suspension is too soft

[GGR]

Hi all,

now that the brakes are working properly I took the car for a test drive and the chassis need quite some attention. By the way the car behaves under acceleration I can tell the trail arrms bushing are shot. The rear axle also moves laterally.

In the front things look better. No play in the steering, and the bushings look better. But I may replace them as well.

The shocks are shot, and they are worse in the froont than in the back. When I push on the fenders the car really goes down easily and dives a lot while braking.

My first question is about the shocks. These are stock Bilsteins with four green strips. I heared Bilsteins have a life guaranty and that in case of problem they can be sent for refurbishing for free. Is that a legend? If no, where should I send them? If yes, is it still a good option to have them refurbished compared to buying new ones?

I read on this forum that some have fitted progressive springs. I also read that some sport rated springs are available. Did anyone ever tried to fit springs from a W108 sedan? They are rated a bit stronger. If yes, only in the front or all round? with what results?

Also, would the sway bar fron a w108 4.5 (23mm) fit on the Pagoda? Would that be a good upgrade?

Thanks!

[dseretakis]

I can't answer any of your questions but it seems like you're going to get your car sorted out soon enough. Does this mean we will be driving our brown babies out to PUB this summer?

[hauser]

Koni shocks are adjustable.  You can dial in the setting you're comfortable with.

[ja17]

Only the Bilstein replacement shocks have the guarantee. In addition I believe you must be the purchaser of the shocks. All Bilstein shocks have a date stamp on them. Most likely they are original. Fresh Bilstein shocks make a major improvement in ride quality and handling. These gas filled shocks will also improve ride height a bit.

[zoegrlh]

Bilsteins for me all the way.  I replaced my old shocks a few years ago with Bilsteins and my ride improved 100 per cent.  I also replaced my steel wheels with alloy wheels, this too improved the ride.
Bob

[stickandrudderman]

You've identified that you need some new rubber bushes; cheap and relatively easy to do.
Any new shocks over old knackered ones are going to be an improvement, so unless you're going to do back to back tests with different manufacturers to see which gives the ride that suits you best, I'd stick to simply fitting std shocks. The springs are an often overlooked item that stands little chance of giving the same performance as when they were new, and fitting new ones from MB is nearly always going to improve ride quality and restore the correct ride height and without costing the Earth. I fit a lot of springs.........
It's a shame that so many of these cars are not performing as well as they should for want of knowledgable upkeep. I drive very few that drive as good as they should but not all owners have bottomless pockets or indeed the inclination to improve their cars over and above the legal minimum requirements. There's the old arguement about which is best, 230, 250 or 280. My contention is that there are many 230s that will out perform 250s and 280 just because the comparison between 50 year old cars doesn't really bare scrutiny and you should buy whichever one feels the nicest to drive. You're not after all, looking for improved lap times around Silverstone are you?

[W113SL]

Regarding changing the front sway bar:  Any of the 108 and 109 bars will fit, however there will be some interference with the weld flange.  I fitted a 300SEL 25.5 mm bar on my vintage race car along with urethane bushings and it improved handling greatly.  I also installed shorter and higher spring rate coil springs from Hypercoil.  Of course the biggest single improvement came from custom made dual adjustable Konii shocks from Truesports Racing.  These changes were made for a cae that would be vintage raced, not a street car.  I would replace the tired shocks and any worn bushings first.

[ja17]

Hello Pete,

Nice to see you around.  Might be interesting if you posted some pics of your old vintage racing W113.

[GGR]

Thanks all for your input.

I did some research about springs on EPC and found that front sprigs "with higher loading capacity" were available, p/n 108 321 03 04. These are standard W108 springs and diameter of the wire is 16.20 mm instead of 15.6 and has 10 windings instead of 9 3/4 compared to the original Pagoda spring p/n 113 321 04 04. The workshop manual also reports some springs for "harder suspension for bad roads conditions" p/n 113 321 08 04. Diameter of the wire is 16.20 mm and number of windings is 9 1/2. I measured the wire diameter of my springs in the front and I got 16.20 mm, same as compared to the ones of a spare W111 3.5 Coupe front axle I have. So I guess I have the 108 321 03 04 "with higher loading capacity" due to A/C and auto transmission. I will keep these for now, though I may have to cut 1/2 a winding to get something comparable to the "113 321 08 04" to maintain proper ride height the day when I take out the A/C, fit a manual transmission and transfer the battery in the space behind the passenger seat (a small "Braille" dry cell battery fitted horizontally under the cover).

Regarding changing the front sway bar:  Any of the 108 and 109 bars will fit, however there will be some interference with the weld flange.  I fitted a 300SEL 25.5 mm bar on my vintage race car along with urethane bushings and it improved handling greatly.  I also installed shorter and higher spring rate coil springs from Hypercoil.  Of course the biggest single improvement came from custom made dual adjustable Konii shocks from Truesports Racing.  These changes were made for a cae that would be vintage raced, not a street car.  I would replace the tired shocks and any worn bushings first.

I measured the diameter of my sway bar and it is 20 mm. I'm going to replace it with a 23.5 mm out of a W108 4.5. I compared the shapes with the one on my coupe and indeed the Pagoda one is curved on the sides. Do you mean the sedan sway bar will interfere with the weld flange at the bottom of the front rails? How did you go about that? Did you grind the weld flange as needed or did you put some spacers in front ala 6.3?

I'm also planning to fit poly bushings for the rear trail arms, front axle spring leafs and sway bar from Coxracing. I will need to fit some 6.3 front axle spring leafs which are shorter to preserve caster as the Coxracing bushings do not reproduce the offset in the front axle bushings. I know I will loose a bit of smoothness in the ride as all tarmac imperfection are more directly transmitted into the car, but I did this on my Coupe and precision at higher speed is greatly improved. Another improvement I did on my Coupe that I will do here is to stiffen the rear axle cross strut, by compressing the rubber buffers more. I did this by introducing some thick washers behind the inner pot as the w/shop manual calls it (that big concave flange or washer) and by replacing the outer pot by an inner one (bigger diameter of the center hole) so that it can go over the hedge of the strut. Again thick washers on the outer side and tighten the nut as much as you can. Adjustment of the rear axle centering then has to be controlled. This has eliminated a lot of lateral play in the rear axle of my Coupe and is a great improvement in tight corners especially on degraded tarmac. The back of the car just stays firmly in line instead of "tailing" as it was doing before. I think this will be an even greater improvement on the Pagoda given that its shorter wheelbase amplifies tailing due to rear axle lateral movement.

For the shocks I'm tempted to go with stock four strips Bilsteins for now. Reason is that I looked into Konis for my coupe and by doing quite a lot of reading I discovered that the characteristics of a shock (compression and rebound) is closely matched to the rating of the spring it works with. Going away from that hampers that relation and results are not good unless you really know what you're doing. I'm not qualified enough to determine what adjustment is best. Here W113SL could share his experience with his custom made dual adjustable Koni shocks and the way he determined what compression and rebound adjustments were needed. I tried to find out how this was done on the net but I was not successful.

I also scored a set of four 14 x 6 light W123 300D aluminum wheels that take the hubcap. The spare wheel will be a 14 x 5.5 as I couldn't get a fifth one of the others. This will take a good 50 lbs away from the car and reduce un-sprung weight. But most importantly it will reduce rotation weight by quite a bit. I've read that any lb saved from rotation weight is equivalent to up to 8 or 9 lbs taken off the car. I already have a set on my coupe and I could really tell the difference.

I can't answer any of your questions but it seems like you're going to get your car sorted out soon enough. Does this mean we will be driving our brown babies out to PUB this summer?

I think the car will definitely be able to drive up there this summer as it already drives quite well. It may not have gotten all the improvements I've just described already as I need to finish the engine transplant on my coupe first.

I'm taking the Pagoda to inspection in the coming days. BTW, does anybody know if they check emissions on a 01/71 car in Washington DC? I was unable to find the info on the DMV website.

Thanks all for the help!

[GGR]

I corrected the toe yesterday (had too much toe in) and this had a real great effect on the car's handling. I'm used to the W111 chassis and it's amazing how the W113 shorter wheelbase makes it much more sensitive to any chassis adjustment.

Stangely, the shocks seem also to be improving. I already observed that phenomenon on a BMW 3.0 CSI that I restored some years ago which had also stayed several years in storage before I got it. By then, someone explained to me that shocks that have stayed long without any action needed to be "primed" again by some activity. I don't know how true that explanation is, but the fact is that when I was pushing down on the Pagoda's fenders a few days ago it was going down (and then up and down) very easily while now dampening is much more effective.

[stickandrudderman]

You're not after all, looking for improved lap times around Silverstone are you?

Or perhaps you are?

[GGR]

Or perhaps you are?

Well, I'm surely not planning to race that car though I would not say no to some track laps from time to time. I've learned that track is hard on cars and reveals a lot of what's wrong with them in only a few laps. It's an excellent exercise to put them right.