Suspension de-tuning
 

My Boxster has the M030 factory option, ROW - as it was produced for the German market. It also has the 18" factory wheel option. All this make it somewhat harsh on the not-ideal roads in my area.

As this is my daily driver and touring car (4000+ mile road trip last summer), I'd like to make it a bit more comfortable without sacrificing too much performance. I take it to the track twice a year but just to practice emergency breaking and skid recovery. I don't race.

What would you guys recommend? Springs? Dampers? Bushings? I'd rather not downgrade to 17" wheels.

Oh, of course there's the option that the best thing would be to just leave it alone...

The M030 contains:
Front Springs & Shocks
Rear Springs & Shocks
Front Sway Bar & Bushings
Rear Sway Bar & Bushings

I would recommend to replace everything with non M030 stock parts if you want to keep the 18" wheels. That is better / less harsh but doesn't mean a comfortable ride.

Easiest way to get the car a little less stiff is to use 17" wheels with the M030. If your Boxster is a non S, there'll be also the option to use 16" wheels and the M030 setup. Maybe this doesn't look sporty, but it drives better than 18" and M030 on bad roads.

I don't think wheel size in the 17- 18 range matters much. It's the springs that you're feeling. If you could swap in base Boxster springs front and rear you would have coosh. The tire sidewall ratio matters next. This is expressed as a percentage of the tire width. You may have a 35 aspect ratio and increasing that to 50 or thereabouts would soften things up. Maybe you could swap your struts with some else. Either way the car can be softened up a large amount. The rear matters most but it's a system you don't want to upset by doing one end only.

I think the point is that you can run a taller sidewall with smaller diameter wheels.

Going to 17" would mess up the looks of the car :( so it's now a question of what do I prefer to sacrifice.

Tell me more about the springs, though. Can I really fit non-M030 springs in mine? Does that raise the ride height?

Should not, US M030 sport suspension (which I have) has the same height as non sport. ROW M030 is a little lower. Have you driven an equivalent car without the sport suspension to see if there is a difference? I can't say as I has been so.long since I have that I can't remember a difference.

All north American cars have the same ride-height due to bumper height regs. Since your car has ROW 030 it is lower than our M030. I don't know if it's lower than the European base suspension.

if you are running the turbo twist wheels on your car, the looks will not change much. no one will notice the difference. with the 17s on your car, inflated to factory specs (many overinflate), you will notice a notably less harsh ride. the first step would be to try running 30 psi in your fronts and 32 psi in the rears. on my car, I have removed the 19s from the factory and replaced them with 18s for the same reason. the ride quality has improved dramatically with no loss in the handling characteristics.

Also consider tire choice. Some have much better ride than others. Hankook V12s and Continental tires tend to offer a more comfortable ride. 30/32 tire pressure also helps.

European M030 lowers the car 10 mm.

Would not recommend to change only springes, because all components work together. M030 springs and dampers are stiffer. M030 sway bars are thicker and the sway bar bushings are also "stiffer".

If you want an adjustable chassis, check out the Bilstein B16. There you can adjust dampers and ride height.

17" give a more comfortable ride, because the tyres are higher and a little smaller. 205/50/17 and 255/40/17 instead of 225/40/18 and 265/35/18. So the tyre itself can dampen more.

16" dimensions are 205/55/16 and 225/50/16 which work only on non S cars.

Thanks, everyone!

Will try to find some 17" wheels to put on and try out. Don't know what shop will be crazy enough to let me do that, but it does seem to be the way to go to avoid changing the car too much.

...hmmm, except that looking it up right now, OZ (producer of the Ultraleggera and Alleggerita wheels that I wanted to get) doesn't make any 17" with 5*130 mounting. :(

Okay, so to refresh this thread...

Found out today that the uncomfy ride wasn't (in part) due to improper alignment, but failing shock dampers up front. So now I'll need to replace the shocks and possibly the strut bearings and mounts. Any suggestions on what to get?

To remind everyone, I've got the ROW M030 suspension. I don't track the car. And I don't want to spend PSS9 kind of money.

If you are only replacing the front then replace like for like. You could also upsize the tyres. The 987 uses the same width but a tad more on the aspect ratio.

Comfy ride;

1. Taller sidewall
2. Less aggressive tire (softer sidewall)
3. Softer shock (in compression)

Stock base or 030 springs are still relatively soft so they should be fine.

I suggest downgrading the shock to the standard model Bilstein.

I've just removed the 'touring' suspension from my 1999 Boxster to put on the RoW M030. I'd be happy to sell you my old suspension - cheap! Springs, struts, sway bars.

Koni has some new shocks for 986s that might be a good choice to look into. In particular, they have a FSD option that is supposed to ride better than stock, and may fit your needs perfectly. The only thing is I'm not sure if it's ROW M030 ride height compatible - you might want to check with Koni on that. Here's a link:
Porsche Boxster - Koni U.K

http://www.koni.uk.com/home/images/s...ster%20FSD.jpg

I'm trying a set of the Koni sports (their manually adjustable shocks) on my 986 that now has 110k miles on its original shocks. They're also a new product for the 986 - haven't seen anyone else view them (or the FSDs) yet. I've had very good experience with Koni shocks on every other car I've ever put them on, though. Konis tend to have exceptionally good valving.

Thanks, jakeru, for your very first post ever!

pharaohjb, thanks for the offer, but decided against changing the whole setup.

You're welcome! (Your thread was enough to bring me out of lurk mode. :) )

I had another idea - you might also want to look into whether your springs have settled so the ride height is below factory specifications. This happened on my 986 (which originally came with the standard/non-sport US-spec spring, but I found in measuring the ride height that it has settled to now have basically the ROW M030 specification ride height!)

Too low a ride height for the spring rate could mean more crashing on the bump stops more than the designers intended. For that matter, check out whether your bump stops are still in good shape. You can do this easily without disassembling anything. My rear ones appear ok on my 110k mile 986, but the front ones are badly crumbling apart and need to be changed. These bump stops effectively become part of the spring when the suspension is under compression.

Best of luck!

Will have my mechanic do that. Thanks.

Now that you're not lurking, do post a thread in the "Show and Tell Gallery" section with pictures of your ride. Everyone always appreciates when you introduce yourself there and you get to brag about your car.