2000 986 Boxster S - Suspension Upgrade Advice
 

Hey All,

I'm upgrading my 2000 Boxster S suspension over the winter for 2017 HPDE events. My Boxster is a second vehicle with 60,000 miles for fun around town and HPDE events. This past spring I had the IMS fix done, new clutch and flywheel, 60K service and new front rotors. I had a great HPDE season but want more....

My current plan is to upgrade to the following...
Bilstein PSS9 or H&R RSS Coilovers
Tarett Engineering GT Series Front and Rear Sway Bars
Tarett Engineering Front and Rear Drop Links
Tarett Engineering Adjustable Rear Toe Control Arms
Tarett Engineering Toe Link Locking Plate Kit

Any opinions about Bilstein vs. H&R shocks or the Tarett stuff vs. other brands? I really appreciate your advice and guidance.

i think all good choices. if on a budget, i am running ksport coilovers and they are working good for me (they come with adjustable top mounts too, which let you get more camber without spending more $). also, i have top speed pro rear toe control arms and they are also working fine. depending on how low you set your car (don't set it so low that the lower control arms are past horizontal, otherwise you will lose camber when you load the suspension in turns) you may want to think about bump steer both front and rear - the rear tarett units get a lot more expensive if you want them adjustable for bump steer. for front bump steer, after a bunch or research the cheapest i could find was the stomski units from pelican.

The rennline rear toe arms with bumpsteer adjustment includes the locking plates so that saves a little, they are the ones I am running. They also sell an adapter that you can pair with a tie rod end from the front, to get affordable toe adjustment without bump steer capability. Also I think 986piper from this forum is working on an affordable option.

I'll write back tomorrow about my suspension upgrade experiences on my 2000 S, it is all sorted out now but I made a few missteps along the way that I can share :)

I fitted the PSS9's to my 2001 Boxster S quite a few years ago - probably 50,000 km on them and no problems with leaks, spring sag or fade that I can notice - the ride height is still as I set them up when they were first installed.
The rest of the suspension is stock, although all the shock top bearings, drop links, coffin arms and control arms were replaced with the Bilstein upgrade.
On the softest compression / rebound setting they are +/- 20% stiffer than my original ROW suspension - acceptable but I wouldn't want to go any stiffer for road use. HPDE / track work is a different thing....

Thanks All. I'm really looking forward to your feedback.

Upon installation, I'd also like some advice on alignment settings that won't be too aggressive for the street. I plan on having the car weight balanced at that same time.

I would save the corner balancing for the end once you get everything else sorted first, otherwise with any change in ride height you will have to get it corner balanced again. Of course if you nail the ride heights the first time (unlike me...) that won't be an issue.

Video please.... :)

I did a suspension upgrade this spring 2016, from my worn-out 120,000'ish miles OEM M030 sport suspension. I went with KSports and also replaced some of the track/trailing arms and rear lower controls arms (basically all new suspension parts except from tie rods)

My first setup experience was a disaster - I setup up the car to where it looked really good, but the front was way too low, both all up, and in relation to the back. I also paid for a corner balance, which took only a few adjustments and cost $250. The car was very loose and was scary to drive on the track:

http://986forum.com/forums/performance-technical-chat/61437-any-tricks-reduce-oversteer-limited-adjustments-tbe-track.html

Several members here jumped in with info and hot tips to get me squared away, including several lengthy email exchanges, very valuable information, thank you! I raised the front (therefore losing the results of my corner balance), set a front to back rake that matched ROW M030 specs, added an adjustable rear sway bar in case I needed to do some tuning at the track, and took the car to the FIRM in FL to shake it out:

http://986forum.com/forums/general-discussions/62408-few-laps-firm-mobius-camera-beluga-racing-exhaust.html

The car did awesome, ran my fastest laps ever at this track, the car rotated like a champ on this very tight technical course.

Then I took it to Roebling Road in Savannah, a very fast flowing course with lots of sweepers. They have scales there and my numbers looked very good, to get to corner balance would have required moving only 7 pounds, so I decided not to pay for another corner balance (would have been half price though, $125, but I decided to skip)

http://986forum.com/forums/boxster-racing-forum/63423-went-big-spin-last-weekend-unusual-abs-interaction.html

Had a big off my second session, the car was still biased towards oversteer and spun in a place where I have never really even been in jeopardy before. So I had the car dialed in for shorter technical tracks, almost every corner a hard trailbraking/car rotation corner, but on the sweepers I still didn't have the setup. My fastest laps were still 6-7 seconds off my personal best at this track.

At this event, I resolved to go back to the OEM sport suspension because I was tired of fiddling and tuning :) After I made this change, I did some research on sway bar stiffness and discovered that my aftermarket rear swaybar was TWICE as stiff as OEM, even on the softest settings. Paired with the OEM front bar, that was almost certainly my problem, dang it. However I am a tinkerer so it all worked out and the KSports went to a good home so all's well that ends well.

I did this, and replaced my worn out struts with Koni FSD struts, and the car is freaking awesome, and I ran a string of laps within 1 second of my personal best. Also I am using Harry's Lap Timer, and I am really liking the g-force information, which seems to be a good way to see where I am leaving more on the table.

This was with a Bob Woodman Tires open track day, so I had a lot of clean track. Note that I ran 75 laps that day, pretty cool :) I started off the day running TC and it was coming on more and more as the day went on, mostly inside wheelspin I think on corner exit. This is the first time I have felt TC holding me back here. I turned it off for the last few sessions and it felt great.

<iframe width="560" height="315" src="https://www.youtube.com/embed/MwLo3LqlXk0" frameborder="0" allowfullscreen></iframe>

https://youtu.be/MwLo3LqlXk0

Inside the car (only got 2 laps, 3rd was not recorded)

<iframe width="560" height="315" src="https://www.youtube.com/embed/-eDEin0MbHo" frameborder="0" allowfullscreen></iframe>

https://youtu.be/-eDEin0MbHo


Here are my two fastest laps at this track from last October 2015. Note that outside of this single "magical" session, which was 2 seconds faster than my previous bests, I have never run a 1:30.x at Roebling until last weekend.

<iframe width="560" height="315" src="https://www.youtube.com/embed/HXTRO-jeJAI" frameborder="0" allowfullscreen></iframe>

https://youtu.be/HXTRO-jeJAI

I am back!!!

My lessons learned? Go with a proven combo of suspension parts and settings*. Don't be like me and use a lot of money and time to re-discover the wheel. Share your proposed setup ideas here and compare with what other folks are using. That way you can get it right the first time, unlike me :)

*Edit to note - "Go with a proven combo of suspension parts and settings" is not meant as a ding on the KSports - my problems were caused by improper setup, and then a mismatched rear sway bar. On the tighter track they were awesome and I have no doubt that they would have continued to be awesome on faster tracks once I got the setup dialed in.... Sigh

Thanks again, this advice was most helpful. Any other opinions out there?

I'm interested to hear more about the Koni FSD set up. I'm just about to replace my M030 with FSD and H&R springs keeping the M030 anti roll bars. They will go with the already fitted adjustable rear toe links and newly acquired solid adjustable top mounts. This is for the road.

I love the FSD, I think they go really well on the Boxster. They feel really good on the street, and for me really good on track. They are supposed to be firm.at low frequencies for roll and body control, and soft for high frequency oscillation like road bumps. I am taking the car to Sebring in a few weeks and am curious how they will do there.

Note that Koni approves them with OEM springs and Eibach Pro Kit lowering springs (still sold overseas and van get on eBay) - unsure how those compare to the H&R.

I really.like the FSD and would get them again if I ever had a different street boxster that needed struts. For the best price get them from Gert at Carnewal.com

The H&R I have are -10mm so similar to the OE M030 and Eibach. I've bought from carnewal before so will double check his price but not so good now due to fx.

I had adjustable control arms and Ksport coilovers for three years on my boxster and it was great on the track, but brutal to my back on the street so I finally removed it all and went back to stock parts.

Just know that putting a race suspension on your boxster is going to drastically change the handling for the better and the ride for the worse... in my case, much worse.

Last ping to see if others have opinions...

If you are between PSS9 and H&R coilovers and you are for track purposes, I would go with PSS9 as I believe it to be much more proven for track use than H&R coilovers.

Not on the list above, Consider adding some solution for more neg camber up front. If you lower some you will get more from.the OEM setup, maybe an additional -.5? I have GT3 LCA and run -2.0 in front which works very well for me.

Very good advice! (in bold)