Phyxius Posted July 4, 2005 Share Posted July 4, 2005 I've been thinking about this a great deal. I think it would be possible to build your own 2(or 3) disc clutch pack with some basic machining equipment, some longer pp bolts, a stock pp and 2 clutch discs. You would need to machine a plate of steel the diameter of the flywheel with a nice big lightening hole in the center. In order to keep this plate rotating with the flywheel, you could make holes that match the pp bolt pattern approximately 1.5 cm in diameter. You would have a set of spacers of a SLIGHTLY smaller diameter for the center plate to ride on. These spacers would allow the longer pp bolts to go through the center and into the flywheel while also holding the pressure plate in the right position. You would also need to machine part of the splines off of one or possibly both of the clutches so that splined parts wouldn't hit each other. You would probably also have to have one of the shorter throwout bearings...i know i've seen pictures of them somewhere.... The best that i can figure, this entire thing would set the pp into the tranny an extra .25-.5". I don't know if that would clear the bell housing or not. It may have to be clearanced as well. This could be expanded to 3 discs by adding another steel plate and clutch disc Anyone think this is a good idea? or am I way off base? Quote Link to comment Share on other sites More sharing options...
260DET Posted July 6, 2005 Share Posted July 6, 2005 Sounds good to me Most twin plate clutches require their own special flywheel though don't they? The question in my mind is - can a twin plate as you describe be secured sufficiently to the stock flywheel? Quote Link to comment Share on other sites More sharing options...
Phyxius Posted July 6, 2005 Author Share Posted July 6, 2005 I don't know about the special flywheel thing. I've never seen one in person. You could mill the entire flywheel to a thinner version to offset the distance that the pp now goes into the bellhousing... If you were really concerned about securing it, you could drill and tap extra holes in the flywheel or even make some dovetail type slots in the flywheel and pp for some pins or something... I've been trying to figure out what kind of steel you would want to use...and where you could get it cheaply...i'm thinking a 1000 series steel would probably work... Quote Link to comment Share on other sites More sharing options...
MONGO510 Posted July 6, 2005 Share Posted July 6, 2005 I would have to think long and hard before I built and ran something like what you describe. Any off center movement of the floater plate is going to cause a severe imbalance. Sounds like a recipe for a nasty clutch explosion to me. My $.02 worth. Quote Link to comment Share on other sites More sharing options...
Phyxius Posted July 6, 2005 Author Share Posted July 6, 2005 it would have to be balanced, no doubt.... Quote Link to comment Share on other sites More sharing options...
260DET Posted July 6, 2005 Share Posted July 6, 2005 I would have to think long and hard before I built and ran something like what you describe.Any off center movement of the floater plate is going to cause a severe imbalance. Sounds like a recipe for a nasty clutch explosion to me. My $.02 worth. Yes, it would want to be tested in a controlled environment before use. Rotate it all shielded and mounted on a flywheel and see if it can take the revs Quote Link to comment Share on other sites More sharing options...
johnc Posted July 6, 2005 Share Posted July 6, 2005 Are you talking about building an 11" diameter double disc clutch? Why? Quote Link to comment Share on other sites More sharing options...
2126 Posted July 6, 2005 Share Posted July 6, 2005 Are you talking about building an 11" diameter double disc clutch? Why? I'm with John.....I thought the idea behind multi-plate clutches was to reduce rotating mass, hence their small diameter. Quote Link to comment Share on other sites More sharing options...
Phyxius Posted July 6, 2005 Author Share Posted July 6, 2005 my idea was to use the smaller L series flywheel and clutch...9" i think it is... I always thought the idea was to have a more streetable clutch that could hold as much power as the metalic ones without the wear and tear, grabbiness, etc. Quote Link to comment Share on other sites More sharing options...
johnc Posted July 6, 2005 Share Posted July 6, 2005 Having run a 5.5" double disc clutch I can tell you the following: 1. They are noisy and rattle when disengaged. 2. They require greater clamping force from the pressure plate. 3. They require an annular release mechanism (forget the clutch fork). 4. They make installing the transmisison a bitch. Just stacking stock clutches on a common splined shaft with a stock pressure plate will not increase torque capacity. It will most likely decrease it by a significant amount and lead to rapid wear of the transmission synchronizers due to the increased MOI. Multi-disc clutches are a race only item unless you're adding significant electronic control a la Ferrari. Quote Link to comment Share on other sites More sharing options...
Phyxius Posted July 6, 2005 Author Share Posted July 6, 2005 well...this is why i posted on here before i actually tried it... appearantly i had several misconceptions about dual disc clutches... thanks for the info... I see what you are saying about using the stock pressure plate. It will only produce so much force, and even though I may double the surface area, I've halved the pressure between the clutch and mating surface. It's impossible to tell if the torque capacity would increase or decrease without some solid numbers. If I had some standard coeff. of friction numbers for the clutch material vs. mating surfaces, I could come up with some solid numbers as to what force would be required by the pressure plate to create the necessary torque capacity for a given motor... The reason that I was considering this is because I haven't been impressed with the power that most aftermarket single discs can handle reliably. Not to mention the cost you pay for a quality unit. Having reached the limits of the stock clutch, I was hoping to find a cost effective, reliable solution to this problem. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted July 6, 2005 Share Posted July 6, 2005 How much hp are we talking about here? If you don't want grabby, use a stock disk and a heavy pressure plate. My 225mm ACT with stock disk been holding up to my ~240 whp just fine. If you're really going to be pushing a lot of power the 240mm Nissan Comp has a lot of clamping force. Use that with a stock 240 mm disk, or maybe the heavier of the ACT pps and their kevlar disk. I can't remember what that setup is supposed to hold, but it should be quite a bit. I understand where you're coming from. The puck clutches are a bit brutal on the car and the driver for street use. Quote Link to comment Share on other sites More sharing options...
Phyxius Posted July 6, 2005 Author Share Posted July 6, 2005 i'm at about 250 right now, but i hope to making about 400 soon. Quote Link to comment Share on other sites More sharing options...
spork Posted July 6, 2005 Share Posted July 6, 2005 Contact robin at Superior Friction. He built the clutch for my car as well as the one for Jeff Priddy's car. Both of ours are pushing over your 400whp goal Quote Link to comment Share on other sites More sharing options...
Phyxius Posted July 7, 2005 Author Share Posted July 7, 2005 i have no doubt that there are clutches out there that can hold the power, but i don't want to break the bank trying to get one... Quote Link to comment Share on other sites More sharing options...
260DET Posted July 7, 2005 Share Posted July 7, 2005 Hmmm, there is a limit to what can be done with the stock configuration single plate job due to the clamping pressure required. The clutch gets just too heavy, with attendant short life of the actuating components. I was under the impression that a twin plate clutch was fine for road use and required less clamping pressure. In fact I think there are a few high performance cars fitted with them by the factory aren't there? I'll ask around and admit my sins if wrong . Quote Link to comment Share on other sites More sharing options...
260DET Posted July 7, 2005 Share Posted July 7, 2005 OK, the high performance versions of the Aussie Ford Falcon certainly do have twin plate clutches and from all reports are fine to drive. Can't be so specific with other makes, but some do, perhaps certain Ferraris and Porsches? The roughness of some twin plate clutches seems to be associated with racing type clutch plates, not the usual road type sprung centre fully lined ones. Quote Link to comment Share on other sites More sharing options...
Phyxius Posted July 7, 2005 Author Share Posted July 7, 2005 that's more along the lines of what i was thinking Quote Link to comment Share on other sites More sharing options...
Phyxius Posted July 7, 2005 Author Share Posted July 7, 2005 i found this on the ACT website: http://www.advancedclutch.com/proveit/clutch101/clutch101-benefits.asp I do not believe their mathmatics are entirely sound, but I think that the ideas are. I did some numbers for an average z car clutch using a 1800lbf pp and .25 coeff of friction and came up with a torque capacity of about 400 ft-lb. That seams a little high to me, but I'm sure the coeff of friction and pp numbers do not exactly match what the z car clutch's characteristics are. I think there should be a few more factors in the equation to take into account the speed differential between the motor and the tranny and heat effects. Those would probably make it somewhat more accurate. However, I can't see any way around adding a plate and at least nearly doubling the torque capacity. There is still the problem of the added clutch weight making the syncros wear out faster...I havent quite figured out how to get around that one yet....shift slower maybe...lol...or be prepared to change out syncros regularly. You could go with an unsprung disc to cut down on weight, but that is a hit on streetability..although not a big one. I ran a solid disc in my vw for years without and ill effects. I believe that chatter can be addressed with a few light springs in key locations to help keep everything seperated when the clutch is disengaged... I'll have to think some more on this though. Quote Link to comment Share on other sites More sharing options...
Phyxius Posted July 15, 2005 Author Share Posted July 15, 2005 Would it be possible to use a flex plate from an auto and add the friction surfaces? This sounds much lighter, and it would open up more clutch diameter options. My only concern would be that flex plates aren't meant to take the strain of a flywheel... Quote Link to comment Share on other sites More sharing options...
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