boomboomthump

Thanks for the continued input. Taking notes here and trying to bucket-ize these comments. That last one really helped.


I think for now I'm going to immediately focus on RS sways with new bushings and also do my control arms with Elephant "sport" bushings.

Was also debating between the "sport" subframe bushings from Elephant or the solid ones. Any thoughts on the solid ones for a street car? They say the solid ones raise the subframe by 10mm, which is a benefit to lowered cars as you can extend the suspension by the same amount for more travel while keeping the same ride height (so they claim but makes sense in principal).

boomboomthump

What's the story here P? Did those seals just fall off or what? I'll gladly let you pay me to take those off your hands.

samurai_k

@boomboomthump on the blue car I have done a few mods to the suspension over the years and it has settled closer to your Street/track2 setup based on your definition.

BillV who commented earlier influenced it as his guides on suspension is great reference material if you have a technical/engineering background as to why each component upgrade has a purpose to improving the different parts of the suspension system.

Here is my opinion

1. The rubber bushings and the ball joints in our suspension if still original are now close to 25-27 years old. In most cases the rubber bushings are past their service life
and is a consumable, and for the ball joints depending on road conditions may too as well. So at a minimum have your mechanic who knows what to look for or yourself inspect every single one. You will start to find some will be in various state of failure conditions which the symptom would be the bushing/ball joint being "loose" if you jam a crow bar or lever to move it, vibration at speed, or inability to get a consistent/repeatable alignment. New ones will not deflect/move that easily. Assuming you have good bushings and ball joints then...

2. Strut/shock upgrade. Again these too are consumables and at some point will wear out depending on bad the roads or mileage. Relatively modern shocks (PSS series from Bilstein that are popular are not that new tech) is still way better than stock You will notice huge difference in how much the car sways/bobs/dives absorbs bumps etc... Immediately.

3. Then it's all about tightening the feel up, want more or less grip (under/over steer) thicker / adjustable anti roll bars.

4. Want more feel on turn in, pin the steering tie rod inners or replace them with solid RSR tie rods. Basically the same thing.

5. Want less bump steer when the car is lowered, get the RS carriers or the elephant bump steer tie rods

6. Want to keep the rear suspension dialed in lower than RS, get the solid subframes bushings

Etc...

On my blue car I have it close to the street/track 2 setup and has hovered around RS height over the years as I have messed with different settings and alignments. I still have the rubber suspension top hats front and rear and rubber bushings.

Last year I switched to NT01 tires and did feel a huge improvement in grip, but then started to feel new things with my suspension. Sure as you push the car to it's limits cornering with really sticky tires the last step is making everything solid that was rubber.

At least for me the blue car is still a daily and a toy at the same time so I am balancing the need to make it civilized for the street which it is and have fun on an ax or track day, which the car is more than capable and my instructors keep showing me the limits which is more than enough with it's current setup.

Bill Verburg

The subframe bushes are icing on the cake, use thin solid to raise the suspension back up into the car if running down near RSR height, ~95mm+/- f/r, if at RS or higher use stock thickness, w/ lots of hp you can use the angled ones to increase antisquat. These aren't really going to do much except on track and then the lowered version that corrects geometry, the 993RS did use stiffer rubber here

boomboomthump

Back again, small update and also another question.

First, I'm replacing all the control arm bushings with Elephant "sport" bushings front and rear. Will be doing solid subframe bushings at the same time. My goal is to knock that stuff out now while I'm rebuilding the car and get a good alignment.

Second, not exactly a priority (may or may not happen before the car is all back together and the alignment done) I'm also going to do RS sway bars and drop links. I'm not necessarily prioritizing those right now as they have no effect on the static geometry and alignment (unless I'm mistaken). So I figure it is not critical to get those installed before the alignment.

Third, I am on the fence about bump steer correction tie rod kit. A nice to have and would make sense before the alignment but I need to draw the line somewhere and not sure bump steer is up there on my priority list. Might be something to revisit and address after everything else is dialed in and if I observe bump steer to become evident.


Now my question...

Thoughts on these eccentric rear toe control arm (track rod) bushings? They're "sport" hardness as well and you can install them two ways. I'm confused by the two applications as they seem to both apply to substantial lowering...

• In the short config it says it addresses issues on "lowered cars" that don't have enough adjustment to correct excessive toe-in (due to too much lowering?)
• In the long config, it says it addresses issues with too much toe-out when there is a lot of negative camber (but a lot of negative camber is also a result of lowering the car substantially)

So which is it? Longer or shorter config for RS heights (or thereabouts)? Suppose this is a question for Elephant but anyone have any experience with these and should I consider them?

Bill Verburg

Bump steer is an issue that gets worse the car is lowered, for a 993 mitigation in front is from either the factory RS wheel carriers or an aftermarket o/s tie rod end. I n back it is from side mounts that move the suspension back up into the chasssi.

Whether you need it and what to do are strictly determined by the ride height.

My issue w/ the o/s tie rod ends is that you have no idea what effect they are having unless you do a bump sweep to actually measure the effect. Virtually no one does that, It sis just as easy to make it worse as it is to make it better
Here are the kinematics of a 993 front suspension w/ stock wheel carriers, the red toe curves are the bump steer curves, An ideal bump steer curve is a vertical line w/ a little toe in, The original x-axis is for RoW ride height, both US & RS have been added, You can see that w/o correction a car lowered to RS w/ std. wheel carriers has moved to a far less desirably position on the toe curve. The RS wheel carriers move it back to a more vertical place. The most interesting thing is the stability of the roll ctr height



Again, if going to solid rear sides use thin for very low cars way below RS height, use std, height for most street ride heights

lastly The RSR tie rods in conjunction w/ the RS wheel carriers make a significant improvement is vehicle dynamics on lowered cars
The pictured eccentric bushs don't appear to be 993 parts, A 993 uses eccentric adjusters at the inner pickup end
Here is a stock and and RS camber eccentrics,




For track use these are not reliable which is why the turnbuckle type w/ eccentric locks was developed

boomboomthump

Thanks Bill.

Regarding the eccentric bushings, perhaps you're not familiar with them. Yes, agreed the adjusters are eccentric (as noted in your pics) but these bushings for the track rod are "eccentric" (not really; bad name). They don't move, you press them in but the hole through the bushing is offset. You pick whether you want it offset so the track rod gets shortened or lengthened by 6mm. They are a more economical alternative to getting adjustable turnbuckle track rods where you have full control of the length. These basically just give you two options and you have to pick one before pressing it in (+ or -6mm). You still use the eccentric bolt to adjust them.


That said, I still have the question I posted earlier but perhaps only Elephant can answer. Confusing because in the -6MM orientation it says it solves problems with lowered vehicles (too much toe-in; provides more correction range). And then in the +6MM orientation they also imply it solves problems caused by lowered vehicles (too much toe-out caused by negative camber from lowering; provides more correction range).

So which is it? Do lowered vehicles create too much toe-in or do they create too much toe-out (they say both).

Here's the full description:

ToSi

Note the application list. On the water-cooled cars, camber can be increased (a lot!) by adding shims to the 2 piece GT3 lower control arms. Elephant is saying the eccentric can be used to lengthen the effective toe arm to match a longer lower control arm. Not related to lowering in that case.

Obviously that doesn't apply to 993's since camber is adjusted using the upper arm. That said, you shouldn't need the offset toe arm bushings (or RS camber eccentrics) anyway. There's plenty of range in the original adjusters for stockish settings at RS height and below.

edit: re sways, the front bar is a pain so consider installing it while you have the car apart. The rear can be changed anytime. Also, the rear m030 bar is the same diameter as the RS (the arms are a slightly different shape but the overall stiffness is mostly dictated by the diameter). There's room to drill an extra hole inboard of the original to mimic the stiffer RS setting if you want to try it before splurging for the real RS bar + end links. Can also use the 21mm rear bar from a turbo.

IMHO, most of the improvement comes from changing parts in the front of these cars. In the rear, just swap the kinematic and lower rear a-arm bushings to RS stiffness & fix anything that's worn out. Put the savings toward the front uprights if you're going to run the car low.

boomboomthump

Thanks. I'll skip the offset bushing (better name than "eccentric" bushing).

I see what you mean regarding the front sway. Was focused on the alignment aspect but had a look just now and see what you're talking about with the way it mounts up and around the steering rack.



While I was having a look around, spotted some bad news. My right rear toe arm has a torn boot on the ball end. Presume the boot isn't replaceable and one should consider the monoball compromised if dirt has gotten in there?


All others look ok, with exception of all my drop links (those aren't long for this life anyway with the impending sway bar changes).

samurai_k

@boomboomthump

Chuck at Elephant is a local shop to me and he showed me an easy check for the ball joints when he serviced my control arms.

Basically rotate them in a full circle at maximum diameter in both directions. If there are any notches or binding they are done and need to be replaced.

Also they need to be firm and hard to rotate with your wrist. If they easily turn with your finger tips, the ball joints are also worn out. I didnt realize this until he showed me the new toe arm ball joint vs the worn ones he tossed.

If you have any new ball joints from drop links, tie rods, or control arm etc..try it out. You will feel what I am talking about above.

boomboomthump

Thanks, will give it a closer look soon. But today's goal is getting the frunk wiring all buttoned up and the gas tank and firewall back in place.


Can someone confirm though, if the boot/seal on those joints is torn, there is no way to replace them?

ToSi

Officially, yes. Boots not offered separately.

Someone here found replacement boots a few years ago that might work on ebay. I wouldn't trust a urethane boot to hold up though.

Coleman

Mr. Tubby-

This is exactly my experience as well. I just purchased a pair because it seemed like those were the only option I had available with KW's and RS sways in the rear.. Couldn't believe the crap quality of their solution- granted, putting boots on Heim/misalignment joints is a complex engineering challenge.... But this solution was a Band-Aid to start with but executed in a way that is embarrassing.. Cement was all over the place and they were only tacked down in a few areas.. I wrote a long email to them and I didn't even get a response.. Here I was thinking that elephant was the pinnacle of quality etc... These days, everybody knows everything. With a very engaged enthusiast (dare I say Fanatic) market; making dodgy products and having non-existing customer support is going to destroy your business very fast... Just from a business standpoint, I can't imagine a market more detail obsessed than the individuals as Porsche racers & owners.. Looking at the construction of those boots and cement, I can't imagine somebody thought they were OK to ship...

I had boots on Tarrett Control arms previously and after about 10 years of daily driving in winters, I found that the upper boots with the large opening towards the ground worked well in preventing corrosion and keeping the pivot joint clean, but on the lower joints where the large opening for the rod was facing upwards; the boot acted as a container, (winter salt) water would get in and ferment the joint with nowhere to go.. It was incredible the amount of damage soaking them in water for years did.. Now I'm on the opinion that open Heim joints are best- in my newest build, I opted for stainless Heim joints with Teflon seals, though they have a bit less tensile strength than CAD plated versions, they they are still plenty strong for sway bar solutions...

boomboomthump

Back to provide an update on my slippery slope and also ask a follow-on question...

Here's where we're at:

• KW V3's (already had these)
• Strut tower brace (already had this)
• Elephant front monoball camber plates
• Rennline rear monoball strut mounts
• Elephant "Sport" bushings front and rear
• OEM RS uprights (welcome to the big leagues...)
• Front & Rear RS sway bars
• Elephant solid subframe mounts
• RS motor mounts (already had these)

Question time...

I'd like to do the RSR-style tie rods (no longer factory available). Is it possible to buy just the OEM RS outers without the inners? I dont want to buy complete factory RS tie rods to simply toss the RS inners for aftermarket RSR-style inners.

I see Tarett sells some nice looking RSR-style inners (pic below)... $300/pr (inners only). BBI does as well for the same price. I also found these inners for $200/pr?



This FVD option seems to be the only "complete" kit I've seen which includes RSR-style inners and RS-style outers (aftermarket reproductions). Any experience with these quality-wise?
https://www.fvd.net/us-en/9933470318...p-1995-96.html $322/ea

Bill Verburg

If you need both pieces It seems that the FVD is the way to go

I have oe's but bought a set of the Tarett inners as spares