Christer

How do coilovers differ from other suspension setups? What does this term refer to? Why?

<img src="graemlins/c.gif" border="0" alt="[ouch]" />

TIA

Cupcar

The term "coilover" referrs to a spring shock unit with the coil spring installed concentrically around the shock. The parts are assembled as a unit and can be taken as one from the car without decompressing the spring. Porsche uses this design on the 964 in its most pure form on the rear of the car, the front is technically a Mac Pherson strut but is assembled as a "coilover" package. The alternative is to install the spring and shock separate from each other in the suspension system as many cars do. The term is used as a marketing term as well to indicate a kit of both springs and shocks-as opposed to just a spring kit- sold together configured this way. <img src="graemlins/yltype.gif" border="0" alt="[typing]" /> <img src="graemlins/burnout.gif" border="0" alt="[burnout]" />

Christer

ok, so pretty much as obvious as it sounds then right?

Bill Gregory

[quote]<strong>The alternative is to install the spring and shock separate from each other in the suspension system as many cars do. </strong><hr></blockquote>

One example of this would be the pre-89 911's with torsion bars (springs) in the a-arms.

Cupcar

Interesting this topic came up. I just got my H&R Stage 4's in the mail today.

Yes, to my knowledge when one referrs to a "coilover" it implies it is an assembly removable as a unit, spring and shock, from the car.

Some cars have a coilspring with a shock inside it, but the shock can be removed separately leaving the spring in the chassis. My old Corvair Spyder was like this. <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

JC in NY

Cupcar,
Why did you go with the H&R stage 4 rather than the Porsche Cup suspension?

Greg Fishman

True coilovers are also height adjustable.
Some come packaged together with springs (pss9, H&R), some are sold seperately so you can pick your spring rates (Bilstein HD, JRZ, Moton, etc.)

Cupcar

JC-

I went with the H&R Stage 4 because it is cheaper and easier to obtain than the factory Cup parts. H&R is OEM to Porsche for racing springs and the H&R shocks are Bilstein components, beautifully made, more adjustable and the spring rates are about the same, although double sprung unlike Carrera Cup. Interesting though, the H&R box the kit came in is tagged with a typed label saying: "Porsche Carrera Cup Kit 964" on the side. The rear shocks are aluminum BTW and have a spherical bearing, unlike Carrera Cup. Looks more like the stuff in my Carrera 3.8 RSR parts book than Carrera Cup stuff. <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

Cupcar

Here are pictures of the factory Carrera Cup racing parts (not Euro RS parts) note that they are not adjustable at the strut mount, the rear shocks are steel, the rear shock mount is rubber, the springs are not tandem.Shocks are Bilstein, springs are Eibach.

JC in NY

Cupcar,
Yes I see what you mean, the H&R setup looks a bit better than the stock parts in the areas you pointed out. I'd be curious to know what the difference is between the two setups in terms of spring rates and shock valving. My guess is the H&R kit is very close to the Porsche values especially because of what it says on the box.

johnfm

I know its an old thread, but I've jsut searched the archives & found it. My question to Cupcar is:

did the top mounts for the front & rear struts come included in the Stage 4 kit (I take your pics are the Stage 4 SuperCup ??

I guess, they did, which is why they are a load more expensive than the standard coilovers.

joey bagadonuts

Okay, John, here's what you've been looking for:

<a href="http://mall.rennlist.com/scripts/listings/ads.pl?search_and_display_db_button=on&db_id=36953&query=retrieval" target="_blank">Used RS Suspension form Rennlist Classifieds</a>

I was actually hoping to save up enough pennies to make an offer, but after all you've been through, I figured you were due a break. I'm sure you can talk this JC fellow into a really kind price after all your trials and tribulations.

On the question to Cupcar, I think you need to be more specific. The H&R folks make at least two versions of the Stage 4 for 964 and one comes with the monoballs and the other doesn't. Here's their <a href="http://www.hrsprings.com/" target="_blank">web page.</a>

Cupcar

The pictures above are of the stage 4 H&R kit for the 964. I have been doing the installation slowly as time permits, but it has not been pleasant since there have been surprises requiring a few trips to the machinist.

I found that the front mount is flawed in it's design. It appears that H&R supplies the same mount for the 964 Turbo as well as the 993 and the standard C2 964. In the Turbo application the installed position of the monoball is fully outboard and in the 993 it's in the middle of the slot. This allows more negative camber to be dialed in by moving the strut for these cars. However, in the narrow body 964 the monoball has to be installed all the way toward the midline of the car and no furthur travel is possible. I found no more than stock negative camber could be dialed in. I also was dissappointed that the slots are not covered and allow water to come into the trunk.

So, I made new mounting plates which move the strut closer to the midline of the car for more negative camber and also are of a sealed design.

I also found I had to machine the rear mounts to get them to fit into the chassis. The parts supplied by H&R had too large a diameter and were too thick. For easiest fit I milled a bit off one edge as well. I'll let you know how the rest of it goes when I get the car completed. Pics of the new front mounts plates comparing to the blue colored H&R plates follows.



Here is what a trial fit of the new mount looks like installed in chassis. Capture nut for bearing not installed.



Here is the stock H&R mount installed. Note how the body would have to be notched if the nuts over the adjustment slots are to move the entire length of the slot. Moving the strut all the way to the right puts it in the stock position. Also note that the dark areas to the left in the slots are open to the wheelwell so water can enter the trunk.