Doc Hawk Posted November 24, 2008 Share Posted November 24, 2008 Time for a new clutch for my 240Z with a 240mm (turbo or 2+2) flywheel. I purchased the "XTR Racing Stage 3 Clutch Kit," item #XTR-51008R3-SS, based upon the many positive reviews I've read of the XTD clutch, which is the name under which the clutch was previously marketed. The kit includes a sprung 6-puck Copper Ceramic (also known as MIBA) disc, a pressure plate rated at 420HP, 388 ft/#, release bearing, pilot bearing, and an alignment tool. There's also a simple one-page sheet with basic instructions. It was shipped and delivered with lightning quickness, and the MegaTuning customer service was good. I sent the plate to the machine shop that was balancing my newly lightened flywheel for mounting and balancing the unit. I got a call later telling me that the pressure plate didn't match up to the pins - in other words, it didn't fit. I went down there the next day and they had figured out that the first guy hadn't bothered to rotate it around to see if the three pins lined up with different holes. The master machinist had taken a look, rotated the plate 120 degrees, and the pins and bolt holes lined up perfectly. That was one stress relieved. When I picked up the assembly, they told me they were very concerned about the as-delivered balance of the pressure plate. It was out of balance by a massive amount - I don't have numbers yet but I will get them when they open after the weekend. The master machinist told me that they see dozens of pressure plates a week, mostly for race cars or performance vehicles, and they are all balanced from the factory. This one was way off, and took some significant drilling and even welding on big lugs for weight on the opposite side. Here is the finished, balanced pressure plate: Closeup of the added weight: Closeup of the drilling to remove weight: So from what they tell me, this is an extraordinary amount of balancing to do on a mass-produced pressure plate, and they were concerned that people are going out and bolting these straight up to their flywheels and driving off. The rotating mass is so unbalanced that they think it will screw up motors at best, and shatter flywheels at worst. Please, if you buy one of these clutch kits, pay the $40-$60 a reputable machine shop will charge to balance it for you. Anyway, mine is balanced and I'm happy. It goes into the car on Wednesday. I'll update once I've felt it in the car. Quote Link to comment Share on other sites More sharing options...
josh817 Posted November 24, 2008 Share Posted November 24, 2008 I've had mine for about 1200 miles and it does its job. I don't make enough power to cause any problems. No vibrations from it either from balancing issues although that may mean nothing. One thing is that because its ceramic, if you try to slip it a lot at a light you will get lots of chatter. This is ok though unless you have someone riding up your ass on a hill. As far as driving goes you really need to drive a couple of city miles for that thing to heat up. Once it heats up it grips nicely. If I pull right out of my garage after it sat over night, the clutch feels very gentle and the pedal feels soft. Like I said though once you pump the pedal, start driving, blah blah blah you can feel the stiffness in the pedal and how it bites when you pull away. The real test I guess is how long will this last. My clutch seemed to bite much more at first and I'm a heavy driver so I'm not sure if its already on its way out. XD I doubt it though as its not slipping and I'm probably just getting better at shifting. I was pretty bad when I first hopped in with the new motor since I hadn't driven a manual tranny in months. And yes the holes won't match up unless you get it right on the dot the first time. They have several holes drilled I guess for different pin spacing. I think this clutch was worth it though considering ACT is very expensive (but very good too) for the performance figures that XTD claims. Quote Link to comment Share on other sites More sharing options...
Tony D Posted November 24, 2008 Share Posted November 24, 2008 Very good warning to post! This is hand-in-hand with guys who lighten a flywheel and don't think anything of the mass of the pressure plate... That kind of out-of-balance condition may not affect people running a stock wieght flywheel at lower rpms, but someone zinging up in the rev band regularly on a lighter flywheel will probably wonder what the 'buzzy' feeling is... Good Information. Quote Link to comment Share on other sites More sharing options...
naviathan Posted November 24, 2008 Share Posted November 24, 2008 Very good to know. That amazes me, I would have probably never thought twice about balancing the pressure plate, but then again, I'm not running a lightweight flywheel and balanced anything yet... Quote Link to comment Share on other sites More sharing options...
1 fast z Posted November 25, 2008 Share Posted November 25, 2008 You ALWAYS balence a pressure plate. I just balenced my new one this weekend. They are always out. Some more than others. BTW, RPM doenst have much to do with balence, its a harmonic issue. That harmonic can come at 2500, or 8500 and it will repeat itselft in some sort of sinusodal wave. Quote Link to comment Share on other sites More sharing options...
Tony D Posted November 25, 2008 Share Posted November 25, 2008 I would agree with 1FastZ, the balance is a combination of parts. Even a VW operating at 4000rpms peak has form thefactory, marks which are to be aligned with marks on the flywheel to keep maximum imbalance of the flywheel/pressure plate combination wihtin specification. I have not balanced a flywheel and then stuck on a pressure plate, the cover and flywheel always went in together. And at a minimum they are individually balanced to the tightest tolerance I can get out of the balancer otherwise, with a 'heavy spot' mark pla ced on them. A good balance shop should be able to give you a printout of hte balance of the item (Shenck and Hoffman do this, not sure on other machines) Knowing where the 'heavy point' is on each component makes arriving on a field balance solution easier if this is required. Quote Link to comment Share on other sites More sharing options...
z-ya Posted November 25, 2008 Share Posted November 25, 2008 If you are going to spend the extra $ to balance your engine, you should balance everything. Flywheel, pressure plate, damper, etc. The entire rotating assembly, otherwise it will not be balanced when you bolt it all together. I have a Powerforce damper on the race car, and by itself it balanced perfect. When I bolted my EDIS trigger wheel on, the balance was off enough where we had to drill and 1/8" deep 3/8" hole to get it balanced again. So even a trigger wheel on the crank damper can effect balance. That pressure plate looks like a stock OEM replacement type. I've had good luck with Clutchmasters. Pete Quote Link to comment Share on other sites More sharing options...
jeffer949 Posted November 25, 2008 Share Posted November 25, 2008 I didnt balance my xtd when i put it on. I havent had any problems. I am making to much power for it now though. I slip in boost at 20psi when im at the track now that i have wide tires. I need to get a new one but it served me well untill i started turning the boost up alot. For a stock or slightly modified turbo motor and pretty much any NA motor i say they work great. they do chatter from time to time though. Quote Link to comment Share on other sites More sharing options...
Tony D Posted November 26, 2008 Share Posted November 26, 2008 What balancing spec are you guys using for the balancing anyways? The place I go usually used 57mg/in (0.002 oz-in) which is tighter than the VW Spec of 1gm/in... As I recall, our L20A engine was toleranced around 35 mg/ in total, due to running it higher than normal in the rpm range. Kind of curious, if anybody else has any spec they are willing to share. Quote Link to comment Share on other sites More sharing options...
Daeron Posted November 28, 2008 Share Posted November 28, 2008 .... due to running it higher than normal in the rpm range. Understatement.. It's whats for dinner!! Quote Link to comment Share on other sites More sharing options...
lifegrddude Posted November 28, 2008 Share Posted November 28, 2008 I've used this clutch for about 2000 miles so far. It's not bad for a budget clutch, although it does have a short range of engagement so some chatter is present during stop and go at times. I followed the break-in schedule, and so far up to 16 psi it hasn't slipped. I'll be trying it on 20 psi later once the roads here have dried up. Quote Link to comment Share on other sites More sharing options...
Jeff260z Posted June 10, 2011 Share Posted June 10, 2011 Curious if the clutch is still doing well... Quote Link to comment Share on other sites More sharing options...
josh817 Posted June 10, 2011 Share Posted June 10, 2011 Mine still performs flawlessly. I never had mine balanced, nor do I ever wind the motor past 6500RPM. When I swapped trannies sometime back everything looked good from the outside... Quote Link to comment Share on other sites More sharing options...
Doc Hawk Posted May 4, 2013 Author Share Posted May 4, 2013 5 year update: this clutch still feels and performs great. Car is autocrossed monthly and driven on weekends. Quote Link to comment Share on other sites More sharing options...
78zstyle Posted May 5, 2013 Share Posted May 5, 2013 Thanks for the update posts. Quote Link to comment Share on other sites More sharing options...
280zex Posted May 8, 2013 Share Posted May 8, 2013 My Z has eaten 3 so far. I got an email from them stating that they will not warrenty another one, so I upgraded to a pressure plate rated for 500 torq. I'm waiting for another transmission (again) right now. I will post up how things work out... Quote Link to comment Share on other sites More sharing options...
78zstyle Posted May 8, 2013 Share Posted May 8, 2013 280zex how much power are you making? Quote Link to comment Share on other sites More sharing options...
280zex Posted May 8, 2013 Share Posted May 8, 2013 280zex how much power are you making? Don't know yet. Sense I have assembled my blow thru L28 I have had a chain effect of improper/incorrect drive train components , then breakage. This is directly due to me underestimating the power out-put potential of my current setup. T3/To4e-60 trim @25lbs max blown thru a Holley carbed, bored and stroked L28. Quote Link to comment Share on other sites More sharing options...
Jesse OBrien Posted May 8, 2013 Share Posted May 8, 2013 I just installed a 225mm ka24de XTD clutch/flywheel combo, and hope to have it running and driving this month. From what I can see, it's made of metal, some machining has been done to it, and the mounting holes all line up where they should. I'll happily throw my feedback into this thread, once I have some miles on it. Quote Link to comment Share on other sites More sharing options...
Doc Hawk Posted May 12, 2013 Author Share Posted May 12, 2013 If you threw it in there without balancing, and you have a driveline vibration... at least you'll know why Quote Link to comment Share on other sites More sharing options...
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