JMortensen

I was more thinking that I could move the LCA pivot fore/aft to try and compensate for any bend in the crossmember, but I really don't think that's a problem with the one I'm using after looking at it again yesterday. I think the rack wasn't straight because I just welded the brackets on in the wrong spot.

That hasn't been my experience with bumpsteer Wiisass. The inner tie rod is nowhere near the LCA pivot on the stock rack on a Z car. I just took a quick look and I would estimate that the centerline of the inner tie rod is about 1.25" higher than the stock LCA pivot hole on the crossmember. Same deal on the outer end, the tie rod is higher than the ball joint. I don't think that it would be physically possible for me to move the LCA into line with the inner tie rod with the stock rack mounting, even with a rod end pivot on the LCA. There just isn't enough room inside the crossmember for that by the looks of it. I don't think I'll be able to do it on mine even with the rack slightly lowered. I fixed the bumpsteer previously by moving the LCA pivot up 7/16". I did this on a home made bumpsteer gauge, without using any modeling software. I just slotted the hole and moved it up until the bumpsteer went away. Did the same thing on both sides, and it turns out my front suspension wasn't bent so it was the same on both sides. I was able to move the suspension thru about 3" or 4" of travel with no sign of toe change whatsoever, so I called it good at that point. As long as the LCA and tie rod follow the same arc the bumpsteer should be eliminated (on macpherson strut suspension) as far as I know, and that was the case with the previous setup insofar as I tested it. I'd like to know if there is more to it than that, but if you or Cary can put it in plain terms that would be great. I know Cary has this idea to have the rack and LCA move together which would keep the angularity constant, and I think that was part of what he was talking about. I won't be doing that this time around, so my emphasis is on getting the Ackerman in there and getting the bumpsteer minimized again. What I can do is measure the change in the LCA pivot height and add an equal amount to the bumpsteer spacers at the tie rod end, so that was the plan.

IME widening the track reduces understeer. I learned about it from my ex-roommate, who was redoing his front suspension and gained about 6 inches in total track width in the front, then started KICKING MY *** at autox! I didn't go as far as he did, I just lengthened the lower control arms, but I also noticed a big difference. I'm looking forward to adding some more front track width and seeing what difference this makes. I just read Tune to Win, and even though it is 30 years old, Carroll Smith addresses the track width issue. From "Tune to Win": "The situation becomes more complex when we consider the relative width of the front and rear track dimensions. I believe that the front track should be considerably wider than the rear track. More heresy! My reasons have to do with turning the car into corners and jumping on the power coming out. The wider the front track the more resistance there is going to be to diagonal load transfer and the lesser will be the tendency for the car to "trip over itself" on corner entry and/or to push into the wall from the effect of the drive on the inside rear wheel when power is applied. I believe most of our present road racing cars, with roughly equal front and rear tracks, would benefit from and increase in the front track width. The slower the corners to be negotiated, the more important this relative track width becomes." You also have to consider that Cary directly contradicted me in that thread you linked to, and although I haven't autoxed with him (yet) I know that he's a lot faster than the guys that are a lot faster than me. I think if you have understeer and long studs, its an easy thing to try out and see what the difference is. All the really fast guys I used to autox with ran a wider front track, whether they were driving Mustangs, Rabbits, Fiestas, 510s, or whatever.

What ever happened to the laser cutting idea? I'm glad to hear you got ours done. Does that mean you're ready for some $$$?

Gotta be careful comparing Ford to Nissan. Most of the Ford and GM diffs and some of the Danas use a spring setup, almost like a Phantom Grip unit. The spring sits in between the side gears and pushes them onto the clutch pack. When the clutches wear, there is less preload, and the preload is the only thing that determines the resistance to slipping. Most of the American LSDs use a lining on the clutch plates that wears off fairly quickly. On this page you can see a pic of the "S" spring which preloads the side gears on the 8.8 Ford diff: http://www.mustang50magazine.com/techarticles/130_0301_slip/ Our Nissan LSD's use a Salisbury type LSD which is torque sensitive. The cross pin in the diff works like a cam to spread the pressure rings under load, and the pressure rings push on the clutch stack harder and harder as more torque is applied. So clutch wear and preload isn't as dramatic in its effect on the stack, because when you punch it it isn't JUST the preload that determines how much limiting of the slip you get. Preload matters, but it isn't the only thing in play, like the Ford Traction Lok LSD. Our clutches are all metal. I pulled mine apart and wasn't able to measure the wear on the clutches with a caliper. Here is the description of the two types of LSDs from my old workplace, Randy's Ring and Pinion http://www.ringpinion.com/content/technicalhelp/default.asp?pid=128: Traction-Lock (T/L) (Also referred to as a Track-Lock, not to be mistaken with the Dana Spicer Trac-Lok) This is the second design limited slip that Ford used in both the 8-" and 9" rearend designs. It is a fairly good design for moderate horsepower applications. This is a clutch type design that uses four plain steel clutches, four fiber lined clutches, and one plate that is steel on one side and has fiber lining on the other side. It uses a two-piece case that looks very similar to the standard open carriers, except the parting line between the two case halves is covered by the left half that "wraps around" the right half. The parting line between the two halves on a standard case is easy to see and is not covered. Traction-Locks are not very aggressive and tend to wear out fairly quickly if used heavily. Newer design Ford rearends such as the 7.5", 8.8", 9.75", 10.25", and 10.5" also can be ordered with Traction-Locks. These differentials use a one-piece case with two spider pinion gears, except for the heavy-duty 10.5" rearend, which uses three spider pinion gears. The 7.5" and 8.8" designs have soft clutches that tend to wear-out quickly and are not aggressive even when new. The 10.25" unit uses composite clutches that holdup fairly well, but it is not aggressive and tends to slip too much when needed off-road. Trac-Lok is a medium-duty limited slip and will hold up without breaking, but will wear out the clutches quickly under heavy-duty use. If the unit wears out it usually can be rebuilt. (factory) Here is the one for the Chrysler Powr-Lock, which is very similar to our Nissan LSD: Powr-Lok (P/L) This clutch type limited slip is the strongest and most aggressive limited slip differential available from Dana Spicer. It is a clutch type unit using floating cross shafts that ride up on ramps in the case. When power is applied, the shafts ride up the ramps and load the clutches for a positive engagement. A Powr-Lok will not lock up 100%, but it is a very durable unit that will hold up fairly well with tall tires. It can be rebuilt, and can be set up smooth or aggressive by changing the clutch design or stacking configuration. Powr-Loks are easily identified by their 2-piece case. They are a very strong unit due to the 4 spider gear design that provides twice as many teeth to carry the load as a 2 spider gear unit does. However, the case bolts can stretch or loosen after severe use over time. (4 pin, 4 tab clutches) (factory)

My old boss used wheel spacers on his 911 race car that saw 170+. Lots of the Porsches I used to work on had spacers, I think some were factory. They were all lugcentric, FWIW. Nice thing about spacers is they are a tuning tool and varying the track width varies the grip on that end. If you get the bolt on adapters you're stuck with whatever width you bought. If you're just looking to put Honda offset wheels on your Z as long as you get good quality stuff I don't think you'll know the difference. I remember Ross C posted a story about his ZX getting stolen and the theives ran it off the road. The car was totalled and I think it had quite a bit of suspension damage but the bolt on adapters were fine.

You can probably just run it as is. If the gears look good I'd throw it in and see what it does. The bearing that tends to go bad is the ball bearing on the very front end of the pinion shaft. You can replace the pinion seal and that bearing if you want, but I would try it out first. $700 is little high, but not too bad. I think I paid $150 for a 4.11 diff and $350 for the LSD, but I also paid a shop to rebuild the diff when I got it because I was afraid to take it apart 10 years ago. Turns out it wasn't necessary and the shop screwed it up 3 times! So I have more than $700 in mine. By way of comparison you can buy the LSD new from differential.com for $500, but coming across 4.38 gears in an R200 is damn near impossible.

Went back out and figured a couple things out. First I flipped the mounts around and found that it doesn't work that way, the tie rods are hitting the crossmember. I also figured out that there is only about 6" in the middle where the crossmember is straight, and I had previously had the clamps in the beginning of the curved area. So I moved them into the straight area of the crossmember and now it's just barely different at one end and the other with respect to the boots rubbing. I think basically I didn't have it straight before because of the curve in the crossmember, now its closer but still not exactly right. So I'm going to play with it a bit more, but I think its basically going to come down to setup before I weld. I think the crossmember is pretty straight, and I will definitely have to grind some of that flange off the ends for clearance.

I guess I'm not following here. The rack is currently 3/8" lower than it was before I started, I was going to raise it up so that it will probably be 1/8" higher than stock. I figured that as long as the tie rod and LCA remained parallel then the height of the inner pivot wouldn't matter. Am I missing something there? I don't really know how to do this. I did the TC mounts by tape measure so maybe I'll bolt this rack in and do the same. On the TC mounts I measured from the center of the rad support, from the top of the frame rail, and from the bottom of the frame rail, and that seem to work out pretty good. I was kinda thinking about butting it up against a wall and trying to measure distance from the wall to the rack. Then measuring from the bottom of the inner tie rod to the table to make sure it is level. I can also change the spacers that locate the LCA to change the pivot position fore/aft if necessary. That's about all I can think of to do, so if you have instruction on how to do something better with plumb bobs I'd love to hear it. This I can do, thanks for the heads up. Engine is in the stock location. Not moving it as the plan when I blow it up is to go to an LSx so it just isn't worth the hassle to move it at this point. Once I get it all figured out I'll check clearance on my engine which is on the stand right now. I have the AZC aluminum pan, but I'm not going to be raising the rack very much, so I'm hoping that this won't create any issues.

Allergies are kicking in big time so I'm on mega doses of drugs today and I got about 4 hours sleep last night after attempting to drink myself into oblivion last night to get away from the itching. Probably shouldn't be doing anything with power tools at all, but it sucks even worse just sitting here being miserable. So I went out and tore up my spare rack and crossmember, and this is what I've come up with so far. This is just kind of mocking everything up to mount the rack with the clamps. I really think that mounting this way with the clamps is going to be plenty strong, and nobody has said otherwise, so I think this is the way it's going to go. I just tacked the brackets on to see what kind of height I could get on the rack. I measured the stock rack at 1 7/8" from the table to the bottom of the tube. When I tacked the brackets to the crossmember I got 1 1/2" inches. I could move the brackets up another 1/2" or so, but I can't really do anything in between. I think that moving them up would be better than leaving it where it is, because moving it up means moving the rack that much farther back, and the lower position will require more spacing on the tie rod end. I'm worried about rim clearance on the tie rod if I use a big spacer. I want to stay with 15's if possible. When I get the rack mounts finalized I'm going to cut a pipe lengthwise and weld it in to fill in the hole I ground out for the pinion housing clearance. One weird problem is that the rack doesn't appear to be sitting straight on the crossmember, or maybe the crossmember isn't straight. If you look at the last 4 pics you can see that the boot is going to interfere with the driver's side of the crossmember. They overlap by about 3/8". On the pass side they will barely rub. Don't know what to make of that. I'd hate to put the rack on crooked, and the mounts appear to be the same, and they're both welded to the crossmember the same way. I'm going to have to check that out really closely and try to measure as many ways as I can before I weld those brackets in permanently. The flange on the driver's side does appear to be about 1/16" wider than the passenger's side flange. Anyway, that will have to be dealt with when the time comes.

It seems to me that Drax started this same thread before, but I looked and wasn't able to find it. My 70 with L28, 5 speed, R200LSD, Autopower roll bar, Recaro seats, full interior with extra sound deadening and carpeted tunnel and strut towers, etc. was 2350 lbs. With my 200 lb *** in the drivers seat these were the corner weights: LF 640 RF 620 LR 650 RR 640 So 49.4 front 50.6 rear and cross weights of 1270 and 1280. Can't wait to see what it weighs with no interior, different roll bar, chassis stiffening, only one race seat, lighter rear sway bar etc. Hoping to be under 2100 lbs but will probably be more like 2200 I'm afraid.

Don't worry trying to look up a picture, that is definitely a clutch LSD. If you want to look into shimming it tighter, check this thread here: http://forums.hybridz.org/showthread.php?t=92629 Probably not necessary for a street car, but if you're concerned that's the way to do it. The bummer part is pulling it all apart and lubing the clutch stack each time to get a realistic breakaway figure.

Squid = squirrely kid. Commonly used to indicate that some 15 1/2 year old moron is about to kill himself on a crotch rocket. In my circle it is used for ricers as well. That didn't go over too well around here, so I have to try to remember not to call it Squid Compact Car as is my habit whenever the subject of that magazine comes up.

Uh, yeah. There's going to be a joint. I'm not a retard. I'm using the stock inner tie rod end. The stock rack has 14 x 1.5 RH threads on one side and 14 x 1.5 LH threads on the other, which makes it harder because you'd need a RH and LH threaded tap to tap the hex aluminum. But the idea with the hex aluminum is to make a turnbuckle, which threads onto the stock inner, and a 5/8" outer rod end. This is the same idea that Cary had, except he modded a circle track 5/8" turnbuckle and welded in the 14mm threaded portion from the stock outer tie rod, so that would fit between the stock inner tie rod and the 5/8" rod end. I'm going to use the same bumpsteer spacers that everyone else in the circle track world does. I can't imagine that I'll have a problem. Sounds to me like maybe the 240SX needed a steering stop and didn't have one, so maybe it was using the power of the rack to try and bend the bolt or something. I've heard of people breaking tie rods, but never bending the bolt so that's just a guess. Right, parallel steer or really close to it is what the Z has. As I said before, I had already moved the LCA up. Now the intention is to move it up farther, but I need to move the tie rod down to minimize the bump steer. You can't move it too far with the stock crossmember, only about 1 1/8" from the stock pivot location, but I want to be able to use anywhere from stock to 1 1/8" up from stock and then space the tie rod to match if possible.

Can't you get the same effect by putting washers under the bottom lug nuts? $30 is a major rip off.

No kidding. Funny how everyone thinks that they're the persecuted ones and the bikers or the classic cars or whatever other group doesn't get hassled. BS. My buddy with a 66 Ranchero that had headers into Supertrapps used to get hassled all the time, I already told the Harley story. Everyone who is breaking the law SHOULD get hassled. And if you don't like that, work on changing the law and quit bitching.

Well I'm sure my next post isn't going to convince strotter or anyone else who believes that NB isn't accurate, but I can say that I've one of 4 guys who has tuned a carbed car quite successfully with a NB. I will say this too, there is a difference in which brand O2 sensor is used, so there is a pretty good amount of variation between the sensors. I started with a Bosch sensor because that's what I was told to do. One friend of mine bought the Autometer light gauge and wasn't having any luck at all. He then swapped the O2 sensor out with a Bosch sensor, and suddenly his gauge was accurate. In a semi-related way, this kind of bears the not all sensors are created equal: I have a friend who was getting 15 mpg in his Toyota 4x4 truck. He was running the cheapo generic O2. He switched to the $250 factory sensor and immediately got 23 mpg. Another time I saw a guy change the O2 in his Pontiac Grand Am. It didn't need to be changed, but he swapped it out thinking he'd prevent some problem down the line. He installed a Bosch sensor, and the car ran like dog ****. He swapped in a new AC Delco sensor after taking the car to the dealer and voila, car was fixed. I know this only helps prove the inaccuracy of the NB in general, but those of us who have used the Bosch on a voltmeter or gauge in my group of racer friends have had very good results. I had mine tuned to where you could start at 3000 rpm and punch it and it would go all the way to redline and never go below .800 or above .850. There was an old thread that showed what voltage equaled what a/f ratio, but it is gone now, it was by ZmeFly, and apparently when his little scam got discovered he went back and erased all of his posts.

Still looking for some feedback on using the U-bolts...

The 6AL also has a module built into it, and you might be able to do away with the 260 module and run the one in the MSD instead. I was able to do this on my 280ZX distributor. I just ran the two wires that come out of the dizzy to the "Magnetic Pickup Connector".

I can't address much of that, but the 225/250 I think I can explain. There are not too many struts available for old Z cars, and probably the best street car strut is the Tokico Illumina. It tops out at about 250 lbs, any more than that and there is a tendency to blow out the seals. 225 in front because Z's will turn in better with a lower front spring rate. I run 200/250, there are lots of guys running in the 175/225 or 175/200 range as well. It's not the best for racing, but it is about as stiff as most people want for a street car.

I can't address much of that, but the 225/250 I think I can explain. There are not too many struts available for old Z cars, and probably the best street car strut is the Tokico Illumina. It tops out at about 250 lbs, any more than that and there is a tendency to blow out the seals. 225 in front because Z's will turn in better with a lower front spring rate. I run 200/250, there are lots of guys running in the 175/225 or 175/200 range as well. It's not the best for racing, but it is about as stiff as most people want for a street car.

1/8" is okay for everything but the windshield. I think you can buy a Lexan windshield which is 1/4" thick, but the weight savings isn't much, and then you have a super easy to scratch windshield. You can buy smaller pieces at Lowes or Home Depot, but check the yellow pages for plastics and you'll probably find a dealer who will sell you a 4' x 8' sheet for a better price per sq ft. I think when I was getting "the deal" I could buy a 4x8 sheet for about $60. I want to say it was about double that for the average Joe who just walked in. It's been about 5 years since I had the plastics hook up though... EDIT- Yes you need straps for the hatch!

I'm not sure what the stock Ackerman is, but I believe it is close to 0. I know that when autoxing I drag the inside tire pretty bad. I think having a clevis machined would be more expensive than having the aluminum hex tapped for the 14 x 1.5mm, don't you? I mean you'd have to drill and tap the clevis for the metric threads on the rack, then machine the clevis. If they were just to drill and tap the hex for the 14 x 1.5, then they'd be done, and it would thread right onto the stock inner tie rods. It's pretty widely accepted that Z's handle better on the track with a LOT of static toe out (1/4" seems to be the going rate). I figure whatever Ackerman I can get will be an improvement on this as I will get dynamic toe out and can run static toe closer to 0. I was planning on getting as much as I could, then just running toe out until I don't get any more benefit from it. Since we've got the steering rack in front there really isn't much room to bend the steer knuckles laterally. I have to mock it up again, but I think it's only about 1/2" clearance before the knuckle hits the rotor. I had previously fixed the bumpsteer issue by raising the lower control arm pivot up 7/16". That worked fine and I was very pleased with the results, but I figure that if I can adjust the outer tie rod, then I can move the LCA up another 3/4" or so. This would allow me to try different roll centers in the front, but that means that I'd have to move the outer tie rod down 3/4" to minimize the bumpsteer. I'm not worried about the bending load on the bolt too much, the 5/8" bolt is way bigger than the stock tie rod and it should be 1" or less from the spacer to the rod end.

The picture shows a long nose. Long nose, clutch style LSDs did come in the Skylines, and they did have LSD and 4.38s. If that's the picture of the diff that you bought, you should be in good shape. I'm also sure that the later years had the short nose R200 with the viscous LSD. But that's not what you took pictures of.

Read the sticky messages at the top of each forum. They'll give you the basic rules. Since this site is mostly for V8 swaps, it would be very unlikely that a question about how the swap affects the handling has not been discussed before. You are expected to search the archives and find out the answer for yourself, rather than asking that question for the 4867th time. Next you jumped in on somebody else's thread and asked your totally unrelated question. This too is bad form. If you want to ask a question that isn't directly related to the topic going on in the thread, start your own. Then, before you post, read the rules. If you had done this you would have searched first and the question wouldn't have needed to have been asked anyway. I'm always amazed when I come up with a question that hasn't already been answered here. So much territory has been covered it is pretty incredible. So read the FAQ's, read the stickies, then search, then ask your question if you haven't already learned the answer.