Be nice

These suspension mods are like new math...2+2=5, doesn't matter if you get the correct answer/result, purely graded on effort.

I learned a new definition for "progressive" springs...put two coils in tandem and one compresses and the other follows

Why care about spring rates, compatibility with dampers, design geometry...


Automotive engineers have been wasting time and effort with all these mundane calculations...
Just slap anything on as long as your oil pan can scrape the tarmac and your tires can't turn fully because they hit the fender inner sheetmetal...
Mistakes can always be cured with camber adjustments

 

They don't typically come in tandem. They've been around for a while. Here's how they actually look.

 

Ronald, with all due respect...
I have an inkling of an idea of what a progressively wound spring is compared to one that is linear wound.

But this is what you stated:

"Me and my friend were speaking that it would be best if the primary spring were to hold the load until we have stronger metal mounts. In this case, under compressive load, the original springs are compressed first then the strut springs second. So in other words, the setup would work similar to a progressive spring."

Not "same-same" as you posted...

I'm beginning to see the Dunning-Kruger effect on many of these posts...
If you just want to be able to slam your car so it will not handle then just do it.

Please stop with the guise of improved handling using mismatched tandem springs and dampers....
You fail to grasp the importance of spring rates as part of the overall chassis design

 

You guys have to stop bickering with theory. These "performance" arguments are getting old, fast.

Would anybody be so kind as to explain to me why a relatively successful rally team in Hungary uses tandem springs on both of their C124 rally cars? Or is somebody going to tell me these guys are complete morons and they don't know anything about suspension theory. This rally team has been around for over a decade and their sprint times are just seconds off of Mitsubishi Evolutions and they consistently best Audi Quattros. If you're going to tell me a simple tandem set up with height and damper adjustment is going to negatively effect the performance of a W124 - GTFO. The OP and this rally team have helper springs on their cars - not the actual coilover springs. HELPER springs. Read - helper. I've been following this rally team for a few years and they're always consistent. Sometimes they get a little too carried away and flip over when they fly into a ditch, but that's okay.


Maybe it's about time somebody came around with something that you can actually SEE happening instead of some ridiculous theory arguments which never cease.

 

And when I did the PBX dirt rally, I beat every car except the 4WD trucks, bone stock. So, I doubt the springs are the thing that're making that rally team's times good.
I'm not sure whether or not the dual spring idea is bad, but I do have to agree with the idea that the current w124 strut mount is not a piece I'd put any significant weight upon.

 

oh c'mon guys, the w124 is a handling beast at speed. From personal experience, the car's balance and my suspension upgrades have gotten me outrageous traction even with the worse summer tires through SNOW STORMS. These cars are a nimble bunny at highway speed.

We gotta realize that rally car has a lot of power. The stock engine with all the gearing changes puts out. That's not any transmission in there.

Vogtland springs are progressive, whatever that means. City driving and autoX you can't really tell, on the highway, sure, i guess.

Someone post a video of autoX to compare both suspensions. That rally car is too unique, a stock drivetrain 300e can't do that, period.

 

You're an intelligent guy and you know why they use "helper" springs in a rally application.

But why try to compare a suspension designed for a specific purpose when the discussion is about throwing BMW coilovers without consideration of strength of mounting so one can drop a car to it's oil pan !

Makes your point a bit specious as there is no real comparitive.

Radical modification/redesign of any suspension takes into account strength of materials.
A specific purpose suspension design and I reiterate specific purpose which usually means single purpose will and does work.
Look close at the pix you post of the rally car and see the mods made to the chassis.
If they are rallying then I'm sure there is a sanctioning body that inspects and approves the safety of the overall vehicle.
Far from what this thread is about.

However when you are contained by the parameters of the original suspension geometry, you then limit yourself to using aftermarket or factory performance parts that are compatible with the original design.

So as you are very familiar with the referenced C124 the rally car suspension, I ask you what improvement in handling would a slammed 124 achieve with the replacement of the strut with coilovers ?
Or are we now discussing different concepts?

The stock power output is well within the suspension handling capabilites of any street driven 124 !

Theory arguments aren't ridiculous as you may believe.
Especially when it appears to the novice as a performance mod which results in a diminished performance and potential hazard.

The thread is not about rally cars with modified suspensions DESIGNED to handle the stress of the circuit under speed..
My concern is about road safety and potential injury to innocent people if a suspension that is not well thought out fails.
Live and learn, just don't hurt anyone else while you're learning...

 

Oh I think its ridiculous that he's running coilovers on those feeble rubber mounts...that's why I brought that up a page back when he first posted it..i was the first one to mention it lol

if done properly with correct camber plates, we would be having a discussion whether or not the metal in those areas can withstand the extra force...which, from my metal banging experience, should have no problem.




@ptoro,
http://var-car.hu/motorsport/versenyauto.htm

213ft lbs torque is basically a stock cis m104 - the car is running an efi system and a 4 speed race trans. what you're seeing is basically my car - stripped to the bone with race transmission

what i think makes it so quick is its ridiculous weight shedding. awesome to know that these cars are really built like tanks.


as an aside, I do believe we're all agreeing with each other here.

 

We all agree. For an EASY $250 to change your struts to coilovers, SOMEONE WILL GET HURT.

That's why I asked about the 2nd firewall and the strut tower. This is not a simple effortless drop in mod.

METAL STRUT MOUNTS ARE OBLIGATORY


bsmuwk...yes we agree... translated from hungarian...that rally car has valve and crankshaft mods, efi, 3.92 rear diff and a sequential tranny. says 240HP so not quite stock m104.
Under suspension it says customs A-arms.
All custom body as well...total weight of 1250kg...super light.

I'm betting top speed of 80mph...with 240hp, that gearing, a sequential tranny, it must be scary quick.

THE MAGIC IS NOT IN THE COILOVERS

 

never said they were, but they sure help a lot.

 

I hoped coilovers were a suspension option but I change my mind.

That car is very light in the front. I'm almost talking honda civic weight.

Just check all the facts, its a bad idea.

 

then tell the rally team that they're idiots. they obviously don't know what they're doing with years of experience.


since a w124's suspension is beyond perfectly engineered for race and performance applications to you guys that no thoughtful modern combination of anything can improve it, so be it.

those who want coilovers will get coilovers. those who don't will continue to bicker about how dangerous it is - simple.

 

Lol. Im amazed to so how far this thread has gone. But I do agree with bsmuwk's statement. Time only makes advances. Our cars are OLD technology.


About the rubber mount failing, the most that will happen is the coilover breaking though and hitting the hood. It wouldn't cause much danger since the spring holds most of the cars weight. I wouldn't go as far as to say death.
But don't get me wrong I wouldnt follow through with the coilovers unless I had some sufficient metal as my strut mounts

 

This.

 

This entire debate is about....tadahhhh... a stiffer shock absorber!

Helper springs, adjustable coilover, coil spacers, bump stops, coil cutting are all temporary fixes.

Now the solution...LETS PETITION BILSTEIN TO MAKE A SUPER-SPORT

We want... SUPER-SPORT
When do we want it... NOW
We want... SUPER-SPORT
When do we want it... NOW
We want... SUPER-SPORT
When do we want it... NOW
...

 

theory bleary blah blah....stiffer lower= handles better....higher gayer= handles worse...
safer...who cares its your car the only thing getting hurt if it breaks is your bank account, and you have to be pretty stupid for it all to break in a dire situation. If you want your car on the pan or frame...get airbags. If you want low and tight rig up some coils. If you don't want anything and want your car stock, then don't hate on people trying to get they're cars the way they want them. w124 sites seem to only be about peoples stock cars and when anyone does anything other than an oil change with MB oil everyone has a fit. Rarely do any modification surface here and when they do people ***** about it, wheels rubbing, cars being to low, not being oem equipment. Ive been a member of alot of car sites and this one has the most deby downers. I say hell yes to coils and hell yea to layin the car on the frame and makin sparks everywhere you go if you want and hell yea to wheels and stance that are so agressive/tucked/poked/stretched you dont even know how they did it. Anyways......i wouldn't mind a Bilstein super sport ether haha

 

no, we want adjustability. we have that already since koni makes adjustable front dampers



but we'd like some height adjustment as well that's where the coilovers come into play.



although, i do wonder what color bilstein would make those super sports. my yellow bilsteins go pretty well with my red-orange B&G springs.

maybe i should paint the LCA's pink

 

Did you ever stop to consider that maybe Bilstein knows a bit about shock absorber design?
I know that many here don't feel theory or technical suspension design considerations have naught to do with anything

Is it possible the the B4-B6-B8 range offered for the 124 chassis has taken into account the compatibility of stock, sportline, AMG and aftermarket springs?
Interesting that the suggested replacement for the Sportline and even the 6.0L 124 is the B4 touring class?

How many of the suspension experts on this thread have any competitive motor sports experience excluding "bench" or "video game" racing?

If you want to be "en vogue" then slam your cars, but please stop justifying it as a performance modification.

 

Of course they do and they make fantastic products. Its a matter of who their target audience is, they are a business and want to sell their product to as many people as possible. These are luxury sedans, not sports cars. Most people enjoy the added cornering ability on the street.

But, look at DTM cars and sporty street cars from a suspension point of view, there is a major performance gap. I understand critical components might be different but there is a compromise point that would be nice to reach.

On the other hand, I do not understand the need for adjustable coilovers. There are plenty of spring pads if you want an even wheel gap front to back. I guess...if you park on a hill and want to compensate or something but c'mon people...

 

SCCA for me.

 

different types of tarmac (bumpy, smooth, etc etc) will often require different height settings to keep those wheels in constant contact. that along with proper center of gravity, roll center, etc etc...its a bundle of misery. something i learned from Ed in regards to the inner wheel keeping in contact with the ground for more traction even though it seemed that the inner wheel wasn't doing anything anyway.....yeah, that's right Ed, your preaching isn't going unheard.

 

That's what they make wheel scales for...

You may appreciate SAE papers on racing:

Read the abstract as it tells all about what I've been trying to open eyes to !

http://papers.sae.org/2000-01-3572/

If you are serious this book contains the above paper and twenty seven more:

http://books.sae.org/book-pt-90

Includes these papers:

http://www.sae.org/servlets/PaperEve...&PROD_CD=PT-90

Going fast and not killing yourself requires a bit of thought..
That's why those that are not technical need to rely on what the OEM and aftermarket provides...
A lot of guys much smarter then me do the design on a daily basis, why not take advantage of another's brilliance?
Nothing is done randomly

 

All these technical papers.... SO INTERESTING!

THANKS! You made my scholarly life way interesting.

 

that book i got off of ebay last year!! haha can't believe people actually know about it.

that as well as maximum boost by corky bell...recommend it for anybody going into turbos

 

yes sir!


So much misinformation and stubborness in this thread..


Conventional shocks have WAYYYY too much travel and are not good for lowered cars..

Why do you think whenever you dudes with shock and spring combo raise your cars it takes like forever for the wheel to come off of the ground?

With coilovers it has limited travel, firmer dampening, and better ride(in my opinion)

I daily drive my car to college and work and pretty much everywhere and been doing so for about a month now with the coilovers and they are AMAZING.. only if i can figure out something for the REAR!!!

This isnt my first rodeo with coilovers either.. i havent read books from some dude 50 years ago but i have been in professional racing/drifting for about 10 years now and am 1.5 years away from my Mechanical Engineering degree.

Stop telling people made up bull**** about how coilovers are unsuitable because you are too dumb to know how to install or use them properly on your cars.. thats just great way to keep ingenuity and fresh ideas out of the W124 community..

No wonder there still isnt a decent replacement available for the W124 wagons yet..