When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I contacted OS Giken directly regarding my manual base C2.
This was their response as I didn't have my transmission code:
As Porsche fitment can vary depending on build specifics and trim levels, I would suggest you contact one of our Porsche specialist dealers who should have first hand fitment knowledge:GBOX, INC.
I was also interested to learn that Bernd Kahnau (known at Porsche as "the 911 maker" responsible for 4-5 generations of the 911...993 to 991 I think) chose NOT to put an LSD in his "F22" 911 hot rod when I interviewed him.
For what its worth, I run full traction control off.
My car is highly modified. It was lifting the inside wheel and lighting up out of every corner. Stiffer front springs than I already had, plus a new tractive map for the DSC has settled that down.
The one last remaining issue is the E-Diff (LSD) gets hot and starts to struggle and then gives up.
I have seen this with quite a few cars at the track. Even the SF90 Ferrari cannot handle hard tracking. Mine starts to struggle coming onto the main straight. It cuts the power . With Full traction (all nannies off) it feels almost like the car is slipping the clutch.
A full mechanical LSD should fix the issue.
The one I pictured above is the unit. It was only released in Feb this year. It is for 991.2 GTS.
The GTS already has an E-diff which is an electronically controlled LSD. Whereas it will now be full mechanical - controlled by torque.
When you exceed the torque, it full locks.
You can get a 1 a 1.5 and a 2.
A 1 only locks on acceleration.
A 2 Locks fully on both acceleration and deceleration. (Great for drifting and rally)
I have chosen a 1.5. Which means it locks fully on acceleration, and you customise a lessor amount for it to lock on deceleration. Which is perfect for the track.
To me it means that i will be able to steer the car with the throttle. Which kinda has always been the point of performance cars.
It’s far more predictable and controllable.
It also raises the threshold before the wheels spin, getting more power to the ground.
It’s the first thing every race team does, is get rid of an E-diff and replace it with a mechanical one.
From experience swapping out a factory diff for a proper plated one (in my case e46 CSL with a Drexler diff) I can agree it was such a huge step forward, I have a PDK T and considering buying a used S/GTS gearbox to fit one of these in to pending your feedback
It's a one-off 911 3.2 hot rod that was built on the production line in Zuffenhausen as a company car for an engineer/executive who was obsessed with light weighting while others were busy lusting after 928s and Slopenose Turbos. For many years, the car has been mistaken, or even labeled, as a "prototype" for the 1980s 911 Club Sport—so I wanted to get to the bottom of the story. Turns out it was more of a studie, and "because I can" project.
The man responsible went on to be known as "The 911 Maker," and played a big part in keeping weight gain down in the 993, 996, 997, and 991. Neat guy, for sure.
It's a one-off 911 3.2 hot rod that was built on the production line in Zuffenhausen as a company car for an engineer/executive who was obsessed with light weighting while others were busy lusting after 928s and Slopenose Turbos. For many years, the car has been mistaken, or even labeled, as a "prototype" for the 1980s 911 Club Sport—so I wanted to get to the bottom of the story. Turns out it was more of a studie, and "because I can" project.
The man responsible went on to be known as "The 911 Maker," and played a big part in keeping weight gain down in the 993, 996, 997, and 991. Neat guy, for sure.
Guys, turns out that there are two diff sizes for the G91 transmission in a 991.2 - narrow and wide. Apparently, the 7MT transmission with an open diff can use one of the two. Without knowing this, my shop scored a Guard 991.2 LSD that didn't fit because it was too wide, so I'm going to try the "narrow" LSD from Giken and will report back.
Here's the difference between the Guard LSD that didn't fit and my 991.2's open diff.
For the manual transmissions, does anyone know if there is a true LSD in the T transmission or the S/GTS for that matter?
I thought that the T had a different transmission with different gearing from the Base, S/GTS.
I found the part numbers for the Base and the S/GTS, but can't find it for the T. I was thinking about finding a wrecked car with a manual and swapping them if it has a true LSD.
Base P/N: G9106 1 002001>999999
S/GTS P/N: G9105 1 002001>999999
For the manual transmissions, does anyone know if there is a true LSD in the T transmission or the S/GTS for that matter?
I thought that the T had a different transmission with different gearing from the Base, S/GTS.
I found the part numbers for the Base and the S/GTS, but can't find it for the T. I was thinking about finding a wrecked car with a manual and swapping them if it has a true LSD.
Base P/N: G9106 1 002001>999999
S/GTS P/N: G9105 1 002001>999999
What do you mean by "TRUE" LSD?
There are many types of LSD's and TRUE is not one of them.
I have a 991.2 GTS that comes with an LSD. It is an E-Diff, which means it is controlled electronically. All LSD's in 991.2 are E-Diff's, with the one exception, Manual GT3's. Manual GT3's have a Mechanical LSD. Which is what you probably mean by TRUE LSD.
OS Giken have made a Mechanical LSD for my 991.2 PDK which I an ecstatic about. It is booked in to be fitted in just over a weeks time. Whilst the E-Diff is an LSD, it gets hot when heavy tracking and gives up. A full mechanical diff does not give up. It is far more predictable and allows you to steer the car with the throttle, without electronic interference. I run full traction control off and the E-Diff still manages to occasionally interfere before giving up fully.
For what its worth, I have two totally insane track guys in my group. (Well more than two, but just speaking about these two) One has a GT3, Manual (With Mechanical Diff) the other has a GT3-RS (PDK E-diff)
Both of these guys are Pro level drivers and can absolutely drive the tyres off the cars. (Both trailer their cars to the track, as they frequently won't have enough tyre left to drive home, from brand new.) Everyone would immediately assume the GT3-RS will be faster, That is not the case. They are constantly leap frogging each other.
The GT3 now has the BBI cup suspension (Same spring rates as RS), and both cars run Cup2-R and both run Endless N35S track pads. The RS has Aero advantage, and wider tyres and PDK. But it doesn't matter. All of that has been counter acted by a Mechanical diff. Remember both guys drive at 11/10ths.
So I am really excited to see how the Mechanical diff will transform my monster. (I bet the GT3-RS guy gets one after seeing the results.)
Not just GT3 manual, all of the manuals have regular mechanical diff where equipped with an LSD, the e-diff is a PDK only thing.
I suspect that the poster was asking if it was a TBD or a LSD, in that context “real LSD” makes sense as a lot of people refer to TBD as LSD when they are quite different. All Porsche state is “mechanical LSD” rather than the specifics.
For the manual transmissions, does anyone know if there is a true LSD in the T transmission or the S/GTS for that matter?
I thought that the T had a different transmission with different gearing from the Base, S/GTS.
I found the part numbers for the Base and the S/GTS, but can't find it for the T. I was thinking about finding a wrecked car with a manual and swapping them if it has a true LSD.
Base P/N: G9106 1 002001>999999
S/GTS P/N: G9105 1 002001>999999
T has same final drive as Carrera S rather than anything unique in the range. I assume it is just an S/GTS gearbox?
Not just GT3 manual, all of the manuals have regular mechanical diff where equipped with an LSD, the e-diff is a PDK only thing.
I suspect that the poster was asking if it was a TBD or a LSD, in that context “real LSD” makes sense as a lot of people refer to TBD as LSD when they are quite different. All Porsche state is “mechanical LSD” rather than the specifics.
TBD only lock on acceleration and are open on decel. So they are more like a 1 way LSD.
I’ve ordered a 1.5 that locks on decel as well, but less that a 2 way which is 100% both ways.
Locking on decel helps stabilise under heavy braking.
So a 1.5 LSD is superior for tracking.
OP needs to be clear why he wants one, for what specific purpose. Is he sick of one tire Fire? 🤣
06-18-2021, 04:12 PM
It is booked in to be fitted in just over a weeks time. Whilst the E-Diff is an LSD, it gets hot when heavy tracking and gives up. A full mechanical diff does not give up. It is far more predictable and allows you to steer the car with the throttle, without electronic interference. I run full traction control off and the E-Diff still manages to occasionally interfere before giving up fully.