stock clutch
08-04-2006, 11:03 AM
#16
Supercharged
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Originally Posted by Imo000
Mark,
Are there differences in the DD clutch disks between the years? Do you know what they are?
Are there differences in the DD clutch disks between the years? Do you know what they are?
08-04-2006, 11:14 AM
#17
Captain Obvious
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Andrew,
Thanks for posting it. Just to make this clear. The early DD pressure plates were slightly weaker than the '84-86? Was there any change to the early 32V plate?
Thanks for posting it. Just to make this clear. The early DD pressure plates were slightly weaker than the '84-86? Was there any change to the early 32V plate?
08-04-2006, 11:18 AM
#18
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I can't answer about changes in the plates, but according to the tech speec book, the clamping force range on the 84 was about 200N more than the earlier ones.
08-04-2006, 11:20 AM
#19
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The early DD pressure plates were slightly weaker than the '84-86?
So where are these questions about differences between years leading us?
Marton
08-04-2006, 01:11 PM
#21
In Your Face, Ace
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Originally Posted by Imo000
Well the stock DD clutch can handle quiet a bit. I’m only running 6psi but managed to get many 2.0X sec. 60’ times at the drag strip and that was on stock 225 tires. So you can imagine just how hard the clutch was working to keep the tires from spinning too much and still get a descent launch off the line. If you are plan on running 16psi with drag radial, the clutch you’ll need with be an on/off type drag racing clutch. I’m not sure if any of the higher torque kits will hold up to that much stress. Drag clutches are never street friendly they act like they are either fully engaged or fully disengaged. Slipping them for a smooth start is extremely difficult if not impossible.
Since you’ll be running drag radials, what is your planned weak link? Is it the axles or the torque tube, cause you don’t want the transmission to be the one.
Since you’ll be running drag radials, what is your planned weak link? Is it the axles or the torque tube, cause you don’t want the transmission to be the one.
Yes. Drag clutches are, well, a drag.. There is no slipping them for a smooth start and Carl's kit is not supposed to be like that.
I plan to stage the boost at launch and all 16psi would not be at once. I'm going to have to play with it and yes there will probably be a weak link that breaks. It won't be the clutch though.
08-04-2006, 01:12 PM
#22
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Originally Posted by Kevin Michael
Since sc'ing, My stock clutch just ain't up to the task. To be fair, I think it was slipping before the sc. Anyway what do you guys recommend as far as replacement clutch that will take the power? Abby and I were discussing it and he decided on Carl's clutch kit. I found a complete gts kit for 850.00 even includes an alignment tool! What do you think?
Thanks, Kevin
Thanks, Kevin
The GTS pressureplate has higher clamping force but can't remember how much more. I think you would be fine with it. I think the DD isn't as straightforward a switch as you might think. Louie Ott had some issues with it. IIRC you need a different ring that might be hard to find. I can't remember the specifics.
08-04-2006, 04:00 PM
#24
Captain Obvious
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You can but only if the flywheel and the PP are not damaged by the slipping clutch. 9 out of 10 times the PP has to be changed and the flywheel requires machining. If you car was N/A I would say go with only a disc and a new bearing, but since you are running a SC, the power output is a lot more and you want the clutch to operate at 100%. Another economical option would be to buy a used but in a really good condition, complete clutch assembly that came off a wrecked 928.
08-04-2006, 04:47 PM
#25
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Specs have been posted so no need to repeat. But, I can write from personal experience that a new GTS pressure plate is a HELL of a lot stronger than a 19 year-old S4 pressure plate. My arm-o-meter would indicate 50% more clamping force. YAMV (Your arm may vary...)
08-04-2006, 06:40 PM
#26
In Your Face, Ace
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Originally Posted by Kevin Michael
GET ready to fire..... Can I keep the p-plate and just get the disc,T.O. bearing, etc.?
08-04-2006, 07:59 PM
#27
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I believe I am going with the gts kit. Everything I've read says it will be fine. One thing with my slipping clutch though. Shouldn't I be able to smell the dang thing when its slipping? This is the third manual 928 I have owned and the first one for clutch trouble.
Kevin
Kevin
08-08-2006, 01:41 AM
#28
Captain Obvious
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Originally Posted by Kevin Michael
I believe I am going with the gts kit. Everything I've read says it will be fine. One thing with my slipping clutch though. Shouldn't I be able to smell the dang thing when its slipping? This is the third manual 928 I have owned and the first one for clutch trouble.
Kevin
Kevin
08-08-2006, 09:43 AM
#29
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Originally Posted by Imo000
You'll only smell the clutch slipping if it severy over heats, and by theat time it's usually too late.
Kevin
08-08-2006, 01:40 PM
#30
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Originally Posted by Kevin Michael
I believe I am going with the gts kit. Everything I've read says it will be fine. One thing with my slipping clutch though. Shouldn't I be able to smell the dang thing when its slipping? This is the third manual 928 I have owned and the first one for clutch trouble.
Kevin
Kevin
I will have it back with a GTS clutch on the 19th, I'll let ya know how it is. I never had clutch slip in my 86 or 86.5 but those motors were a bit weaker (dyno run tomorrow for the 90 should shed light on how much weaker).