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I'm looking for a new clutch setup that can handle an upcoming E85 tune. The GT3 RS 4.0 clutch disc should be able to handle the increased torque right? Will keep the VTG:s and injectors stock for now so we are not talking crazy numbers here. And yes, I plan on switching to the RS LWFW and an appropriate pressure plate.
Thanks Kev, I am reving to 7400rpm max so I'm sure the 764 suffices.
I was intrigued by Pwdrhound's comments on the 487 somehow being "better" to use, I think he was saying it had less moment of inertia which somehow made it superior in use than the 764 even on lower rev applications ?
Just saw this. The 487 is simply a beefed up bolted 4.0 pressure plate. Since a failure of the riveted straps ends up ruining the bell housing, I feel that the bolted PP is cheap insurance especially if you track your car. I frequently see 7800-7900 on Motec so if you run track your car and run an elevated redline, the 487 is a no brainer. When I replaced the 764 with the 487, the clutch simply felt better, smoother if you will. I would never go back to the 764 personally. You must run a factory LWFW with the 487. It is not compatible with a DMFW.
I've been having an issue for 2 years now. It would come rarely in the past. Recently it happens everytime I drive a certain way.
2 years ago:
The car had the 764/ 890 nm clutch kit with the RS LWFW, & a Europipe exhaust.
When I would slow down (pull up to a traffic light for example), if either the clutch is engaged or the gear is in neutral the rpm would drop below idle & the engine would die (the lights would come on also)
*Extra info: This was not after I upgraded my clutch setup, this was after 3 years of having this setup with no trouble*
Last year the car was tuned (intercoolers, y pipe, turbo inlet pips, catless europipe, meth kit and a custom tune) - done November '21
The last few months the engine dying has happened more frequently
I took the car in to diagnose the issue. MAF sensors replaced, Throttle body, alternator and ground cables, starter motor, all these replaced
I also "upgraded" my clutch kit as the car has been putting more power.
Clutch kit I went for was; Sachs 764 PP, Sachs Racing Clutch, and the RS LWFW
Recently the problem has become a lot more frequent.
Everytime I accelerate (any speed, any gear) what I noticed was that as long as boost builds up, then I let go of the accelerator and press the clutch, the engine dies.
If I do the same but accelerate gently (no boost builds up). the rpm will drop to idle or slightly above idle and then stabilize. The car will not stall unlike if I accelerate with boost. I'm not sure if that's related but the more info the better.
There are no fault codes... It's like chasing a ghost
I heard that the RS LWFW is not suitable because the GT2RS has a different crank and pulley which mates better vs the "standard" GT2. Also heard it's okay. imo i might install the GT2RS pulley. Again, not sure if that fixes this issue..
What is the part number of the RS Flywheel that you have fitted? If you have the 997GT3RS 4.0 liter flywheel> you will have engine stalling issues.
Install the 964RS flywheel, SRE 487 pressure plate and 4.0 liter clutch disk.
RS LWFW part no. 964 1022 3981 is the one I have installed now and had in 2017 with the sachs 764/ 890 nm clutch setup.
I believe there's another LWFW Porsche do. It's the same part number but ending in 31, not 81. 31 is for the 964RS & 81 is for the 4.0 RS and the GT2RS.
I've been told they don't manufacture the 964RS FW anymore (31)
My car is tuned. I wanna know how much hp & torque the clutch kit you mentioned can hold?
I drive my car a lot on the street... very hard, & 2-4 track days a year
I'm thinking that i had this flywheel since 2017. I never had the engine dying out when clutch engaged until 2020.. 3 years it was good. Wouldn't of happened sooner if it was from the flywheel?
RS LWFW part no. 964 1022 3981 is the one I have installed now and had in 2017 with the sachs 764/ 890 nm clutch setup.
I believe there's another LWFW Porsche do. It's the same part number but ending in 31, not 81. 31 is for the 964RS & 81 is for the 4.0 RS and the GT2RS.
I've been told they don't manufacture the 964RS FW anymore (31)
My car is tuned. I wanna know how much hp & torque the clutch kit you mentioned can hold?
I drive my car a lot on the street... very hard, & 2-4 track days a year
The 96410223931 and 81 are both still manufactured. The 81 is the same part at the 31 but the 81 has more material machined away from the perimeter of the flywheel giving it a lower MOI. The friction surface is slightly narrower as the 81 version was originally used on the 996Cup which used narrower sintered clutch disc pads. The 81 is 2 lbs lighter than the 31 as a result. I have run both versions. The 81 version is used on the 997GT3RS 4.0, 997GT2RS, and 996Cup. I had zero issues with either the 31 or 81 flywheel, no engine stalling issues whatsoever and I even ran the 81 with a lightweight 4 puck Cup clutch disc for a number of years. I'm not sure why people claim you will have stalling issues as that is simply not true if your tune accounts for it. With the OEM 997GT3RS 4.0 disc and the 487PP the clutch held 720 ft.lbs of torque. Good luck.
Last edited by powdrhound; 07-29-2022 at 02:36 PM.
The 96410223931 and 81 are both still manufactured. The 81 is the same part at the 31 but the 81 has more material machined away from the perimeter of the flywheel giving it a lower MOI. The friction surface is slightly narrower as the 81 version was originally used on the 996Cup which used narrower sintered clutch disc pads. The 81 is 2 lbs lighter than the 31 as a result. I have run both versions. The 81 version is used on the 997GT3RS 4.0, 997GT2RS, and 996Cup. I had zero issues with either the 31 or 81 flywheel, no engine stalling issues whatsoever and I even ran the 81 with a lightweight 4 puck Cup clutch disc for a number of years. I'm not sure why people claim you will have stalling issues as that is simply not true if your tune accounts for it. With the OEM 997GT3RS 4.0 disc and the 487PP the clutch held 720 ft.lbs of torque. Good luck.
When you drive and accelerate... If you wanna slow down,, do you decelerate by slowing down in gear, or do you shift to neutral and slow th car down that way?
When you drive and accelerate... If you wanna slow down,, do you decelerate by slowing down in gear, or do you shift to neutral and slow th car down that way?
In normal street Driving, likely both. Bottom line, in all these years of using the .81 flywheel, I’ve never had the engine stall under any circumstance on its own.
In normal street Driving, likely both. Bottom line, in all these years of using the .81 flywheel, I’ve never had the engine stall under any circumstance on its own.
I"m glad it's not the clutch, I mean if youve used the same setup and it doesn't stall that removes the clutch from "what could be" the issue
I"m glad it's not the clutch, I mean if youve used the same setup and it doesn't stall that removes the clutch from "what could be" the issue
Think of it this way, would Porsche sell the 997GT3RS4.0 and 997GT2RS to the public if the car constantly stalled? Of course not. To suggest that would be silly. Your problem lies elsewhere..
Think of it this way, would Porsche sell the 997GT3RS4.0 and 997GT2RS to the public if the car constantly stalled? Of course not. To suggest that would be silly. Your problem lies elsewhere..
The RS 4.0 disc is what you wanna use for street/track duty. While the 764PP is fine, I would personally use the 487.
Before reading any of this I had a new clutch set up installed recently on the car.. Sachs 764PP, Sachs 4 puck racing clutch & the RS LWFW. previously i had the 764/ 890nm clutch kit from sachs with the RS LWFW
imo while the 4 pack racing clutch is good its too harsh for street driving. im considering to replace it with the 4.0L RS disc.... i just wana know how much torque that setup would hold (764pp, 4.0L disc)
btw whats ur opinion to upgrade to the RS lightweight pulley?
03-13-2018, 11:37 AM
