Weld-in e30 adjusters question

[drken]

I am considering adding the weld-in rear suspension adjusters to my e30 race car. I currently have the eccentric adjusters, but find it annoying to have what I desire as a single adjustment (camber) affects toe to some degree as well. I have read that the weld-ins tend to go out of adjustment fairly easily, in part due to the off-axis alignment of the two bushings.
So, my question is this: Why not just add the adjusters only for camber, and leave the toe adjustment side at (or very close) to stock? I have found on the net a page that shows that toe changes very little with ride height changes in this car (until you get to extremes). I am assuming that the "inner" bushings are adjusted for camber, and the "outers" are used for toe.
I also assume a small amount of reaming could be done to the toe side bracket holes to allow the camber adjustment to be made, in order to allow the two bushings to share a common axis. I also assume that a rough concensus could be reached on what the desired (non-adjustable) toe setting should be. Say, 1/8" total toe, measured with toe plates.
Does anybody know if the stock bolt position would result in that setting, or would the fixed toe bushing position need to be adjusted to the plus or minus side?
What say ye?
Of course, I'd like to do the job only once, but I realize I could answer these questions by actually doing the inner adjusters, then bolting things back up, then re-check alignment with the car back on the ground. Only bummer is, if any changes would be needed for the toe, the whole subframe would need to come out to make any changes.
Thanks for any insights!
Ken

[RangerGress]

You should discuss this at SpecE30.com. There's more folks there that have spent time installing, modifying and discussing this. You raise a lot of issues and I'm going to miss some so ask away when I've not answered something completely.

Toe doesn't change with normal amounts of spring compression. I tested this darn rigorously.

Installing only a camber adjuster and doing nothing for toe is not crazy. Everything is a trade-off tho. Installing a toe adjuster helps get the two pivot points coaxial, even if you don't change your toe setting. The OEM "ears" don't allow the bolt to move any and the weld-on kit does. You control the extent that the allowed movement takes the pivot points away from or towards coaxial. With some cleverness you can use that to your advantage to get the toe and camber you want while minimizing toe.

Weld-on kit not staying put. We knocked around a number of theories on this. The best theory I heard said that when the spring fully compresses the wheel puts huge stress on the rtab ears and that's the cause of movement. Our springs are already mostly bound up so full compression happens easily. My personal solution involved welding something to the "weld-on" adjuster's eccentric such that the eccentric couldn't move unless I wanted it to. Note that a couple outfits have come out with new weld-on adjuster kits that are much less likely to allow the eccentric to move. IE and TC Motorsports.

I know of no reason to believe that spring compression increases the off-axis stresses. Therefore if the trailing arm seems willing to be set to a certain position, using eccentrics at the rtabs, it ought to be willing to stay there. The exception was discussed in the previous paragraph. My point is that it might not be the "off-axis" that creates problems, but simple the bound up springs. Folks with coilovers don't have this problem because their springs are not only in a different place, but also aren't mostly bound up in the paddock. In a perfect world SpecE30 would be running an inexpensive coilover and not H&R Race springs.

Your toe reaming idea is good, but making the rtab bolt stay put might be a challenge.

I'd go with neutral or 1/16th total toe in the rear. 1/8th is a lot for a 150hp engine.

The fixed toe setting ought to be ok as you described, but note that you can play with this with the subframe off of the car. As long as you have the trailing arms at something reasonably close to normal, you can experiment with toe ideas and find a winner before you put the subframe back on the car. This is a helova lot more convenent that R/Ring the rear subframe 4X.

[tigruppe]

I used the IE kit and never had it move on me. I also would put in all four of the adjusters because as you rotate the bolts you find that both affect the toe and camber

[thejlevie]

Having both adjusters also allows for correction of toe (within limits) when the trailing arms get bent. They are slightly stiffer than wet spaghetti. One good off track can be all it takes to knock in a bit of toe in or toe out on one side. A thrust angle from unequal rear toe make the car a real handful.

I have weld in adjusters on my Spec E30 and after fighting with the toe adjusters moving (and having the toe adjuster bolts loosen or strip) I formed a theory as to what happens. The camber adjusters have never been a problem on my car. My theory is that the acceleration and braking forces along with movement of the trailing arm imparts rotational forces on the bolts. That in turn causes the nuts to loosen and thus allows the toe eccentrics to move.

My fix for this is a two part solution. First I made new eccentric adjusters using 12-point aircraft bolts & nuts, which are stronger than grade 8 fasteners. To keep the bolts strong I only used an eccentric on the inboard (bolt) side. Then I made up what amounts to jackscrews for the toe bolts using 1/4" drive 12 point sockets, some flat pieces of steel, threaded rods, and jam nuts. The anchor for the threaded rods is welded to the subframe and the socket fits over the bolt head, preventing the bolt from rotating.

The toe locks can be seen in the attached images.

After installing the toe locks I've not seen the toe adjusters loosen or move. Before that I found it necessary to reset toe and tighten the adjusters after every race. Any pray that they didn't come loose during a race, which had happened on occasion.

IE has a new design for weld in adjusters which should help prevent then from moving. But it looks to me like accurately adjusting toe and camber with those may be a problem.

[Irish1]

You might also post your question on E30Tech. Lots of sharp racers there that have worked through the eccentricities of the E30 chassis.

[cosM3os]

You might also post your question on E30Tech. Lots of sharp racers there that have worked through the eccentricities of the E30 chassis.

That'd be nice if they'd actually activate your account when you register.

Ken, is your 3.73 and spec exhaust installed yet? You need to do that before the adjusters.

[robjohnson]

The reason you don't do just camber is this mod is a PITA so you might as well do both at the same time in case you ever need the adjustment in the future.

The reason these loosen up is soley do to ill fitting bushings. Precisely fitting the bushings to a center sleeve of proper length is key. I hand fit the bushings and have never had a problem. When I first installed bushings as they came off the lathe without grinding the sleeve, or cutting the sleeve, at the proper length I had too problems. Firstly I had excess friction on the trailing arm that resulted in uneven weight transfer dynamically. I figured out my drivers side rear would bind upon droop travel in braking causing me to look the right front prematurely. Secondly you don't get an even clamping force from tightening the bolt. You end up overtightening the bolt, or the steel on the tabs galls and you get loosening pretty quickly. I have prepared a car with custom fitted bushings and the bolts loosing torque hasn't ever occured. The key is sanding the bushings down a bit so their total installed width when pressed into the arm is slightly less than the total length of the center sleeve.

I also recommend going to sears and getting two 18 or 19mm box wrenches, whatever the size is I forget at the moment, and grind them down for easy access to the bushings near the subframe mounting bushings. If you grind the wrenches down a bit you can slide them in there easily for adjustment.

My theory is that the acceleration and braking forces along with movement of the trailing arm imparts rotational forces on the bolts. That in turn causes the nuts to loosen and thus allows the toe eccentrics to move.

I think you are exactly correct, reducing friction is the key. And also fitting the sleeve to bushing width accurately. I know a somebody running spec e30 with a custom set with oiling gooves and thrust plates. He may pipe up later but after a certain number of events for testing he will probably offer them for sale.

[ncoker]

I used the IE kit and never had it move on me. I also would put in all four of the adjusters because as you rotate the bolts you find that both affect the toe and camber

Same here. 3-4 years of racing on IE kit and never had any problems.

[JS154]

You might also post your question on E30Tech. Lots of sharp racers there that have worked through the eccentricities of the E30 chassis.

You can do the adj camber toe plates or go full boat like this>



http://www.s14.net/forums/showthread.php?t=54398

[drken]

That'd be nice if they'd actually activate your account when you register.

Ken, is your 3.73 and spec exhaust installed yet? You need to do that before the adjusters.

Yeah, yeah, I know...
Ken

Jim,
I hadn't thought of the potential need to adjust for bent trailing arms, etc. That alone is probably reason enough to do both adjusters. I also like your bolt locks. I assume you don't adjust anything with the threaded rod. Just use them to pre-load against the "back-off" direction of the bolts? Pretty clever!

Ranger, thanks for the input on the toe. Is that pretty much the concensus? You mentioned the Spec E30 site. That is what got me started on this thinking, and I just thought I'd toss it out to a wider audience.

Finally, Rob, is the length of the bushing and sleeve just tailored to the width of the bracket they fit into, or is it a matter of "just so much" difference in length between the sleeve and the bushing? Or both, perhaps?

I appreciate all your help, guys!

Ken

[Z3SpdDmn]

The reason you don't do just camber is this mod is a PITA so you might as well do both at the same time in case you ever need the adjustment in the future.

This ^^

[thejlevie]

Yeah, yeah, I know...
Ken

Jim,
I hadn't thought of the potential need to adjust for bent trailing arms, etc. That alone is probably reason enough to do both adjusters. I also like your bolt locks. I assume you don't adjust anything with the threaded rod. Just use them to pre-load against the "back-off" direction of the bolts? Pretty clever

Correct. I set the locks after setting the alignment just to keep the bolts from rotating.

Another advantage of the 12-point fasteners is that the nuts are much smaller that conventional 6-point nuts. That is a plus when it comes to the outboard nuts of the toe adjusters. It is much easier to fit a 9/16" wrench in between the subframe bushing and the trailing arm.

[albrazzi]

I have done considerable research on this lately and:

1) Most I have read on the eccentric kits is the machined ears are better for holding adjustments than the bent ones. Although there are some E30 racers who will not use them no matter what.

2) The eccentric bushings are generally not acceptable to anyone.

3) Any attempt to adjust without a good idea of what you are adjusting out will surely only frustrate the process.

4) Anything can be bent pushed etc. and all things being equal you will benefit more from new parts even OEM than adjustment kits. Trying to adjust to bent stuff no matter how enevitable is not as good as not bent stuff.

5) It is only new once without some adjustment you will probably not get everything just right without the adjustments added.

6) You can only adjust so much out and without some ability to measure outside the car it is VERY dificult to determine which components are out of spec and create the adjustment range needed to correct.

7) Some people want to add Camber, some want to lessen Camber, so it is even more important to know what your goals are and how to set up to acomplish this.

8) IE has a new Posi-Lock adjustment kit which has a lot more range to it but because of the inhereant misalignment adjustment creates it is not likely you could use much of the available range and a few kits are being installed now so we will see how effective they will be. Note the kits will need modification in Z3s to clearance the fuel tank. Although these will surely stay in adjustment it apears adjustment may be more difficult in the car.

I conclusion; I have built a bench Jig to set up and measure everything out of the car and I can tell you I have found bent ears on the Subframe, bushings pushed to one side, bent trailing arms, and with that the variables of subframe bushings and whatever else might enter in and you can see the dificulties of setting up adjusters blindly. With a proper set up and some digital levels you can get some pretty good results setting up out of the car.
Couple that with the dificulty of alignment unless you have your own rack(some do) or a string setup which I am working on also you can really chase your tail to get everything just right.
I think Toe plates are good in the field but you are measuring the tire and not the rim.

Cheers..AL

[RangerGress]

This was my solution to keeping the eccentric in place. I reamed out the threads of a 6mm nut so a 5mm bolt would move very freely inside of it. Then I welded the 6mm nut to the top of the eccentric. A small plate gets welded to the front of one of the "ears" and the 5mm bolt goes thru the plate.

Once the alignment is set I tighten the 5mm bolt such that the eccentric is not allowed to back off.

I only had one adjustment point that was moving on me....Right Toe. Only a couple laps were necessary to make it move.

Re. removing a little bushing material to ensure inner shaft protrudes. That's good info, thx.

Re. albrazzi's informative post. That too was good info for the community, you the man.

A couple issues that didn't get discussed:
Ensure that the bushing rotates freely on it's inner shaft before you install. You may find that you have to remove a little material from the shaft first.

There is a debate re. the bushing material for the weld-on kit. Soft OEM bushings would offer more compliance for off-axis movement and reduce stress. Harder bushings keep things located better. I decided to go with hard bushings because the idea of "more compliance for off-axis movement" seem to me to be synonmous with "keeps suspension located properly.....except when you use it".

[tigruppe]

I consider myself real lucky that all mine stayed where they were set and my last car saw more stress and probably more track time than most that have posted here.

Eric,
Is that your rear assembly? I had seen pics of something similar from Germany. I like the aluminum blocks for the calipers that allow the bigger calipers and vented rotors.

[drken]

This is all great info. I appreciate all the tips, as it will definitely be easier to incorporate these ideas while everything is out of the car and clean. Do it once, and do it right....
I am confident in my ability to align. I've got a nice flat floor in my garage, and have aligned my own street and track cars for years with good results. I was really concerned with getting that (non-adjustable) toe setting right to begin with, but with the decision to go adjustable, I can start with Ranger's suggestion and adjust as needed from there.

Ken

[tigruppe]

One bit of advice is to have an alignment check bfore you remove the subframe marking where the bolts are. On my first shot of installing the tabs I just put the middle of the slot where the bolt hole was which did not allow enough room for my camber adjustment which lead to grinding everything off and a redo. I had the car aligned on a laser alignment machine made the marks removed the subframe marked where the hole elongation needed to be and started grinding.

[thejlevie]

One bit of advice is to have an alignment check bfore you remove the subframe marking where the bolts are. On my first shot of installing the tabs I just put the middle of the slot where the bolt hole was which did not allow enough room for my camber adjustment which lead to grinding everything off and a redo. I had the car aligned on a laser alignment machine made the marks removed the subframe marked where the hole elongation needed to be and started grinding.

There is another way to fix that. You can put the car on a frame machine and bend the trailing arms. That can also be a fix for slightly bent trailing arms.

I set my camber adjusters to the max and had a frame shop "adjust the trailing arms" for ~4deg of camber.

[MAkard]

You can do the adj camber toe plates or go full boat like this>



http://www.s14.net/forums/showthread.php?t=54398

Looks like a lot of overkill bracing there?

[albrazzi]

This was my solution to keeping the eccentric in place. I reamed out the threads of a 6mm nut so a 5mm bolt would move very freely inside of it. Then I welded the 6mm nut to the top of the eccentric. A small plate gets welded to the front of one of the "ears" and the 5mm bolt goes thru the plate.

Once the alignment is set I tighten the 5mm bolt such that the eccentric is not allowed to back off.

I only had one adjustment point that was moving on me....Right Toe. Only a couple laps were necessary to make it move.

Re. removing a little bushing material to ensure inner shaft protrudes. That's good info, thx.



Re. albrazzi's informative post. That too was good info for the community, you the man.

A couple issues that didn't get discussed:
Ensure that the bushing rotates freely on it's inner shaft before you install. You may find that you have to remove a little material from the shaft first.

There is a debate re. the bushing material for the weld-on kit. Soft OEM bushings would offer more compliance for off-axis movement and reduce stress. Harder bushings keep things located better. I decided to go with hard bushings because the idea of "more compliance for off-axis movement" seem to me to be synonmous with "keeps suspension located properly.....except when you use it".

Thanks for the kind words, I spent almost a whole day reading all I could find and it really plugged some gaps for me.
I am toying with an idea to just cut a big hole in the subframe tabs to allow for two dimensional adjustment in both pivot points and machining a plate with a step that would sit inside the big hole and maintain the bushing length so it squeezes the bushing steel sleeve and just move both within the hole in the subframe, this way not misaligning the bushings at all, while giving some adjustment at least untill it is welded.

Being able to put them where you want to would add some value, but without the ability to adjust in place. Not sure about this one yet.

[drken]

I just got turned on to the IE "toothed" (I think they call them Posi-lock) adjusters for toe and camber. That looks like the way to go for me. I think a couple of you guys may have alluded to these, but at the time, I assumed you were talking about the older style that use eccentric adjusters. Thanks for your input everybody!

Ken

[albrazzi]

I just got turned on to the IE "toothed" (I think they call them Posi-lock) adjusters for toe and camber. That looks like the way to go for me. I think a couple of you guys may have alluded to these, but at the time, I assumed you were talking about the older style that use eccentric adjusters. Thanks for your input everybody!

Ken

I am installing them now and some others have also. Be carefull with clearance especially the fuel tank, on the Camber adjusters there is way more scope in these guys than you will ever need, and the outboard bushing will be trimmed a good bit if you go Poly, OEM maybe not but it seems nobody even uses the OEM subframe bushings anymore at least among the Forums.

[drken]

I am installing them now and some others have also. Be carefull with clearance especially the fuel tank, on the Camber adjusters there is way more scope in these guys than you will ever need, and the outboard bushing will be trimmed a good bit if you go Poly, OEM maybe not but it seems nobody even uses the OEM subframe bushings anymore at least among the Forums.

I'll be sure to check that. Thanks for the heads-up!
Ken