Can anyone tell what the differences are between the '01 Boxster S suspension and the M030 suspension?

How much lower?

How much higher spring rates?

How much difference in shocks?

I have the option of this or a new set of Bilstein or Koni Sport shocks.

Thanks!

 

I ran across this old thread. It doesn't answer your questions directly but the information might help.

https://rennlist.com/forums/showthre...ferrerid=98377

 

First, do you mean M030 or ROW030?

I just put the ROW030 in my 2004 2.7 5-sp.

the spec is -15mmF -10mm R. I got less drop than that.

they dont spec the damping nor the spring rates, but it is MUCH stuffer than stock and consequently MUCH harsher. It will be great on the track, which is why i bought it, but for the road - i advise not to do it. Unless you have billiard-table smooth roads or like abusive rides.

That said, i would do it again, but this car gets a lot of AutoX and track use.

Bilstein HD is very close to OEM.

Grant

 

wow, gfl! you're the first person i've ever heard call the M030 abusive. i very much disagree.

it's definitely stiffer overall, but i think the street ride is great. it's a little stiffer overall, but the biggest difference is the neutralization of understeer. the standard setup, S or base, is designed to understeer like crazy. the M030 bars are much more neutral & allow you to rotate the car easily. the tendancy to plow into corners (absent very aggressive turn-in) is greatly reduced. the M030 is a wonderful compromise setup: great street ride, but plenty fun at the track.

 

Here in the northeast, we have lots of pot-holes and very badly patched roads where plows simply pull chunks out of the surface, leaving vertical edges. Everywhere. That's where the problem is.

As to me being the first, all I know is i just wrote a lengthy review on Pedrosboard, and pretty much everyone said "yep, spot on".

So i stand by my advice to people considering it. Its a super setup for performance (also consider 225/45-17 fronts top dial out most understeer) but it is NOT friendly for rough pavement. Or small curbs. etc.

I would estimate 40% plus stiffer if i were to take an unsubstantiated, but educated guess. Compared to the Coil-overs i put in another car, the ride is night and day harsher.

Grant

 

you are right about smoother roads; ours are only nasty in town.

at any rate, the M030 struts & springs are actually not much stiffer than stock. they are maybe 5%. most of the extra stiffness comes from the sway bars. for the '01S, here are your numbers:

S:
Front: 23.6mm x 3.5mm
Rear: 18.5mm x 2.5mm

M030 S:
Front: 24.0mm x 3.8mm
Rear: 19.0mm x 2.7mm

the front M030 S is 10.7% stiffer and the rear is 14.5% stiffer.

if you do go the M030 route, i recommend you use the rear bar from the 2.7L M030 cars. It's 19.6mm x 2.6mm which is about 24.6% stiffer than your factory rear bar. it's a bit more neutral IMO.

 

For the swaybars, not the springs. You are guessing at the springs? Knda unclear. I think the 5% number is wildly off from my experience. I've changed a lot of springs.

Note you have not addressed the dampers, which have a huge impact on, well, impact.

And i am referring to the ROW M030 which is not the same as the M030. You don't specify. Which is it? And if its the USA, not ROW, how does the ROW compare to the US/ We know they are different.

Grant

 

the RoW M030 dampers & the US M030 dampers have the same valving. the only difference is the piston length of the RoW; it is slightly shorter to avoid unseating the (shorter) RoW springs at full droop. the high speed compression /rebound valving (the 'knee' in the curve is ~1.75"/sec for both non and M030) on the M030 is nearly identical to the base suspension. this is the parameter that one would generally associate with harshness over bumps. the low speed curves are a bit steeper on the M030 for sure. this sharpens up handling considerably.

the 5% number for the springs was a guess based on experience with a number of different setups in the boxster. i put the M030 spring rates about half way between the OEM & PSS9. since all of the aforementioned springs have progressive rates, it is difficult to compare them numerically. for those inclined, the PSS9 rates IIRC are 260/370 F/R and the OEM are roughly 180/250. by the numbers, if M030 fell squarely between the two, we'd be talking about M030 at 15% stiffer than stock. it doesn't feel that way to me, but those are the numbers. keep in mind again that PSS9 uses progressive springs PLUS 145lb tenders, and M030 and stock setups are both progressive. this really does make it difficult to compare the two in static terms.

i have installed various components of M030, one at a time & mix/match between S & non S components in my quest to determine the best possible setup using OEM components. in my experience, the dampers made almost zero difference at all. the RoW springs were great for the lower ride height, but they didn't seem much stiffer. the sways, and in particular the rear sway, seemed to make the biggest difference in handling (AND harsher ride). in the end, the thing that made the most economical sense in my mind for a great sporty street / track setup was to use the 'S' M030 front sway, the base M030 rear sway, the RoW M030 springs, and skip the M030 dampers. in my opinion, this setup is comfortable on the street with MUCH sharper driving attributes.

much of this is obviously my opinion. much of this is backed up w/ lots of drive time (street & track) and in some cases, data acquisition & shock dyno time.

 

Its great input. Not 100% matching my experience, but hey, maybe its the cold weather...thick oil....

Agree about the difficulty in specifying numbers both for springs and especially dampers. Dampers have curves on two different axes (velocity and excursion), so its a bit of an integration effort to reduce to a figure!

Grant

 

Wow. Great thread. While I'm new to the 986, I'm not new to shocks and springs. On progressives, they are as much art as science. My extensively modded Audi A3 had H&Rs which I hated. Then I switched to Vogtlands which were fabulous - not stiffer. Rather, they transitioned from soft to hard way better than the H&Rs.

Thanks - you've given me some really good ideas for moving forward.

 

Old thread, I know ..

I recently did a suspension overhaul on my 03 Boxster S 6sp; I replaced stock S suspension with M030 struts, springs & anti-roll bars (w/bushings) along with new shock mounts & drop links.

I'm still in the early days of experiencing the new setup but my worst surprise so far is the "lift" my Boxster gained !!
I took measurements before & after the installation; my car was lifted around 15mm in each corner.

I searched part numbers & confirmed that my springs are US-M030: yellow & white + blue at the front, brown & gold + blue at the rear.
RoW M030 springs as far as I can tell should be: red & yellow + blue at the front, silver & red + white at the rear & they are supposed to achieve the widely mentioned lower ride hight.

I'm not particularly keen on the suspension drop but on the other hand, I hated the "lifted" look on my Boxster so I'd like to hear from the board:
- should I go back to stock springs?
- should I get RoW springs & install them over US struts? (would that be an issue as mentioned above i.e unseating the springs)

TIA

 

Awaiting expert opinions ..

 

Ride quality is a subjective thing, much like ride height. I acquired my 03 S in the summer of 2022, with 43k miles, and three very careful previous owners. I was initially disappointed on how the car handled, compared to my very well sorted 993. Moving forward, a set of custom built Tramont cup wheels, wider, with more aggressive offset…with the same tires installed on them, made a big initial differential in the cars composure.

Suspension research was next, I hoped to not compromise the ride quality too much, but wanted to lower the ride height for a slightly more aggressive stance. I considered the ROW M030 set up…expensive, and only an estimated 10mm drop. I ended up getting Koni Sport Yellows, with H&R lowering springs. All the factory top mounts were in good shape, stock sway bars left untouched.

The drop ended up being well over one inch, nearly 1 1/2”. That suspension change, ever so slightly changed the ride quality, but absolutely transformed the car’s handling. The stance is spot on to my eye, and the car is a weapon in the twisties.

I bought the bits from @Gert at Carnewal, a Rennlist sponsor. Unrivaled knowledge, service, price, and integrity, IMHO.

Now I just need to get the exhaust note to my liking.

Good luck with whatever direction you choose.

 

Thank you for taking the time & sharing your experience..

with my current suspension setup, the ride quality is minimally affected. I'll be putting the handling to test in an upcoming track day.

with regard to exhaust, I believe we are on the same path; I'm too still searching for more of the characteristic flat six note in my Boxster.
I have the PSE but it sounds muffled to me so I'm considering Euro/ ROW headers (the details on my recent thread) but it seems to be a hassle.

 

I have a US spec 2001 Boxster that I have installed aftermarket equal lenght headers without cats, 200 cel sports cat downpipes and 986.2 muffler without PSE.
The sound could be still better, but is now much nicer than with original headers and downpipes.
Only thing that was a bit more to do was to make the O2 sensors wire extensions to each O2 sensor. Not a difficult to do, but takes a bit of time.
After the change the car accelerates a bit more freely and sounds better.
To work on the sound dilemma, I am working on with modifying the muffler.