Carbon/carbon clutches anyone?
10-18-2011, 07:48 PM
#16
And too rich for my blood, too. I wish this stuff was free. However, I need to solve the "void" between a "beefed" Porsche dual disc and a Tilton competition clutch. It has to be streetable.
After somewhere around 450 ft lbs, the Porsche dual disc clutches are very marginal.....time bombs. If they aren't rippping the lining off of the discs, they are breaking the "weak" strap springs.
The Tilton clutches will hold the torque, but are too severe, for street use.
After somewhere around 450 ft lbs, the Porsche dual disc clutches are very marginal.....time bombs. If they aren't rippping the lining off of the discs, they are breaking the "weak" strap springs.
The Tilton clutches will hold the torque, but are too severe, for street use.
The top end hyper cars like Pagani have carbon clutches but Ferrari and Corvette make do with relatively normal clutches at normal prices, have you looked at the ZR1 clutch for instance.
10-18-2011, 08:14 PM
#17
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Greg I have the Tilton carbon/carbon or carbon titanium version in 7.25" it is only the 3 plate version however I wouldn't be sure that the 4 plater would fit in there but it might, this would allow greater street life. I was told anything less than 7.25" would wear way too quick on the street. I was also told the pedal effort is very light, I never got around to fitting as my health intervened but haven't given up on the idea. It would be used with the Tilton hydraulic bearing.
The top end hyper cars like Pagani have carbon clutches but Ferrari and Corvette make do with relatively normal clutches at normal prices, have you looked at the ZR1 clutch for instance.
The top end hyper cars like Pagani have carbon clutches but Ferrari and Corvette make do with relatively normal clutches at normal prices, have you looked at the ZR1 clutch for instance.
11-17-2011, 08:35 PM
#19
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I'm making progress on this project.
Pretty amazing stuff.
The clutch maker claims the "best" way to break these things in is to hold the engine at redline and "side step" the clutch pedal.
Edwards didn't seem to think that this was going to be a valid method....
Pretty amazing stuff.
The clutch maker claims the "best" way to break these things in is to hold the engine at redline and "side step" the clutch pedal.
Edwards didn't seem to think that this was going to be a valid method....
11-17-2011, 08:40 PM
#20
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I dunno, I have a couple of sets of tires that are close to the DOT 'sell by' dates....
11-17-2011, 08:54 PM
#21
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Greg,
Awesome project and needed by all the DD 5 speed crowd. ZF will miss out on a lot of business stopping production of the Sachs parts. I did notice that Porsche just stocked up on the two clutch discs but they are not a lot of use without the rest of the clutch mechanism.
Roger
Awesome project and needed by all the DD 5 speed crowd. ZF will miss out on a lot of business stopping production of the Sachs parts. I did notice that Porsche just stocked up on the two clutch discs but they are not a lot of use without the rest of the clutch mechanism.
Roger
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Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
George Layton March 2014
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
George Layton March 2014928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
11-18-2011, 02:40 AM
#22
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Greg,
Awesome project and needed by all the DD 5 speed crowd. ZF will miss out on a lot of business stopping production of the Sachs parts. I did notice that Porsche just stocked up on the two clutch discs but they are not a lot of use without the rest of the clutch mechanism.
Roger
Awesome project and needed by all the DD 5 speed crowd. ZF will miss out on a lot of business stopping production of the Sachs parts. I did notice that Porsche just stocked up on the two clutch discs but they are not a lot of use without the rest of the clutch mechanism.
Roger
For me, there's a huge void between a modified dual disc clutch, which we are just on the "cusp" of overwhelming with torque (Rob Edwards), and the Tilton race clutches, which are too severe for street use.
I've personally had vehicles with "puck" discs....and I don't consider them to be very streetable, either. Anyone that can get one of those to release consistantly smoothly is a way better driver than I will ever be.
Once I had finished Andy's car (which was a very complex job, due to the automatic transmission) someone mentioned that it would have been a lot easier with a 5 speed. The truth is, I don't think I could have ever built Andy's car, if it had a 5 speed, due to the the complete "lack" of a really streetable clutch.
Just trying to fill that void....so I can build that 5 speed monster.
11-18-2011, 02:49 AM
#23
Nordschleife Master
I have the spec stage 3+ discs in my car now, along with an aluminium flywheel.
It's engagement is actually very controllable, but it does not like to be ridden. So a slow start is not always an option.....
It's engagement is actually very controllable, but it does not like to be ridden. So a slow start is not always an option.....
11-18-2011, 05:48 AM
#24
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Greg,
All this talk about needing a more robust clutch system makes me wonder about using a stock old drive shaft in this application.
We can manufacture new 928 drive shafts out of 300M material, would this be something needed for these kinds of projects?
As you, just trying to fill a void.
Cheers,
All this talk about needing a more robust clutch system makes me wonder about using a stock old drive shaft in this application.
We can manufacture new 928 drive shafts out of 300M material, would this be something needed for these kinds of projects?
As you, just trying to fill a void.
Cheers,
11-18-2011, 04:12 PM
#25
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Greg,
All this talk about needing a more robust clutch system makes me wonder about using a stock old drive shaft in this application.
We can manufacture new 928 drive shafts out of 300M material, would this be something needed for these kinds of projects?
As you, just trying to fill a void.
Cheers,
All this talk about needing a more robust clutch system makes me wonder about using a stock old drive shaft in this application.
We can manufacture new 928 drive shafts out of 300M material, would this be something needed for these kinds of projects?
As you, just trying to fill a void.
Cheers,
11-18-2011, 04:14 PM
#26
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Probably not very nice, in "stop and go" traffic?
11-18-2011, 04:32 PM
#27
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I just want a clutch that'll hold 500 ft-lbs and not make me cry when trapped in an hours' worth of SoCal stop-n-go traffic. Is that so hard? 
I can imagine Mark's Tilton clutch in freeway traffic, he'd have to leave a 50 foot gap so that he wouldn't leap into the trunk of the car in front, but then people would fill the gap and he'd never go anywhere.....
Constantine-
When I put the stroker together, I used a TT that I rebuilt myself- its bearings are already making graunchy noises (I think I cooked the bearings' grease in the process of grinding the welds on the bearing carriers- dumb rookie mistake.)
When the new clutch goes in, I have a spare TT here and a set of your superbearings all ready to go in as well, but I could be talked into putting a 'new' driveshaft in- I could swear you were already making new 25mm shafts? (EDIT: yes- https://rennlist.com/forums/928-foru...ed-update.html)
Or is 300M a 'better' alloy? Begs the question of how much thinking Porsche did about the engineering compromise of finding the right mix of strength and elasticity for such a long thin driveshaft.
I know Anderson eats 5th gears like candy, and he's broken a clutch intermediate shaft. Mark, how many TT shafts have you broken?
I can imagine Mark's Tilton clutch in freeway traffic, he'd have to leave a 50 foot gap so that he wouldn't leap into the trunk of the car in front, but then people would fill the gap and he'd never go anywhere.....Constantine-
When I put the stroker together, I used a TT that I rebuilt myself- its bearings are already making graunchy noises (I think I cooked the bearings' grease in the process of grinding the welds on the bearing carriers- dumb rookie mistake.)
When the new clutch goes in, I have a spare TT here and a set of your superbearings all ready to go in as well, but I could be talked into putting a 'new' driveshaft in- I could swear you were already making new 25mm shafts? (EDIT: yes- https://rennlist.com/forums/928-foru...ed-update.html)
Or is 300M a 'better' alloy? Begs the question of how much thinking Porsche did about the engineering compromise of finding the right mix of strength and elasticity for such a long thin driveshaft.
I know Anderson eats 5th gears like candy, and he's broken a clutch intermediate shaft. Mark, how many TT shafts have you broken?
Last edited by Rob Edwards; 11-18-2011 at 04:51 PM.
11-18-2011, 04:36 PM
#28
Nordschleife Master
Greg,
I also am running the floor mount wilwood master with a much larger bore. (.75"). As well as using an S4 slave.
Due to this the engagement point is VERY small. But the required pedal motion is small too.
If I was to lower the master bore to .625" or .5" the engagement would be MUCH easier. And the pedal pressure would go down.
But as it stands now. Stop and go is not overly pleasant no.
I also am running the floor mount wilwood master with a much larger bore. (.75"). As well as using an S4 slave.
Due to this the engagement point is VERY small. But the required pedal motion is small too.
If I was to lower the master bore to .625" or .5" the engagement would be MUCH easier. And the pedal pressure would go down.
But as it stands now. Stop and go is not overly pleasant no.
11-18-2011, 04:42 PM
#29
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11-18-2011, 07:19 PM
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I just want a clutch that'll hold 500 ft-lbs and not make me cry when trapped in an hours' worth of SoCal stop-n-go traffic. Is that so hard? I can imagine Mark's Tilton clutch in freeway traffic, he'd have to leave a 50 foot gap so that he wouldn't leap into the trunk of the car in front, but then people would fill the gap and he'd never go anywhere.....
Constantine-
When I put the stroker together, I used a TT that I rebuilt myself- its bearings are already making graunchy noises (I think I cooked the bearings' grease in the process of grinding the welds on the bearing carriers- dumb rookie mistake.)
When the new clutch goes in, I have a spare TT here and a set of your superbearings all ready to go in as well, but I could be talked into putting a 'new' driveshaft in- I could swear you were already making new 25mm shafts? (EDIT: yes- https://rennlist.com/forums/928-foru...ed-update.html)
Or is 300M a 'better' alloy? Begs the question of how much thinking Porsche did about the engineering compromise of finding the right mix of strength and elasticity for such a long thin driveshaft.
I know Anderson eats 5th gears like candy, and he's broken a clutch intermediate shaft. Mark, how many TT shafts have you broken?
I can imagine Mark's Tilton clutch in freeway traffic, he'd have to leave a 50 foot gap so that he wouldn't leap into the trunk of the car in front, but then people would fill the gap and he'd never go anywhere.....Constantine-
When I put the stroker together, I used a TT that I rebuilt myself- its bearings are already making graunchy noises (I think I cooked the bearings' grease in the process of grinding the welds on the bearing carriers- dumb rookie mistake.)
When the new clutch goes in, I have a spare TT here and a set of your superbearings all ready to go in as well, but I could be talked into putting a 'new' driveshaft in- I could swear you were already making new 25mm shafts? (EDIT: yes- https://rennlist.com/forums/928-foru...ed-update.html)
Or is 300M a 'better' alloy? Begs the question of how much thinking Porsche did about the engineering compromise of finding the right mix of strength and elasticity for such a long thin driveshaft.
I know Anderson eats 5th gears like candy, and he's broken a clutch intermediate shaft. Mark, how many TT shafts have you broken?
Hi Rob,
Yes we are already making drive shafts from a stronger alloy. We just received a shipment of 944 drive shafts and will soon be ordering our first full batch of 928 automatic and 5 speed drive shafts.
Although one would think it would be easy to just copy the original drive shafts, it wasn't and there is a learning curve in getting these done to a high specification.
300M is a stronger alloy than our regular drive shafts and is considered "the" material for such uses. You can ask Gregg B. more about it since you are using him for your build up. Don't really want to talk you or anyone into anything. If you consider it a needed upgrade for your project, we can get it done for you.
The Porsche drive shafts do quite well but are getting older and more are fracturing from what we are seeing coming in, both the 25mm and 28mm automatic drive shafts. 5-Speed drive shafts not so much, more of a problem with the transmission end splines going away.
What Mark A. is doing though is on a whole other level. That he has only broken two in his racing career speaks well of the original drive shaft.
Good luck with your interesting project!
Kind regards,