jj99c2

I am having some Elephant Racing bump steer correcting tie rods installed and want to freshen/tighten the suspension as well. My car currently has PSS9/M030 sway bars and runs at RS height and I definitely get a bit of bump steer. I am planning to have the following bushings replaced as well. Anything I am missing? I did a forum search and got a bit confused if I should be replacing the KT arm bushings or if there is an actual RS version of the KT arm I should be buying? All the bushings below are the "Sport Hardness" version from Elephant Racing.

Bill Verburg

There is an actual RS version for both the rear arm and the KT arm. The RS used the same parts as all other 993 fro the other rear arms.
an issue has been the availability of the KT arm, I don't know the current state.

You can either go w/ the rear bush kit and replace these 3 bushes/side: KT, A arm, Camber arm. or replace the arm itself and get the benefit of new outer ball joints.

A third option is to partially do each. I'd want a new RS arm. w/ this you get new bushes on both legs(bush kit above only does the rear leg) and new outer ball joint. Then either buy just the KT bush or the KT arm. Repalce the camber and toe arms w/ new stock or just bushes.

The arms that I see the most wear on are the toe and A-arms, the others are much less stressed.

Additionally, for some track use, the toe arm is better if it's a mono-ball version w/ locks.

jj99c2

Thanks Bill - that is exactly what I was trying to understand. I will try to source the RS arms.

Spyder_Man

You probably read my old post about this where Bill V provided heaps of advise. I ended up configuring elephant sport bushings in an RS-like arrangement as Bill V recommended, and I'm quite pleased with the result.

The one thing I regret though is underestimating the amount of labor cost associated with replacing the exhausting bushings with new ones. The old bushings are stubborn b@stards and required a lot of heat and force to get them out. In hindsight it would have probably been cheaper to replace the various suspension bits with RS-oem equivalents (where available) that to buy the sport bushings and spend a bunch on the labor. As Bill just pointed out above there aren't RS-oem versions of all of the suspension components, so you will have to replace some of the bushings in your existing components if you want the full RS-like setup.

And as for, should you do it? Yes! Go as close to full RS-suspension as you're willing (or beyond depending on intended use) and enjoy it!

samurai_k

I second spyder_man. Removing the control arm bushings is a big PIA job. Installing new ones will require a press and some special adapters to prevent damage to the front ones. I believe Andreas (AKA AOW162435) who is on this forum has the workshop to install them for you. Alternatively, you can send your control arms to Elephant and they can inspect them if the ball joints need to be replaced and do the removal/install for a fair price. I did the later and it was well worth it!

Bill Verburg

The only RS specific suspension parts other than shocks, sways and mounts ever used for those are shown here
front wheel carrier parts, RS on left, all other on right


outer & inner tie rods, outer has a different bend, inner has a stiffer rubber bush, shown is the RSR part w/ the RS outer and mono-ball inner


Trailing leg of the front A-arm has a stiffer bush , leading leg is the same on all. It's a good move converting the front to stiffer rubber too.

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In the rear only the KT arm and trailing leg of the A-arm are stiffer, the next one to stiffen is the toe arm(this is a hugely abused part and is always the first to need replacement. for track a mono-ball arm is highly recommended here.
the subframe mounts are also stiffer rubber, it's just that there isn't much gain from using sport rubber here. There is a huge gain from using solid mounts but only if the car is much lower than RS height

jj99c2

Bill - thanks again for the information and I finally understand the toe vs camber vs KT arm from your picture!

Spyder_man - I did read through your thread - very useful.

Samurai_k/Spyder_man - Understand on the labor/install - looks like elephant refurb option is way to go as they can put the sport bushings in both front and rear for control arms.

samurai_k

Chuck (owner) and Shane (tech support) at Elephant are good guys and can help recommend a setup. The refurb of rear control arms and install of their bushings is something they don't widely advertise besides the front control arms but they do it. Well worth it. I did the job last fall and there are pictures of it along with the slippery slope of mods thereafter in my build thread below. Good luck!

jj99c2

Thanks again for all the details/support samurai_k, spyder_man and Bill.

I got the car back after the installation of the bushings (elephant sport for all front and rear rubber) and bump steer correcting tie rods. The project took longer than expected as the steering rack and hoses were leaking. The hoses took some time to locate.

I was really surprised with the handling improvement. The car already had PSS9/M030 sway bars with an aggressive alignment so the only real changes are the sport bushings/tie rods. The car is much more predictable, no more "wiggle" in the rear exiting corners, bump steer basically gone and the level of steering feedback is dramatically improved.

I also ended up using a 964 steering rack in the car. It was originally sent by mistake, but I did some research and the 993 RS uses the 964 rack. The ratio is a bit slower (around 18 vs 16 in the 993) but it has a heavier/less assisted feel that I really like.

JZ98-993

Boris993

Hi everybody,

I'm brand new to the forum and I need your help about the 993 front A-arm.
My bushing are cracked, so I need to replace them. I choose harder one (RS like).

My question is, I read that the front A-arm and side members are specifics for RS cars.
I'm wondering if the difference is the angular position of the bushing keyway (difference due to the lower ride height)?

If my car is lowered to the RS+10mm height do I have to modifiy the angluar position of the bushing compared to the original one (to reduce the shear)?

samurai_k

Great question. When I had my front control arm sport bushings installed the first time by elephant, Chuck the owner installed them like the stock one with the nubbin/notch parallel with the a arm plane... Did the same again on a second set.

Boris993

Hello samuai_k,
Thanks for your interesting answer.
So I assume that there is no difference between RS and C2 A-arm (except harder bushing of the back hub).
And do you know if the RS cross members have a difference in the keyway position (A-arm installed with a different angular position on the RS car)?

Bill Verburg

The only difference between RS and regular front control arms is the trailing leg bushes which are harder in RS

the angular orientation of the arm is set only after the car is sitting on it's wheels, before that the arm bolts are only snugged, final tightening is done while sitting on the wheels

Boris993

Thanks Bill for your answer,
I thought exacly as you, until I removed the A-arm from the car.
Once removed, I noticed the slot in the cross member which avoid the A-arm to take its natural angular position.
So even tightenning the bolts while the car is sitting on his wheel, the front bushing can't rotate to take a center position