neuroguru

Hi All,

I loved my Guard LSD in my 6.2GT3. I understand the PDK-friendly Guard LSD has been used in the 991S for a year or so. Anyone popped it into their 1.1GT3 yet?

Any feedback on some of the forged rims that are out now for the 1.1GT3?

I am waiting on the CCWs. Should be out soon, but I wouldn't mind some BBS or Fikse options.

Anyone using Nittos or Hoosiers yet?

BK Anti-sub bar?

orthojoe

1) Correct me if I'm wrong, but if the 991 GT3 has an e-diff, it's not possible to swap to a mechanical diff like the Guards unit
2) There aren't any Nitto sizes that will fit on a 991GT3 with 19" or 20" wheels. 18" wheels wont work with the new GT3. Someone has run properly sized 19" hoosiers and the car has done just fine.
3) BK anti-sub bar is for the GT2 bucket seats. Unknown, but unlikely they will be compatible with the new LWB seats

mooty

u can run 19 hoosiers
in 19" u can get BBS or forge line, that's why I will do.
have u actualy talk to joh at ccw? he was pretty adamant that he will not produce CL wheels for 991 gt cars

GrantG

That is my understanding too. PTV is an integral system designed to work with the stock diff and it cannot be tuned or turned off, afaik.

Guard may at some point provide upgraded internal parts (if needed), but you can't just slap in one of their great mechanical diffs.

Z356

Guru: Along the lines of Ortho's response, I don't believe Guard Transmission LLC thinks the totally 'new' 991 gt3 limited slip needs to be 'improved' in the way his company did for past Porsche models. When I visited Matt Monson at his business in Colorado in the summer of 2013, he told me he had been shown detailed information for the system PAG had designed for the new 991 gt3 and he was (at the time) pretty impressed with the engineering behind it. But just to make sure, please check with him at <gtgears@yahoo.com> and let us know what he says.

http://www.guardtransmissionllc.com/...differentials/

I'll also drop him an email to see if he has the opportunity to come to our forum and update his views on the topic of the 991 gt3 limited slip. Matt is a very talented guy (basically a one-man operation) and many of us are impressed with how he has taken over Guard, learned the business from the ground up and continued to create innovative products while offering excellent follow-up service to his customers! The latter are mostly in the auto racing community worldwide and Matt & his company are a valuable asset to our hobby!

Saludos,
Eduardo
Carmel

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neuroguru

I talked to John at CCW 2 months ago and he was planning on making rims for the 991GT3.

GTgears

Hi Guys,

Eduardo pinged me and asked me to pop in and shed some light on this. Let's start with a picture since everyone likes pictures. And then I will explain.


This is a picture of the LSD found in the 991 GT3. It is called PTV+. PTV is used in the other vehicles. PTV+ is only used in the 991 GT3, the Turbo and the Carrera S. What you are looking at is how the LSD is actuated to provide variable locking rates in real time. That double row ring with bearings is to distribute the load when force is applied from the outside. The pin he's putting back in the LSD body is what the ring presses down on to apply more force to the clutches, and thus more locking factor.

There is an oil pressure feed that clamps the rings. When the car detects wheelslip the ring is pressurized. It is truly a zero preload LSD with 0% lock in steady state.

Porsche first used this approach back on the 959 and 964 C4 gearboxes. Back then there were slave cylinders applying the force though. This is the next wave in high tech LSDs. At this point we see zero reason to attempt to do better.

The only other thing I would add is that PTV is also a mechanical LSD in conjunction with electronic babysitters. Our LSD will replace that one with a more aggressive unit for owners of 991 Carreras.

mooty

Matt makes some of the very best LSDs!

neuroguru

Yes, he does! Thanks for sharing, Matt!