jdistefa

^ that's a great deal, 3 for the price of 2 re. ERP

chaoscreature

Wow,
I am so glad I asked this question. The diagram in post 10 was what really got me thinking about this whole thing and what the effects of the KT is.
I am ***-uming that replacing any 8 of the rubber bushings with monoballs would essentially net you something like a double A-Arm suspension and that IF you replaced the final link with solid mounts you would get some binding... that's my guess anyways and would explain why they don't sell ALL of the joints as a kit.
Very interesting reading. I had no idea the KT gauge was simply a level like that. I did a bunch of research trying to find a "how-to" for KT settings and everyone said you needed the special Porsche tool. Obviously I missed some information . I thought they actually had to cycle the suspension and measure the toe change (like performing a castor sweep, but in the rear somehow...)

I posted on the PCA website that I was looking for someone with some scales that I could borrow or drive my car onto. I should have posted here as well. I am still interested to see where I am at. I am not looking for perfection, but I would like it to be as close as possible.

Thanks again for all the information!

Macca

chaoscreature. Did you weight the JIC shocks? If so would be interested as Im looking to order the new gen ones when they launch in June. Are they lighter than the factory ones or previous ones you had in the car do you think?

Cheers
M

Bill Verburg

It does seem to have 1 arm too many to work. That's why I need to model it. I assume the engineers knew what they were doing.

The thing is they went to a simpler 4 link setup for the 996/997

chris walrod

Yes sir. Let me see about getting a few pictures, find my old ones (on an older laptop) or just go out to the garage and snap some new ones

chris walrod

OK, got some pictures a few minutes ago

Bill Verburg

Thanks Chris! That explains a lot

chaoscreature

Macca,
They were a little bit lighter but it wasn't a large weight savings for the coilovers themselves. They basically have the same components as the factory ones, so without a major re-design or going to exotic metals I don't think you can really save a lot of weight replacing shocks/struts.

Chris,
That makes perfect sense in conjunction with the diagram fom post#10. According to that picture it's the trailing A-Arm that has the "give" in it. It's really a fascinating suspension system and an interesting concept. My car feels absolutely wonderful so Porsche definitely did something right there... it's just odd like Bill pointed out that they would develope something so complicated, use it for 5 years and then drop it.
If my graphics card didn't crap out on me I would try to model the suspension to see how it works. I have modeled a few differnt A-arm designs back when I had more energy and wanted to build a can-am style race/street car (Think 1963 Ford Falcon with mid-engine, tube frame and fiberglass panels).

sonny1

I see that you guys are increasing front track by using wider rubber which it is ok, another way for increasing the track is by changing the front suspension pick-up points outward,there is provisions for it on the chassis itself.,(a la RSR's)cheers.

MarinS4

Chris is that true on both the front and rear lower control arms?

berni29

Hi Chris

Thanks for posting the pics. Those joints on my car were very worn and had noticeable play.

Berni

vincer77

Thanks for the explanation and yes, this all seems to agree with Bill's post of the Porsche explanation of the suspension. So back to the original post, if the trailing arm bushing is replaced with a solid monoball, wouldn't you lose the kinematic toe? And as someone else posted, a problem with binding?

Macca

subscribed to this. It would appear the factoru were very specific in the design of the 993 rear suspension components right down to what we have to presume was careful selection of rubber mount density and deflection.

So the question still stands and is a good one. Outside of race car application for 993 would changing just one item of the 5 to monoball affect the KT or how the suspnesion operates as a whole. Is infact it only adviseable to replace all three arms with monoball at the same time?

M

trophy

Looking at the arm, if you remove the softer rubber bushing (which gives the car the dynamic toe) then I would suspect you loose some if not all K-toe.

ERP have been making the monoball replacement for the rear a-arm for a long time, I would suspect that if it was binding they wouldn't produce it.

Putting all of these components in the car reducing or eliminating the k-toe, i would think you would basically end up with a suspension that reacts more like the 996/997 suspension (that Porsche eliminated the k-toe in).

For racing / track cars where you are trying to remove variability (soft rubber) going to the monoball would ensure you knew what the suspension is doing at any particular time. With rubber you never quite know how much it is compressing, or that you are outside the operational specs of the suspension (due to other changes or geometry etrc)

Bill Verburg

w/ monoball you lose all of it. W/ the RS harder rubber it's just reduced. On mine I have RS and it is really nice, i couldn't ask for better.


the 996/997 still has toe changes w/ suspension movement it's just not adjustable as on a 993