johnc Posted March 19, 2004 Share Posted March 19, 2004 Explained: http://www.betamotorsports.com/benchracing/index.html and click on the "R200 Handling Issue" link. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted March 19, 2004 Share Posted March 19, 2004 Thanks John. Interesting information. The shaft length difference really became obvious when I had to swap the CV shafts from side to side when I put the LSD in, and found the long shaft no longer "fit" on the drivers side. I had to disassemble (again) the shafts and put the diff stub onto the opposite side (short) shaft to make it fit) The fully compressed length of the halfshafts, as measured from yoke centerline to yoke centerline, is 12 3/16". The fully extended length of the halfshaft, measured the same way, is 14 3/8". This gives total travel of 1 7/16" I this not 2 3/16" of travel? 2. The rear doesn't take a set, constant steering correction is needed on right turns while racing on an autocross course or a track, and its difficult to put the power down on corner exit. Can you tell us why this is? Is it because of the binding issues? Now let's add insult to injury: If one uses camber plates, and draws the top of the strut inboard for more negative camber, guess what? Your 1/8" play starts to disappear. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted March 19, 2004 Share Posted March 19, 2004 Interesting post, but I gotta say I've never noticed those problems. I know that I've bottomed my rear suspension, so maybe I've just been flexing the hell out of everything back there. I do remember getting together with a Z freak and a 510 freak and going thru about 10 halfshafts to find the shortest one to put on the driver's side. Aren't the 280 shafts supposedly narrower than the 240 shafts? Have I been fooling myself all this time? Or maybe because I've got camber adjusting bushings the pivots are moved out enough to prevent bind??? Regardless, you've put one more mod (CV conversion) on my list of things to do... maybe I won't get to autox this summer... Thanks, Jon Quote Link to comment Share on other sites More sharing options...
johnc Posted March 19, 2004 Author Share Posted March 19, 2004 I this not 2 3/16" of travel? Yeah, you're right. That's what I had written down but its not what I typed. Can you tell us why this is? Is it because of the binding issues? Yes, the driver's side spring rate increases and some exponential rate. Interesting post, but I gotta say I've never noticed those problems. I know that I've bottomed my rear suspension, so maybe I've just been flexing the hell out of everything back there. A lot depends on what spring rates you're running and the type of diff you're running. The problem would be less pronounced with an open diff and/or high spring rates (over 250). Aren't the 280 shafts supposedly narrower than the 240 shafts? I haven't seen that but I've only measured one set of 280Z halfshafts that came out of a R180 equipped car. Quote Link to comment Share on other sites More sharing options...
CruxGNZ Posted March 19, 2004 Share Posted March 19, 2004 Now that was very interesting! All the more reason to install my CV's. Also, I didn't know the 280Z was slightly wider than the previous years. Would you happen to know by how much? !M! Quote Link to comment Share on other sites More sharing options...
johnc Posted March 21, 2004 Author Share Posted March 21, 2004 Both Jon and another person have said that some 280Z halfshafts are shorter then the 240/260Z halfshafts. Does anyone know this for sure and what are the measurements? Regarding the 280Z chassis width, again its not something I've measured but the person who told me should know his stuff. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted March 21, 2004 Share Posted March 21, 2004 Just an interesting side point. I have 250 lb springs in back and a clutch type LSD. So you'd think that I would have this problem, right? You can see in my video that the butt swings to the right on one launch, and to the left on the other in my video previously posted here: http://hybridz.jimzdat.com/zpics.htm Also may not be a problem for me because of G Machine bushings as stated earlier. Jon Quote Link to comment Share on other sites More sharing options...
A. G. Olphart Posted March 22, 2004 Share Posted March 22, 2004 How difficult/is it possible to move the diff 3/8inch towards the passenger side and cure the problem? (That should leave 1/2 inch on each side if I'm lookin at this right). I'd guess that there should be room in the driveshaft tunnel, but is 1/2" travel (from rest, as described) enough? Quote Link to comment Share on other sites More sharing options...
johnc Posted March 22, 2004 Author Share Posted March 22, 2004 The fabrication work to move the diff wouldn't be that big a deal, but then you'll have to move the transmission and engine 3/8" to the right to maintain the correct driveline angles. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted March 22, 2004 Share Posted March 22, 2004 This was a consideration I took as well, but after measuring the ~1" offset of the differential propeller shaft centerline from the transmission output shaft centerline, I decided not to move it any further toward the passenger side. The centerline of the two shafts (output shaft and the propeller shaft) are parallel, but with the added torque of the V8 onto the U-joints, I chose to leave things as they were, especially with such a short driveshaft. Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted March 22, 2004 Share Posted March 22, 2004 Sounds like a reason to reconsider an R180 with a Quaiffe. Heard all the real racers run that set up anyway I put an R200 into my 240 (with the stock 240 half shafts), but in all honesty I probably have not run my car hard enough to noticed such a problem. I will say the handling *seemed* to improve with the new diff, but I attributed that to moving the diff back to correct the half shaft alignment problem with the early 240's. Thinking out loud, why would you have to move the engine? You want some U joint angle, so as long as the diff and transmission centerlines are parallel (and the angle is not excessive), then what difference does it make if the angle has some side to side component as well as an up and down one? I thought as long as the angle between the transmission and driveshaft is the same as the angle between the diff and driveshaft, then all is good? Quote Link to comment Share on other sites More sharing options...
A. G. Olphart Posted March 22, 2004 Share Posted March 22, 2004 Pop, that's been my take on it too... if a guy slotted the mustache bar 3/8" and moved the nose the same distance (but nothing up and down) there would just be a slight amount less (more?) angularity in the driveshaft. I thiink that as long as lines projected through the center of the tranny output shaft and the center of the diff pinion are parallel, a guy would be OK. (Saw a post recently on building laser tools to verify this/set things up). My question mainly went to the amount of travel required; does anyone have the measurement for half shafts from full droop to full compression for a 240? Terry, isn't the engine offset towards the passenger side? This mod would decrease offset by 3/8" if that is the case. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted March 24, 2004 Share Posted March 24, 2004 I don't have an L6 Z, so I couldn't answer that. A 3/8" offset would change the angle by about 1.2* (based on 18" joint-to-joint length). Quote Link to comment Share on other sites More sharing options...
Guest 350zgto Posted March 30, 2004 Share Posted March 30, 2004 The axle for the R-200 car is shorter to compensate for the increased width of the R-200, the increase is displaced to the left side. R-180 axles can be installed in an R-200 equipped car, but while the axle works, it is actually too long. Quote Link to comment Share on other sites More sharing options...
johnc Posted March 30, 2004 Author Share Posted March 30, 2004 A number of people have said that but no one has come up with any measurements or put one in my hand. Quote Link to comment Share on other sites More sharing options...
mobythevan Posted March 30, 2004 Share Posted March 30, 2004 All I can say is that I have halfshafts from a 72 240z R180 and halfshafts from a 280z R200, not sure which year 280z and they are identical when compressed. Not to say a shorter one may not exist, but mine are the same. Quote Link to comment Share on other sites More sharing options...
ThomaZ Posted March 30, 2004 Share Posted March 30, 2004 I am in the process of doing the R200 swap into my 240Z -72 right now. So I went down in the garage an measured the two rear driveshaft that a removed from a 280Z-78 in a junkyard: I forgot to label them with which side I removed them from so I just call them Shat A and B. Here goes: Shaft A: Fully compressed 316 mm (12.44â€) Shaft A: Fully extended 350 mm (13.78â€) Shaft B: Fully compressed 314 mm (12.36â€) Shaft B: Fully extended 342 mm (13.46â€) Seams inconsistent that they should be longer then the 240Z compressed but shorter extended, but I measured them twice to be sure. On the other hand they came from a junkyard car and lots of parts could have been shifted on that car during its 25+ years. Quote Link to comment Share on other sites More sharing options...
johnc Posted March 30, 2004 Author Share Posted March 30, 2004 Those are even longer, fully compressed, then the four I measured which were consistently at 12.185" (12 3/16 or 309.5mm). Did you measure the center-to-center distance of the u-joint holes in the halfsafts? There's an example of how I measured on the web page linked at the firs tpost in this topic. Quote Link to comment Share on other sites More sharing options...
ThomaZ Posted March 30, 2004 Share Posted March 30, 2004 Yes, I did measure center to center. Even had printout from your webpage next to me when doing it. I can re-measure, but my working schedule is kind of hectic right now so it can take a couple of days. A taught. When compressing I just rested one end against the floor and pushed the other one down until it stopped. Is there any more to it? Quote Link to comment Share on other sites More sharing options...
johnc Posted March 30, 2004 Author Share Posted March 30, 2004 No need to re-measure, you did it right. So far, no one's been able to find the supposed shorter R200 specific halfshafts. Hopefully they exist and we can get some parts numbers. Tony D is going to look through his pile of stuff and measure a set of known R200 280Z halfshafts when he gets time. Quote Link to comment Share on other sites More sharing options...
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