ptoro01

That's why I asked about the length of the assembly... coilovers are much different than the stock strut assembly

Legionere

I was wrong, the length works. I had a pair of koni's in my mcoupe struts, which are the same as M3 struts. These BMW struts go in after you cut off the lower perch and all the other things hanging off the strut. You have to ream out the upper ear of the strut, but otherwise its the same size. I don't know how well it works since I discovered one of the struts were blown and I called it quits at that point. My confusion over the length came the 500E strut puliing in from the internal spring, making the overall length shorter than the BMW strut. Too bad one koni was blown.

ronald7410

I believe these are KW's coils along with Intrax Springs

ronald7410

I dont think it's only length that we have to take into account. There's also weight of the vehicle. They might be slightly off where if we install their coils on our cars, they can blow within a year being that those coils came from a 3 series...

Legionere

I agree. If you assume perfect 50/50 weight distribution, the 500e would have about 200 lbs more over the front of the car. I don't know enough about the konis to say how quickly they would fail with this added weight.

Dievs2

if you are afraid about weight, you can put two springs in front, like in the photo before

ronald7410

Hey Dieves,
I love the website but i cant read it! lol. Do you know anyone that has been running this setup for a while? I just want to make sure the shocks wont blow on me...

RBYCC

What are you achieving with a coilover and a spring????

Dievs2

think about it. e36 is a bit lither than mb, so extra springs help coil overs to support extra weight. if coils is not hard enough for you, it helps a lot.
i my self not on coils yet, my coupe is under restoration. but guys in my club runs on coils for over a year now, totally for sport, without any problems. some just with coils, without extra springs. one maniac now planing to put 5.5 AMG kompressor with mechanical transmission into w201. he's already has engine and most of the parts. oh yeah

RBYCC

I have thought it through and with a fairly decent knowledge of the 124 suspension geometry, I'm not sure what if any difference coilovers with or without additionial springs will make on a 124.

Only thing that would convince me is a lap time that shows improvement over a standard or conventionally modified suspension.

Sometimes changes such as too low of a car or limited strut travel actually diminishes handling and performance...unless of course the mod is made for show and not go !!!

ptoro01

The coilover setup is nothing more than just adding another spring to the suspension. Similar as going from stock shocks on a lowered car to bilstein sports. But this is the potential next step, the stiffer the shock, the less body roll. The lowering springs will give the car its stance. The shock dampens and adjusts for road surface. Of course they interact, thus finding the right balance is hard.

So if you are driving on a track, or fabulously even pavement, this additional spring over the shock will add performance, I guarantee improved track times, faster corners. But if you also drive your car everyday, ouch.

Replacing both the spring and the shock to a coilover, will change your whole car, these are heavy cars. My point is to replace the bilstein sports for a coilover for a stiffer suspension. We are trying to eliminate body roll and the 500e sway bars can only do so much.

the_widebody

what a load of toss, it will not make the car better than a well sorted original suspension set up.

using two springs will negate any improvement the coil overs may have made, plus coilovers are only to speed hight adjustment

utter rubbish.

bsmuwk

everybody's entitled to what they please gentlemen.

coils are just another step close to a popped oil pan. atleast it'll look good doing it.

ptoro01

Homeslice, explain how coilovers are an improvement over a finely setup lowered suspension like say the factory sportline in brand new condition.

RBYCC

I keep on forgetting how this 124 forum has become more a "pimp your ride" venue

Has anyone ever considered the "design roll center" of the chassis and that lowering a car does not change it ?

How about a bright young forum member with an aptitude for mechanical engineering applying "Kennedy's Theorem" to the salient points of this discussion.

Extreme dropping, stiffening, whatever else without considering the design roll center will oft times cause a wheel to lift under hard cornering.
Not a good thing for lap times...
Always best to keep the contact patch as large as possible.

You ever notice how a suspension with coilovers has upper and sometimes lower front and rear strut/shock tower bars?

ptoro01

Yuppers A+

Sooo that's why you put wide tires on your car

hmmmmm makes sense eh?

Huuuuh so its not just for looks

RBYCC

I put extremely wide tires on 17x10 ET negative 7 rims on the rear...
Not for looks, but to handle the increase in power
Still has nothing to do with the roll center of the 124 chassis.

ptoro01

Agreed, your outrageous tires have nothing to do with roll center, but everything to do with traction. The extra width they add to your car just provides a more stable base.

My opinion is based on auto-crossing my car, I can tell you that I am not able to toss into corners as in the youtube video earlier in this post. I understand that car has a transmission geared for such events which is why it jumps off the line, but the suspension is also critical. The roll center has to be supported by a stiff suspension so it doesn't sway, so the car can hold sharp corners.

Take for example, at highway speed, an SUV will roll over far easier than a sport sedan from the same dangerous left-right maneuver, because there is more suspension travel allowing the roll center to sway. The term tipping point comes to mind.

I just want that roll center to sway less. Once it sways less, corners become faster. (Screwed up engine mounts can mess with handling so much)

Fact. A stock suspension 300e is slower around a track than one with H&R Bilstein Sports and 500e swaybars.

Ps. We might be agreeing while disagreeing with each other

bsmuwk

Sway bars and strut braces are your friend with roll center arguments.


Please explain what that inside wheel is doing on a corner. Just wondering as I see track prepped 911's (obviously not a fair comparison but i'm curious) lift inside wheels all the time.

And gentlemen,

nobody, as far as i've read, have been intending to use their slammed w124's on the track....so what is the reasoning behind all of this

ptoro01

I thought coilovers were a performance thing. If I'd want looks, I'd cut the springs schlap on some blown shocks, and a custom diamond plate skidplate front to back. OH Of course, a custom license plate that says SPARKLES.

I want to go fast! Go kart fast!

Saijin_Naib

What is the definition of slammed here? I'm thinking its much lower than the 1.3" or so I'm shooting for with H&R Sports, correct?

I only ask because I'm looking to improve my handling characteristics for SSCA/AutoX by doing suspension work, not screw things up. So far the LWB and 500e sways have been an absolute gift. I'm always looking toward the next step.

RBYCC

Good point...which is why Porsche redesigned the suspension to give a lower roll center and use softer springs which help keep the tires planted !!!
Too much stiffness causes a wheel to lift

Here's a press release for the 2011 Nissan GT-r:
•For the rear suspension, toe performance is modified by changing the roll center height to a lower position in order to improve tire grip while making turns and to better communicate driving feel.

A similar comment on the C63
This is the first AMG product to be designed from its computer-conception for extreme performance. Its predecessors (like most AMG models) are essentially tuner specials, with bolted-on performance. This time, practically everything forward of the firewall (except for the two energy-absorbing frame-rail stubs) is unique to AMG. The front track is 1.4-inches wider, standard 18-inch wheels permit larger knuckles, and a new engine cradle accommodates longer diagonal links that completely change the geometry. A lower roll center, for example, helps the car corner flatter while preserving ride quality with an anti-roll bar that’s only 0.04-inch thicker. New ball bearings offer twice the rigidity of the stock front-axle bearings. Camber increases from 0.5 to 1.4 degrees and caster is reduced by 15 degrees. The steering ratio tightens from 14.5:1 to 13.5:1, and there are new bearings atop the struts. The effect of all this front-end work is vastly improved steering feel and agility with reduced understeer.

And the CLK63 Black Series went even further with the most advanced suspension that MB ever offered.

RBYCC

Not totally disagreeing with you

Problem is that when you begin to modify a suspension in such a way that it is not compliant with the design geometry you will realize diminished handling.

Using coilovers in tandem with stock location springs doesn't make sense.
What set of spring is the dominant spring in the suspension?

The 124 with a Sportline or equal suspension is probably the best handling 124 you will experience.

A great deal of engineering went into the 124 suspension and it is what it is...
It has it's limits.

The wide tires with negative rear offset that I will be running will eliminate the majority of body roll even in conjunction with H&R springs, Bilstein HD's ( yes HD's ) and front and rear Sportline sway bars and strut tower bars.

You can't just add/change/modify one component without seeing how it effects other components.

I have a Merc that is heavier then the 124 that came stock with KW coilovers.
Tracks like a slot car only because the suspension geometry was designed for coilovers.

I'll repeat once again that the 124 suspension is fantastic considering it was designed in the late seventies, but it won't track like a newer AMG suspension

P.S...the SUV will "roll" because of a high CG..don't confuse CG with design roll center

ptoro01

Huh so the CG and roll center are different things, I learned something today. Which components influence the roll center? Ball joints and tie rods? I always assumed a big brake kit would do good things for handling, am I wrong?

I'm only going in my own experience. First suspension tweak were vogtlands and bilstein sports, obviously less body roll but way bouncy. Then came a set of k-mac rear camber/toe, that moved camber from -3 to -1.3 and toe set to sportline specs, that was a monumental change, it made the car able to roll again(hard to describe). Then a set of 500e sways, that added bunches of steering feel and stopped the bouncy bounce crap.

As far as looks, with 225-45-17 et35, my wheels are flush in the back and the front fenders have spacers. On level ground, I can squeeze 1 finger in the wheel gap. It doesn't look slammed by modern standards and my wheels don't look as if I had bodies in the trunk. Has the stance of a w210 e55.

But while auto-x, I can still extend the suspension to fit both fists in wheel gap.

What bothers me is that body roll under extreme cornering. The car in the youtube video does things my car has pipe dreams about.

I see your point about the dual spring thing. But I figure a stiffer shock is the solution, especially after seeing that example.

What do you suggest, apart from learning to drive or getting something light weight for autoX !

Saijin_Naib

SCCA @ Englishtown - 06-28-08 (pre-swaybar update)

Do you mean sway like this? I feel like after the swaybars, this has been slightly negated, but the car still dips like crazy.