jacob80 Posted September 22, 2009 Share Posted September 22, 2009 L28ET with 73 4 speed transmission, needs to be able to hold ~at least 300 hp, have a brand new spec but does NOT hold. What do you guys recommend? I hear good things about clutch masters, ACT, centerforce. Just let me know, will be a street driven car/occasional track car. Thanks! Quote Link to comment Share on other sites More sharing options...
zeeboost Posted September 22, 2009 Share Posted September 22, 2009 No problems with my stage III ACT in my 240z turbo, and the centerforce dual friction works great in my '76 280z. Not sure what exactly you're looking for - both are good street/strip clutches. Quote Link to comment Share on other sites More sharing options...
MAG58 Posted September 22, 2009 Share Posted September 22, 2009 I've used ACT clutches and they hold up great. But at 300hp, how long that old 4 speed will survive as a semi DD/track car may be another story entirely. Quote Link to comment Share on other sites More sharing options...
zuum Posted September 22, 2009 Share Posted September 22, 2009 71b series of trannies SHOULD be good up to somewhere close to 275-TQ, now we know these aren't ferrari's so the QC isn't that high, so some will hold more, some will hold less. Now it depends on how the power is applied, and also the harder your clutch grabs(ie; stage 3 grabs pretty dang hard), the more likely the hard parts are to fail... Quote Link to comment Share on other sites More sharing options...
aarang Posted September 22, 2009 Share Posted September 22, 2009 I had a Spec stage II, couldn't hold a measly 250ft lbs after 1600 miles. I now have an ACT street disk and HD pressure plate and now life is good. Quote Link to comment Share on other sites More sharing options...
JessZ Posted September 22, 2009 Share Posted September 22, 2009 I have a stock 83et setup in my '71; it thrashed my four speed. At that time I was also using a stock clutch, which did not hold well either. I put in a five speed and dual friction center force clutch and it's been solid for the last two years. I was going to go ATC but got a better deal on Centerforce at that time. As you know any advice you get here will serve you well. Quote Link to comment Share on other sites More sharing options...
Pyro Posted September 22, 2009 Share Posted September 22, 2009 What size flywheel are you using (225mm or 240mm). My spec stage 2 240mm has been doing great for 4 or 5 years now. Over 300ftlb of torque and no problems. Plus i drive it hard each and every time I get in it. Quote Link to comment Share on other sites More sharing options...
jacob80 Posted September 23, 2009 Author Share Posted September 23, 2009 I have the Fidanza flywheel, I believe its a 225 mm. Do these flywheels come in different sizes? As far as ordering the clutch, do I order it for the 240z or for the L28ET/83 280zx?? Quote Link to comment Share on other sites More sharing options...
zuum Posted September 23, 2009 Share Posted September 23, 2009 I believe the turbo cars use a 240mm flywheel/clutch. The 225mm clutch will be lighter than a 240mm, just get a clutch that minimally rated for the power your making... better to get a clutch rated for more. Another option is to get a pressure plated thats rated for more power and a clutch disc rated lower, this will let the clutch give a little more and less likely to eat your tranny (this is only insurance not a guarantee). I would avoid hard clutch dumps no matter the tranny/clutch setup you choose... unless you're just made of money. Quote Link to comment Share on other sites More sharing options...
Pyro Posted September 23, 2009 Share Posted September 23, 2009 If you have a turbo, then you really should use a 240mm clutch setup. The 240mm flywheel is the same size as the 225mm but it has 9 bolts that hold the pressure plate instead of 6. The extra weight of the 240mm setup is from the bigger pressure plate. The 240mm setup also requires the use of the 240 bearing hub which is shorter than the 225mm hub. the 240mm pressure plate throwout bearing hub is 48mm tall and the 225mm is 52mm. a stage 1 240mm clutch holds the torque of a stage 4 or 5 225mm. 240mm pressure flywheels were used on turbo engines and all 2+2 cars. Quote Link to comment Share on other sites More sharing options...
jacob80 Posted September 23, 2009 Author Share Posted September 23, 2009 If you have a turbo, then you really should use a 240mm clutch setup. The 240mm flywheel is the same size as the 225mm but it has 9 bolts that hold the pressure plate instead of 6. The extra weight of the 240mm setup is from the bigger pressure plate. The 240mm setup also requires the use of the 240 bearing hub which is shorter than the 225mm hub. the 240mm pressure plate throwout bearing hub is 48mm tall and the 225mm is 52mm. a stage 1 240mm clutch holds the torque of a stage 4 or 5 225mm. 240mm pressure flywheels were used on turbo engines and all 2+2 cars. so the only difference is the number of bolts holding the pressure plate on? What measurement is 225 and 240 as in what is that measuring? Maybe I do have a 240mm do they make a 225mm fidanza for these cars? Quote Link to comment Share on other sites More sharing options...
zuum Posted September 23, 2009 Share Posted September 23, 2009 I have both 240mm and 225mm clutches out in the shop, they both use 6bolt pressure plates. The measurement is the diameter of the clutch disc, the flywheels are the same size, but the dowels and bolt holes are further out on the 240mm. If you measure the friction surface on the flywheel you have, it will measure out to approximately 8 3/4" for 225mm, and approximately 9 1/2" for the 240mm. Quote Link to comment Share on other sites More sharing options...
Pyro Posted September 23, 2009 Share Posted September 23, 2009 Not sure what fidanza does, but the factory 240mm flywheel uses 9 bolts. Quote Link to comment Share on other sites More sharing options...
jc052685 Posted September 23, 2009 Share Posted September 23, 2009 I've used ACT clutches and they hold up great. But at 300hp, how long that old 4 speed will survive as a semi DD/track car may be another story entirely. 71b series of trannies SHOULD be good up to somewhere close to 275-TQ, now we know these aren't ferrari's so the QC isn't that high, so some will hold more, some will hold less. Now it depends on how the power is applied, and also the harder your clutch grabs(ie; stage 3 grabs pretty dang hard), the more likely the hard parts are to fail... Well the 4spd in my car now has survived more abuse than the 5spd that was in it. Yup, 11.8 sec pass and I am now spraying a 100 shot on top of the power it made to do the posted time. Have yet to be to the track but its holding. I love them stoplight 2nd gear clutch dumps too lol. As far as the clutch. act or spec stg-III Quote Link to comment Share on other sites More sharing options...
Pyro Posted September 24, 2009 Share Posted September 24, 2009 check out the spec clutch torque ratings. http://www.nipponpower.com/product.phtml?p=368&mmk=491 the 240mm has 150 to 200 ftlbs more holding capacity as compare to the same stage 225mm. the spec stage 3 is tough to drive on the street. very quick engagement and chatter if you try to release the clutch slow (like you would driving on the street). A stage 2 drives like stock. Quote Link to comment Share on other sites More sharing options...
jacob80 Posted September 24, 2009 Author Share Posted September 24, 2009 Yeah as far as the transmission, we talked to Oliver at Z specialties I believe and he says the 4 speeds are plenty strong for our application, so we went ahead and rebuilt and and slapped on an MSA short shifter. As far as the Fidanza flywheel, apparently you can run wither a 225mm or a 240mm clutch/pressure plate on it: http://forums.hybridz.org/showthread.php?t=138869&highlight=flywheel+dowel So I will be going with a 240mm but which clutch? Should the ACT stage III 240mm setup be fine for street driving with occasional track appearances? Quote Link to comment Share on other sites More sharing options...
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