Hi,

I have a 991.2 C2 with manual transmission and I love it.

However, I was able to recently feel a 991.2 GT3 and 718 GT4 manual transmission and it was sublime. Everything about my transmission but dialed up to 130%!
The shifts feel notchier, smoother, more direct, and shorter.

Would anyone know the internal mechanical differences in manual transmissions between GT and non-GT cars?
How close would a short throw shifter on my car mimic the experience on a GT trans?
Any upgrades can be made to my trans to make it feel more like a GT trans?
Cost aside, are there major hurdles to swap a GT3 transmission into my car?

Thanks!

 

GT4 shifter is an easy upgrade, and will get you a fair ways toward what you're looking for—step into a Carrera T and the difference is noticeable…probably the most immediately noticeable difference in the car from a driver's perspective alongside the reduced sound deadening and totally clear rear window (if the car has the standard lightweight glass).

Swapping to a 6MT is another level entirely—from emissions compliance, gearing selections for a very high-rpm NA flat six in the case of a 991.2, and cost.

 

This is a MUCH easier fix than what you're thinking of doing.
Just order the Numeric shifter and cables and you're mind will be blown. It is the single most important modification you can make to a manual car. It is next level of feel.

Swapping the GT3 six-speed you might as well sell your car and just get a manual GT3. I don't think the transmission will bolt up to the 3.0L turbo engine, so you'd have to figure that out, plus the gearing is setup for an engine that revs to 9,000rpms, not 7,400rpms, so the gearing will be off as well.
Plus, the labor cost will be out of this world. I'd have to venture that you'd be into it for at least $50k.

 

2nd. Def do the cables and shifter, I would say the cables made a bigger difference, but this combo is night and day to the stock setup.

 

thanks for all the helpful tips!

this isn't too bad. I'll definitely start there

https://www.fabspeed.com/porsche-num...AaAvfoEALw_wcB

 

The factory short shifter is actually really inexpensive ($250 from Suncoast) and absolutely TRANSFORMS the car. Might try that before swapping to an aftermarket short shifter and changing the cables.

There are a couple of DIY's on here for doing the swap.

 

Factory short shifter is still mostly plastic. Do a comparison with the Numeric and you'll see there's a major difference.
Get the 2mm spring too.

 

This is really all you need.

 

Go for the Numeric shifter and cables. I did the GT4 short shift kit and it's not all that different from the standard shifter. I'll be changing to Numeric at some point.

 

I had the factory short shifter, then went to Numeric Shifter (2MM) & Cables, night & day. Skip the factory go straight to Numeric, with the cables, you'll be very happy.

 

Numeric and function first **** is fantastic. This coming from a longtime S2000 owner. I didn't do cables, install was little too invasive for me.

 

The gt4 shift link from suncoast makes the car perfect and maintains the oem vibe.

 

^ This.

Curious to try the Numeric unit, and don't doubt the quality of materials as friends have spoken highly of them, but it's hard to imagine a better setup for the 7MT than the one in the Carrera T—which is just a GT4 shifter. Also trying to remember the last time I heard of a factory shifter wearing out. Maybe in a 15-20yo car? Otoh, I can see where some would say the GT4 isn't enough of a change—or simply like something more mechanical feeling/sounding. Good to have choices. There are so many cars where one doesn't have multiple upgrade paths.

 

I looked at a few videos and chose to follow the Numeric video steps for easy install of my GT4 shifter. I added the classic Function First **** and am quite satisfied with the short shifter's feel in my 991.2 C2 with API 93 tune. Curious about the Numeric shifter w/cables. Would like to test one though before going that far in mods.

 

The only things in the factory shifter that "wear out" are the cables, there are numerous stories on the 987 and 997 forums where the plastic bits on the OEM shifter cables break leaving people stranded. Perhaps the 991 is too new to have these failures as cars are JUST starting to hit 100k miles and there are far fewer manual 991 than 997's and 987's. But the construction of the cables look very similar across the 987-997-991.