DennisK Posted April 13, 2000 Share Posted April 13, 2000 Two questions; I know JTR says a 4spd trans(muncie?)is NOT appropriate. Does any one know why-other than the obvious gas mileage and top end? My 65 Corvette sure ran well with this trans and virtually same engine/diff configuration back in 68'. Next question is on Hydraulic throwout bearing-Mcleod is one, Howe another(and LESS expensive from Summit). A dirt tracker told me he uses the Howe with a 5/8 clutch master-PERFECT!??? anyone know for sure on the Z conversion? Quote Link to comment Share on other sites More sharing options...
pparaska Posted April 13, 2000 Share Posted April 13, 2000 I'm using the Mcloed Hyd. TO bearing (with a GM-form-factor Tremec, but that makes no difference, since the clutch disk is from Chevy (1LE Camaro piece). I ended up using a 3/4" Girling master cylinder. I started with a 1" AP Racing, then a 7/8", but the pedal was too stiff. The throw is pretty long with the 3/4" MC, but with the pedal at the same height as the brake pedal, it disengages the specified 0.030" between the clutch disc and flywheel when the pedal is on the floor. The pedal pressure is nice and easy now. BTW, the standard GM car has a 4:1 pedal to MC throw ratio, but the Z is more like 6.2:1, if you are making any calculations for pedal throw/force. Regards, ------------------ Pete Paraska - 73 540Z - Marathon Z Project - pparaska@tidalwave.net">pparaska@tidalwave.net - Quote Link to comment Share on other sites More sharing options...
Mike kZ Posted April 13, 2000 Share Posted April 13, 2000 It's not that JTR hates the 4 speed, it's just that since there are 5 and 6 speed overdrives out there why not use them. But your right it's mileage and top end your losing. Plus you have to mess with the shifter linkages of the 4 speed, and you have to modify the tunnel for them to work. Quote Link to comment Share on other sites More sharing options...
Michael Posted April 13, 2000 Share Posted April 13, 2000 I'm using a Doug Nash 5-speed, which is a modest evolution of a 25 year old design. 5th gear is actually 1:1, so in terms of mileage and top end, it's a four speed. This and some of the older Detroit transmissions are "externally shifted", which means that the linkages are outside of the transmission case. In my '78 280z, that required substantial modification to the transmission tunnel (cutting sheet metal around the shifter, and welding in a new cver patch). However, the external shifting does have one advantage - you can move the shifter around, to get it physically where it's the most comfortable for you. Another issue is torque ratings. The word is that the T56 is very stout, and is even used on Vipers. I don't know for sure, but really hard core hot rodders told me that the Muncie "rock crusher" (and the Doug Nash) are stronger. If you are running around 400 ft-lbs of torque, my assumption is that you have lots of choices, including any old muscle car 4-speed, or the T56, the Tremec, etc. If you have ambitions for mountain-moving torque, the choices narrow down. But I've heard of Doug Nash transmissions behind blown injected-alcohol big blocks. If you really have $$$, look into the Richmond (ex-Doug Nash) 6-speed. Quote Link to comment Share on other sites More sharing options...
Mikelly Posted April 14, 2000 Share Posted April 14, 2000 Torque specs on the 93 T56 are 400Ft#, while all 94-97 T56s are capable of 450FT#. This is the exact same trans being used on Vipers, Corvettes and 93 and newer Fbodies! Very stout, but you would be correct about the Nash, Muncie and Richmond units being very stout! Mike ------------------ "I will not be a spectator in the sport of life!" mjk Quote Link to comment Share on other sites More sharing options...
DennisK Posted April 14, 2000 Author Share Posted April 14, 2000 Thank all of you for your input. This is a great site, and I'm sure I'll have more questions as I go along. Quote Link to comment Share on other sites More sharing options...
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