considering new shocks & springs: background + questions

[kflick]

The shocks and struts on my 95 E300D are badly in need of replacement. The dealer confirms this after my complaints about the car feeling under-damped.

So, I'd like to make the ride more responsive since I'm having to do the replacements anyhow.

My goals are:
less body roll in cornering
more confidence in high speed manuevers (lane changes, on/off ramps, etc.)
a sportier feel - more fun to drive
smooth ride quality (think CLK not Caddy)
comfortable (subjective, I know...) noise and vibration levels
I know my diesel doesn't perform like a sportscar, but I want more fun when tooling around and more confidence when rolling at high speeds.

I've been reading alot in this forum and on mercesesshop.com and am currently thinking about:
H&R sport springs
Bilstein sport shocks/struts
same 15" wheels, new 185/65 tires (or 185/60 @ -3% tire diameter)

I'd happily order these up if I could get a sense of my future ride quality. I have no hesitation to sport-tune my suspension, but I do not want to feel all the bumps on long rides. I want to dive into corners, but I don't want to feel the road too much on long highway trips.

Here are some factoids I've gleaned (feel free to correct if you are absolutely sure):
Bilstein HD & Sport have the same valving, but different ideal travel ranges. (from Bilstein techs via Carl at BergWerks)
Correct Bilstein model numbers for my 124.131 Chassis are sport v36-0365 and b36-1470 and HD v36-0361 and b36-1385
H&R suggests that the W124 sport springs (unsure of model number) can be used on the Diesel, although they are untested in this application. It may require thicker pads up front to compensate for the slightly heavier motor (also some question about whether or not the motor is actually heavier since it may be a reworked normal gas motor).

OK, Question time:
Has anybody used the H&R sport springs on their W124 diesel?
Just how sharp/harsh/stiff/unpleasant is the ride on the H&R-Bilstein sport setup? Would I be taking the nice smooth high speed quality out of the ride?
H&R OEM sport springs & Bilstein HD shocks with wider, lower AR tires? If I don't lower, I can change the tire size to 205/60ish.

Bottom line:
I want a comfortable family sedan that is fun to drive aggressively when I want to, without taking too much away from the comfortable Benz sport sedan feel.

Thanks a ton!
Kevin

__________________
1995 E300D 115K miles (stock)
on biodiesel since 2003 & running great

When you go to these shorter stiffer springs and the shorter, stiffer shocks there will definitely be a much firmer ride.

If you want to do it anyway, you can accomplish the same thing with factory parts for much less money. I have posted the MB part numbers for the 124 Sportline suspension. This includes sway bars, springs and shocks. Since you are lowering the whole car, you will need a good four wheel alignment afterward.

Also I think there an article under Cars or DIY above about the entire Sportline conversion. It was done by JCE on one of the most beautiful 124's I've ever seen. I have met John in person and seen the car and was offered a test drive. Unfortunately we ran out of time.

On my car I took a different approach. I bought and put in the Sportline sway bars and used KYB shocks which turned out too stiff, but does indeed give me good handling. If I had the funds I would do the whole Sportline setup and realign. By going to the short shocks and springs I would probably have a better ride than the KYB's are offering, but lowering the car I'm sure would be a great handling advantage.

If you can't find the part numbers and info by searching let me know and I will look them up for you.

Doing the springs and shocks without the sway bars, I believe, would be a mistake. I would either do the sway bars, or the sway bars AND the springs/shocks.

Good luck,

[gsxr]

1) You need Sportline swaybars (or what I call "Sportline Plus", which is a front limo bar and 500E rear.) That will reduce body roll without a significant penalty in ride quality.

2) Lowering springs will be the main culprit in killing ride quality. Performance improves but you WILL feel every pavement imperfection. If you really want to keep the car comfy, I'd stick with stock springs. Aftermarket springs will work just fine with the diesel, the weight difference compared to the gassers is nil, regardles of what you've been told otherwise. You adjust spring pads to fine-tune ride height and may not need a thicker pad at all. The factory Sportline springs are allegedly VERY firm, so don't get those thinking they're softer than H&R or Eibach! They're probably about the same.

3) Shocks should be purchased to match your springs. Comforts won't work well with lowering springs - not enough rebound damping, you'll want HD's, or preferably Sports (or OE Sportline, or KONI). With stock springs, either use Comfort, HD, or KONI. I would never recommend KYB, they have a reputation of wearing out in 25-50kmi, where Bilsteins have a lifetime warranty and usually work well for 100k. KONI has lifetime warranty also.

4) Stick with the stock tire size of 195/65/15 on stock wheels. One of my favorite upgrades, which I highly recommend, is getting a set of 16x7.0 wheels from a W202/203/208 chassis, with 205/55/16 tires. These fit perfectly, look fantastic, and improve handling dramatically with almost no penalty in comfort. Photos of my car with these wheels are here:

http://www.meimann.com/images/mercedes/87_300D_white/


5) You need to replace your shocks no matter what because they are bad. I'd start there (with either HD's or KONI adjustables), immediately followed by the Sportline (or "Plus") sway bars. More 124 sway bar info is in the PDF linked below.

http://www.meimann.com/docs/mercedes/124_swaybars.pdf

[dieseldiehard]

If you go all the way, you will definitely feel the bumps more. I rode in a lowered, chassis tuned 124 and it was like riding a roller skate. Holes the size of a pecan left noticeable bumps, so the astute driver learns to dodge little defects in the road surface.

You should search over on the Performance Paddock listings (where this thread really belongs) using camber or some such word.
Rear camber kit
I recall there was a lot of whanking over an Australian rear camber kit.
You'll need something to tweak the camber after lowering to prevent the greatly increased tire wear that will come about.
I like my W124 with new comfort Bilsteins, after my experience with the roller skate E500. I like to relax a bit and not have to worry about chipped teeth from bumps in the road.
DDH

[gsxr]

You don't need to worry about camber kits unless you totally slam the car to the ground. The factory Sportline models have no more camber adjustment than any other 124, and sit about 1 inch lower than a normal 124, about the same was the 500E. None of them have excessing tire wear. Going 2-3 inches dropped will cause excess negative rear camber that can cause some rear inside tire wear. My car is about -2 degrees in the back (and lowered about 1.25 inches) but I don't have excessive wear. It helps if you corner hard, that evens out the wear...

[dieseldiehard]

Are you running performance grade tires, Dave? I have a friend that ground down the edges on some in less than 1K miles. Can't recall the brand, they were Japanese I believe. A camber kit solved his problem.
DDH

[gsxr]

I've been through a set of P7000 Supersports, and SP8000's. I have a set of Pilot Sports about to go on when the 8000's are toast.

Mercedes normally wear both edges of the front tires, and to a lesser extent, the middle of the rear tires. Lowering will add more wear to the rear inside but that's about it. You can get the camber within spec up front, but usually it's a bit negative in the rear. Having a PROPER alignment is essential. I only let the Mercedes dealer touch my car for alignments. Almost no independent shops can do it right (unless they happen to be a Mercedes specialist.) If they're not using the steering box lock tool, and the spreader bar, it's not done properly (IMO). BTW - I request the computer printout from the dealer with before & after numbers, so I know exactly where it's at. I'd bet a lot of complaints about tire wear are more related to alignments than lowering without camber kits, but that's just IMNSHO...

BTW - most of the solutions for rear camber kits are in the $200-$400 range. I'd say if you can get the rear camber below -2.0* (preferably about -1.0), that's just fine, leave it alone. If you're at -3.0 or -4.0, yeah, a camber kit might be in order....

[rdetoy]

Kevin-

The only way you'll know if a new suspension will meet your desires subjectively is to do it, since it is a rare thing to find a sporting diesel to use for comparison. I used to own a rather highly modified 124 built at Brabus in Germany--a 'gentleman's express' kind of car. While it did not say so on their invoices, I'm willing to bet that the progressive rate lowering springs on the car were sourced from either H&R or Eibach. By the time I bought the car the previous owner had recently installed Bilstein HDs. The car ran on 16x7 modular BBS wheels with 50 series tires, which are somewhat more extreme than you are contemplating.

The car was not harsh at all. It was highly responsive and extremely satisfying to drive..almost intuitive. Its reflexes were extremely sharp without being edgy. All of this was a good thing since the engine had every Brabus mod available and was very, very strong. Small impacts were well-absorbed by the suspension and the HDs were well-matched to the springs in terms of both compression and rebound. Cornering transitions were much more secure with the performance suspension and the car could be more precisely placed in corners and rotated more easily than would otherwise be the case with stock suspension.

The only meaningful downside was the range of travel was reduced by the amount of the lowering, about 1.5 inches. Thus, on bigger hits the suspension compressed to its stops more quickly than stock suspension would, and no car handles well with infinite spring rates. On the other hand, the suspension recovered better and more quickly from the big hits and was thus easier to drive.

Subjectively, I felt the car looked much better with the suspension lowered--it was, after all, a genuine performance car and not a boulevard poser. Objectively, the modifications to the car were astonishing in terms of showcasing the performance potential built into these cars that is never appreciated in stock form. Stock, these cars offer an incredible array of virtues which can be appreciated as they are, or they can be sharpened and made more focused if the owner wishes. If you desire handling that (dare I say it?) is closer to the BMW end of the spectrum, then I highly recommend the suspension mods you're contemplating. Stick with Sportline/H&R/Eibach for springs and either Koni reds (for the fine-tuning adjustability) or Bilstein HDs. The Sports are too stiff for a daily driver, in my opinion. The sway bars are an excellent option to explore. Before you start with modifications, however, make sure that all your suspension hard and soft parts are up to spec, and make sure the car is properly aligned afterwards.

Though my family groans at the prospect, I will soon be lowering my 300SD, tastefully, in order to better match my preferences in the ride/handling/looks compromise. Enjoy your project and let us know how it turns out!

[kflick]

I really appreciate all the help.

I figured out a couple of days ago that all this stuff is totally subjective - stiff is stiff and soft is soft... people like whatever people like. The thing is that I have no idea whether or not I'm a "roller skate" kind of person or not and I'd just have to try whatever solution seemed best at the time. It is actually rather amazing that there are solutions for every kind of driving style out there.

I thinking to go with just the Bilstein HD's and my OEM springs with slightly wider tires. That'd be a good first step, anyhow, that wouldn't prevent me from doing other things (swaybars, new springs...) in the future. I got a tip from another forum that using the thinnest pads with HD's produced a 3/4" drop anyhow.

To make the decision easier, I just bought a 1976 BMW 2002 that I can totally stiffen up to satisfy my urges for a sharp handling car!

Thanks to all of you for weighing in on the subject.

[gsxr]

Originally posted by kflick
I got a tip from another forum that using the thinnest pads with HD's produced a 3/4" drop anyhow.

This is not true. **sigh** I feel like I'm repeating repeating myself about this. Try searching on the forum for more details. The pads are for small fine tuning, not 3/4" drops. Read the factory service manual for more info as well...

Ok, guys...I was reading your posts and have a related question. Ever since I bought my car, I've been irritated by the relatively high distance between the top of the front wheels and the bottom of the front fender in the wheelwell. The rear wheels are just fine. So, after reading related posts, I discovered that when my struts were replaced (by a previous owner) that they had used Bilstein's instead of the Boge OEM's. They also used a non-OEM set of thick pink-colored spring pads. So, I had the spring pads replaced with the stock, OEM product from Mercedes (Size 1). Although lower, the height still seems to be wrong! And the replacement happened about a month ago, so surely by now they pads have settled in place. The distance is probably almost 4 inches between top of the tire and the bottom of the wheelwell. I saw a '92 300D the other day and the distance between the two was more like 2 inches or so. The other oddity is that the right side seems to be lower about 1 inch than the left side when parked. What could be causing all of this? Any idea? If I were to switch to the Boge shocks, would that suffice? Or should I replace the springs? Thanks!

[gsxr]

More likely the rear is too low. Measure all four corners from the center of the wheel (middle of the star in the wheel center) to the underside of the fender lip. I'd expect it to be about 15.5 inches, give or take a half inch, all around. Let us know what you measure on each wheel, and also note how much fuel is in the tank (a full tank drops the rear about 1/2 inch). Changing shocks will have little, if any, effect on static ride height.

It was 15.5 inches in the rear and between 14.75 (the driver's side) and 15 inches (passenger side) on the front wheels. Is this correct? I still see a wide gap between the top of the tire and the fender wheelwell on the front tires, to the point that I can see the front bumper air dam/grill vents from the inside out. Most other cars I've seen have only two inches of space between the top of the tire and wheelwell, whereas I still have about 4 inches in the front. Any way to get that down?