In what way is a GT3's Transmission different than a 997?
07-19-2012, 11:25 AM
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In what way is a GT3's Transmission different than a 997?
I have 997s 6 speed. I've test driven a few 2007 GT3s and noticed a pretty big difference in the feel of the transmission. (Shifting wise) The gates seem exceptionally better defined. Is there some fundamental difference in the transmissions, or is my 997s transmission just wearing?
07-19-2012, 11:35 AM
#2
the trannies are entirely different - no parts in common etc - it is 'one' of the reasons the GT cars are desired by those that track their cars - there are many suppliers of parts and many shops experienced with rebuilding and servicing it - not so the 997 tranny
i'm not saying it is 'better' - i'm just saying it is entirely different
i'm not saying it is 'better' - i'm just saying it is entirely different
07-19-2012, 11:49 AM
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I have 997s 6 speed. I've test driven a few 2007 GT3s and noticed a pretty big difference in the feel of the transmission. (Shifting wise) The gates seem exceptionally better defined. Is there some fundamental difference in the transmissions, or is my 997s transmission just wearing?
GT3/GT2/RS share plenty of parts unique to them.
997, Boxster and Cayman share plenty of parts unique to them.
07-19-2012, 04:41 PM
#5
Porsche GT3 transmission background...
The gearbox in the road-going 997 GT3 is a development of the gearbox used in the 996 GT3 Cup / GT3 RS / RSR race cars...
Porsche GT3 transmission background...
The very first Porsche gearbox was a transaxle (a common case sharing the gear stack and the differential). All Porsche 356-997 street and race cars share this same design theory. From the first 356 design through the 1980s 911s, Porsche used their own design synchronizers. Even with several evolutions of their own designs, they still proved to be problematic.
The Porsche 911 transmission took on a huge improvement in reliability, durability, and ease of operation in 1987 with Porsche design 950, commonly called the G50 gearbox. They are used from 1987 to present day in all 911, 964, 993, 996, and 997-bodied cars. These heavy-duty gearboxes, made by Getrag, use the Borg-Warner style synchromesh. A variant of this is still used in the 996/997 GT3, GT3R, and 996/997TT/GT2 cars.
As with the earlier Porsche transmissions, Porsche has manufactured many different gear ratios, as well as ring and pinion sets to allow the gearboxes to be set up for virtually any kind of driving. Most of the street car gearing is selected with fuel economy in mind, so there are many opportunities for performance improvements with changing gear sets or ring and pinions. The first version of the gearbox was a 5-speed, but with introduction of the 993 brought on a 6-speed version of the G50 gearbox. The 993TT and four-wheel drive 993 and 993 4S use a similar gearbox with a driveshaft that extends through the nosecone to drive the front wheels.
The G96 gearbox was introduced at the start of production 996/986 cars. The most noticeable difference in these gearboxes is the cable shifter. All 996/986 cars other than 1998-early 1999 996 GT3 cars use a cable shifter.
The 996 GT3 gearbox was different (type G96/90, G96/93, G96/96) from the standard 996. The GT3 gearbox evolved from the 993 GT2 which, in turn, evolved from the 993 TT, and before that, the 1989 930 G50/50. The 996 GT3 box was also used in the 996TT/GT2 and 996 GT3 Cup/GT3 RS/RSR race cars. It has a dedicated oil pump and external oil/water intercooler, steel synchronizer rings on gears 3-5, and interchangeable gear ratios (main shaft assembled from individual ratios that are positioned, not pressed into place), and a 40% / 60% asymmetrical clutch type limited slip differential.
At the end of the 996 GT3 RSR production, the sequential gear selection capability came to Porsche racing, the G97 6-speed gearbox was born. Holinger Engineering was consulted for design and production of the internal gear sets. The 997 Cup brought the sequential to mainstream production. The 997 GT3 RSR also uses the same type dog engagement design. Externally, these gearboxes look the same as their predecessor G96 boxes, using many of the same castings, coolers, oil pump, etc. These transmissions have proven themselves to be quite reliable, and as before offering quite a wide range of gear selections. Early 996 Cup/GT3Rs can be converted to sequential capabilities if a customer so desires.
After a year or so of testing, the 2008 997 GT3 RSR introduced a new "clean sheet of paper" design to the transaxle. With Porsche's recent supercar the V10 engined Carrera GT, a new manufacturer (Hör) was brought in to design the 6-speed gearbox. This manufacturer also designed and developed Porsche's new gearbox for the RS Spyder. This successful relationship with Porsche Motorsport also brought new eyes to one of the biggest issues with the G50 based gearbox. In the Porsche race world the axle geometry has been an issue for the past two decades. As the cars are lowered for racing, the axles tend to have more and more extreme angles, causing axle failure. This issue has been resolved with the new design. The gearbox is also lighter, and focused on details internally to decrease the friction on contact points...
Porsche GT3 transmission background...
The very first Porsche gearbox was a transaxle (a common case sharing the gear stack and the differential). All Porsche 356-997 street and race cars share this same design theory. From the first 356 design through the 1980s 911s, Porsche used their own design synchronizers. Even with several evolutions of their own designs, they still proved to be problematic.
The Porsche 911 transmission took on a huge improvement in reliability, durability, and ease of operation in 1987 with Porsche design 950, commonly called the G50 gearbox. They are used from 1987 to present day in all 911, 964, 993, 996, and 997-bodied cars. These heavy-duty gearboxes, made by Getrag, use the Borg-Warner style synchromesh. A variant of this is still used in the 996/997 GT3, GT3R, and 996/997TT/GT2 cars.
As with the earlier Porsche transmissions, Porsche has manufactured many different gear ratios, as well as ring and pinion sets to allow the gearboxes to be set up for virtually any kind of driving. Most of the street car gearing is selected with fuel economy in mind, so there are many opportunities for performance improvements with changing gear sets or ring and pinions. The first version of the gearbox was a 5-speed, but with introduction of the 993 brought on a 6-speed version of the G50 gearbox. The 993TT and four-wheel drive 993 and 993 4S use a similar gearbox with a driveshaft that extends through the nosecone to drive the front wheels.
The G96 gearbox was introduced at the start of production 996/986 cars. The most noticeable difference in these gearboxes is the cable shifter. All 996/986 cars other than 1998-early 1999 996 GT3 cars use a cable shifter.
The 996 GT3 gearbox was different (type G96/90, G96/93, G96/96) from the standard 996. The GT3 gearbox evolved from the 993 GT2 which, in turn, evolved from the 993 TT, and before that, the 1989 930 G50/50. The 996 GT3 box was also used in the 996TT/GT2 and 996 GT3 Cup/GT3 RS/RSR race cars. It has a dedicated oil pump and external oil/water intercooler, steel synchronizer rings on gears 3-5, and interchangeable gear ratios (main shaft assembled from individual ratios that are positioned, not pressed into place), and a 40% / 60% asymmetrical clutch type limited slip differential.
At the end of the 996 GT3 RSR production, the sequential gear selection capability came to Porsche racing, the G97 6-speed gearbox was born. Holinger Engineering was consulted for design and production of the internal gear sets. The 997 Cup brought the sequential to mainstream production. The 997 GT3 RSR also uses the same type dog engagement design. Externally, these gearboxes look the same as their predecessor G96 boxes, using many of the same castings, coolers, oil pump, etc. These transmissions have proven themselves to be quite reliable, and as before offering quite a wide range of gear selections. Early 996 Cup/GT3Rs can be converted to sequential capabilities if a customer so desires.
After a year or so of testing, the 2008 997 GT3 RSR introduced a new "clean sheet of paper" design to the transaxle. With Porsche's recent supercar the V10 engined Carrera GT, a new manufacturer (Hör) was brought in to design the 6-speed gearbox. This manufacturer also designed and developed Porsche's new gearbox for the RS Spyder. This successful relationship with Porsche Motorsport also brought new eyes to one of the biggest issues with the G50 based gearbox. In the Porsche race world the axle geometry has been an issue for the past two decades. As the cars are lowered for racing, the axles tend to have more and more extreme angles, causing axle failure. This issue has been resolved with the new design. The gearbox is also lighter, and focused on details internally to decrease the friction on contact points...
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cbracerx (06-03-2021)
07-19-2012, 05:44 PM
#6
Nordschleife Master
how's the tranny on your mid life crisis ***** extension?
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07-19-2012, 06:12 PM
#7
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reliable and built strong. It comes with 2 cooling systems. Track proven racing unit shared with the race car.
The pos tranny in my Cayman S in the other end (same crap as your 997S tranny) overheats, refuses shifting after 15 minutes on a racetrack, and becomes numb when hot. The fix is not affordable, around $11k. It is fine for street use, autoX and moving chicane track days.
The 09+ Boxster/Cayman/Carrera have a better tranny.
The pos tranny in my Cayman S in the other end (same crap as your 997S tranny) overheats, refuses shifting after 15 minutes on a racetrack, and becomes numb when hot. The fix is not affordable, around $11k. It is fine for street use, autoX and moving chicane track days.
The 09+ Boxster/Cayman/Carrera have a better tranny.
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07-19-2012, 08:09 PM
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07-19-2012, 08:27 PM
#10
Nordschleife Master
Poppycock.
1. Not anything at all close to the same gearbox as the 997 Carrera gearbox. The Carrera uses a gearbox designed by Aisin specifically for use in the Carrera. The Cayman uses a gearbox designed by Getrag that is a derivative for the Audi TT FWD gearbox.
2.BGB Motorsports got a whole season of Grand Am Continental Tire racing out of one single Cayman S gearbox. Your temperature problems are not the fault of the gearbox. They are the fault of the designers at Porsche. It's not the gearbox's fault Porsche didn't see fit to put a cooler on the box.
What happens when you go to the track is exactly the opposite of what happens on the rear engine cars. On the midengine Caymans and Boxsters, instead of acceleration forces pushing all the gear oil towards the ring and pinion, it pushes all the gear oil out towards 5th, 6th and reverse. The layout of the car runs the ring and pinion dry and then is superheats. Put a cooler on the box that has a return putting oil directly on the pinion head and differential and the problem goes away.
3. Whomever services your car bent you over the table and had their way with you. Up until about 60 days ago, Cayman S replacement gearboxes (remanufactured crate boxes directly from Getrag in Germany) cost around $3800 exchange from a Porsche dealer. Nobody racing them was rebuilding them when they popped one because you can't properly rebuild a gearbox for that cheap. If you really did pay triple that, you got ripped off big time...
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frederickcook87 (05-19-2021)
07-19-2012, 08:41 PM
#11
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I have 997s 6 speed. I've test driven a few 2007 GT3s and noticed a pretty big difference in the feel of the transmission. (Shifting wise) The gates seem exceptionally better defined. Is there some fundamental difference in the transmissions, or is my 997s transmission just wearing?
Poppycock.
1. Not anything at all close to the same gearbox as the 997 Carrera gearbox. The Carrera uses a gearbox designed by Aisin specifically for use in the Carrera. The Cayman uses a gearbox designed by Getrag that is a derivative for the Audi TT FWD gearbox.
2.BGB Motorsports got a whole season of Grand Am Continental Tire racing out of one single Cayman S gearbox. Your temperature problems are not the fault of the gearbox. They are the fault of the designers at Porsche. It's not the gearbox's fault Porsche didn't see fit to put a cooler on the box.
What happens when you go to the track is exactly the opposite of what happens on the rear engine cars. On the midengine Caymans and Boxsters, instead of acceleration forces pushing all the gear oil towards the ring and pinion, it pushes all the gear oil out towards 5th, 6th and reverse. The layout of the car runs the ring and pinion dry and then is superheats. Put a cooler on the box that has a return putting oil directly on the pinion head and differential and the problem goes away.
3. Whomever services your car bent you over the table and had their way with you. Up until about 60 days ago, Cayman S replacement gearboxes (remanufactured crate boxes directly from Getrag in Germany) cost around $3800 exchange from a Porsche dealer. Nobody racing them was rebuilding them when they popped one because you can't properly rebuild a gearbox for that cheap. If you really did pay triple that, you got ripped off big time...
1. Not anything at all close to the same gearbox as the 997 Carrera gearbox. The Carrera uses a gearbox designed by Aisin specifically for use in the Carrera. The Cayman uses a gearbox designed by Getrag that is a derivative for the Audi TT FWD gearbox.
2.BGB Motorsports got a whole season of Grand Am Continental Tire racing out of one single Cayman S gearbox. Your temperature problems are not the fault of the gearbox. They are the fault of the designers at Porsche. It's not the gearbox's fault Porsche didn't see fit to put a cooler on the box.
What happens when you go to the track is exactly the opposite of what happens on the rear engine cars. On the midengine Caymans and Boxsters, instead of acceleration forces pushing all the gear oil towards the ring and pinion, it pushes all the gear oil out towards 5th, 6th and reverse. The layout of the car runs the ring and pinion dry and then is superheats. Put a cooler on the box that has a return putting oil directly on the pinion head and differential and the problem goes away.
3. Whomever services your car bent you over the table and had their way with you. Up until about 60 days ago, Cayman S replacement gearboxes (remanufactured crate boxes directly from Getrag in Germany) cost around $3800 exchange from a Porsche dealer. Nobody racing them was rebuilding them when they popped one because you can't properly rebuild a gearbox for that cheap. If you really did pay triple that, you got ripped off big time...
Rad what happened to being polite? That was not cool.
In fact it just cost you your custom Ferrari title.
07-19-2012, 09:25 PM
#12
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Porsche abandoned the 911 in 1998 with 993, the 2nd to last of the good ones: dry sump engine, race proven engine and transmission, something the brand had done since day 1.
Starting with the 1998 996 and all the way through today, the switch to wet sump and non serviceable transmission to give a 911 to the masses made the car what it is today, a poseur.
The only exception is the 2001-2009 Turbo/TurboS, GT3/GT2/GT3 RS/GT2 RS, real 911 with race proven engines and race proven transmissions.
Unfortunately, it seems that Porsche is one the way to kill the race lineage on the exception cars I just mentioned, they just did it with the Turbo/TurboS and it doesn't look like dry-sump and race-proven tranny/engine are coming back for GT3/GT2/RS.
07-19-2012, 09:29 PM
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Poppycock.
1. Not anything at all close to the same gearbox as the 997 Carrera gearbox. The Carrera uses a gearbox designed by Aisin specifically for use in the Carrera. The Cayman uses a gearbox designed by Getrag that is a derivative for the Audi TT FWD gearbox.
2.BGB Motorsports got a whole season of Grand Am Continental Tire racing out of one single Cayman S gearbox. Your temperature problems are not the fault of the gearbox. They are the fault of the designers at Porsche. It's not the gearbox's fault Porsche didn't see fit to put a cooler on the box.
What happens when you go to the track is exactly the opposite of what happens on the rear engine cars. On the midengine Caymans and Boxsters, instead of acceleration forces pushing all the gear oil towards the ring and pinion, it pushes all the gear oil out towards 5th, 6th and reverse. The layout of the car runs the ring and pinion dry and then is superheats. Put a cooler on the box that has a return putting oil directly on the pinion head and differential and the problem goes away.
3. Whomever services your car bent you over the table and had their way with you. Up until about 60 days ago, Cayman S replacement gearboxes (remanufactured crate boxes directly from Getrag in Germany) cost around $3800 exchange from a Porsche dealer. Nobody racing them was rebuilding them when they popped one because you can't properly rebuild a gearbox for that cheap. If you really did pay triple that, you got ripped off big time...
1. Not anything at all close to the same gearbox as the 997 Carrera gearbox. The Carrera uses a gearbox designed by Aisin specifically for use in the Carrera. The Cayman uses a gearbox designed by Getrag that is a derivative for the Audi TT FWD gearbox.
2.BGB Motorsports got a whole season of Grand Am Continental Tire racing out of one single Cayman S gearbox. Your temperature problems are not the fault of the gearbox. They are the fault of the designers at Porsche. It's not the gearbox's fault Porsche didn't see fit to put a cooler on the box.
What happens when you go to the track is exactly the opposite of what happens on the rear engine cars. On the midengine Caymans and Boxsters, instead of acceleration forces pushing all the gear oil towards the ring and pinion, it pushes all the gear oil out towards 5th, 6th and reverse. The layout of the car runs the ring and pinion dry and then is superheats. Put a cooler on the box that has a return putting oil directly on the pinion head and differential and the problem goes away.
3. Whomever services your car bent you over the table and had their way with you. Up until about 60 days ago, Cayman S replacement gearboxes (remanufactured crate boxes directly from Getrag in Germany) cost around $3800 exchange from a Porsche dealer. Nobody racing them was rebuilding them when they popped one because you can't properly rebuild a gearbox for that cheap. If you really did pay triple that, you got ripped off big time...
I just checked my Cayman S, tagged Getrag made in Germany on the case.
Quote is new transmission, electric pump, radiator, plumbing, parts and labor included. Personally, I won't do it, I would rather dump it for cheap on the used market and find a clean 40k miles 996 GT3.
07-19-2012, 09:40 PM
#14
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Starting with the 1998 996 and all the way through today, the switch to wet sump and non serviceable transmission to give a 911 to the masses made the car what it is today, a poseur.
The only exception is the 2001-2009 Turbo/TurboS, GT3/GT2/GT3 RS/GT2 RS, real 911 with race proven engines and race proven transmissions.
Unfortunately, it seems that Porsche is one the way to kill the race lineage on the exception cars I just mentioned, they just did it with the Turbo/TurboS and it doesn't look like dry-sump and race-proven tranny/engine are coming back for GT3/GT2/RS.
The only exception is the 2001-2009 Turbo/TurboS, GT3/GT2/GT3 RS/GT2 RS, real 911 with race proven engines and race proven transmissions.
Unfortunately, it seems that Porsche is one the way to kill the race lineage on the exception cars I just mentioned, they just did it with the Turbo/TurboS and it doesn't look like dry-sump and race-proven tranny/engine are coming back for GT3/GT2/RS.
Now can u pls enlighten us on your new sig block "2012 Sebring DE Cup World Series Champion"? I wanna win my next DE too... how?
07-19-2012, 09:47 PM
#15
Nordschleife Master
Anybody want my POS?
Seems I need to step up for a real 911
Seems I need to step up for a real 911