NVRANUF

Cross post from 997GT3 GT2 forum:

Has anyone in here done this?
ie, transplanted a 996 Cup transmission into their 997 GT3 or RS.
What are your opinions and impressions?

I know you can do a R&P upgrade, and or, a re-gear of the original GT3 box.

Just looking for some feedback from anyone who's "Been there, done that"!

Thanks!

claykos

It's basically the same gearbox. It just has different gearing, more agressive diff and the motorsports synchros/sliders. 996 cup gearing is not going to be very fun on the street/highway, but if its a track only car then it would fien. I guess financially it might make sense if you can find a good deal on a used 996 box in good shape and sell the street car box you would save money over regearing the street box.

NVRANUF

At the risk of sounding stupid......What aspects would make it non street or hwy friendly?

claykos

The gearing is very short (closely spaced, and meant to keep the engien at high rpm). It's geared for a ~150 or 160 top speed and that is with a 28" diameter rear tire. Most street tires are around 26", so you are going to be looking at a 140-150 top speed at 8400 rpm. So cruising on the freeway at 70-90 you are going to be running over 4-5k rpm.

IPguy

gearing

damn, clay beat me to it

va122

They are straight cut gears,

NVRANUF

So it would save on hwy speeding tickets..
I had a '67 Camaro back in the day with a SB, 4.10 gearing and a Muncie M22 "rock crusher" ...so it would be not unlike reliving my youth..? but in a Porsche!

J richard

...and then theres the issue of the cost of the parts, you don't need all the steel syncros and the cost of the first gear and mainshaft, those are big dollar items that will could set you back the cost of a street box by themselves...

amaist

I have a 996 Cup gearbox in my 996.

around 4k rpm at 75 mph in 6th.

Not very good for a daily driver but a hoot on the track.

Best if used with Cup shifter linkage. The dreaded 2-3 shift is no longer an issue with the Cup linkage.

mark kibort

you also get those cup close ratios too, which would be really fun!
does the GT3 have near the same gear ratios as the cup, but not the straight cut gears?

Bill Verburg

which 996 Cup trans? G96/75, G96/91, G96/96 it makes a difference, also what rpm and tire will you use

I have a 993Cup trans in mine and it's a great all around trans,

GTgears

996 Cup gears are not straight cut. They didn't go straight cut until they went sequential.

Furthermore, 997 GT3 variants have steel synchros on 3rd through 6th. Only 2nd gear steel motorsports synchros will be different on the Cup Car, as most of them have standard synchros on 1st gear.

As for exact gearing it could be anything at this point. This box could be up to 10 years old and depending on the life it led could be regeared or has had gears replaced. Only the seller will be able to accurately comment on the gear stack though it's sure to have the 4.0 ring and pinion set in it.

It will likely have a 40/65 4 plate motorsports LSD, but with a cast body, just like the body in your 997 GT3. They didn't go to a billet body until a couple of years into the sequential box.

mooty

the clutch/flywheel is like an on off switch.
if you think your lwfw is light, hahhaha, try again
first time i drove a 6 cup, i stalled it 9x making 1000ft trek to the hot pit.

mooty

u selling the gear box?
you dont need the 996 anymore.

mklaskin

You have a way with words...