LWF, which pressure plate, RS or turbo?
03-12-2008, 12:43 AM
#16
Rennlist Member
One should be careful about mixing & matching parts,...
If you don't need the extra clamping force for the street or with a mild engine, using a pressure plate with more clamping force puts more stress on the TOB and crankshaft thrust bearings. Remember, you depress the clutch to start the motor and guess what takes the pressure when the pedal is held down? the center crank bearings.
When some use a thin (0w-40) oil, thats not a recipe good for optimal engine life.
As always, parts selection should be matched to the "mission" as its NOT a one-size-fits-all world.
If you don't need the extra clamping force for the street or with a mild engine, using a pressure plate with more clamping force puts more stress on the TOB and crankshaft thrust bearings. Remember, you depress the clutch to start the motor and guess what takes the pressure when the pedal is held down? the center crank bearings.
When some use a thin (0w-40) oil, thats not a recipe good for optimal engine life.
As always, parts selection should be matched to the "mission" as its NOT a one-size-fits-all world.
I'm curious: how does oil viscosity affect this issue?
03-12-2008, 01:09 AM
#17
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Typically, one only needs as much clamping force to prevent disk slip. More than required is needless.
03-12-2008, 01:17 AM
#18
RL Technical Advisor
Those thin oils; specifically 0w-40 and 5w-40 oils, have the viscosity of water when the engine is cold and that doesn't protect the bearings very well when subjected to localized very high pressures. These are OK when the engine is hot after they thicken up to an SAE 40.
The 15w-40, 15w-50 and 20w-50 oils work MUCH better.
Personally, I've disconnected that infernal interlock on all my cars so the engine will start without depressing the clutch. I cannot do that for my customers due to some liability issues but its better for the engine,...
03-12-2008, 02:28 AM
#19
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03-12-2008, 10:59 AM
#23
Drifting
Thread Starter
That's a good idea, thanks. I presume the switch is under the floor board and just needs to be "hot wired" so to speak?
03-12-2008, 11:05 AM
#24
Three Wheelin'
03-12-2008, 11:24 AM
#25
Drifting
Thread Starter
Playing devil's advocate here for a moment, wouldn't depressing the clutch to start put less strain on the starter due to not having to turn the transmission gears, especially when cold?
03-12-2008, 10:53 PM
#26
Technical Guru
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The 993RS and the regular 993 came with the exact same pressure plate. The 964RS pressure plate (which has less clamping strength than the stock 993 pressure plate) became the standard 964 pressure plate in/around ~1992. So if you're installing a LWF into a 993 you're better off just sticking with the stock 993 pressure plate. The RS pressure plate (with the blue paint mark) is not an upgrade!
03-13-2008, 12:10 AM
#27
Instructor
Steve Weiner is an expert on many things, however:
Except for the fluid in the C4 viscous coupler, oil does not thicken up as the temperature increases. The first "W" number is a measure of how thin/thick the oil is at low temperature only (the test temperature varies but is around 0 degress C. At 100 centigrade all oils of the same grade (second number) are the same viscosity.
He is right that a 0W40 oil is thinner than a 15W40 oil when cold. However the viscosity at 100 degrees C for both these oils is still much thinner. So in practice the OW has no negative effect on lubrication.
Except for the fluid in the C4 viscous coupler, oil does not thicken up as the temperature increases. The first "W" number is a measure of how thin/thick the oil is at low temperature only (the test temperature varies but is around 0 degress C. At 100 centigrade all oils of the same grade (second number) are the same viscosity.
He is right that a 0W40 oil is thinner than a 15W40 oil when cold. However the viscosity at 100 degrees C for both these oils is still much thinner. So in practice the OW has no negative effect on lubrication.
03-13-2008, 12:31 AM
#28
Drifting
Thread Starter
The 993RS and the regular 993 came with the exact same pressure plate. The 964RS pressure plate (which has less clamping strength than the stock 993 pressure plate) became the standard 964 pressure plate in/around ~1992. So if you're installing a LWF into a 993 you're better off just sticking with the stock 993 pressure plate. The RS pressure plate (with the blue paint mark) is not an upgrade!
03-13-2008, 10:08 AM
#29
All 993 use clutch and pressure palat w/ 964 part #S
the pressure plate for all 993 except tt is(I used this one)
964.116.027.03
the pressure plate for all 993tt is
964.116.027.53
the clutch disk for all 993 except M003 RS is
964.116.114.90
alternataives are
964.116.113.51
964.116.113.52
964.116.114.51
964.116.114.52
the clutch disk for all 993 M003 RS is (I used this one, be sitting down when you get the price)
964.116.111.61
the pressure plate for all 993 except tt is(I used this one)
964.116.027.03
the pressure plate for all 993tt is
964.116.027.53
the clutch disk for all 993 except M003 RS is
964.116.114.90
alternataives are
964.116.113.51
964.116.113.52
964.116.114.51
964.116.114.52
the clutch disk for all 993 M003 RS is (I used this one, be sitting down when you get the price)
964.116.111.61
03-13-2008, 10:19 AM
#30
Wallflower
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I was wondering why mine was like that... I guess it was intentional.