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Clutch on 997 GT2

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Old 08-29-2013, 01:49 PM
  #16  
M3EvoBR
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Originally Posted by TB993tt
I thought the GT2 has a different disc - is this not what the PET shows below (I101 being GT2) ?



Which clutch bits are different (from the GT2) on the RS - I was pretty convinced they were the same particularly after my mates stock one slipped, I told him "they all do that"
let me see what I can find out here.

1 min please.
Old 08-29-2013, 01:53 PM
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sideways_swe1
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If the gt2 has the same clutch as turbo. The RS must have a stronger one.
Old 08-29-2013, 01:59 PM
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GT2RS part numbers are:

Disc - 997 116 013 91
Pressure plate - 996 116 027 51
Release bearing - 944 116 080 01

Unfortunately for the GT2 I can only see as a clutch kit, so no individual parts.
Old 08-29-2013, 03:00 PM
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Originally Posted by M3EvoBR
GT2RS part numbers are:

Disc - 997 116 013 91
Pressure plate - 996 116 027 51
Release bearing - 944 116 080 01

Unfortunately for the GT2 I can only see as a clutch kit, so no individual parts.
Thanks!

So, with a protomotive tune and exhaust a gt2 makes about 610hp i believe. So an RS clutch should do it. Im having hard to see that porsche would put a clutch on the RS that cant handle the power. I friend of mine had one last summer and didnt complain about the clutch slipping. Of course you can ruin a clutch on any car if not being careful.

Of course if the stronger sachs clutch is cheaper theres no question i take that one. But my guess it is not.
Old 08-29-2013, 03:15 PM
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TB993tt
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Originally Posted by M3EvoBR
GT2RS part numbers are:

Disc - 997 116 013 91
Pressure plate - 996 116 027 51
Release bearing - 944 116 080 01

Unfortunately for the GT2 I can only see as a clutch kit, so no individual parts.
So the pressure plate of the RS is the same as the GT2/turbo and the disc is a new 997 part number where the GT2 uses the old 996 disc presumably from the 996GT2 (different from the turbo disc which is that 997 number ending 013 50).

The GT2RS clutch will not take the torque of a remap, any decent remap will give you 800NM, the GT2RS disc is designed for 700NM (and as I said the stock one slipped with STOCK torque - my pal can drive he races in a Porsche Cup series) the sachs 890NM parts will not be more expensive so they would be the ones to get, if you are using Todd K he will doubtlessly steer you in this direction and be able to provide the parts.
Old 08-29-2013, 03:21 PM
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I just searched a bit more because the new GT2RS clutch disc number 997 116 013 91 intrigued me since with there being no extra torque GT2 v GT2RS there should be no need for a new stronger disc....

It turns out the 4.0RS also uses the 997 116 013 91 disc, I am thinking this disc is designed to work with the LWFW set up which the GT2RS and the 4.0RS use, maybe the dimensions are slightly different ? The torque holding capacity is no better than the 996GT one used by the 997GT2 I would wager

Last edited by TB993tt; 08-29-2013 at 03:37 PM.
Old 08-29-2013, 04:21 PM
  #22  
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This isn't advice and again I have no practical experience in this specific area but something is telling me 100 CEL is a bit much.

Can someone afford me an explanation to the contrary?
Old 08-29-2013, 04:39 PM
  #23  
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Guys, to shed a little information on the Porsche clutches...

Everything is based off the flywheel. Once you have figured out your flywheel>> three factory choices. Then you can start to build your clutch kit..

The reason why we want to focus on the flywheel "is" it dictates which clutch disk one MUST use. For instance you cannot use the 996GT3 or997GT3 4.0 ltr or GT2RS clutch disk WITH a dual mass flywheel. You cannot install that disk in a 996GT2 or 997GT2. Guy have tried, and then on startup you find yourself not being able to get the car in gear of out of gear.. It is a common mistake.

I'm going to skip the clutch disk options for a moment and jump over to the pressure plates. There are 4 factory Sachs pressure plates that get tossed into the mix. Many internet and parts houses for the last 20 years have opted to insert the 964 NA pressure paired with the 964 RS lightweight flywheel. This has happened for years, on 993TT and 996TT. I still get emails and parts breakdowns with shops trying to install it on 997TT/GT2.. Flat out THAT NA pressure plate will not work. The plate will fail within the first week. I think that there is confusion between the 764 plate and the 964NA car when they look at the RS parts breakdown.

The 2nd plate is the Turbo pressure plate. The plate that leaves the factory 993TT, 996TT, 996GT2, 997TT, and 997GT2... Over the years part numbers have changed, but it is still the factory TURBO plate. It is a bullet proof plate but will NOT hold with a good tune. It is foolish to install this pressure plate when you can get two other factory pressure plates that do a better job.

The 3rd plate is a Sachs Race Motorsports plate with a part number that ends in 752.. This plate is a upgrade over the factory Turbo plate. It is great for the stock turbo 993TT, 996TT, 996GT2 and 997GT2RS.. With the normal bolt on mods this plate works well. BUT will not hold more aggressive tunes and track outings.

The 4th plate and best factory Sachs Race Motorsports plate ends in 764. Toby refers this as the 890Nm unit. It would be easier for newbies to call it the 764/890Nm plate. I can post the physical differences of this plate vs others in another post.. This is really the best choice for a replacement clutch, whether you keep the dual mass flywheel or not.

Warning>> Do not get caught up in the sales marketing STAGED kit numbers.. You can get hosed big time. For the Turbo and GT2/GT2RS owner, make sure you ASK which pressure plate you are getting.. Turbo, 752 or 764.... Call it the Stage Master blaster XYZ.. But in the end get the pressure plate that you want to fit your driving and power output. With that said, the 764 plate can and does fail. Drag strip runs, race track events, and extreme HP outputs will make short life of this plate.

The next topic area is the clutch disks. And over the years Sachs has modified the disks to keep up with better manufacturing and higher torque outputs.. I will make a few blanket statements to clear up some myths.

a) The factory 996GT2 disk is a solid centered NON sprung disk. It has a slight edge in torque rating vs the standard turbo disk (the turbo disk is sprung) the organic lining between the two disks are the same.

b) You cannot install a 996GT2 disk and/or 997GT2 disk with a factory lightweight flywheel. The reason is.. The flywheel is thicker>it is closer to the backwall of the transmission bellhousing. Be careful, standard turbo and GT2 disk can only be paired with the dual mass flywheel.

c) The BEST and strongest clutch disk for track use has been the 996GT3 and new improved 4.0 ltr disk. These disks are sprung to absorb the energy since the lightweight RS flywheel is in place. You cannot use these disk with the dual mass flywheel. They are to tall, and the sprung center doesn't clear the internal cavity between the dual mass and pressure plate. Sachs has redesigned the 997 4.0 disk with smaller diameter springs to reduce the rattle. I favor the 996GT3 disk since the organic lining is the same as the 4.0. The torque output rating is similar. The 4.0 with the new springs can handle more torque at extreme RPM's which our turbo engines don't see.

The last option from Sachs is 4 puck race (bronze) clutch disks. These coupled with the RS LWFW turn street driving into a nightmare. You have to rev the engine to 3500 to 4K to get the car moving. The reason for this disk is because the organic lining just isn't up to the task and heat in racing. One option prior to getting the 4 puck version is to use a aftermarket lining manufactured in Canada. It comes with a 6 puck or 8 puck glass lining and one removes the factory organic from either the Rigid GT2 disk or Preferred GT3 disks. This is the better choice for High Output street cars. Once you smoke these disks, you need to upgrade to twin disk and carbon multi disk systems. Such as Tilton units.

Lastly, like I mentioned in the beginning, the flywheels dictate the clutch choice. It is a flow chart, that has to be explained to your tuner. One clutch kit doesn't fit all the boxes. You could have a stock output 997GT2.. But you race it twice a week in DE or open events. If that is the case I would strongly recommend the RS lightweight flywheel with the 764/890Nm pressure plate and either the 996GT3 clutch disk or 4.0 clutch disk. For tuned engines, I would recommend the same. If the GT2 that gets track is tuned, one can recommend the 8 puck glass lining built on the GT3 disk.

My personal opinion, I don't recommend the factory dual mass when placed into service on the track. I think that the LWFW is better option. Modern tuning today will deal with the previous year stalls and low RPM bucking. The noise or rattle will still be there. But if you have a loud exhaust, who cares.. Shedding 18 lbs of weight pays in the long run. Find a fellow Rennlister to get some seat time in. Please note that many failed LWFW kit have been sold over the years. It is a failure to use any LWFW with a non sprung clutch disk. Many kits come with the GT2 clutch disk. It turns this kit into a nightmare light switch event.

There is a difference between the RS flywheels. The early CUP design is tweaked for production in the 997RS.. The ONLY difference is that it is roughly 2 lbs lighter vs the 964 RS flywheel. 9.2 lbs vs 10.5 to 11.0 lbs. What is different is>> the DME trigger ring is back cut. With the RS flywheel, you have finger for the DME trigger wheel (60 -2) versus solid teeth on the 964 unit. I recommend the 964 RS LWFW.

I have sold hundreds of these kits and no two owners are the same. If you hate the LWFW rattle, go with a dual mass kit. Make sure that you are getting the 764 pressure plate.. FYI, I sell the RS LWFW kit with the 996GT3 clutch disk and 764 pressure plate for $2,295.00 If you want the 4.0 disk it's $200 more.. Feel free to email or call me...
Old 08-29-2013, 04:57 PM
  #24  
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If you're going to upgrade and go through the hassle, I'd suggest something stronger than the RS kit
Old 08-29-2013, 05:06 PM
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So in other words before making a decision ring up Kevin
Old 08-29-2013, 05:20 PM
  #26  
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The better hybrid RS kit would be to insert the 764/890Nm pressure plate into the kit!!
Old 08-29-2013, 06:42 PM
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Originally Posted by Tacet-Conundrum
This isn't advice and again I have no practical experience in this specific area but something is telling me 100 CEL is a bit much.

Can someone afford me an explanation to the contrary?
Less back pressure is always good on turbocharged, 100 cell give less post turbo than 200 cell.
Benchmark Cargraphic/RS Tuning stage 1 600hp/826NM kit is new ECU program and 100 cell cats, like my pic above but 100 cell......
Old 08-30-2013, 01:39 AM
  #28  
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Wow this thread has some amazing info! Thank you kevin for an awesome post! Stronger clutch it is and no RS clutch. It makes sense since torque gets so much more.
Old 08-30-2013, 08:19 AM
  #29  
TB993tt
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I read a thread on (I think) 6bling where a guy has a noisy LWFW, he posted videos and it is NOISY. I was quite alarmed to see lots of posters commenting on the LWFW rattle and many saying this sort of noise was normal.

Above Kevin mentions If you hate the LWFW rattle ......

Well I would like to tell those guys interested who have 997 turbos or GT2s that you DON'T have to have this rattle with a LWFW.

I have 890NM clutches with LWFWs in my 993 turbo and in my 997GT2 and they hardly rattle at all, I thought of doing a video to show it in the 997 but it is so quiet that there would be nothing really to hear above the exhaust and road noise.

There is a slight rattle when pulling in high gear from low revs but seriously it is hardly noticable - I use this car (and the 993 before) as daily drivers in traffic and would not put up with any rattling.

So I am thinking why are both my 890NM LWFW clutches so civilised ? I am not sure of the answer to this but it has to be that the combination of components is correct and maybe the installation is done correctly.

Reading Kevin's interesting post above it leaves me as a punter completely confused and my recommendation to any 997 turbo GT2 owner would be to find a shop/tuner/engine builder who will guarantee that the 890NM clutch they install will NOT be noisy, here is the key you need to get the shop you choose to supply and fit the clutch and give you this guarantee.

My clutches I think come from RS Tuning who have done all the testing and matching and who I think supply Cargraphic, see the link below for CG's offerings.

http://www.cargraphicts.com/index.php?id=124315&L=1

So my recommendation is to find a shop who will supply and fit CG packages with the guarantee of low level of noise - DO NOT put up with some of these ridiculously loud cement mixer set ups which people are peddling.

If anyone wants me to do a vid of mine idling to illustrate what "you" mean by low level of rattle I will happily do so ?
Old 08-30-2013, 12:09 PM
  #30  
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Toby, your LWFW better NOT make any noise. You have a solid centered clutch disk. That's a nasty clutch for street city driving. Parking on any sort of ramp, or parking garage would be a chore. With the large sprung centered disk my wife can drive the car. Can your wife back the car out of the garage with the solid centered disk?


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