Andrew Dent Posted August 26, 2002 Share Posted August 26, 2002 Having had the clutch pedal almost on the floor on Sunday in the second practice round, it needed some serious adjustment to get the thing working again. Then I started thinking how many starts the clutch had been in the receiving end of. Curborough x 2 double drive, Marshals sprint x2 double drive and MIRA. That’s getting on for 40 standing starts and overall abuse. Add on a various amount of track days and I started to wonder about the life left on poor old clutch. This got me wondering if a twin plate 5 ½” was a possible winter option. Anyone got any ideas on what works well, and is it worth it. The car is an SLR with 217bhp and 159 ft lb, currently running ACBs. 4 wheels on my 7 Link to comment Share on other sites More sharing options...
Alex Wong1697456877 Posted August 26, 2002 Share Posted August 26, 2002 Depends how extreme you want to go. No point having a twin 5 inch clutch unless you have a featherwight flywheel to go with it. This isn't really ideal for roard use. A twin plate should dissapate heat a bit better but if you look at the torque that your average race single plate can handle, it should be plenty for a Seven. Having said this, my twin plate 7.25 clutch has gone up in smoke. I think a 7.25 would be good for the road and track use your car gets and a 5 inch is probably too extreme. Don't forget that twin plates rattle alot when the clutch is disengaged. Link to comment Share on other sites More sharing options...
Jason Plato Posted August 27, 2002 Share Posted August 27, 2002 Andrew , If you are running the R500 AP clutch from caterham , then it should handle that power OK for considerably longer than it has . Have you checked the clutch release arm ? . Mine had bent at Oulton Park a few weeks ago giving the effect of a worn clutch . Dave Link to comment Share on other sites More sharing options...
EFA Posted August 27, 2002 Share Posted August 27, 2002 "and a 5 inch is probably too extreme" Big girl Mr Wong...... 5 inch is fine - you can only fit it to a featherweight flywhhel and it changes the dynamics of your engine enormously (in a favourable direction) and frees up the power normally reserverd for accelerating a heavy flywheel, and gives you much faster gearchanges. Pedal is very firm but not overly heavy, and after you get used to it and bed the initial set of plates in (500 miles) its a scream! Fat Arn Visit the K2 RUM site See the Lotus Seven Club 4 Counties Area Website here Link to comment Share on other sites More sharing options...
EFA Posted August 27, 2002 Share Posted August 27, 2002 echo in here??? Edited by - fat arnie on 27 Aug 2002 08:17:15 Link to comment Share on other sites More sharing options...
Paul Ranson Posted August 27, 2002 Share Posted August 27, 2002 If the clutch plate/cover is actually failing then that seems rather premature. Are you riding it at all doing your standing starts? I ran a standard Rover Spec nothing-at-all-VHPD clutch on a standard Superlight for a whole season of sprint/hillclimb (about 20 events), and then upgraded the engine to 180ish BHP for another season. After all that the clutch was fine and went back in... OTOH you have way more torque than I did. Anyway standing starts don't wear clutches much as long as they don't get slipped. The AP twin plate 7.25" sintered job in my Pilbeam is on its second full season without any replacement parts. I think most of the wear comes from moving about in paddocks. Paul Link to comment Share on other sites More sharing options...
Peter Carmichael Posted August 27, 2002 Share Posted August 27, 2002 My 5.5 inch clutch is easy enough to use to the extent that Sarah managed to spend the whole of the ladies day driving the car with only 2 clutch related stalls. Not bad seeing as Sarah had only been in a Seven on two occasions previously: as a passenger in Graham Ridgway's R500 and as a passenger in my car. Total time in a seven up until yesterday => ~45 minutes. Time driving => nil. The first time Sarah stalled was when the sprint battery ran out of charge from all the waiting around. The 5.5 inch clutch is abrupt, but with a proper hydraulic release it is manageable. It probably is worse from a heat capacity point of view than the one you have in there presently. A modified production clutch is probably unsuitable above 8500rpm. Race clutches are fine to 10+ Link to comment Share on other sites More sharing options...
Roger King Posted August 27, 2002 Share Posted August 27, 2002 Andrew, You might find that a race clutch is a bit of a culture shock after your present unit. It is possible to get a 7 1/4" twin plate clutch with organic plates. This fits on a full race lightweight flywheel and might be a good compromise. We've not tried one, so I can't speak from experience, but it sounds good. We find that a twin plate clutch tends to last around four times longer than a single plate in the same application. Link to comment Share on other sites More sharing options...
Roger King Posted August 27, 2002 Share Posted August 27, 2002 Andrew, You might find that a race clutch is a bit of a culture shock after your present unit. It is possible to get a 7 1/4" twin plate clutch with organic plates. This fits on a full race lightweight flywheel and might be a good compromise. We've not tried one, so I can't speak from experience, but it sounds good. We find that a twin plate clutch tends to last around four times longer than a single plate in the same application. Link to comment Share on other sites More sharing options...
Roger King Posted August 27, 2002 Share Posted August 27, 2002 Andrew, You might find that a race clutch is a bit of a culture shock after your present unit. It is possible to get a 7 1/4" twin plate clutch with organic plates. This fits on a full race lightweight flywheel and might be a good compromise. We've not tried one, so I can't speak from experience, but it sounds good. We find that a twin plate clutch tends to last around four times longer than a single plate in the same application. Link to comment Share on other sites More sharing options...
Roger King Posted August 27, 2002 Share Posted August 27, 2002 Dunno what happened there. Every time I tried to post it came up with an error message, but it seems to have posted anyway. Link to comment Share on other sites More sharing options...
Alex Wong1697456877 Posted August 29, 2002 Share Posted August 29, 2002 My twin plate had organic plates and it was just right for what I needed. It lasted 9 sprints, 25 trackdays and approx 10,000 road miles and has just gone up in smoke. Before that it was perfect for what I need for my usage. It's a Quatermaster 7.25 twin plate with "sport" organic plates. I expect that with a change of plates, it will be fine again. Link to comment Share on other sites More sharing options...
Alex Wong1697456877 Posted August 29, 2002 Share Posted August 29, 2002 Big girl Mr Wong...... I might wear a frock in the privacy of my bedroom but I was faster than you at Curborough, despite your umpteen top secret tweeks!! 😬 Edited by - Alex Wong on 29 Aug 2002 01:48:06 Link to comment Share on other sites More sharing options...
Andrew Dent Posted August 29, 2002 Author Share Posted August 29, 2002 Well Ive inspected the release arm, and it looks to be OK, so will check out the cable over teh weekend. What is required to move from single to twin plate clutches? 4 wheels on my 7 Link to comment Share on other sites More sharing options...
Roger King Posted August 29, 2002 Share Posted August 29, 2002 Flywheel, balancing, clutch assembly, modified release bearing assembly, money, etc. Link to comment Share on other sites More sharing options...
EFA Posted August 29, 2002 Share Posted August 29, 2002 Beaten in ABsence now is it Mr Wong.... And I thought we were on the same team..... Fat Arn Visit the K2 RUM site See the Lotus Seven Club 4 Counties Area Website here Link to comment Share on other sites More sharing options...
Alex Wong1697456877 Posted August 29, 2002 Share Posted August 29, 2002 We were right up until you started going quickly and threatening my third place in May!! 😬 Edited by - Alex Wong on 29 Aug 2002 08:59:19 Link to comment Share on other sites More sharing options...
Mike Bees Posted August 29, 2002 Share Posted August 29, 2002 I've found that wear on the stock AP/VHPD/R500 (all the same thing) clutch is minimal. 2 full seasons of sprints & hillclimbs with tyre warming etc plus quite a few thousand road miles and the wear on the friction plate was almost immeasurable, despite the smells it sometimes gives off during the treatment. Mike Link to comment Share on other sites More sharing options...
Jason Plato Posted August 29, 2002 Share Posted August 29, 2002 Yeah real shame you were'nt at Curborough Arnie , glad to see normal service has resumed with the car though Dave Link to comment Share on other sites More sharing options...
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