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+--- Thread: Suspension noob here. what's the perfect setup (/showthread.php?tid=5946)
Suspension noob here. what's the perfect setup - Ekstra - 10-26-2014
Hey suspension gurus need your help. Planning on rebuilding the whole undercarriage of my car so sway bars, control arms, bushings, ball joint, shocks, springs, brakes. and control rods. Im aiming for a 1-1.5 inch drop in my ride height with a tight but not uncomfortable ride quality what i had in mind was:
Sway bars:
Front: "Limo Bar"
Rear "500e" sway bar
Brakes:
400e or 420e brake convertion
Springs:
H&R 1.3" sport springs front and rear
Shocks
Bilstein "HD"
Bushings:
Hedgehog motorsports (urethane) or just plain oem (urethane may be too harsh)
Im not really sure if my setup will be good. i drive a 1993 w124 300d 2.5TD. Its already quite low. I just want it a tad lower. With reasonable handling. Right now everything is creaking and over all the car feels floaty. Can anybody help me?
RE: Suspension noob here. what's the perfect setup - raysorenson - 10-26-2014
Sidestepping the perfect metric I'll provide some info.
W201,w124,r129 suspensions are, for the most part, the same. R129 shocks and struts will be shorter, IIRC. Springs will swap between all these. The R129 will generally have much stiffer rear springs than the sedans. The sedans will have stiffer fronts. Wire diameter is the best indicator of spring rate. Diameter info here http://www.w124performance.com/images/W124_suspension/124_coil_spring_specs.pdf
Since cutting springs works so well on these cars, using MB springs can allow you to make a more educated choice with greater ride height options than aftermarket lowering springs.
Possibly the best coilover option will be the ground-control setup for the 190e. It's fairly expensive and it's built around custom valved Koni yellows, which are known to be fairly harsh dampers. There's also yellowspeed. There are no digressive-valved options, which do a great job of taming massive spring rates, unless you go with E36 BMW stuff.
I don't mess with sway bars and won't tell you what I think of sway bar tuning out of respect for everyone else who swears by them.
I'm using Kmac LCA bushings which are essentially metal drums with a thin layer of urethane bushing. They're probably harsher than the race durometer hedgehog stuff. It's harsh if you're looking for it. The uninitiated don't even notice. The first thing I notice when I drive my wife's stock '93 124.128 is miserable mushy vagueness rather than smooth sailing. Tire choice can do a lot to take the edge off of bushings. I use 225/50/16 Cont DW's over 8" wide EVO 1 wheels. Conti DW's are noted for ride quality in summer tire tests.
My setup is uncut 400e sportline springs up front and R129 SL500 springs out back. The rear spring wire diameter is the same diameter as the stiffest available W124 rear spring from the E60. Kmac LCA bushings front and rear, hedgehog everywhere else, including rear subframe bushings. Your rear axle will never generate the kind of cornering force modern summer tires can provide with stock subframe bushings. Koni yellows for adjustable rebound to handle the spring rates. The R129 springs required a lot of cutting. Ride height is 10-13mm lower than the '93 124.128. The front battery is gone, with 2 in the spare tire well and I have a trailer hitch. When alignment was set at zero toe front and rear and -.5* camber front and rear handling was generally neutral. With the front camber moved to -1.5* it's definitely moved more to the oversteer side.
The front axle generates amazing traction with good tires and I'm not easily impressed. Front axle traction is better at lower speeds due to the huge amount of caster Mercedes dialed in on these cars. At speeds above 70 the car gets a little more neutral. Auto X machine. Without added weight in the rear, the chassis likes to completely unload inside rear tire in tight cornering. This negates all tuning to reduce understeer. The batteries and hitch fixed that. The rear Koni's have harsh compression, probably due to a little "I don't give a shit about this dinosaur of a car" on Koni's part.
If you install springs with a serious spring rate in the rear, you can only lower it so much before the spring comes completely loose in it's perch at full droop. I don't need to use the compressor to remove my rear springs since they're only compressed about 6mm at full droop.