rusnak

History:
I have been making adjustments to the rear after installing the Neatrix rubber bushings. I found that the bushings will not stay glued onto the spring plates. When they broke free from the springplates, they turned and the spring assist effect was lost. The spring arms did not "spring back" to original ride height, and the suspension "sagged". I compensated by increasing springplate inclination by 15mm or 1.7 degrees. This was not enough, and I need to increase ride height even more to get the torsion bars to be pre-loaded so that they fight the resitance of the Neatrix bushing, and return to normal height.

Adding all of this pre-load increases "negative camber". At this point, without using the eccentric camber adjustment, the rear wheels will now sit at negative 3 degrees. Prior to this, with factory spring plates, and with the eccentric bolts not yet installed, they sat at negative 1 degree.

Problem:
I think the eccentric bolts will only give me about 1.5 degrees or so of camber adjustment.

Question:
Can I use the washers on the two rear springplate/swingarm bolts as "shims" to assist camber adjustment?

I'm not completely clear on how the camber eccentric bolt works, so I don't know if shimming the springplate will fight the eccentric bolt, or vice versa. Is this a bad idea? Too much torque and not enough structure?

Basically, I'm using the eccentric to adjust the rear wheels from a natural position of negative 3 degrees to about 2 degrees negative. I'd like to get 1.5 negative or 1.2 negative, so I need to get .5 degrees more postive camber. I guess I'm saying I need to increase camber.


The other possibility is to increase torsion bar thickness, and go back to stock pre-load, which may help me get normal .45-1.5 negative camber adjustment.

Any thoughts? Recommendations? Can I use the washers as shims? Say I get two hardened washers that together are as thick as the stock single washer? Can I put one inside and one outside, thereby shimming the upper of the two mounting bolts?

Amber Gramps

The eccentric bolt rotates the banana. The banana face is angled where it hits the spring plate and as you rotate the eccentric you rotate the banana and that changes your camber.....oh screw it, I don't know how to say it. No is the anwser to your question...


....All I know is that as I rotated my eccentric I was able to go from way too much neg. to just past pos. and doing so dropped the back end of my car in the process. in other words my tail is lower at neg 1.5 than it was at neg 2.5.

Ed Hughes

To me, it sounds like you're going down a bad path. The problem all stems from the Neatrix bushings; any jury-rigging to compensate for problems with those is just asking for issues. I've not read much good about these anyway, why not go for a set of PB's or Chuck's rubber bits?

If this was a Hyundai you were trying to make right, I'd say shim away, but its a Porsche.

rusnak

Yeah, I think you guys are right. I think the Neatrix bushings are like a 70's style MG Mitten funky mod. One of the problems is definitely friction. A really bad road like Hwy 41 on the way to the central coast might pitch me right off into the weeds.

I bought Chuck's rubber for the front, but I had the Neatrix bushings lying around since around 2002. I think it's time to call Elephant again. Chuck's rubber bushings are working well on the front. Very well, in fact.

Anyway, here's what I've got right now, thanks for talking me away from the window ledge, guys!!

TT Oversteer

That doesn't look like anywhere near -3 degrees rear camber to me. How did you measure it? My car came with Neatrix and when I took it apart they were spinning freely on the spring plates. They were either never glued or the glue failed. I'm just now finishing up the PB installation and I'm very happy with the ride quality. Not harsh at all and no squeaks. It took some patience to set up correctly but there is absolutely NO binding or stiction on my rear suspension. However, having done the PB installation I do understand the positive attributes of rubber. Problem with PB is you are installing a precision bearing into a non-precision hole and it takes a lot of fiddling to do it correctly. Rubber accepts a large variation in mfg. tolerances and doesnt squeak or need lubrication. I don't think Neatrix is the right solution but maybe Elephant's rubbers are better. PB is awesome but installation can be tricky and there is maintenance required for the life of the car. I agree with the above.........don't mess with the eccentrics or any shims. Do it right!

Amber Gramps

Not exactly the high tech method you were hoping for, but holding my 9" HUSKEY up to the computer it looks like 4neg (I'll now and forever be known as the idiot cambermeister) Of course all the magnetic rainbow lines are really hard to see through, but what the heck.

Is that the maximum amount of camber you can dial out? If so, It may be time to dial down eccentric #18 and see if that will give you more rotation of the banana. It is the relationship between the spring plate and the banana that gives you camber so if you can't get all that you need from one you are going to have to use both. You will throw off your ride height and you may have to re-index the T'bars, but that is half the fun. good luck, you are doing great.

rusnak

TT, you are correct. I had neg 3 before dialing it out. Yes, DB this is the max that I can dial out. It's about 2 degrees right now. Actually around 1.9 negative. I'd be happier with 1.2-1.5, so that is my goal. Eccentric #18 is ride height. I've been increasing ride height for a few days now. The Neatrix does not rotate freely on the left side, so it is experiencing sticktion.

Yes, I think it is time to try Elephant rubber on the rear. I have a second pair of spring plates (the original ones are now out of the car). It's standard for me to buy parts in advance, since I prefer to have them ready to go before I remove the original ones. So I need to get out the Mapp gas torch and have at them. I think I'll try torsion bars from an '86, which should be 25mm, according to the above diagram. I should be able to keep my Bilstein HDs but may have to go with stiffer front springs.

rusnak

More pics as a "thank you" to you guys.

Front suspension

Ed Hughes

A happy pup! I have a happy one too, he's always smilin'.

Yikes, that brings back some memories. One weekend, the front. The next, the rear. The single toughest thing I've ever done with my car was removing the rear bananas to put the monoballs in. It was a 4 hour battle to get the first one off. I'd walk away to avoid kicking the side of the car from time to time. But once I figured out how much leverage I needed to break those effin' bolts loose, and then made the contraption to do it, the second only took 15 minutes.

rusnak

That settles it. I'm not going to touch the bannana.

Ed Hughes

Well, I was glad I changed them. I don't think all are as hard to remove, who knows?

It really took a fairly long breaker bar, then a HEAVY combination wrench looped over the end using the kink in the box end to angle the wrench up away from the floor, and then a 24" cheater pipe on the end. Literally about a 4 or 5' lever arm.

The rest of the job was a cakewalk, relatively speaking.

rusnak

I have several 4' breaker bars made from 1/4" boxed steel. If I wanted to, I could weld them together and make a 8' breaker bar. I need to buy a heavier 1" drive ratchet wrench though. I use the heavy stuff on the big equipment like tractors and the disc. Those things stay outside year round and get rusty.

We should start a thread "The hardest job I performed on my 911 was....." The answers could be very interesting.

dshepp806

an 8 ' breaker?,..you're not messing around are you, Rusnak?

(heheheeh)


Doyle

Amber Gramps

Hold up Rusnak, now you're just screwin' with my head. What's with the coilovers?

I'm new, but I ain't that new. I sure don't remember seeing springs on the front of my car. What gives?

rusnak

oh those? It was the dog's idea. I'm just trying them out.......