Suspension component advice needed
 

Hey guys, I finally have some spare change to throw at my suspension on my 1999 Boxster with 89k miles. First the rear struts are worn and second I want more performance. I was going to order a set of Bilstein PSS9 coilovers. I mostly use the car for spirited mountain drives and have not yet tracked it but would one day like to do a track day to learn the car more. I've searched a lot but some of my questions are a little specific so its hard finding an answer. Hopefully someone here can help me out a little.

Since I am installing coilovers, should I replace any of the components that attach the suspension to the car? Specifically stuff like strut top mounts? Should I wait and see what they look like before hand? What has everyone elses experience been? Are there any bushings that anybody recommends to be replaced? I mainly ask this so that the car isn't sitting on jack stands for too long while I'm ordering and waiting for parts. I have also heard you need adjustable rear toe control arms when lowering a car or it can't be aligned as well. I'm not looking to slam the car and was wondering at what point of drop are these recommended? How low can I go without needing these?

I plan on eventually adding adjustable sway bars and end links in the future and was wondering how much more performance the adjustable sway bars and end links provide when being paired with the PSS9's. Part of me wants to do it all at once but it can get costly doing that. I do understand its to help fine tune handling. Lastly, when I go to install the coilovers, is there anything I should do specifically? I remember seeing somewhere to make sure you have them set equal or something before installing to make the shops job easier as far as alignment and corner balancing. The less I have to pay the shop, the happier I'll be!

Hopefully, I didn't miss something in all my searching and perhaps these questions have been answered. I believe I've found some of the answers to my questions in the past but can't seem to locate the threads anymore.

At 18 years and 90k miles you probably need to replace all the rubber bushings in the control arms and trailing arms unless they have already been swapped out.

Congrats on making the move to coilovers!
Now is a good time to replace the top mounts on the front. They are bearings, they rotate, and they wear out. Doing it later will be an expensive PITA. You may want to look into top mounts that allow you to adjust the front camber.
You will need adjustable rear toe arms to keep from having excessive toe-in and tire wear.
I'd wait on the sway bars. See what the car's like with the coilovers. Do some autocrossing or something to really push the limits to see if you've got oversteer, understeer, or a good balance. If your tires are old/worn, replace them before any testing, as they will screw everything up.
You are on the right track about "setting up the coilovers equal" before taking it for balancing & alignment. Once you've got the coilovers on the car, measure the height from the fender lip to the ground. Get the ride height that you want and be sure that both fronts are the same and that both rears are the same. Having the rears 1/4" to 1/2" higher works for me. The alignment & balance won't be right, but it will be in the ball park. As long as you don't go over about 50mph the car will be drivable to the alignment shop.
Make sure you find a shop that's done alignments/balancing with cars w/ coilovers. also, search on this site for alignment specs. You really want to set the car up to the way you drive. Done right, it's unreal the way the car handles. Done wrong, you'll be in the trees before you know it.

Thank you for the advice. I'll have to make sure I order the top mounts adjustable rear to control arms soon. I was planning on going with oem Porsche for the top mounts. I will need new tires probably in the next 5000 miles or so and want to go wider than the stock 205 front width.

I appreciate the advice on how to install the coilovers. Will adjusting height mess with the corner balance? I'll have to see what some of the popular height settings are and figure out what will work best for me. I have also heard about setting the rear a little higher as far as ride height. Now to search for some alignment specs!

Yes, adjusting the height will affect the balance. It would also affect alignment. There's an order to doing things, and you want to set the height first. The amount that you'll adjust the coilovers for the balance won't change how the ride height looks. A good technician will have his/her own order to getting things right in an efficient manner.
Where in VA are you? I'll be autocrossing with the Porsche club just north of Staunton on Sunday.

I'm out near Sterling, Va near DC. I often take Driving trips through WV and usually end up going through Staunton or Harrisonburg on the way home.

coil over height
 

After installing the KW-V3 coilovers I took my car to get it corner balanced at Steve Alarcon alignment shop (SoCal), he is a member of the POC and has great reputation.

After 95k miles, I replaced the lower control arms, also removed the KW-V3's and send them to KW to get them overhauled and I used the same ride height as when got the corner balanced (Steve mentioned that as long I get the same ride height again, the end result should be the same)

I have the heights from the original settings (after corner balancing), I can share them with you if you want, these should help you to get a starting point.

Please note I have a Cayman, therefore the weight may be a little different from the Boxter one but should be in the ball park, please let me know.

Good luck.
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