Improving my W124's handling
Improving my W124's handling
Goals: reduce body roll and front lower control arm bushing deflection, slightly reduce center of gravity while doing my best to not lower the front suspension roll center.
Parts:
R129 500SL springs. I'm sure the SL's suspension was tuned with a higher frequency (stiffer) than an '87 124.133. Adding the fact that the SL has about 1000# more curb weight than my 124, I think it's safe to assume that there will be a significant increase in spring rate. I can't use a slammed car for a daily driver and I don't like progressive springs, so used Mercedes springs are my favored choice.
Koni Sports (yellows). I'm not crazy about Koni yellows, but they're the only dampers I can find with adjustable rebound to keep the extra spring rate under control.
Kmac lower control arm bushings. They should keep my lower control arm bushing deflection within acceptable limits. I thought about turning some delrin or polyurethane stock on my lathe to make some bushings but Kmacs have the added advantage of allowing me to raise the lower control arm pivot point to help keep the roll center from dropping as much as it would if I had just lowered the car.
Stock sway bars. I'm keeping them for now. I'm not a fan of thick sway bars, they add spring rate to the outside wheels in corners that your dampers aren't tuned for, causing a goofy bounce in undulating corners. Hopefully the stiffer spring rate coupled with precautions to keep the front roll center higher will provide an acceptably low amount of body roll.
This is my Christmas present to myself. All the parts are being shipped to me as I write. I'll post impressions.
Modified K-mac front lower control arm bushing. The though bolt used to turn both the inner bushing cam and the eccentric washers to adjust camber/caster. Now the bolt only turns the bushing cam, which I will use to adjust the height of the front control arm pivots and thus, roll center. I'll use the modified washers to adjust camber/caster and twist them with the welded on nuts. It's gonna take a few extra hands to align this front end
Update: First I installed just the R129 front springs. No mods to the springs, no other parts installed. The unloaded springs were shorter with fewer coils, spaced farther apart than the stock W124.133 springs. I drove it like this for a couple of days. It wasn't a dramatic change. Ride height dropped only 19mm giving the car only about 6mm rake, where it had none before. It still looked stock. Spring rate was up, but not dramatically, and ride actually improved since front rebound damping had been reduced by the extra rate.
Tonight I installed the rear springs. The R129 rears had roughly the same unloaded length as the original springs, they had thicker wire than the stockers and the coils were spaced farther apart. I had to remove one coil to get rear ride height back to stock. Since it was apparent that rear spring rate jumped significantly, I installed the Koni yellows on the rear and adjusted rebound to the stiffest setting.
A higher rate on the rear was what I was hoping for and I got it. Body lean is massively reduced, front traction is way up and rear traction is down. This would make a good drift car, but a track car/daily driver is what I'm looking for. The high spring rate on the rear will not be conducive to a 300hp diesel, which is okay because I'm a 200hp kinda guy.
(01-02-2013, 07:55 PM)raysorenson Update: First I installed just the R129 front springs. No mods to the springs, no other parts installed. The unloaded springs were shorter with fewer coils, spaced farther apart than the stock W124.133 springs. I drove it like this for a couple of days. It wasn't a dramatic change. Ride height dropped only 19mm giving the car only about 6mm rake, where it had none before. It still looked stock. Spring rate was up, but not dramatically, and ride actually improved since front rebound damping had been reduced by the extra rate.
Tonight I installed the rear springs. The R129 rears had roughly the same unloaded length as the original springs, they had thicker wire than the stockers and the coils were spaced farther apart. I had to remove one coil to get rear ride height back to stock. Since it was apparent that rear spring rate jumped significantly, I installed the Koni yellows on the rear and adjusted rebound to the stiffest setting.
A higher rate on the rear was what I was hoping for and I got it. Body lean is massively reduced, front traction is way up and rear traction is down. This would make a good drift car, but a track car/daily driver is what I'm looking for. The high spring rate on the rear will not be conducive to a 300hp diesel, which is okay because I'm a 200hp kinda guy.
larsalan I guess I need to look at this stupid ass drip shit. What you have to like mess with those elements on the pump? What a fucking hassle. then use some wire to hold the throttle open or some shit?
(01-02-2013, 07:55 PM)raysorenson Update: First I installed just the R129 front springs. No mods to the springs, no other parts installed. The unloaded springs were shorter with fewer coils, spaced farther apart than the stock W124.133 springs. I drove it like this for a couple of days. It wasn't a dramatic change. Ride height dropped only 19mm giving the car only about 6mm rake, where it had none before. It still looked stock. Spring rate was up, but not dramatically, and ride actually improved since front rebound damping had been reduced by the extra rate.
Tonight I installed the rear springs. The R129 rears had roughly the same unloaded length as the original springs, they had thicker wire than the stockers and the coils were spaced farther apart. I had to remove one coil to get rear ride height back to stock. Since it was apparent that rear spring rate jumped significantly, I installed the Koni yellows on the rear and adjusted rebound to the stiffest setting.
A higher rate on the rear was what I was hoping for and I got it. Body lean is massively reduced, front traction is way up and rear traction is down. This would make a good drift car, but a track car/daily driver is what I'm looking for. The high spring rate on the rear will not be conducive to a 300hp diesel, which is okay because I'm a 200hp kinda guy.
larsalan I guess I need to look at this stupid ass drip shit. What you have to like mess with those elements on the pump? What a fucking hassle. then use some wire to hold the throttle open or some shit?
Update#2
I got the Kmac bushings in the front and roll center adjustment idea worked just fine, it's not too difficult to align, just a little more involved than one bolt adjustment. I was able to dial in 1.1* negative camber at 13.25" front ride height and was still able to keep roll center raised. This nice thing is that once you've maxed out your camber/caster adjustment with the washers you can swing the bushing from 6 O'clock to 4 or 7 o'clock with minimal changes in bushing height (roll center).
I cut the front springs too short and they're too soft. Relocating the battery to the trunk should help ride height marginally, but the springs are still too soft for my taste. I've ordered 400e sportline springs, which I'm hoping will firm up the front adequately.
With the new bushings, the front end has amazing grip considering my Michelin 195/65 15 stock sized tires. Once the chassis has settled into a turn, it takes just a little throttle input to kick out the rear even with an open diff. Since this car has a manual trans and revs stay higher during spirited driving, you do *not* want to lift the throttle during hard cornering. It's a lot of fun, but a slight stiffening of the front spring rate would still be welcome since I could give it more throttle mid-corner or on corner exit to make better use my OM603 torque.
larsalan I guess I need to look at this stupid ass drip shit. What you have to like mess with those elements on the pump? What a fucking hassle. then use some wire to hold the throttle open or some shit?
If you're looking to get lighter up front you can always relocate your fluid reservoirs as well. knock off 20lbs if you move your washer fluid and radiator overflow back too.
larsalan I guess I need to look at this stupid ass drip shit. What you have to like mess with those elements on the pump? What a fucking hassle. then use some wire to hold the throttle open or some shit?
Hmmmm. Didn't think about that. I could route some W/W hoses when I run the battery cable. That would also free up some room in the engine compartment should I ever go with an A/W IC.
Why not just go with H&R springs or the sport lines??? Interesting about the kmacs for the front, when I went for an alignment they said I was maxed out... What are you doing for rear camber?
(01-09-2013, 07:20 PM)winmutt Why not just go with H&R springs or the sport lines??? Interesting about the kmacs for the front, when I went for an alignment they said I was maxed out... What are you doing for rear camber?
(01-09-2013, 07:20 PM)winmutt Why not just go with H&R springs or the sport lines??? Interesting about the kmacs for the front, when I went for an alignment they said I was maxed out... What are you doing for rear camber?
You should check out 190rev.net for a fully poly rear bushing set. I need to do my diff and subframe mount bushings. You can use the r129 subframe mounts but I'm thinking about making my own poly's.
larsalan I guess I need to look at this stupid ass drip shit. What you have to like mess with those elements on the pump? What a fucking hassle. then use some wire to hold the throttle open or some shit?
Convert the trunk and fuel door locks to electric (cheap using eb*y actuators) and use the old vac lines to run your washer fluid, etc.
larsalan I guess I need to look at this stupid ass drip shit. What you have to like mess with those elements on the pump? What a fucking hassle. then use some wire to hold the throttle open or some shit?
I know this is an old post, but I was wondering if you had any updates Ray?
I just got a great deal on some non-SLS SL500 front and rear springs for my 87 300D. After measuring both springs, it looks like the rears will be perfect for stiffening up the suspension. The front springs however do not look like they will be much of an upgrade over the stockers. Like you, I am trying to stiffen up the suspension while maintaining a mostly stock ride height. Looking through Dave M's chart, it looks like a better front spring for me may be off an E320 Cabrio. I believe those cars had a similar ride height to an 87 300D, but the springs specs make me think they would be much stiffer.
I know you went with 400E sportline springs, but I really don't want any ride height reduction and I doubt I would be able to find a good deal on a set. Are you still running stock sway bars?
Thanks for sharing your knowledge and experience. It is really appreciated.
Now that I look back, I suspect the stock '87 300d springs are probably about the same in stiffness but the 400 springs have slightly lower ride height. I agree, it looks like the cabrio springs are a little stiffer.
Yes, stock sways.
Are you sure you don't want to lower? The early W124's look like rally cars next to later ones. Mine is lowered slightly from stock height and is about the same as my wife's stock '91 300d. Before lowering I was getting some weird bumpsteer over dips. Regardless, the R129 springs will require cutting in the rear unless you like the '70s jacked up in the rear look. I was cutting a quarter coil at a time to find the desired height. You can't lower the rear very much with the R129 rear springs before the springs will be loose in the perches at full droop, so beware.
I love driving my car. The spring rate is in no way exceptionally stiff compared to modern cars. Tire wear is great. My wife and I have the same tires and her car is eating them much faster than mine. The real difference in handling came from the Hedgehog Motorsports urethane bushings. In hard cornering, the car is resting on the bumpstops anyway, so the bulk of the increase in cornering force came from the suspension being able to better maintain ideal alignment through less bushing deflection.
Edit, alignment is -1.5* front camber and zero toe at all corners. I was getting a little extra outer edge front tire wear with -1.0* front camber so I moved it to -1.5*. This is with the urethane bushings. I'm not sure a stock bushed W124 would achieve the same tire wear results with the same alignment.
Quote:Are you sure you don't want to lower? The early W124's look like rally cars next to later ones.
Quote:The real difference in handling came from the Hedgehog Motorsports urethane bushings.
Quote:Are you sure you don't want to lower? The early W124's look like rally cars next to later ones.
Quote:The real difference in handling came from the Hedgehog Motorsports urethane bushings.
No, I didn't measure. The '91 is ~14 3/4 all the way around. My '87 was clearly taller.
The bushings are pricey. Small market
Cabrio springs are in. With 1 nub springs pads, front ride height is exactly where with was with the 245k mile stock springs, 15.5". Handling is GREATLY improved. Without having anything to compare against, I do not know if these spring are any better than R129 springs, but I am very happy with these. Ride is only slightly more harsh. Really just feels like a more modern car. I will do the rear springs soon. Shooting for 16" height to have a slight rake. Ray, do you have any ideas where to start on how much coil to cut off the rear springs? I know you went for a lower ride height than I want, but it would be sweet if I could make an educated guess so maybe I could get the height right on the first try.
There's no way of telling. You'll have to install them uncut first then go from there. As I said, once I started getting close, I was cutting a quarter coil at a time. It's time consuming.
Anybody know if the v8 rear subframe will wit in a wagon? I am going to buy one and see. They have another cross brace to prevwnt torque steer apparently.
I ordered sportline springs for the front and cut them to match the rears. They are fine but could be a bit stiffer as I get a bit of rub with 8" rims and 205 16" rubber on the front right over large bumps. So it needs even stiffer spring for lowered ride. I am not lowered much. Just enough to match the back where the sls still works but springs are cut also. It is an 87 wagon with 606.
Also, dont urethane bushings always squeak? I would hate that.
Springs stiff enough to keep you off the bumpstops would be insane. Like 2 or more orders of magnitude stiffer than stock. Have you done the fender and fenderwell clearancing outlined in the MB AMG trunk kit .pdfs? I have 225/50/16, 8.25x16" et34 and never rub. Make sure you've got healthy bumpstops too.
http://www.w124performance.com/docs/mb/W...5_ET40.pdf
My urethane bushings have not started squeaking, but the internet says they can.
larsalan I guess I need to look at this stupid ass drip shit. What you have to like mess with those elements on the pump? What a fucking hassle. then use some wire to hold the throttle open or some shit?
I've never had poly bushings squeak, and I run them on everything. Allegedly the black ones are self lubricating, the red ones aren't.
Delrin is the best if you've got a lathe or cheap machinist.
larsalan I guess I need to look at this stupid ass drip shit. What you have to like mess with those elements on the pump? What a fucking hassle. then use some wire to hold the throttle open or some shit?
Just buy coil overs with the adjustable rear spring perch. You can get proper spring rate by design and set ride height as you wish. I use to mess with all this a long time ago when there were not products on the market but you can buy a pretty nice coil over frt and adjustable rear setup fro around 1500.00 or less.
Sway bars, sway bars, sway bars are the biggest change in handling in these cars. Especially the rear. Get at least the 500e stuff. There are some people doing limited production runs of slightly stiffer stuff.
On the rear end if you lower to much you will wear tires. If you start to make changes to fix that then you need to do the whole thing or you will induce horrible bump steer. Setting up the rear end after you put all adjustable arms on is a big undertaking.
Thanks for the input everyone.
Ray I will have a look at the liner clearance doc. The fenders are rolled a bit already, so it is just the liner rubbing.
Whipplem I am a total neophyte on this coilover thng. There seem to be a lot of crappy coilover brands that squeak etc. I will have to do some reading on this to figure out what to buy. Thanks for the suggestion though; it seems to be the most sensible approach really.
On the rears. I have adjustable camber links back there. They are maxed but the camber is still ok per the alignment guys. So far no terrible bumpsteer. Lowering the car a bit seems to make it corner very nicely, but I never test the limit so I am not actually sure what its limiting characteristic is.
I will post about the 400e subframe going into the wagon when I dive into that.
Coilovers. I am thinking ohlins. Any suggestiins welcome.
For static bushings urethane will work. For moving bushings rubber seems better suited.
Are you seriously considering Ohlins? I'm not aware of anyone making a kit and my personal experience on an Audi S4 is that they rattle like hell. Intrax is the only high-end setup I can think of for a W124. I would be pleasantly surprised to find any high end 4 way damping monotube setup with O.E. quiet operation. If you put an $8000 coilover kit on a W124, you'll probably have an $8500 car unless it's a 500e. Just sayin.
whipplem104 is almost certainly talking about the Ground Control Koni setup, yet for some reason not mentioning them. They come highly recommended by pretty much anyone who seriously tracks the W201. The G.C. W201 kit will fit a W124 perfectly, but if you get the wrong person on the phone, I've heard they'll tell you they don't have anything for your car. They will need to know the weight on your front and rear axles for spring rate and damping.
There are a couple of companies offering coil overs now. GC is the 1st I know of. But there are a few more now. Of course they are going to be noisy and harsh. You are trying to turn it into a race car.
Subframe bolts in but you have to have the 210mm differential and the rear cover to bolt it in. Otherwise it is a drop in.. Done it quite a few times.
It is not any stiffer from a handling perspective that I can tell. It has a tube in front. But the rest is pretty much the same. I am going back to a standard one for my new differential. I am just going to triagle the hell out of it and box it in for stiffness and strength.
Your bump steer is bad. I promise. If you adjusted the a single arm and not the others in length and dropped the car it is going crazy.
I have done a lot of homework on this and all you have to do is go check it. If you are driving around town and doing normal stuff it is not bad but if you are running the suspension through the ringer then it is crazy high bump.
A lack of harshness is the thing that differentiates the high end dampers from the others. My Ohlins setup somehow made tripling my rear spring rate and doubling the front seem like I hadn't taken it far enough, and that was the most common thing reviewers said. They wished they'd gone with a higher spring rate. It made the "Ohlins rattle" that much more of a disappointment.
RE: bump steer, are you just talking about rear suspension? I assume low AF?
Interesting on the bump steer thing. I am not very low but it could easily be dodgy on the limit without me knowing.
All this mod stuff is not really going to be cost effective. It doesnt really make sense to think about how much someone will give you for it when done. It is about what it is worth to you to have the car you want.
I figured the subframe would fit just was not sure about the sls part. Also figured I could probably weld the existing one up a bit and paint it.
Thanks for the differential info. I have a 2.24 I may stick in from my e420; since traction seems to be the limit anyway I might as well gear the diesel up some to reduce wheelspin in the lower gears. I think it runs a 2.65 now.
2.24 gears are terrible. Do not do it. I have them in one of my cars right now because I had the diff laying around and sold the one I had in the car. It essentially makes your car 2 speed. I can run the quarter mile in basically 2nd gear. Reduce power in lower gears or lower speeds with a boost controller. If not you could just make a lot less power and have 3.06 gears and be faster.
Ok thanks. I thought maybe with more torque the 2.24 would be ok, but using a boost controller sounds smarter. I put 2.82 from a w140 into the e420 and it is definitely a lot more driveable now.
The only power that matters is power to the wheels. So just do the math. And remember that you have to have the power in the engine in an RPM that is actually usable. Making 7000lb/ft of torque at 1500 rpm is absolutely meaningless because you will never be able to use it. The factory rates this stuff this way as well. Even the V12 TT engines and what not are making full tq at 1800 rpm. But guess what you are never going to use it. Or if you do it is at launch for about 2 seconds. And guess what you cannot use it because it is to much. Look at your power curve and do the math per gear in your transmission and then to the wheels through the final drive.
Even though we make 700wtq at 4000rpm or so it still does not make any sense because at 450wtq at 6000rpm is still more to the wheels in the next lowest gear. Until you start getting into the upper gears. It about evens out at the top of 2nd to 3rd and then 4th it is almost even the other way around. Slight advantage to 4th gear over 3rd when tq drops below 500ft/lbs. Where in 2nd it has to drop below 445ft/lbs.
I tend to live in the 0-50 mph zone. So early boost and torque for drive ability are important. There is nowhere for me to apply full power for more than a few seconds. Would love to be able to track it for fun eventually recreationally, but doubt it will ever get a cage.
Thanks for advice on doing the math. Seems like a fun spreadsheet to put together.
(10-26-2017, 06:09 AM)atypicalguy Anybody know if the v8 rear subframe will wit in a wagon? I am going to buy one and see. They have another cross brace to prevwnt torque steer apparently.
IIt is an 87 wagon with 606.
Also, dont urethane bushings always squeak? I would hate that.
(10-26-2017, 06:09 AM)atypicalguy Anybody know if the v8 rear subframe will wit in a wagon? I am going to buy one and see. They have another cross brace to prevwnt torque steer apparently.
IIt is an 87 wagon with 606.
Also, dont urethane bushings always squeak? I would hate that.
OK I found an old 500sl non ASR diff and axles to put in. Seems like the SL rear cover has a nicer arm on it to counteract axial rotation of the diff housing, with a long protrusion to one side, so it would be cool to have a subframe that allows use of the SL rear cover.
How hard are these wavetrac things to set up?
Anybody try an SL subframe in a w124? Otherwise I will get a w124 v8 subframe from Jeff in Irvine.
And is hedgehog really the best urethane bushing outfit for these cars?
The sportflex guys in poland had a full bushing kit, so I went for it. Be here in a few weeks I reckon.
I wonder if the e420 and 400e rear subframes are the same. I will have to crawl under the 420 and have a look. I guess the 500e used an SL subframe? Tempting but the track is wider hence the fender flares.
(03-06-2018, 03:08 AM)SurfRodder I recommend getting the rear half of the driveshaft and matching input flange for the diff (and diff cover) from the donor. I have mixed and matched front and rear driveshaft halves many times with no issues..always made sure to match up the mating arrows and never had any vibes or noises...
(03-06-2018, 03:08 AM)SurfRodder I recommend getting the rear half of the driveshaft and matching input flange for the diff (and diff cover) from the donor. I have mixed and matched front and rear driveshaft halves many times with no issues..always made sure to match up the mating arrows and never had any vibes or noises...
(07-26-2018, 02:50 PM)atypicalguy I thought the 300td and the v8 driveshafts had different numbers of splines at the joint between front and rear driveshaft. Apparently I am wrong on this! Could save me swapping the transmission output flange, if so.
(07-26-2018, 02:50 PM)atypicalguy I thought the 300td and the v8 driveshafts had different numbers of splines at the joint between front and rear driveshaft. Apparently I am wrong on this! Could save me swapping the transmission output flange, if so.
Seems like the 87 had the smaller three bolt flange, whereas later cars had larger/beefier ones. So either way on the 722.3 I would be switching the flange. Might as well use the 8 hole setup on both ends as long as it clears the transmission mount.
Does anyone know what spring pads I should use to achieve stock ride height on an 87 wagon with stock sportline springs?
(11-08-2018, 01:35 PM)SurfRodder(07-26-2018, 02:50 PM)atypicalguy I thought the 300td and the v8 driveshafts had different numbers of splines at the joint between front and rear driveshaft. Apparently I am wrong on this! Could save me swapping the transmission output flange, if so.
I think M-B (at least of this era) only made 2 different spline versions...it's been a while since I've tried to swap between V-8/12 cross pattern and larger /6 trilobe halves, but I think I remember that it worked.
I'm pretty sure there were only:
smaller splined section (~25mm) for low power cars (small displacement I6 and I4)
larger splined section (~30mm) for everything else
(11-08-2018, 01:35 PM)SurfRodder(07-26-2018, 02:50 PM)atypicalguy I thought the 300td and the v8 driveshafts had different numbers of splines at the joint between front and rear driveshaft. Apparently I am wrong on this! Could save me swapping the transmission output flange, if so.
I think M-B (at least of this era) only made 2 different spline versions...it's been a while since I've tried to swap between V-8/12 cross pattern and larger /6 trilobe halves, but I think I remember that it worked.
I'm pretty sure there were only:
smaller splined section (~25mm) for low power cars (small displacement I6 and I4)
larger splined section (~30mm) for everything else
(09-20-2019, 09:03 PM)atypicalguy Does anyone know what spring pads I should use to achieve stock ride height on an 87 wagon with stock sportline springs?
(09-20-2019, 09:03 PM)atypicalguy Does anyone know what spring pads I should use to achieve stock ride height on an 87 wagon with stock sportline springs?
(03-27-2018, 08:38 PM)atypicalguy OK I found an old 500sl non ASR diff and axles to put in. Seems like the SL rear cover has a nicer arm on it to counteract axial rotation of the diff housing, with a long protrusion to one side, so it would be cool to have a subframe that allows use of the SL rear cover.
How hard are these wavetrac things to set up?
Anybody try an SL subframe in a w124? Otherwise I will get a w124 v8 subframe from Jeff in Irvine.
And is hedgehog really the best urethane bushing outfit for these cars?
(03-27-2018, 08:38 PM)atypicalguy OK I found an old 500sl non ASR diff and axles to put in. Seems like the SL rear cover has a nicer arm on it to counteract axial rotation of the diff housing, with a long protrusion to one side, so it would be cool to have a subframe that allows use of the SL rear cover.
How hard are these wavetrac things to set up?
Anybody try an SL subframe in a w124? Otherwise I will get a w124 v8 subframe from Jeff in Irvine.
And is hedgehog really the best urethane bushing outfit for these cars?
(10-05-2019, 09:49 PM)JoeB(09-20-2019, 09:03 PM)atypicalguy Does anyone know what spring pads I should use to achieve stock ride height on an 87 wagon with stock sportline springs?
Mercedes used a points system to determine the correct shim and spring parts.
firstly, you need to provide your VIN, to which it will aggregate all the SA codes and provide a baseline number of points. then the option codes from the datacard are added and the vehicles total 'points' determines the correct spring part numbers and the shim pad part numbers.
Wagons have SLS in the rear as well, so the sportline springs and shim pads are very sensitive to the levelling valve adjustment, and it needs to be set correctly, else the dampers can bottom out on the valve and permanently damage them.
If you can find the part number on your sportline springs (stamped into the first coil near the tail), and the number of nibs on your rubber shim, then it will make it a little easier to determine, but not necessarily correct if you have taken sportline springs from a sedan which has different axle weights.
Please read the attached EPC info. Get your vin, and your datacard or take a pic of the metal plates on the radiator support which has all the option codes. use the info in the attachments.
If you do not have sportline suspension as standard and you are only addidng the springs, your rear struts will not correctly dampen the spring, leading to premature failure of the accumulators and strut seals. There is a sportline strut part and also a heavy duty spring and damper set of parts. You need to verify the option codes on your vehicle, else it will only make things worse.
(10-05-2019, 09:49 PM)JoeB(09-20-2019, 09:03 PM)atypicalguy Does anyone know what spring pads I should use to achieve stock ride height on an 87 wagon with stock sportline springs?
Mercedes used a points system to determine the correct shim and spring parts.
firstly, you need to provide your VIN, to which it will aggregate all the SA codes and provide a baseline number of points. then the option codes from the datacard are added and the vehicles total 'points' determines the correct spring part numbers and the shim pad part numbers.
Wagons have SLS in the rear as well, so the sportline springs and shim pads are very sensitive to the levelling valve adjustment, and it needs to be set correctly, else the dampers can bottom out on the valve and permanently damage them.
If you can find the part number on your sportline springs (stamped into the first coil near the tail), and the number of nibs on your rubber shim, then it will make it a little easier to determine, but not necessarily correct if you have taken sportline springs from a sedan which has different axle weights.
Please read the attached EPC info. Get your vin, and your datacard or take a pic of the metal plates on the radiator support which has all the option codes. use the info in the attachments.
If you do not have sportline suspension as standard and you are only addidng the springs, your rear struts will not correctly dampen the spring, leading to premature failure of the accumulators and strut seals. There is a sportline strut part and also a heavy duty spring and damper set of parts. You need to verify the option codes on your vehicle, else it will only make things worse.