/20 w/ 8:32 CWP

g50/21

g50/30

g50/31

g50/32


and a couple of regeared /20s

Tlaloc75

Cool, thanks!

MarinS4

The re-gear increases average HP in that particular gear. If the after shift RPM is 500 higher than before that's the new starting HP for that gear. That combined with peak divided by 2 equals average HP. There's really more RPM points needed to be accurate but you get the point. Depending on the power curve and where you shift that difference could be significant. Then you have mechanical advantage improvements. That's a bit more difficult to quantify but the two combined together make for some real seat of the pants improvements. Track stuff gets trickier, a re-gear could send you backwards (not likely), give a very marginal improvement or be real significant in lap times.

The change in personality alone is worth the price of admission in my book. I am in the middle of some evil plans myself.