Cutting late dual spring plates down to single?

[FJCamper]

Hi Piledriver,

I have no experience with the Bilstein SG series shocks, just Konis.

I believe you've done a lot here to educate the forum on exactly how different the Type 3 suspension is from the Type 1!

And, you're touching on a serious subject I had let alone for sake of brevity, the camber changes during suspension travel. But you are aware of it and know how to limit it. That's where the innocuous spring plate factors in again.

The T3 rear subframe was very innovative for it's day. You can spot some of its hybrid features in later 911 designs. The subframe, btw, was the reason the twin spring plate was invented, not just to handle extra weight. The twin plates added extra rigidity to keep handling predictable while the rubber "doughnut" mounts isolated noise, harshness, and vibration.

You are certainly braver and more energetic in your projects than I let my racing mechanics be. Our work is just to optimize the factory parts, and try not to introduce a new problem for every old one we fix. We don't need to be helping out Murphy.

I'm really eager to find out how your project goes.

FJC

[Bruce2]

The stock camber "adjustment" in the 3 rear bolts only is ~1 degree limit to limit, keeping toe and ride height constant.

If you increase the slots vertically, you get way more range on camber adjustment. IMO this is what you should do rather than creating some mickey-mouse adjustment on the inner pivot. Altering the spring plates is so much less work, and completely reversible if you don't like it.

When I saw the effect of tilting the rear of the TA up or down on camber, it was easily noticeable. We didn't measure it because significant positive camber on the rear is known to be bad. Tilting the rear of the TA back to straight eliminated the positive camber by eye. FJC, how much camber change is noticeable by eye?

[Piledriver]

Thank you, I'll give it a shot with wider spring plate slots tomorrow.
That would be far less work, and I'm a huge fan of far less work.

I have 4 days of good 70+f dry weather off, so I'm making the most of it.

After massaging ~everything in an aborted attempt to forego the spacers completely (stopped as I didn't want to weaken the shock tower) I think i have more fender clearance and inner sidewall clearance now than I did with the 205s on 914 Mahles.(with the 15mm wheel spacers)
It could probably fit 255/40s or even 265/35s on 9s, with only baseball bat rolled fender lips and a slight hand powered pull, using the lower fender mount slots to good use...

The only mod it still needs is the inner fender outer lip needs to go up to allow full suspension travel, and its not structural, just needs to seal to the fender as thats the floor of the cooling air channel, haven't pulled the fenders yet.

Might still work spacer-free if the wider spring plate slots give me enough camber adjustment.

[Bruce.m]

Remember to widen in the correct direction.

[Piledriver]

Remember to widen in the correct direction.

Up in front, down in back if I'm thinking right?
Drill out the TA holes a bit and try it looks best plan.

I can actually use part of the cut off outer plate as a giant thick spring steel washer on the 3 rear bolts, the TA is trimmed back a bit behind where the 4th bolt was. The rim inner lip is just past the forward bolt and head out its no issue. I was considering turning them into 935-ish plates with a raised pivot and match it with raised inners but that's just the power of mild OCD.

May need more toe adjustment with above mod but that's free too.

I suspect it will go coil over out back, I still have all appendages after plenty of practice swapping/adjusting torsion bars back in the day but a 2 minute adjustment to ride height feels a lot better on these old bones than games with the jack etc.

Had the bars out to cycle the suspension fully while making mods, would be beautiful simply being able to jam coil overs in and go from there.

Need to research how much additional work the arms need at the shock mounts for coil over, welding them fully is a gimme.

[Bruce.m]

Rear of trailing arm up = positive camber change.

So widen the hole downwards.

(Found that info on this forum & confirmed by Kerscher instructions for fitting the 944 adjuster)

[FJCamper]

Eyeballing camber changes

A trained eye can usually see one to one and a half degrees.

An untrained eye needs more, two or more degrees before it begins to look slanted.

FJC

PS: Slotting the spring plates is within our "optimizing" the stock parts philosophy.

[Piledriver]

That got'r done, I owe you fellows a refreshment of your choice.

After some quality molestation of the holes in the trailing arm, I can set it for ~1 degree negative camber...
...at the hard stop. (bump stop removed, this would be ~dragging the pan high)
Not remotely planning to go there, but as a datapoint.

Took the front hole up and the rear ones down. also opened just a hair to 9/16" to get the toe back inline...
(That and also I had a new 9/16" drill bit)

There's about 3 degrees of adjustment limit to limit, took the hole edges up/down ~1/8" respectively, it is about at the limits with setting toe and the spring plate fights you pretty good... Have not extended the spring plate slots for toe, may be no need. I am ONLY using the rear 3 holes.

Aiming for ~.5 degree negative camber, 1/8" toe at static ride height.

Would have been neater/faster with a 1/2" cobalt burr in a die grinder, but we do what we can with what we have.
********
The dual spring plate is only fully welded (both sides) on the cut OUTER blade, so I'm looking at HD ones or T1 singles again... May be able to weld it 3/4 the way around, but with coil overs it should not be an issue.

[Bruce2]

Aiming for ~.5 degree negative camber,

Go more.

20+ years ago when I fitted the max tire possible under a stock Beetle fender, I had the pro's align the car. It was -1.5º at the rear. Or so they said. My uncalibrated eye said one side had more than the other. I didn't do anything because the pro's said it was correct. After a few years, I could easily see accelerated wear on the inside of the tread of the side that looked like it had more camber, so I measured it. It was -3º (the good side was -1.5º). Once I corrected the -3º to match the other side at -1.5º, I noted that the new tires wore out evenly all across the tread.

This is why I suggest you go at least -1º. Or -1.5º, and it will really hold in the corners!

[Piledriver]

I'll aim for -1 and minimal toe in, the 245/50s probably like to stay flat, and that's about what I was running on the 205s with excellent wear.

The T3 even has some camber gain on the front end as the lower bars are not parallel to the upper... they angle down a few degrees. (bars are full width and cross)
...Just needs a little more adjustment range, but I have an evil plan involving a ~1/4-5/16" spacer i want to try.
Shouldn't take much.

The splined front bars bolt in, planning on installing a stud in the end and spacing out the inner end 1/4", trailing arms bolt and clamp to other end as well, bars locate them.
Top bar is a sway bar in the beam---this mini project probably after the brakes.

Will probably round off the remnants of the outer spring plate and at least skip weld the inside tomorrow, and slap it back together with the original big bars etc, just dropped a spline.
Pretty sure I can reach it with the MIG.

I'm probably into new spring plates anyway as there are some nasty irregularities and wear in the friction surfaces, since delrin is eventually going in it probably prefers smooth/flat and round.

I sadly assume the chrome EMPI spring plates are typical EMPI quality or it would make a great surface to run on the delrin bushings.

Did do some light sanding of the high spot on the urethane bushings where they were obviously extruding, now the spring plate actually moves by hand with a little CV grease. (sans the bar of course) I curious how much effect the stiction had. I couldn't rotate them with a 3lb hammer on drivers side once tightened back up, and required great levels of persuasion to get apart.
That's part of the reason I want to try the delrin bushings.

[FJCamper]

Hi Piledriver,

Derlin is better than urethane. Urethane is better than stock, if you hone, files, and lube the hell out of it.

If you have to fight it to get it to move now, it will bind up on the road.

FJC

[Steve Arndt]

I put a big sanding drum in the drill press to hone the inside of the bushings until they fit the spring plates nice.
Make sure to knock down the welds on the spring plate snouts, and debure the chamfer on the bushing for clearance.
Sand/profile the OD of the bushings so they fit the covers, and the torsion housing perfectly.
It takes me about a half hour per bushing to fit them correctly. Not a money making job compared to just slamming them in and giving urethane a bad name for squeaks and binding.

[Piledriver]

I have some HD spring plates and the bushings coming from SACO next week, adjustments were set for max, and min toe.

SACO apparently doesn't "do" email very well, or answer their phone for that matter, but persistence pays.
Their policy seems to be to send you a postcard if any part of your order goes backorder, which probably made sense in 1970.
...As they require your email for online orders it's asinine.
They were out of 1.5" exhaust flanges.

The TA arm rotation and the bolt locations forced it into slight toe-in, will fix next time in via extending the offending lower toe slot in the new spring plate, some toe probably OK set at -0.5, at -1.5 I will likely want ~zero toe to even slight positive due to camber thrust

It ended up at ~-0.5 degrees but it actually needs a bit more, fender clearance is now tight at .5 degrees, even w/slightly pulled fenders and rolled lips.

I wanted to see what new adjustment limit was, camber angle came out identical as well as ride height, so decided to declare victory and move on, jack games and indexing torsions to match is hard on these old bones on the ground.

Will set it for more like the suggested -1.5 when that stuff goes in next week or so.
I can pass my fat paw through at the knuckles at the inside "tight" spots as set right now.

This got me back to almost zero camber, would be zero or slightly positive at std ride height.
Oddly, the lower shock mount on the TA has a better angle/more clearance like this over full travel.

I need to figure out how/where I can put jack bolt(s?) to set toe and caster quickly and repeatably.
Tweaking ride height is easy/fast with the 4 way coil-over setup, as I can add positive or negative preload.

trailin-arm-camber-adjust.JPG

Evil plans:
Also bought a cheap weld-in mid mount plate, as part of a planned (removable) rear subframe///kafer brace. May be built sort of "upside down" to later allow an automatic.

Goal is for angled UP frame horns (over the axles) and trans mount loop will hang from top--- bars from shocks will be ~horizontal.--- we'll see how the triangulation angles/clearances look next time I get under the car, may mock it up first on the lonely 944 torsion I have lounging in the back.
.

[Piledriver]

Hmmm EMPI 17-2558, ball joint front wheel hub.
http://www.mooreparts.com/vw-front-whee ... 1968-1977/

Moores parts lists them for $53ea, would have saved me a lot of work.
Flange is thick with no ribs, so stud placement would be no issue.
The only thing that concerns me is EMPI makes them.

[Piledriver]

Finally got the front 205/55s on, so now hubcentric on all 4 corners with the forged 16" 944T manhole covers and the sticky Cooper RS3-A tires.
Still has the same brake setup, deferred the upgrade, need to finish one project at a time, and it still works great.

The 6x16 ET52.5s went on 1" spacers up front and tire moved out some, fills the fender better and makes some other upgrade ideas possible...
It doesn't rub///I have not needed to roll the front inner fender lips yet, but I may for insurance.

Drives like a completely different vehicle just with the new front shoes.
The car is dead level, looks a little funky seeing space over the front tire and the rear is up in the fender a bit, but the rears are noticeably taller and larger.
May drop it another inch but that's about it.

Steering is now very light even at parking speeds, I was concerned it would suck with about a half inch additional scrub radius, but it instead feels I also installed power steering. (the 205/60-15 Yokohama 580s that were on it are newish and had ~ full tread, so it isn't only new flexi treads)
Two fingertips is all thats needed at parking speeds.

At highway speeds, the steering feels as light as an early 911 with new 165s, and absolutely no tramlining over grooved concrete or seams, that must have to do with the tread pattern.
It even seems to ride better, even running 32 PSI on all 4 corners.
(was running that with the 580s and big rears as well, it helped but harsh, day/night difference with the new front setup)

The rear suspension seems to work ~infinitely better with the hand-fitted (used) black poly bushings with CV grease, looking forward to doing same with the delrin bushings the coming weekend or so. I didn't have to work the ID, I just had to reduce the "squish" horizontally, basically just sanded off the extruded bits and made them flat again.
When assembled with CV grease I can lift and depress the spring plate by hand force (no bars at that point)
With the thick silicone urethane bushing goo I couldn't move them with a hammer or 3' prybar, before or after fitting. Weird. Stiction sucks.

I have not done any work on the front end other than drilling//studding the rotors and grinding the rotors hubcentric nub to porsche OD, but I am likely to swap the much stiffer late upper bar in (sway bar) and perhaps push the lower bars (and arms) out some with spacers on the end of the inner bar mount, depends on how deep the splines are, haven't found a picture yet so will simply have to take the spare 73 front end apart to see what's practical. May be able to "get some" on the arm end as well. Will fab seal spacers as needed. May be limited by the bearing wear surfaces width.
...Anything to get out of positive camber will be an improvement, even just getting to zero should be a win, as the T3 front end does actually have some camber gain due to the angles the lower arms are mounted at. (arms/bars go back and up slightly from the arms so they can cross in the middle)

I guess i could heat and bend the lower arms out but i don't want to go there.