Unable to adjust camber koni strut, '66 911

[oscillon]

Hey All,

The full story is tedious, but let me set this up a little. '66 coupe with all new suspension components all around. e.g. new bushings, new Koni inserts front and new koni shocks rear. Long and short of it, the components are refreshed and done "properly" by a very reputable shop. The final alignment, not so much.

So here is the problem...

I was going over the car the other day and I noticed there was some very bad wear on the front right tire. Essentially, a lot of negative camber that resulted in the harsh wear pattern (no tread on the inside to full tread on the outside). All of this done within very few miles. If it's important to anyone the tires are Vredstein sprint classic 165R15 on steel wheels. I took the car to a qualified shop that performs alignments on early porsches and the mechanic told me that it was already at the maximum of the positive side of the camber adjustment as is, remaining very negative, and therefore completely un-alignable.

I took the strut off and crudely compared the spacing between the insert tube and the cast piece at the base (the spindle) and found that distance to be much smaller (indicating an increase in the negative camber) as compared to a few other Boge struts that were available to compare to; to the tune of 3+ mm. Indicating that the strut was damaged at some point in the car's history.

Now, my problem is that I would like to keep the car as original as possible, which would mean finding a koni (tapered) strut tube/spindle. This may be possible, and someone here may have one (hint hint). But what I'm wondering at the moment is: Is it possible to correct the strut tube to spindle distance without sacrificing the integrity of the strut? In a sense, reversing the damage.

[Flieger]

People like Clint at Rebel Racing can and do change the camber on the spindle for racers. This would be the same type of process. Just make sure you know they want it to look original. It will involve cutting and welding.

[oscillon]

Thanks for the tip. I'll get in touch with them.

Dan

People like Clint at Rebel Racing can and do change the camber on the spindle for racers. This would be the same type of process. Just make sure you know they want it to look original. It will involve cutting and welding.

[304065]

I don't understand your point about the spacing. Are you saying the tube is bent or the spindle is bent toward the tube?

I scored an early strut alignment jig a few years back and I gave it to Damon at Series900. Using this jig you can determine whether the strut is bent. You might reach out to him and see if he'll measure yours and bend it back.

[oscillon]

I don't understand your point about the spacing. Are you saying the tube is bent or the spindle is bent toward the tube?

I scored an early strut alignment jig a few years back and I gave it to Damon at Series900. Using this jig you can determine whether the strut is bent. You might reach out to him and see if he'll measure yours and bend it back.

The angle between the tube and the spindle is smaller than what it should be (presuming). Making the setup have a larger negative camber.

I saw your post with the picture of the jig from a while ago, that might be a definite possibility. I'll get in touch with him too.

Thanks!

[oscillon]

Hey All,

I just wanted to update my own thread as I find it unsatisfying to find a dead thread on a topic that may pertain to me. First and foremost, my original assessment of the issue (bent spindle) was completely a boondoggle. Below outlines the real issues and a "solution".

After a lot of thought and plenty more spent than intended, I finally had my car looked at by another mechanic that has a lot of experience on setting up suspensions on track cars. I figured he might be able to shed some light on the complete lack of drivability and mad tire wear on my front right.

Long story short. I think that the car has experienced two issues in the past. One is that it must have received a shunt to the front right, that was followed by a lower pan rust repair that didn't necessary preserve/correct the geometry of the front suspension components. In the end, this resulted in the ~3deg of negative camber at the full positive position on the upper strut adjustment. i.e. totally whacked and unadjustable.

This meant two solutions were considered. One: cut away at the upper strut mount inside the trunk; to me this seemed to only accentuate the botched aspect of things. Two: take the solution to the lower control arm by slotting the mounting holes for the lower ball joint (see pictures below). Well, after some debate and testing, we decided that the latter was slightly better as a temporary fix. As a result, we were able to put the camber back into the "proper" range for a SWB car (slightly negative, close to zero). Luckily, the caster, although very oddly adjusted, was also in the acceptable range.

The overall result, with some tweaks to the rear suspension camber/toe is a transformed ride! I actually can drive this car with a genuine smile on my face knowing that it's handling like it should be. Prior to this, it always felt as though the car was driving itself and I was simply along for the gas/gear/stop. As such, this car always let me down in the drivability and handling characteristics. Being that it was my first ever Porsche, and knowing the rumors that the SWB cars can be a "handful", I was never really sure that I knew how it was supposed to handle. Well, now I know. It's amazing what proper alignment can do for the driving experience.

So, I have to thank a few folks (as a way of plugging them)

Taylor Chapman (http://www.taylorchapman.com). Honest and responsive guy with a lot of experience (owns a '72). Located in NOVA
Elephant racing (http://www.elephantracing.com). They were extremely helpful with providing the motivation for slotting the lower ball joint.

Here are a few pictures of what we did:

[304065]

Thanks for bringing this full circle. I guess whoever did the pan installed it too far outboard? That would put the control arm too far out which would give you excessive negative camber even with the strut top as far out as it will go. I am wondering how they could weld it in that position- it's like a bathtub up there, and the vertical fender should hold the pan inboard. Maybe they replaced that too?

In any event, glad you have a working solution. Those lower control arms are pretty stout and there are TWO M12 bolts holding the whole thing together. Does the ARB clear OK, it's going to be pointed further in at the bottom now.

[oscillon]

Thanks for bringing this full circle. I guess whoever did the pan installed it too far outboard? That would put the control arm too far out which would give you excessive negative camber even with the strut top as far out as it will go. I am wondering how they could weld it in that position- it's like a bathtub up there, and the vertical fender should hold the pan inboard. Maybe they replaced that too?

In any event, glad you have a working solution. Those lower control arms are pretty stout and there are TWO M12 bolts holding the whole thing together. Does the ARB clear OK, it's going to be pointed further in at the bottom now.

Yeah, not sure what actually happened down there. It seems a number of bad locations conspired to set the right side completely off. The amount needed at the bottom wasn't onerous, and the anti-roll bar seems to be free an clear. So, fingers crossed, one less thing to worry about. Come on summer!

[304065]

That is good news. When I put the suspension together for '065 I did it myself with string and an iPhone level. While this got it going down the street straight, when I finally had it aligned the sensation was much as you describe . . . "Hey, this car drives like a . . . .Porsche!" Good luck and enjoy.