Cupkit? Coil Over?

CKlasse · 01-06-2003, 10:45 PM

Ok so its time to upgrade the suspension of the 95 c220...

I have Drilled front discs, rear discs, new pads around, e-brake, front axle repair kits, bilstein shocks... ready to be installed.

I also have.. a set of C280 springs to be cut (I chose C280 because of its stiffness compare to C220 OEM springs), Yeah I know you aren't supposed to cut progressive springs.. but I've done it to Audis and VWs with good result for the cost..

However, on the way out of the parking lot, I saw a nicely tuned Subaru Imprezza.. I pulled over and chit chat abit. The owner said he lowered it with coil over and suggested the least I could do is H&R CUP KIT.

Although i have known and seen these kits, I personally havent had any experience with either of them. I have cut my own springs all this time. Suggestions, comments on cupkits or coil over?

Keep in mind..COST effectiveness is priority. And for a 4 banger, I am going for look rather than performance.

**nokia8860** · 01-07-2003, 07:19 AM

speedybenz has a set of coilovers. hopefully he will see this thread and chime in.

**speedybenz** · 01-07-2003, 08:55 AM

Yes, I do have a set of coilovers or a better description would be adjustable spring perches. They work great and because I can change the spring rates and raise or lower the car with the simple turn of a bolt the kit works well.

I will post pics today.

Jeff

**nokia8860** · 01-07-2003, 05:12 PM

Speedybenz coilovers

The question I have is what happened to the thread in the last pic?

**speedybenz** · 01-07-2003, 05:47 PM

The treads are still there but you cant see them as the black plate that supports the spring sits right over the black plate that sits on the lower control arm.

The upper treads on the spring perch are used to set the load on the spring to a good midpoint load that allows the lower treaded bolt to be used to raise and lower the car. That lower thread is part of a bolt that extends through the bottom of the lower control arm. This bolt has a 19mm bolt head, so you just get out your rachet and 19mm socket and turn right to raise the car and left to lower it.

The spring rate I am using now is 600 lb/in compared to the Eibach sport kit spring rate of approx. 450 lb/in.

Jeff

**nokia8860** · 01-07-2003, 08:02 PM

Are you still using the spring pads with this setup?

**speedybenz** · 01-07-2003, 09:36 PM

No more spring pads, thankgod.

Jeff

CKlasse · 01-07-2003, 10:13 PM

Speedybenz & Nokia,

Thanks for your posts. How much does the whole system cost you without installation? I noticed you have Penske shocks, any perticular reason?

I have plenty of questions if you dont mind.. however I am too beat tonight.. I spent the last 8 hours fixing or replacing every single thing that squeeks in my car... including pulleys, tensioners, v-belt, brake pads, and so on. Whew...

I am sure I ll come up with few more questions tommorrow.. Thanks!

**speedybenz** · 01-08-2003, 10:05 AM

CKlass,

I really have not figured up a price for the system because I made it myself. The upper treaded spring adjuster was purchased from Coleman racing but then I had to modify it to work in this application.

The reason I use Penske shocks is that I used them on my Superbike when I raced and have a good relationship with them, they also have great products and service. The shock I run is a modified Circle Track shock with adjustable valving. A knob on the bottom of the shock allows you to change the damping very quickly. Also the shocks are rebuildable and in-fact the valving in them now is the 2nd revision and works very well. When the shocks get worn out I can take them to Penske and have them rebuilt at a fair cost.

Jeff

**Renn 208** · 01-08-2003, 10:55 AM

Jeff...any plans to do some stress/durability testing to your design? The system looks great, but are there steps that can be taken to weed out any structural weakness? What's the loadhandling of the lower control arm bolt? I'm not the most technical person in the world, but just posing the question.

Thanks!

**speedybenz** · 01-08-2003, 12:01 PM

Renn 208,

Good questions. The bolt and support plate are items used in Nascar race set-ups and are sold by AFCO and Coleman racing for use as seen in the photos, to load the spring and adjust ride hts. of the race car.

However I did do a quick calc. and the 1" diameter bolt has an area of 0.785 inches squared and using a safety factor of 2 on the 600 lb/in spring at max commpression would be 1200x4.5"=5400lbs of load on the bolt. 5400lb/0.785" squared= 6880psi. This is the stress to the bolt. Grade 8 bolt steel has a strength of at least 60,000 psi. So plenty safe on compression or tension.

It is more calcs for the bending forces and I don't want to go through that calc. I will let the final durability determination be the performance on the car where it is seeing 1G corner loads two to three times a week.

Jeff

**Renn 208** · 01-08-2003, 05:16 PM

Thanks for the response Jeff...that's some beautiful work you're doing.

BTW, do you think you might want to make the Feb 1 session at Willow springs?

CKlasse · 01-08-2003, 09:46 PM

Jeff,

I showed this thread including the pictures to the guys at work, your setup create a good arguement here. I am thinking about doing the exact thing just for experience sake.. Do you mind?

If the ride proves to be great, you should start thinking about selling them! If the design is unique enough... patent it

**speedybenz** · 01-09-2003, 08:48 AM

Renn 208,

I would love to go to Willow Springs, I've won a lot of motorcycle races there and would be curious to see how my Benz would compare lap time wise vs. my superbike I rode. I did lap times of 1.22's mins on my bike.

But when I told my wife she had a fit. The reason I don't race bikes anymore is due to injury.

But soon I hope to get down there for some fun. I want to see if I can hold my foot down all the way thru Turn 9 and see how fast I can go through Turn 2, my most favorite corner in racing.

CKlass,

Feel free to copy, steal all or part of the set-up. I posted the pics so people could do just what your planning.

Jeff

**nokia8860** · 01-09-2003, 09:10 AM

Originally posted by speedybenz

Feel free to copy, steal all or part of the set-up. I posted the pics so people could do just what your planning.

Jeff

Jeff. Thats so cool. Mind posting partnumber of what you used so some of us might imitate it?

CKlasse · 01-09-2003, 10:53 PM

Jeff,

I stopped by the machine shop and made a prototype base on your concept. I am leaving most of the suspension stock other than an 'adjuster' on the top part of the springs. It's pretty much a good size bolt and ring to hold the spring down. I could adjust the spring height by adjusting the ring up or down. However, I fail to see an inch or two drop other than getting stiffer sporty springs.

Does yours adjust the height or simply the stiffness? Thanks in advance!

PS: Will take pictures tommorrow.. !

**speedybenz** · 01-10-2003, 09:08 AM

CKlasse,

The setup I have adjusts the load on the spring by compressing it. When the spring gets compressed enough the compression is equal to the weight of the car on that wheel. Anymore adjustment does compress the spring slightly but will mostly raise the car.

The parts you need can be found at Coleman racing. Then go to the suspension section and scroll down to the last three items. These parts make up the primary setup.

You don't need the upper threaded adjuster if you go with a 10" long spring, which is what I did on the back of the car.

Please send me your pics and I can tell you what needs to be changed or added. It will save you a bunch of time.

Jeff

CKlasse · 01-10-2003, 04:55 PM

Sorry about the bad resolution.. I used webcam instead of digital cam.

its basically a 2" bolt with adjustable ring. The kit goes on top of the stock spring. Tomorrow I will install them.. and let you know the result.

Meanwhile... any advices, Jeff? am I wasting my time?

**speedybenz** · 01-10-2003, 07:07 PM

CKlasse,

Looks good. Your spring collar maybe too thick which may not give you much adjustment, or it will force the car up.

Put it on and then adjust it from there. Don't be afraid to shorten the spring some to get things to fit.

Jeff

CKlasse · 01-12-2003, 11:07 AM

I put them on today... the car dropped 1.5". It looks great, but the ride is too stiffed as I am getting more feedback. The steer vibrates at around 90mph. I am thinking new set of springs all around??

Now... anyone has any camber kit laying around???

**speedybenz** · 01-15-2003, 10:25 AM

CKlasse,

Post some pics. Glad I could help you out. Did you use the stock springs or Aftermarket?

Did you have to cut the springs.

Need more details.

Jeff

CKlasse · 01-15-2003, 09:49 PM

Will do as soon as I am done. I cut the top coil off a C280 springs and the 'kit' fit right in. I love the stiffness, but hate the feedbacks. Few new factors: New front shocks (KYB - hey I just love them), new ball joints, and new set of PZERO ASIMM (Road noise is worse than the cheaper KUMHO I had previously)

Currently, I am having problem with MAP sensor.. perhaps even vacuum leak.. so I ll put any free time I ll have on this issue for now.

The Genysis Scan Tool doesn't really show anything.. I wish I could get my hand on MB OEM Scan Tool!

**Captain - X** · 01-15-2003, 11:41 PM

Hmmm, think about one thing guys, if im not completly wrong, when using coilovers and lower/raise your car, your interfering with the camber angle, and without adjusting that after lower/raising your car, you're gonna get abnormal wearing on your tires, and bc mosty of you guys are rolling on 17"+ that means a lot of $$$

BUT I can be totally wrong about this.

CKlasse · 01-16-2003, 10:40 PM

the camber angle

Thats when the Camber Kit comes in!

My stock ones are still +-.3 of normal with 18" and lowered suspensions..so its all good!

**MBATF** · 01-18-2003, 10:01 AM

dude, i m rolling on 18s, it cost banks for teh tire i use...and soon i will post some pics of tire warn by incorrect cambers... its truly paintful and scary..

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