Originally Posted by JB911

These days Porsche makes what, 13 variations of the 911?
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Originally Posted by XrussianX

I counted 20 variants and that does not include any GT3 or GT2 so I guess 24 models total?😆

Originally Posted by rbahr

Here are the gear ratios: https://rennlist.com/forums/996-gt2-...-question.html

Very similar beyond that...

Ray

Originally Posted by GTgears

Just one point of correction. The G96.00 & G96.01 used in 996 Carreras is also a Getrag gearbox, and is actually identical to the G86.20 used in NJ-GT's 2001 Boxster S with the ring gear on the opposite side. They are German made and very robust. They use a G50 based differential, just like the GT3 does, and a very large ring and pinion gear.

The shortcoming of the box is the press fit gears that only allow you to rebuild it once before the tolerances get too loose and you've got to toss the shafts. But by then your ring and pinion and 1st/2nd gear should probably be timed out anyway. But service parts are readily available for them, and unlike the GT3, you can buy just a single loose 2nd gear idler gear if you have bad dog teeth. On the GT3 one must buy an all new mainshaft with 1st and 2nd attached to the tune of $2000 instead of the $350 the G96.01 2nd gear idler costs.

The G97 gearbox is the Aisin gearbox. And as of about a year ago it also became serviceable. You can buy bearings and synchros for them but they are stupid expensive. Designwise, it's pretty much a Japanese knockoff of the G96.01, though there is no parts cross compatibility. And 3rd gear does seem to be weak and a problem child on it when they are raced. But on the upside the ratios are a bit tighter together and shorter than the G96.01 ratios. And if one has an LSD equipped one, it's actually a decent functioning LSD that lasts a fair bit of time on track. GT3s don't get that.




The jury is still out on the 991 GT cars. The 991 Carreras are getting the PDK based 7MT. But here's the really weird one on this front. The PDK is a ZF designed and manufactured gearbox. The 991 7MT has been farmed out to Aisin. I'm totally amazed that ZF/Porsche would share the technology like that. Maybe the cost benefit of having them made in Japan/SE Asia makes it worthwhile. It is just out of character for them to share technology that openly and I also wonder how the bean counters at Porsche sold ZF on the idea unless they get a really nice fat licensing check for every gearbox made by Aisin.

Originally Posted by sumbaco

I know this is an old thread, but I've been thinking about this topic recently. The 7.1 GT3 gearbox is pretty slow and stiff to get into gear, so I've been thinking about how to make the shift slicker, as I mainly drive it on the street. The gearbox reportedly had Mobilube PTX put in it about 3k miles ago, but it is super stiff when cold, and even when warm the shift is pretty balky. The description of Delvac when cold fits my cars shift action, making me think Delvac is actually in it. My plan of attack is to try Redline 75w90NS oil, then Delvac, then PTX to actually see if any of those make a difference. Lubing the transmission ends of the cables helped in a 987, so I'll try that. If that doesnt work, then I'll install the Numeric Shifter I have. In the longest setting, it actually felt like a stock length 987 throw, so maybe the longer throw and stiffer housing will help smooth the shift. The last resort will be to test a stock 996 shifter (since the cup shifter is no longer available) to see if that length of throw improves the synchro engagement. If that works, then I'll swap in the Function First bearings and hopefully have a long term solution. I'm not really interested cup cables because I drive the car on the street and do not want any buzzing or noise coming through the cabin. Anyone actually gone through any of this and successfully smoothed the shift action on their GT3?