blueovalz Posted December 11, 2003 Share Posted December 11, 2003 3/16" toe. I can't help it, but it just sounds like too much, but if it works in a particular case, then..... I'd be afraid the cords would be showing after a few laps. I also investigated the use of inboard rod ends instead of outboard. My last idea was replacing the bottom caps that hold the rubber bushings in place with fabricated caps that were in essence "blocks" with a hole in each one that allows a long 3/4" rod to be inserted through both "blocks". this rod would pass through the rod ends as well. A spacer tube between the two rod ends would insure the rod ends always stayed the same distance relative to each other and that forward thrust torque would be distributed evenly between the two rod ends. One advantage to the inner rod end option was the spacing between the rod ends was almost double the distance verses using outboard rod ends, thus the minimum incremental adjustment was half of the outboard design, making toe adjustment more attractive. Quote Link to comment Share on other sites More sharing options...
jeromio Posted December 11, 2003 Share Posted December 11, 2003 I have a completely different idea inspired by a member here (whose name escapes me but his car was published in SportCompact). I would like to leave the control arms alone, but get some toe adjustability (because for whatever reason, my car is tweaked out of alignment back there and it's too squirrely). So, I am considering making the rear transverse 'bar', that folded steel piece of metal that caps off the pivots for the rear bushes and rides right behind the diff cover, adjustable. I would like to cut out a section and replace it with a turnbuckle. The upper part is the head scratcher. I could just oval the holes in the vertical plates where they attach to the frame. But then adjustment would require loosening the 4 bolts and then taking care to make sure those verticals slide in (or out) when adjusting the turnbuckle. I don't think making a pivoting connection for those would be a good idea - unless it could be rigidly fixed in place. Kinda stumped. Seems like an easy way to gain the adjustability I need - just modify one easy to remove and replace part. But there is this one puzzler.... Quote Link to comment Share on other sites More sharing options...
JMortensen Posted December 11, 2003 Author Share Posted December 11, 2003 3/16" toe in is really not that much. If memory serves, it's within factory spec. On the racing Porsches I used to set up, we ran as much as 3/8" total, but as I've said before, driving a 911 is like throwing a dart backwards, so anything that keeps the @ss end behind is a good thing. I can run on one set of slicks for an entire season of autox and about 3 track days. Jeromio's idea is interesting too, but you'd also have to space the turnbuckle away from the back of the diff. I'll have to have a closer look at that one... Jon Quote Link to comment Share on other sites More sharing options...
blueovalz Posted December 11, 2003 Share Posted December 11, 2003 In regard to Jeromio's thoughts, since in his idea (which is a good one) bolts must be loosened and retightened, then how about modifying it a bit. Using two transverse links, cut and modify each of them so that a single link is created by two mating halves that are held together by a couple of bolts placed within overlapping slotted holes on each half. This transverse link is held onto the uprights from holes in the vertical sides of this link, which gives them enough room to be slotted as well. To adjust, loosen the two bolts in the center of the link, and one side of the upright-to-link bolts, slide the half-link (lengthing or shortening) just a bit, and then tighten down on all four bolts (nuts back-welded to ease the job) making the link rigid once again. In my case where the uprights are replaced by one large single plate with no need for a transverse link, I can simply slot the holes of the "saddles" and move them independently. Quote Link to comment Share on other sites More sharing options...
jeromio Posted December 11, 2003 Share Posted December 11, 2003 Heeey. I think I'm catching on. So the uprights stay put. Preferably with a welded cross brace for stability. Then the strength of the turnbuckle, or whatever adjustment mechanism is used (tie-rod adjuster?) is not an issue. Especially if an all out TerryO one piece upright setup. This looks do-able. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted December 11, 2003 Share Posted December 11, 2003 Exactly, and the upright crossbraced bar is a good add-on as well. I looked at these pieces, and without any work other than slotting the holes, the parts have enought margin to move 1/4" across the uprights easily. The most complicated part will be mating the two sliding half-links together so they function well, and look good. but that not a big deal. A welded piece of angle on one halve can be bolted to the other half to make them slide in and out relative to each other along slotted holes. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted December 11, 2003 Author Share Posted December 11, 2003 Not sure I'm following Terry's idea fully, but if I have it right in my head it is a pretty good one. I don't understand how you would use a turnbuckle in addition to the slotted holes, unless you were to weld a RH and LH nut onto the left and right hand side of the link on the back of the link with the turnbuckle in between, and slot the right and left sides along the flat area along the bottom. Use a very small turnbuckle like the ones used in the Mike Kelly control arms??? I think that would work. Is that pretty much what you guys are saying??? Jon Quote Link to comment Share on other sites More sharing options...
jeromio Posted December 11, 2003 Share Posted December 11, 2003 One way to think about it is this: imagine your uprights are stable and strong, independent of that stock cross brace. Further imagine that the stock cross brace is not even used. Instead, in order to complete the bottom of the pivot holes for the rear control arm bushings, you use the same little metal brackets as are used on the tops of the pivot holes. Except that thes actually bolt to the uprights. These lower holes of the uproghts are ovalled to allow for side to side adjustment. So now, in order to make sure that the to pivot hole bushing holders don't manage to slide back and forth (since bolt clamping friction will not be sufficient by itself), you connect these 2 by a turnbuckle. Or some other adjustable mechanism. I am definately gonna be doing this mod. Quote Link to comment Share on other sites More sharing options...
Tim240z Posted December 11, 2003 Share Posted December 11, 2003 Or something like this: Tim Quote Link to comment Share on other sites More sharing options...
Mikelly Posted December 11, 2003 Share Posted December 11, 2003 Gentlemen, the simple answer here is the use of a manufactured turnbuckle like the units I had made for my control arm packages. I believe that these would be a great part that should be a common and available part in many sizes... Sure would be nice if a manufacturer would make them... Hmmm.... Click whir, Click Whrrrrr Mike Quote Link to comment Share on other sites More sharing options...
JMortensen Posted December 11, 2003 Author Share Posted December 11, 2003 Jeromio, That's what I was thinking. I like this idea A LOT. I think I will do it too. Should be even easier than the threaded end on the control arm. I think that the compact turnbuckle that Mike Kelly suggests would be easy to make work with the RH and LH nut idea. Jon Quote Link to comment Share on other sites More sharing options...
jeromio Posted December 17, 2003 Share Posted December 17, 2003 I may have found a source for turnbuckles. It's a boating hardware supply place: http://www.suncorstainless.com. They have some nice looking turnbuckles in stainless steel, either forged or welded. They even had a "clearance" section with prices. I sent an email to see if it's possible to order stuff via CC (since it seems as though they mostly deal with re-sellers). I'm after this unit: with 1/2 inch threads it is just the right size. I am a bit worried about one aspect of this concept however. Adjusting the one pivot will make the arm arc over on the front pivot, moving the wheel forward or back within the wheel well. Edit: Added this diagram: Quote Link to comment Share on other sites More sharing options...
Mikelly Posted December 17, 2003 Share Posted December 17, 2003 Umm, THAT is NOT designed to be load bearing... The turnbuckle I had made for my arms is essentially 1 inch hex stock steel that has left and right hand 3/4 16 threads cut. Mike Quote Link to comment Share on other sites More sharing options...
blueovalz Posted December 17, 2003 Share Posted December 17, 2003 True, but I don't think the amount of change is going to be visually apparent. Being the arm is about the same length as the distance between the two supporting bushing, then an 1/8" change at the turnbuckle should only push the wheel forward or backward by about the same amount. Mike, I think his idea using the turnbuckle was simply for ease of adjustment and that once the adjustment was made, then the bolts holding the bushings would be cinched down tight. If I understand the direction of this string, he wanted a screw type of adjustment when the bolts were loosened instead of having to tap it left or right with a hammer until it was "right", before re-tightening the bolts. Quote Link to comment Share on other sites More sharing options...
jeromio Posted December 17, 2003 Share Posted December 17, 2003 What Terry said. It doesn't need to be load bearing (although this unit is rated for like 2400lbs of stretch). The turnbuckle is there to make fine adjustment easier and also keep the geometry correct. Without the turnbuckle, the pivots would be held in place only by the friction of the bolts, which I don't think is adequate. The problem with adjusting toe this way is that the angle being adjusted is the really big one formed by the 2 long lines: pivot to spindle pin and pivot rear to pivot front (bushing ends of control arm). So it takes a big change in my proposed adjuster to cause a noticeable change in toe. I'm guesstimating it's a 1:2 ratio. IOWs, about 1/2" adjustment by turning the turnbuckle and you see about 1 degree change in toe - and the wheels move about 1/2inch too. I still think it's worthwhile, if only because it shold be a very easy mod. Much easier than making adjustable control arms. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted December 17, 2003 Share Posted December 17, 2003 As with my setup where I use a large single plate instead of two smaller uprights. But in reference to the amount to be adjusted, I don't think you'll need as much as you think. If there is, for example, 13" between bushings (and I have no idea the exact length here) and you want a 1/4" difference in toe-in adjustment, then a 1/8" change at rear bushing mount would give you this 1/4" change at the tire (based on a 26" tall tire and based on my assumption that toe is a measured difference between the front and rear treads of the tire). According to my rusty trig, that's about .55 degrees change (.125" by 13") Quote Link to comment Share on other sites More sharing options...
Mikelly Posted December 17, 2003 Share Posted December 17, 2003 OK Terry, I'm tracking with you now... For a TOE only adjustment (Which is what a lot of folks look for) that would be perfect. Mike Quote Link to comment Share on other sites More sharing options...
JMortensen Posted December 17, 2003 Author Share Posted December 17, 2003 Why don't you just use a rod end sway bar end link Jeromio? I happen to have some 5/8" tap tube, so I was thinking I'll do a 5/8" rod end, possible sleeved down to a 1/2" bolt. That turnbuckle you've got just doesn't look like it should be on a car. It looks like something that fisherman attach to a scale to weigh their haul. Jon Quote Link to comment Share on other sites More sharing options...
jeromio Posted December 17, 2003 Share Posted December 17, 2003 I don't want to have to remove the thing to adjust it, so I need a turnbuckle. I could use something like a tierod from a straight axle truck. Something with a half right thread, half left thread, wrenchable hex in the middle, and then 2 pieces of tubing, one with female left threads, one with female right threads. Haven't found that yet though. Here's a representation: Quote Link to comment Share on other sites More sharing options...
JMortensen Posted December 17, 2003 Author Share Posted December 17, 2003 Yeah, that's what I'm talking about. I have tap tube, which is what they use to make tie rods on circle track cars, and LH and RH 5/8" taps. Then you just plug a rod end into either end, and twist the middle to expand or contract. What you've got would probably work, but as you stated, it is designed for tension because it is a piece of rigging or netting for a boat. It's not that it wouldn't work, but it definitely looks out of place and if something happened to your lock down bolts on the uprights that thing would fold pretty quickly I think. Jon Quote Link to comment Share on other sites More sharing options...
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