blueovalz Posted October 21, 2005 Share Posted October 21, 2005 Finally, after talking and thinking about this for 10 years I finally reached another personal milestone. The Porsche 930 CV jointed halfshafts are finished (yeah, I know, it's like killing a mosquito with a 5 lb sledge, but I just HAD to try it). When I test install these, I'm going to move the differential toward the drivers side by about 1" to line up the driveshaft U-joints. I think this is where my vibration is as nothing else has been found to cause it (it's about 5º off from straight back and have always wanted to line this plane up but the halfshaft lengths prevented me from doing it). Quote Link to comment Share on other sites More sharing options...
510six Posted October 21, 2005 Share Posted October 21, 2005 I have a set of 930cv for use in my 510 after all of the Nissan soild U joint axels that I have wear out.They look great BTW. Quote Link to comment Share on other sites More sharing options...
260DET Posted October 21, 2005 Share Posted October 21, 2005 Look like bought ones, nice work. A 'test to destruction' session coming up? Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted October 21, 2005 Share Posted October 21, 2005 What are the end pieces in the pic? I mean, what is this going in? I have been working on Porcshe CV adapters too. Mine are for the 280Z stub axles and the CV flanges used on a 720 truck front R180 diff. These will go into my 71 240Z. Do you have drawings are pictures of these adapters alone? I think this is the best option for CV conversion. They are very strong, plentiful and cheap. Also, they are shorter than the ZX tulips which means the boot clears the sway-bar link through full articulation. NEVERMIND, I went to your gallery and saw them. They look very close to my design. Great minds think alike... Quote Link to comment Share on other sites More sharing options...
Guest jmanz6 Posted October 21, 2005 Share Posted October 21, 2005 If you line up the driveshaft to be exactly in line with the trans and there is no angle in any direction, you will destroy the u-joints. They must have an agle to be able to operate. The CV's look really nice. I've never heard, or thought of using them but my 240 is pretty stock and wouldn't benefit from it. Nice job. Quote Link to comment Share on other sites More sharing options...
jeromio Posted October 21, 2005 Share Posted October 21, 2005 If you line up the driveshaft to be exactly in line with the trans and there is no angle in any direction, you will destroy the u-joints. They must have an agle to be able to operate. The CV's look really nice. I've never heard, or thought of using them but my 240 is pretty stock and wouldn't benefit from it. Nice job.That's not necessarily true. In theory, Ujoints will operate better if there is an angle b/c the bearings will roll (back and forth) and lubrication flow will be improved. But this is, as far as I can find, merely theory, subject to debate. For example, if the ujoint was truly mounted in a perfectly straight orientation, then it's not being "used" at all. Therefore, the bearings wouldn't roll and would not wear at all. Regardless, it's nice to see an update from Terry. He's like an engineering "found object" artist, making use of various junk-yard parts to achieve state of the art results. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 21, 2005 Share Posted October 21, 2005 If it's perfectly straight why have a joint at all??? I suppose it makes driveshaft removal easier, but from a strength perspective you might as well have a torque tube setup... Quote Link to comment Share on other sites More sharing options...
buZy Posted October 21, 2005 Share Posted October 21, 2005 Nice Job Terry! Quote Link to comment Share on other sites More sharing options...
blueovalz Posted October 21, 2005 Author Share Posted October 21, 2005 These arguments are valid ones indeed (driveshaft arguments). Even with the cage, the chassis still flexes, so theres no way I'll eleminate the joints. Even with the differential moved 1" over, it will not be perfectly aligned but it will be a lot better than it is now (and besides, the vertical plane is not perfect either). Combining the vertical and horizontal shifts, I'm well into the 6º shift, and I'm not comfortable with that. Quote Link to comment Share on other sites More sharing options...
DavyZ Posted October 22, 2005 Share Posted October 22, 2005 ...it's nice to see an update from Terry. He's like an engineering "found object" artist, making use of various junk-yard parts to achieve state of the art results. Ditto on that. Terry, those CVs look truly brutal; a real thing of beauty. Are the 930 CVs all that plentiful or cheap???? For a one time deal, this might be the thing to do, but I'm looking at this from a cost/benefit standpoint. Just curious. Davy Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted October 22, 2005 Share Posted October 22, 2005 So we have curious and curiouser.... Quote Link to comment Share on other sites More sharing options...
blueovalz Posted October 22, 2005 Author Share Posted October 22, 2005 The cost/benefit ratio is questionable. The CV joint by themselves are about $80+/joint. The axle shafts were very reasonable (about $170 for both) and the machine work on the adapters could have been cheaper (I piece-mealed the adapters to ensure the first run would work, which made the maching price a bit more expensive). These assemblies were not a "must have" item, but more of a "can I do this?" item (much like the rear toe-adjuster from last year). This particular set is made with a salvage 930 axle set ($350 for used but decent CVs and Boots), about $400 in machine work, and about $110 (used) for axles, and another $20 for bolts. Advantages: 1) These joints are used a lot in small car racing and can be purchased easily. The inner and outer joint are the same part, as well as the boots and axles. The Nissian stuff is nearly impossible to find for the ZXT, and I suspect this will be the case for the Z31/Z32 in the future as well. 2) They are nearly indestructable (which negates point 1 above) and should never need to be replaced. These joints take a 25º offset (50º swing) without any problem. I'm playing with an idea of a 400 cid motor, and figure the joints may need to be beefed up a bit. 3) With the adapters made for the Z (any Z), these assemblies will fit the 240 and the 280 companion flanges (so if I should ever use a 280 axle, these will work just as well) Disadvantages: 1) They are a few pounds heavier than the Nissian shafts 2) If something breaks in back, it will be an axle or a differential instead of the shafts Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted October 22, 2005 Share Posted October 22, 2005 This might be a dumb question, but why don't manufacturers use CV's on the drive shaft? That might be an intresting next step if angles are a concern... Quote Link to comment Share on other sites More sharing options...
Cal Poly Zmanaustin Posted October 22, 2005 Share Posted October 22, 2005 This might be a dumb question, but why don't manufacturers use CV's on the drive shaft? That might be an intresting next step if angles are a concern... If I am not mistaken, I believe the Germans do on some of their cars. Nice work Terry! Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted October 23, 2005 Share Posted October 23, 2005 A lot of cars use CV's on the driveshaft. I don't know how they decide which one to use. For non performance use, I always preferred the U joints since they are generally cheaper to replace. Most CV equiped drive shafts have to be replaced as a unit should the joints fail. Quote Link to comment Share on other sites More sharing options...
heavy85 Posted October 23, 2005 Share Posted October 23, 2005 The front of the driveshaft in my 240 is a cv joint while the back is a u-joint. Dont know how it got that way as it was already there when I bought the car. About driveshaft angles - the manufacturers (at least the ones I've talked to) will tell you that you need a little angle otherwise they will not live. I'm not talking theory here just what the manufacturers say. Also, the angles should be equal front and back otherwise you can get vibration and reduced lives. If you are moving the diff around you should consider trying to make the angles equal front and back which should help the vibration issue if they are not the same now. I've not played around with this just going by the manufacturers recommendations. Cameron Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.