JMortensen

You're not crazy. Search "Diamond Racing Wheel" or "DRW" and you will probably come up with quite a few hits. I would rather have aluminum wheels, but you can't beat steel (especially those Bassetts) for price.

They're really not that heavy when you get the spun shells. They are fragile though. If you talk to Diamond Racing Wheels they'll tell you so, and also remind you that you can buy a spare wheel or two for the price of one custom aluminum rim. Those Bassett wheels look like they're a lot cheaper than DRW's. DRW has prices from the late 80s on their website last I checked. Call and you get zinged with the real prices...

zcarnut has done this I believe. Pictures were posted years ago. You might PM him and see if he remembers the details.

Clutch needs additives, helicals do not generally use additive. The parts store should have it. Gear oil weight? I'd check Subaru's recommendation, but I use 80W-90 in the R200 and in all the R180s I have owned.

Have you looked at the rear stub axles yet? I've got some that will hold down the power that you're going to make. Satan can tell you all about them (hell, he told ME all about them): http://m2differentials.com/index.php?main_page=product_info&cPath=773_2627&products_id=10262

Any oil should work, it's the additive that you will need. All LSD additives, whether they say Chrysler, GM, or Ford on them, do the same thing. Lost of guys like Redline, I like SWEPCO 201, but any good oil should do the job just fine really.

My bro-in-law has quite a few of these as I recall. Mat M AT m2differentials DOT com. Last I heard he was practically giving away E31 heads, so he should be pretty reasonable on these. He is outside of Sacramento.

OK, I've got it all figured out. $575 is the regular cost for the pair, $350 is the cost for just the LH shaft. If I can get 10 sets ordered I can sell them for $500 per pair, you can sign up here: http://forums.hybridz.org/index.php/topic/102798-short-z31t-cv-shafts-group-buy/

Did you try the airdam on it?

Well actually, now that I think about it, you can't change the inner cage (wouldn't matter anyway since the inner CV doesn't plunge), and you have to take both joints off of the shaft. If you wanted to flip the cage while you're in there, it's easy to do, but not necessary.

Checked these on my car with the cages in the standard orientation (not flipped) because I don't think anyone particularly wants to go through the greasy hassle of flipping cages if it's not necessary. I had 3/4" of movement on the LH side and 13/16" movement on the RH side with the suspension fully drooped from the position where the CV was when attached at both ends to fully compressed, so that's right in the middle of the range. Again, my car has the MM billet adapters which add about 3/8" of clearance and I put stock length control arms on to measure. I think these would be about 3/8" from bottoming on a car with stock control arms and the welded adapters from Ross. This should work out fine as we've seen from the previous measurements that the shaft needs to get longer as the suspension compresses. Again, switching the driver's shaft to the passenger's side looks REALLY close on my car, even with the cage flipped. YMMV. I don't think the boots are stretched so far that they will split. They really weren't that hard to get on there. I suppose only time will tell though. I think I mentioned it in passing, but these threads are cut, and the material is chromoly. Between the chromoly being stronger and the removal of the snap ring groove at the inside of the splines, I think this is going to be a big step up in strength. This first set is spoken for. I'm going to check again with the machinist on Monday and figure out what the final price will be, then I will set up a vendor thread and will try to do a big order like Coffey does for the R180 side stub axles. Some pics. The stock shaft is the driver's side from my car.

Got the new CVs and they match my measurements from earlier in the thread, but didn't have time to check them on the car today. Will check tomorrow and if they are OK will add to the website so you guys can start ordering them.

I don't know much about metallurgy, hardening, or machining, so I have stuck with changing the clutch stack around and shimming for my own vehicles. On the different LSD's that my business sells, there are different springs and clutches, but nobody gets into ramp angles and that sort of thing either. I think to get that far into it you have to be a pretty hardcore road racer or autoxer. Most of my stuff is geared towards 4wds, where it's all about increasing lockup, and that is relatively easy to do. Judging by your response it sounds like you made a 2 way LSD into a 1.5. Is that right?

Why would the helical be somehow inherently smoother? When you describe smoother as "not knowing it's there" that means that you want an LSD so weak that you can't feel it working. If you had a clutch limited slip with no preload and had the clutches setup to minimize friction (stack them plate plate plate disk disk disk for example so that there is only one plate face working on one disk face) what would make the friction that it generates feel different than a helical's friction? The nice part about clutch LSDs in my view is that the clutch stack arrangement is a more efficient friction generation mechanism so you can generate a much higher torque bias ratio than you can in a helical, and you can also tailor it to suit your particular car/driving style. While we don't have different ramp angles and pressure rings from Nissan, if someone were inclined they could make their own. In fact I believe Ron Tyler did this at one point. You can add more clutches and put more surface area to work, or you can stack them so as to minimize the surface area. With the helicals you can change the pitch of the gears to increase or decrease friction as well, but they don't seem to have the capability to get the TBR near as high as a clutch type can. Thanks for the article Flexicoker. Interesting stuff in there.

Can you get those in CA? I know you can in WA...

No adjustable suspension that I'm aware of comes preset at the factory settings. Camber plates, control arms, none of it. Just make the lengths of the rods even and drive it to an alignment shop. As VKLR states, it's not a tire wearing adjustment. If the chassis is square, having them the same length should result in no pull.

The whole point is to be able to adjust the caster. If you're having the car aligned, have them set the caster to where you want it. Stock is 2.5 degrees, most racers like more, although you may run into fender/airdam clearance issues when you start getting 4+ degrees.

Is there some reason why you MUST run without the venturis? I think I was making about the same power through 37mm venturis, I think zredbaron is making more power than either of us through 40's, I can't recall what size choke tubes he is running.

The back is not one long axle. You might have bent the uprights which locate the rear control arms.

Thanks! I did slide a boot on just to be sure. It was tight, but it went on just fine.

I'll probably do it both ways, but to start it would be a kit with the stub with more splines than stock, flange, and short CV shafts (you would still need the Z31T CV shafts to pull the CV joints from). I need to track down another 280Z stub axle and companion flange to do a stock sized shaft and spline count. Got my CV prototypes today. They took a larger 1 5/16" shaft and turned down the end, so there will be NO strength issues on the shaft. It is BEEFY. They also deleted the inner snap ring because that sharp edge is a big stress riser and put a step in the splines to locate the CV races. On the outer ends of the shaft the CVs will slide on and be retained by the outside snap ring on the outer and the circlip on the inner. Problem though... they forgot to print my measurements out and give them to the machinist, so the shafts I got were the same length as the stock RH shaft that I sent as a sample. They already sent me a call tag and have said they can cut the splines up further and get these back to me in a few days.

If it is a track day car and nothing more, then you're free to do what you want. If you think you might race autox or door to door with an actual sanctioning body, you can quickly make the car ineligible for a bunch of classes by doing things like subframe connectors. Figure out the class first, then build the car to suit. And I would suggest you look really hard at 75_5.0L_Z's cage for a street car. He doesn't have halo or A pillar bars. The Z just isn't tall enough to get those bars far enough away from your head unless you're pretty short. I know I'm not alone in the opinion that a full cage basically renders a Z a track only car, because you really don't want to get in an accident without a helmet on.

What class are you running in?

NOT constant rpms. UP and DOWN, over and over and over.

Might have something for you soon on this. I don't want to get too specific, just in case I get jerked around again like I did with the last guy.