GT2 Slave Conversion wear the clutch faster?
07-31-2010, 12:54 AM
#1
Instructor
Thread Starter
GT2 Slave Conversion wear the clutch faster?
A Porsche mechanic said that upgrading to the GT2 Clutch Master and Slave Cylinder Conversion is a nightmare for a daily driver due to the fact that the pedal being extremely stiff, as well as it wearing the clutch down faster.
Anyone have any real world knowledge or experience with this mod? I have the engine and transmission out right now and figured I'd go ahead and do this if it makes sense.
Anyone have any real world knowledge or experience with this mod? I have the engine and transmission out right now and figured I'd go ahead and do this if it makes sense.
07-31-2010, 07:18 AM
#2
Rennlist Member
I can't speak to the wear issue but I personally love the stock clutch just because of the ease factor. I've driven Corvettes and other cars with heavy clutches and I don't ever want to deal with that again. Even though the 996TT clutch is sometimes a bit difficult to modulate in first gear, it's much easier in all other gears, and I much prefer that to a heavy clutch in all gears.
07-31-2010, 07:24 AM
#3
I do. I have the EVOMS kit in my car, along with the ClutchMaster's upgraded Fibertuff material on a Sprung GT3 hub clutch disc, along with a sachs 999 motorsports pressure plate that has a fulcrum mod specific to the mods to the clutch disc. I'm also running the 964RS lightweight flywheel.
The clutch pedal will be stiffer. However, you will no longer play the guessing game with your foot trying to decide where the clutch engages and disengages. I've driven a number of high pedal effort cars over the years, and this upgrade is NOTHING like those of the Ford Mustang King Cobra clutch or some of the stiff clutches of the Vette I owned.
The real benefits to doing this mod are two fold. You get rid of the link between your clutch and your power steering that has fire potential AND has been known to fail with great frequency, and you really do gain the ability to feel the clutch at the same exact time every time. I can now slip the clutch in traffic as needed.
As to the wear question, I for one have NEVER heard this.
The cost will be the cost of the kit (Evoms wants about $1000) and the cost of labor, which is about 6-8 hours if you go to someone who has experience doing it properly.
I'll never go back to a stocker, and for reference, I live about an hour outside of Washington DC. and have driven my car in rush hour traffic. When sitting for long periods, I'd recommend to slip the shifter into nuetral and let the clutch out. But my leg honestly has never gotten "that" fatigued by this particular mod. I just don't see it as an issue... It IS stiffer, though...
Mike
The clutch pedal will be stiffer. However, you will no longer play the guessing game with your foot trying to decide where the clutch engages and disengages. I've driven a number of high pedal effort cars over the years, and this upgrade is NOTHING like those of the Ford Mustang King Cobra clutch or some of the stiff clutches of the Vette I owned.
The real benefits to doing this mod are two fold. You get rid of the link between your clutch and your power steering that has fire potential AND has been known to fail with great frequency, and you really do gain the ability to feel the clutch at the same exact time every time. I can now slip the clutch in traffic as needed.
As to the wear question, I for one have NEVER heard this.
The cost will be the cost of the kit (Evoms wants about $1000) and the cost of labor, which is about 6-8 hours if you go to someone who has experience doing it properly.
I'll never go back to a stocker, and for reference, I live about an hour outside of Washington DC. and have driven my car in rush hour traffic. When sitting for long periods, I'd recommend to slip the shifter into nuetral and let the clutch out. But my leg honestly has never gotten "that" fatigued by this particular mod. I just don't see it as an issue... It IS stiffer, though...
Mike
07-31-2010, 07:28 AM
#4
Larry, When you upgrade those turbos, you'll then have to upgrade the clutch/PP/FW. You will also then have to upgrade that hydraulic setup. I'm convinced the stiffer pressureplate is what killed my slave/accumilator...
Oh and I forgot to mention, my steering is also lighter without the added pull on the power steering system from the slave/master/accumilator.
Mike
Oh and I forgot to mention, my steering is also lighter without the added pull on the power steering system from the slave/master/accumilator.
Mike
I can't speak to the wear issue but I personally love the stock clutch just because of the ease factor. I've driven Corvettes and other cars with heavy clutches and I don't ever want to deal with that again. Even though the 996TT clutch is sometimes a bit difficult to modulate in first gear, it's much easier in all other gears, and I much prefer that to a heavy clutch in all gears.
07-31-2010, 09:48 AM
#5
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
There are two options when doing this conversion. One is the EVOMS kit that Mike describes. This can be done with the transmission still in the car. If you are having the clutch replaced at the same time, then the trans will be out. In this case, you can move the actuator to the other side of the bell housing and change the clutch fork. This configuration is what is actually in the GT2/3. I got all of the parts for the conversion from Kevin at UMW, along with the 964 RS clutch, when I upgraded my turbos.
The clutch is stiffer because you lose the power assist. Like Mike, I am used to it and think it's ok. I moved my seat forward one notch to make it easier to hold the clutch to the floor.
I too have never heard of anyone wearing the clutch faster with this conversion. I can't think of a reason why that could be true.
Jon
The clutch is stiffer because you lose the power assist. Like Mike, I am used to it and think it's ok. I moved my seat forward one notch to make it easier to hold the clutch to the floor.
I too have never heard of anyone wearing the clutch faster with this conversion. I can't think of a reason why that could be true.
Jon
07-31-2010, 02:23 PM
#6
Addict
Rennlist Member
Rennlist
Site Sponsor
Rennlist Member
Rennlist
Site Sponsor
You won't get "clutch disk" wear.
If the gearbox is out on the table, I would recommend installing the Porsche components. While there are different kits out there. I like mounting the GT3 slave in the correct place which is on the drivers side of the bell housing. Jon has just mentioned his "factory" conversion.
I will go one step further and recommend updating the power steering pump and reservior at the same time.
Between Mike and Jon they can give you there recommendations for "pedal stiffness"
Jon originally told me 25 to 30% over stock.
I think that this is a accurate statement.
The benifit is that we get cheaper component prices for future slave repairs. When mounted to the bell housing "factory" style the replacement labor is cheaper. Pedal feel is "more" precise.
If the gearbox is out on the table, I would recommend installing the Porsche components. While there are different kits out there. I like mounting the GT3 slave in the correct place which is on the drivers side of the bell housing. Jon has just mentioned his "factory" conversion.
I will go one step further and recommend updating the power steering pump and reservior at the same time.
Between Mike and Jon they can give you there recommendations for "pedal stiffness"
Jon originally told me 25 to 30% over stock.
I think that this is a accurate statement.
The benifit is that we get cheaper component prices for future slave repairs. When mounted to the bell housing "factory" style the replacement labor is cheaper. Pedal feel is "more" precise.
07-31-2010, 06:43 PM
#7
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
I followed Kevin's recommendation and replaced the P/S pump and reservoir.
Kevin tells me that I said 25-30% stiffer, but I honestly don't remember saying that. It's stiffer. I don't know what percentage. It's ok though. A bit reminiscent of my '87 911, although the clutch pivots from the top rather than the bottom.
It *is* more precise, and I had already had one accumulator failure and the old slave was leaking when we did the mods. Much safer too, as the Pentosin is gone.
Overall, I think that it's a good thing to have done.
Jon
Kevin tells me that I said 25-30% stiffer, but I honestly don't remember saying that. It's stiffer. I don't know what percentage. It's ok though. A bit reminiscent of my '87 911, although the clutch pivots from the top rather than the bottom.
It *is* more precise, and I had already had one accumulator failure and the old slave was leaking when we did the mods. Much safer too, as the Pentosin is gone.
Overall, I think that it's a good thing to have done.
Jon
Trending Topics
08-01-2010, 07:33 AM
#11
You'll need the plugs to block off the power steering pump, or buy a GT2/3 power steering pump as well... You also will not need that servo spring...
The method Kevin recommends is the way I would have gone had we spoken, but honestly, my Indy was taking so long to do my transmission rebuild, and I was in such a foul mood, I didn't want to deal with adding more to the list...
From my understanding of Kevin's mod, you'll also need to drill the holes in the bellhousing so you can bolt the slave in there... With the evoms kit, It sits in the factory location and is still pretty simple to swap out if the unit fails... The slave cylinder is now two bolts that hold in place, and breaking loose the fluid pipe. Should be an hour job to swap and bleed either unit on the lift.
Mike
The method Kevin recommends is the way I would have gone had we spoken, but honestly, my Indy was taking so long to do my transmission rebuild, and I was in such a foul mood, I didn't want to deal with adding more to the list...
From my understanding of Kevin's mod, you'll also need to drill the holes in the bellhousing so you can bolt the slave in there... With the evoms kit, It sits in the factory location and is still pretty simple to swap out if the unit fails... The slave cylinder is now two bolts that hold in place, and breaking loose the fluid pipe. Should be an hour job to swap and bleed either unit on the lift.
Mike
08-01-2010, 04:55 PM
#12
Addict
Rennlist Member
Rennlist
Site Sponsor
Rennlist Member
Rennlist
Site Sponsor
I have the GT2/3 conversion, and am very happy with it. I also have the 964 RS clutch with LWFW. You definitely don't want that clutch/FW because it is very stiff and fairly noisy in neutral with clutch out. I wouldn't recommend it for a street only car.
To Jon, I'm sorry if I didn't "hear" you correctly. But from my own experience the NON power assisted clutch pedals will be 20 to 25% MORE stiffer.
Mike where do you put the percentage at.
And yes, with the gearbox sitting out, following the factory parts list for the conversion is my recommendation.
Joe, I will forward the quote to you.
08-01-2010, 06:57 PM
#13
Percentage of stiffness for me isn't going to equate to others... I used to be a regionally ranked competitive cycles (although these days I'm a little to round for that) and my leg muscles/strength is a little higher than the average Joe... I'd say it's at least 20% stiffer...
As to the comment about the LWFW, and all the parts associated wtih this mod, I agree. If you plan to sell this car in the next 2-4 years, then I'd re-think it. I did the conversion knowing I'd be keeping this car for at least 10 years... Resale would only be geared towards true track hounds and performance drivers...
Mike
As to the comment about the LWFW, and all the parts associated wtih this mod, I agree. If you plan to sell this car in the next 2-4 years, then I'd re-think it. I did the conversion knowing I'd be keeping this car for at least 10 years... Resale would only be geared towards true track hounds and performance drivers...
Mike
08-01-2010, 09:07 PM
#14
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
The above quote was from Jon. I am not tossing him under the bus. Joe if you are keeping the car for the street and selling the car I would NOT recommend installing the GT2/GT3 slave kit. You will knock out 80% and maybe more buyers. If you are going to track your car this is the mod to make.
To Jon, I'm sorry if I didn't "hear" you correctly. But from my own experience the NON power assisted clutch pedals will be 20 to 25% MORE stiffer.
To Jon, I'm sorry if I didn't "hear" you correctly. But from my own experience the NON power assisted clutch pedals will be 20 to 25% MORE stiffer.
Just kidding -- I don't know the percentage stiffer. I will say that I am not a very big guy (165 lbs), and it's ok for me.
The quote that Kevin gave was from another thread where the OP specifically said that he didn't like the feel of a stiff clutch. That's why I was warning him off of the conversion.
Jon