JoeK Posted June 25, 2015 Share Posted June 25, 2015 I'm just starting installing AZC coilovers and camber plates on my 240z. It seems there are plenty of ways to skin this cat, I just want to make sure it tastes good when it comes out of the smoker. This all based on my own logic and reading, please correct me if I've got something wrong. The AZC website instructions say to make sure the camber plates are 90 degrees to the centerline of the car. Am I wrong in thinking that it is more important that they be parallel with the front cross member? It may be the same thing, but one is certainly easier to measure than the other. With this thinking in mind, I put centerline marks on the front frame rails. I then ran a string across the engine compartment over the fender rails, put a square on top of the frame rail and lined the string up. Then to the other side with the square, line up the string, rinse and repeat until it's dead on. What this revealed to me was one of the original struts was about 1/8" out of parallel with the cross member. I've yet to double check this, I was short on time last night, but given this is a 40 year old car I'm not at all surprised. And whatever it is, I can bring it back into alignment when weldsing in the new camber plates. Where I place the camber plates with regards to front and back of the car, this effects Caster. Is there any sense to pushing them one way or the other, or do I just want to basically center them as well as I can on top of the towers while ensuring they are in line with each other and the crossmember? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted June 25, 2015 Share Posted June 25, 2015 Z handling benefits from an increase in caster, which would be moving the plates to the rear. I don't think you'd be able to move it very far to get a large caster change, but if you want the front end to grip better, you can increase caster by lengthening the TC rods under the car as well. There are some nice adjustable setups out there. Quote Link to comment Share on other sites More sharing options...
LSB_11 Posted June 26, 2015 Share Posted June 26, 2015 I just finished mine, I had the same questions about alignment. I found a topic on here somewhere that explained it well. But what I got out of it was perpendicular to center line so the caster would be the same side to side. Since your strut towers look to be off forward and aft on the car I would not go off any point of the front or a cross member. Everything seems crooked. Mine was a little of from a fender bender so I had lto find center line and try to put a square on it to line up either side camber plate indepently of each other. You can lay a strait edge ocross them an they are strait, just not perfectly occross from each other. Quote Link to comment Share on other sites More sharing options...
JoeK Posted June 26, 2015 Author Share Posted June 26, 2015 I guess it will be easy enough to check that the crossmember is perpendicular to the centerline of the car. My thinking is that it is important to be parallel with the crossmember so that the lower control arms are the same angle. I do plan on getting adjustable control arms and TC rods, but if you have stock TC rods, then perhaps what you need to do is verify that the centerline of your camber plates is equidistant from the TC mounting buckets on the frame. How much caster change would you need to start seeing a difference? Some quick math tells me that if you had an overall strut length (from center of spindle to top of camber plate) of 18", then you'd have to move the camber plate 5/16" to get a 1 degree caster change. Quote Link to comment Share on other sites More sharing options...
TUME Posted June 26, 2015 Share Posted June 26, 2015 Don´t know how much chance you need to notice a difference. But there is a rule of thumb, caster 1/2 of amount of SAI. Therefore i made this. Btw, you should measure lenght of strut from balljoint to top of strut. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted June 26, 2015 Share Posted June 26, 2015 I think my stock caster was about zero. I'm at 5 degrees now and the wheel takes noticeably more arm to turn the car, especially with hot slicks (I suddenly understand why some guys want power steering). Its not bad with street tires. I'm going to max caster this winter that my smallest diameter tire will allow (limited by airdam and fender clearance) to try to make the car feel more confident over 150mph. I can report back then, but the data will be somewhat confused due to skinny tires. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted June 26, 2015 Share Posted June 26, 2015 Don´t know how much chance you need to notice a difference. But there is a rule of thumb, caster 1/2 of amount of SAI. Therefore i made this. Btw, you should measure lenght of strut from balljoint to top of strut. I hope there is more structure to that on the bottom side. Looks like you missed the frame rail and just have the strut tower connected to the fenderwell. Quote Link to comment Share on other sites More sharing options...
JoeK Posted June 26, 2015 Author Share Posted June 26, 2015 To be perfectly clear, I know only enough about suspension to get myslef in trouble. I am trying to learn, and puttiing my assumptions out there so that people who know more can tell me where I am wrong. Google-Fu informs me that SAI = Steering Axis Inclination. Same google-fu informs me that caster should be with .5 degrees side to side. Thanks for the strut length measure clarification. To be clear, I was not actually measuring anything, just lying in bed trying to get a rough idea of how much difference say an 1/8" would make. Photos from last nights battle. The tops of the strut towers aren't very flat. I read a post from JohnC saying there shouldn't be any gap. That would require alot massaging, and I havent seen any talk of massaging the towers to conform to the flat plate. Largest gap is 1/16", except the front corner where I'll need to bend the plate. Quote Link to comment Share on other sites More sharing options...
LSB_11 Posted June 26, 2015 Share Posted June 26, 2015 Looks like you are doing fine, just get good penetration on top and bottom and keep the top of the plate pretty much like the old one was. It's my first time with weld in camber plate. It took me so long to do the front two, and like a third of the time to do the back two. You are on the right track Quote Link to comment Share on other sites More sharing options...
JoeK Posted June 27, 2015 Author Share Posted June 27, 2015 Got the fronts burned in. Tested my welding abilities to the limit, and was probably beyond the limit of my little Hobart 130 mig. Burning through the thin top layer of sheet metal to get the lower one, then getting good penetration into that was difficult. I found the trick that seemed to work was flick into the thin part to burn through it, then push the weld puddle into the hole, flick to create a hole, and push the puddle into the hole, again and again like that, if that makes any sense. I'l stilll go back in from the underside and weld a couple runs, especially at the fender side where I really couldn't get a very good bead because the gap was too small. The pics of the completed weld already have a second pass over them to give me enough metal to grind and finish, as seen in the last pic. Quote Link to comment Share on other sites More sharing options...
johnc Posted June 27, 2015 Share Posted June 27, 2015 Fit up for welding should have the gaps no wider then the diameter of the filler wire. In reality there are times when that isn't possible. Get good penetration, take your time, and try to get it in one pass. Multiple passes can work harden the weld. Your work looks fine. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted June 27, 2015 Share Posted June 27, 2015 (edited) I think my stock, unwrecked car with bolt-in camber plates using the stock holes is only accurate to within 0.5 degrees in caster. All these settings influence one another, so it is really hard to get them exact. Go over a bump with one wheel, and they are all upset a little anyway, since ride height influences them all. Realizing that a circle is 360 degrees, +\-0.5 degrees is pretty damn exact. I think with my bolt-ins, one side is -3.25 camber and the other is -3.5. The next bolt hole on the bolt-ins reduced camber to like -2.7. I don't think we have to get this down to a gnat's ass in perfection. I've let other, more experienced drivers drive my car, and they are complimentary of its balance and ease of turn-in. Toe-in is the most critical, then just know that lots of camber reduces tire wear at the track and lets you use the whole tire in corners, but increased wear on the street, and vice-a-versa. I may have enough camber in to hurt braking performance, and perhaps straight-line stability so camber can negatively affect some aspects of driving performance. It's all trade-offs in an imperfect world. I may go to that other bolt hole next year and see how it goes. The great thing about coilovers and camber plates and adjustable TC rods is that it lets you experiential and learn. I'm currently learning about bumpsteer: how it works, affects driving, and how to adjust it. These little cars are so much fun! Edited June 27, 2015 by RebekahsZ Quote Link to comment Share on other sites More sharing options...
JoeK Posted June 29, 2015 Author Share Posted June 29, 2015 Yes, I absolutely realize that these cars are never going to be perfect, and probably don't need to be. And I'm not trying for pefect either, but if it takes me an extra 1/2 hour to align things to some reference point I don't mind one bit. So if I try to get things within a 1/32", then it'll end up +/- 1/16". This isnt valve lash we're talknig about here, and I'll be driving this thing on the pothole riddled streets of Oakland, Ca so I'm sure it'll be close enough. This is all just for fun anyway, and I'm really quite enjoying myself. And on to the rears. The mark with the little arrow pointed to it is 1 1/2" from the center of mustache bar mounting post. This gives me a reference point. Thinking about this now, this really doesn't have much to do with the rear suspension, just the location of the differential. I think i'll re-lay it out from the center of the lower control arms poly location. either way, this is all within the adjustability of the camber plates anyway so doresn't make a difference in the end. I just want them to be pretty close to equal when both sides are set to the same amount of camber. Location of camber plate with regard to front to back of the car doesnt matter, in my mind. There is no caster at the rear, or whatever amount there may be is controlled by the lower control arms and there is no adjustability. So I just lined the plates up with the existing strut bolt holes. There is a good write up by Sunny Z about his camber plate installation. His car is a '78 280z, and the rear strut towers are constructed slightly differently on my '71 240z. The sheetmetal on top is different, on his the thin top layer of metal is spot welded on. On mine, it was welded around the perimeter, and doesn't go underneath any additional sheetmtal. I just ground out the welds and removed it, as can be seen in the last picture. This will make welding these in much easier, as I won't have to burn through that top layer. Of course, access to actually weld looks worse, but you take the good with the bad. Kids playdate ended early so I didnt get to finish up the cut outs, but I'll use the die grinder to round out the cuts. That's a rotary file mounted on it, which cuts quick when sharp. And yes, those are some cheap tools, but it leaves me more money to buy expensive beer. I considered buying a plasma cutter, but I've come this far without one. I'll leave this one comment about cheap tools. If I'm not sure how much I'll use a tool, I buy a cheap version. If I burn it up, I replace it with the best I can afford. Those Harbor Freight grinders are crazy cheap but keep on running. The Harbor freight wire wheels are crazy cheap, but throw wires all over the place and I consider them dangerous. Finding a good balance can be difficult. Quote Link to comment Share on other sites More sharing options...
JoeK Posted July 6, 2015 Author Share Posted July 6, 2015 Finished welding in the rear plates. Welds look prety good to me. I turned down the feed speed just a tiny bit, from like 34 to 33, sure made for a tighter weld. I won't be grinding these ones smooth like the fronts. 1st pic is drivers side, 2nd pic is passenger side. Starting on the sleeve to spindle welding. I'll only be doing the fronts, the rear is getting a TTT set up so the backing plate mounts will get welded to sleeves. Anyway, realized today that unless I'm missing something, the front struts will not be adjustable without major disassembly. Guess I'll start with it set in the middle. Quote Link to comment Share on other sites More sharing options...
280zzzzz Posted July 31, 2015 Share Posted July 31, 2015 Front Camber Plate Installation Experience. I obsessed about the installation of my front plates for...... a long time. I ran with stock - mounting insulators / bearings with GC coil overs / sectioned struts / Koni 8710 - until adding the DP Racing plates. With front fenders off, and struts removed, I measured / marked the c/l of strut to firewall distance using a piece of stainless steel as a straight edge between the two strut towers. I used a large blob of plumbers putty jammed up into the strut tower to use as a pattern to form the outside shape and bend angle required for the camber plate. I then used the plate as a pattern to mark the top of the tower leaving 1/4" to weld the plate to. At this point I secured a piece of 1" plywood under the strut tower through the three mounting insulator attachment bolt holes - this wood was used to center the pilot bit of a 3 1/2" metal cutting hole saw, driven with a Hole Hawg. This was the perfect size for the inside cut on the top of the tower, only three straight cuts with a zip grinder finished off the strut tower top modifications. After metal prepping the under side of the strut towers, aligning them, the camber plates where welded to the bottom of the towers. I know - long winded... I hope this helps someone through this process. I have wondered why I don't see more camber plates installed BELOW the top of the strut tower, since the forces will be up against the underside of the tower, rather than being resisted just by the weld when mounted above. - Also the PillowBall flat surface mates nicely against the underside of the camber plate without any interference with the cut surfaces of the strut tower, which sometimes happens when the plate is mounted on top. A couple other things that where required... The top of the Koni damper rod required some machining in order to fit the sleeve in the PillowBall -- Also the top nut for the damper rod required a little machining in order to fit the top of the PillowBall. Thanks Andy. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted July 31, 2015 Share Posted July 31, 2015 (edited) Nice. Similar argument exists about bolt in plates on top. I've got my bolt ons underneath for the same reason even though they look very pretty on top. I would figure the main objection to putting them in on the bottom is that it's a lot harder to weld to the underside of the strut tower if you don't have a rotisserie. Welding upside down sucks. Edited July 31, 2015 by JMortensen Quote Link to comment Share on other sites More sharing options...
280zzzzz Posted July 31, 2015 Share Posted July 31, 2015 The bolt ons' do look nice on top... These DP units look about the same either way. I think it turned out pretty clean - I stressed out for the longest time about cutting into the towers... I would not have cut them if the car had been perfect in every other way... My MO is function first - it made sense to mount them below. Welding overhead does tend to markup my nice helmet... I appreciate your comments Mort. Quote Link to comment Share on other sites More sharing options...
NylonAdmiral Posted August 27, 2015 Share Posted August 27, 2015 Hi guys, haven't checked in to HybridZ for a bit (mainly because I've been doing my camber plates too!) so missed this when it was originally posted. I'm sure other people will find the thread useful as I know I searched for similar ones before I started mine.I documented how I did mine in case it's of any interest to anyone. I'm not suggesting it's the right way or the wrong way, I just documented what I did in case it helps anyone learn from my mistakes. I included pics/video to try and make it easier to see what I was doing. Here's how I did the fronts Here's how I did the rears. 1 Quote Link to comment Share on other sites More sharing options...
260DET Posted August 28, 2015 Share Posted August 28, 2015 Around 8 degrees caster is good for a circuit S30. Quote Link to comment Share on other sites More sharing options...
TUME Posted October 9, 2015 Share Posted October 9, 2015 I hope there is more structure to that on the bottom side. Looks like you missed the frame rail and just have the strut tower connected to the fenderwell. I think I have this covered. Quote Link to comment Share on other sites More sharing options...
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