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Pressure plate and clutch 3.8 VS 4.0

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Old 10-24-2011 | 12:58 PM
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Default Pressure plate and clutch 3.8 VS 4.0

Just got back from Daytona and I need a new pressure plate. I knew it was coming but at the dealer it was fine at cool temps. I will drop ot off at the dealer today or tomorrow..

The car will still clutch, but the pedal feels weird and the car fibrates when I let the clutch out to move it. Cables are OK.

I want to make sure I get the right one.
What are the part numbers and what is the actual difference?
Who makes them, what do I need to know? I barely understand what the things do...

I know 911SLOW posted the part # and GT3north posted that in NA the 3.8 pressure plates were being taken of the shelf and replaced with the 4.0 part numbers, but I could not find the thread with a quick search.

Thanks in advance

Last edited by TRAKCAR; 12-01-2011 at 07:08 PM.
Old 10-24-2011 | 01:12 PM
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https://rennlist.com/forums/8791085-post93.html


My 3.8RS PP is still holding but please do try it first Sir..

Don't know the differences, probably more robust.
When you have it off the car ask the shop to take a few pics.
Old 10-24-2011 | 01:23 PM
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Hi Peter,

I found 911Slow's post, he wrote: "4.0RS pressure plate 997 116 027 91 is new,the clutch is from the GT2RS and it has the 3.8RSs LWFW(old cup FW)."

Also, I was chatting to a buddy on the weekend over (several!) single malts (so my recollection may be a wee bit foggy....hic ! ) about GT3 presure plates, he said that the new 4.0 RS pressure plate is the one to get as it has a new design that actually solves the issues of failed quick shifts for 2nd to 3rd (i.e. you find the gate boundary or 5th). He now has this unit in his 997.1 GT3RS and comfirms that it is indeed true (CUP cables are NOT the answer!). The new design of the diaphram spring tabs apparently facilitates the improvement. I believe SACHS is the manufacturer. I hope this helps (Actually I am still feeling kinda gunned! ).

Good luck and let us know what you find out.

Cheers!
Doug N.
Old 10-24-2011 | 01:32 PM
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Thanks John and Doug!

After the pressure plate went, I tried to forget with Petron and Grey Goose and I am still recovering 2 nights later. Must be getting old.

I'm not worried about the clutch, I'm pretty easy and slow shifter, so no GT2RS clutch needed me thinks.

It just seems that the pressure plate stops working in long, high temps and it gets tired, falls apart etc. No abuse needed, same thing on the MKI's. Maybe even same part number?

I will make sure I get the right part 4.0 part number 997 116 027 91
Old 10-24-2011 | 01:33 PM
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Good luck peter....we all will be getting this soon
Old 10-24-2011 | 01:38 PM
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Originally Posted by DJN
Hi Peter,

I found 911Slow's post, he wrote: "4.0RS pressure plate 997 116 027 91 is new,the clutch is from the GT2RS and it has the 3.8RSs LWFW(old cup FW)."

Also, I was chatting to a buddy on the weekend over (several!) single malts (so my recollection may be a wee bit foggy....hic ! ) about GT3 presure plates, he said that the new 4.0 RS pressure plate is the one to get as it has a new design that actually solves the issues of failed quick shifts for 2nd to 3rd (i.e. you find the gate boundary or 5th). He now has this unit in his 997.1 GT3RS and comfirms that it is indeed true (CUP cables are NOT the answer!). The new design of the diaphram spring tabs apparently facilitates the improvement. I believe SACHS is the manufacturer. I hope this helps (Actually I am still feeling kinda gunned! ).

Good luck and let us know what you find out.

Cheers!
Doug N.
Very interested in getting confirmation on this. Subscribed.
Old 10-24-2011 | 03:58 PM
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Originally Posted by Nizer
Very interested in getting confirmation on this. Subscribed.
No shifting issues on Sat with the 4.0 on track. But I would not interpret this to mean the "problem" is fixed. The Thunderhill T12 shift from 2-3 is where I always had issues and I will be there Wednesday and file a report of shift performance afterwards.
Old 10-24-2011 | 06:10 PM
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Im also looking for a pressure plate as well as a clutch and lwfw kit for my 2008 997 GT2.

Would a 4.0rs pp and a 3.8rs lwfw and a gt2rs clutch work as a package ? What are your thoughts and from where can the parts be sourced ? sorry to hijack the thread somehow, thanks.
Old 10-24-2011 | 06:17 PM
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Clutch under warranty??
Old 10-24-2011 | 07:07 PM
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Come on Peter.... You spend HOW MUCH prepping the car for each event? Why did you just not get the GT2 (old terms) pressure plate from Sachs? Are you really looking for a warranty job? Had the highest clamping force they made. Have not seen specs on the new 4.0, but doubt it still measures up. Rated at think 950nm (like 700+ lb-ft). Used in turbos with double your torque and held up....
Old 10-24-2011 | 07:20 PM
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Originally Posted by GTSilver
Im also looking for a pressure plate as well as a clutch and lwfw kit for my 2008 997 GT2.

Would a 4.0rs pp and a 3.8rs lwfw and a gt2rs clutch work as a package ? What are your thoughts and from where can the parts be sourced ? sorry to hijack the thread somehow, thanks.
First question you have to ask yourself, especially you turbo guys, is what are your intentions, power requirements, launch requirements, etc. What a GT2 owner needs is not necessarily what a trackday driver 3.8RS needs.

I don't even want to guess, just because you said LWFW, that your intentions are trackdays. Is your car running higher boost / over 500 wheel TQ? How many times a year are you going to drop the clutch at a stoplight at 3500rpms? You get the idea.

Peter is a heavy DE guy - so on his 3.8RS, a 4.0 pressure plate with stock friction disk, or maybe slightly upgraded, with lwfw is perfect.

If you told me you were going to do the same with a GT2 with power mods + a couple of hard launches a year, then a LWFW is fine, but I would significantly upgrade the friction disk if 'launches' are in your routine. If you can confirm that the GT2RS and 4.0RS have the same Pressure Plate then that should suffice - unless you are over 600whp in which case you need more PP.

Any PP, FW and FD made for the GT1 block will work.

Do you want a LWFW y,n?
Are you launching the car y,n? (this is a FD, PP question but more FD)
Do you have major power modes y,n? (this is a PP issue)
Are you doing very high rev h/t matching y,n (this is a robust of PP issue - similar but different to very high HP launching needs)
Old 10-24-2011 | 07:35 PM
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heelo,
I work in parts at a Porsche dealership and the 3.8 p/n 99711602790 has been discontinued and supersedes to the 4.0 pressure plate p/n 99711602791.
Old 10-24-2011 | 08:17 PM
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Originally Posted by Viperbob1
Come on Peter.... You spend HOW MUCH prepping the car for each event? Why did you just not get the GT2 (old terms) pressure plate from Sachs? Are you really looking for a warranty job? Had the highest clamping force they made. Have not seen specs on the new 4.0, but doubt it still measures up. Rated at think 950nm (like 700+ lb-ft). Used in turbos with double your torque and held up....
No overrevs, I shift slow motion and i can heel and toe. The 4.0 part number should work.

Last edited by TRAKCAR; 10-26-2011 at 01:22 PM.
Old 10-24-2011 | 09:19 PM
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Originally Posted by partspusher
heelo,
I work in parts at a Porsche dealership and the 3.8 p/n 99711602790 has been discontinued and supersedes to the 4.0 pressure plate p/n 99711602791.
problem solved.
Old 10-24-2011 | 09:34 PM
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Originally Posted by TRAKCAR
No overrevs, I shift slow motion and i can heel and toe. I pay nothing when I buy a new car until warranty expires for non wear items. If they refuse they will never see my car again. Principle.
So get inferior Pressure Plate replaced free and potentially lose entry fees, time, hotel rooms, experience at race tracks, etc for your principle. As long as you are happy and buying my screwdrivers....



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