Unkle

I have recently been gathering some info from Rennlisters regarding the real world applications of uprated suspension and really just asking there personal thoughts on the subject (thanks), and I am about to make a purchase of shocks and springs for my car. In an attempt to better understand what I want and where I am starting from I got this info from this site.

I can't say I fully agree with the info, and its from the very beginning of the list, but perhaps an expert can help. From this info it states that Porsche fitted the same spring rate to the C2 as the C4 even though the car (mostly the front) weights 100kg more? Is that right? Didn't the different dots on the springs count for differing spring rates?

If my question is correct, where does that put the rest of the info?

As a C4 owner I know my car is heavier, so where does that put the soft Eibachs equation if fitted to a C4? Do they really start on 82lbs while the H&R start on 190lbs? That is more than half of the spring rate, surely the C4 would just sag these past the 30mm lowering spec at the front?

Any thoughts on the lists accuracy, where the C4 values may be and how springs relate on an already heavier car than the C2?




Thanks in advance

Dwane

I am running Bilstein HD and H&R Greens on my 1992 C4.
Everyone that has driven, or taken for a ride, on track find the car well setup.
I think the key is cross weight/corner balance and aligning the car properly!
We are going with a little more track focus alignment setup...I am now noticing a little understeer on 2 corners on track.
Hope that helps
Dwane

StanUK951

I have Eibach's with Bilstein HD's all round and a Brey Krause steel strut brace on my C4. These replaced the tired original setup and have transformed the car. It's not 'crashy' at all and generally handles brilliantly. I had a full alignment done with the new shocks but i was disappointed at the understeer I was suffering from. When I took my car back in for a service I mentioned the front seemed to have settled lower than the back so they lowered the back another few mm and it seems to have really helped the understeer and sharpened up turn in. My car is a 1991 so has a 20mm anti roll (sway) bar at the back but I am toying with the idea of H&R bars. Haven't been on track with it yet so can't really comment about my setup for track use.

I had no idea the Eibach's were considered a softer option than H&R's though??

ian89C4

Currently I run H&R reds and Bilstein HD's all around. I have the H&R 24mm and 22mm bars in the front and back respectfully. I also have the Rennline front strut tower brace. I have the car set up geometry wise like a C4 lightweight. At Roebling Road she was solid as a rock and flat through the corners, if the driver was better then the weekend would have been a lot faster. So I give the set up an A+ on the track and for autocross.
For the road, it is a little harsh over the bumps and wears on you after long drives, i.e. 2+ hours (I also have track seats so that may have something to do with it as well). She can be a bit squirrely at the lower speeds, but settles right down at highway speeds, still haven't figured that one out. I give the set-up a B+ for the every day drive.
Overall I love the set up and am very happy with it, looks great as well.

Just a pic of the set-up in action.

Unkle

Interesting points your mention, from what you are saying the Eibach's settled a little lower which would indicate possible sag in the softer coils of the Eibach on the heavier C4, or may be just that they originally set your car a little high at the rear. Who knows but i still can't find out if they really are as soft as indicated.

The H&R reds sound like a perfect track option but like you say perhaps a little wearing on long journeys (what i want the suspension for). Great shot BTW.

How do you find the road use of the springs compared to original setup when riding over expansion gaps in the road or pot holes?



Do any of you feel that moving from a standard to uprated actually relates to the figures in the list? Are the Eibachs softer than the orignal setup before the majority of the spring steps in to take the load? Do they sag? The 993 forum seems to be have a significant amount sold 2nd hand (concerning sag).

nidon

I'm currently running Eibach's with Bilsteins. This was to replace original shocks that were shot on the front with the rears not far behind. The ride is very compliant and doesn't crash or bang, which with the roads around my area is welcome!. The car is firm enough in my opionion and no problems on a long journey. The car however does roll quite a lot but I am hoping that larger ARB's (next on the list) will help to improve this.

Unkle

Thanks Nidon, how does this roll compare to the standard setup?

The reason I ask is suspension feel is very subjective. But we all had a standard suspension at some point so I can work from their, if you say its rolls more than the original I can at least say I now how that will compare to what I have.

Does that make sense?

But does anyone have and view on the opening information?

nidon

Hi,

The car doesn't roll as much as when I first got it and is much tighter, mind you I am comparing it to original shocks and springs (100k miles) the eibachs seem much firmer than original overall. The roll is controlled but I do prefer a flatter stance on cornering. I too looked at H&R and struggled to decide as I was mindful that the H&R's might be too hard hat I wanted.
The decision maker for me was that I was virtually given a new set of Eibach's
Would I change now, probably not , overall very pleased
Got some pictures of track day that will post later to give some idea of roll

meek

Unkle, I have the the Bilstein HDs and H&R springs fitted to my C4. Whichever route you take, I can highly recommend a strut brace once you have firmed up and lowered the suspension from standard. I know that the 964 is a very solid car as it is, but from my experience of my 964 and previous 944 Turbos, such modidfications do naturally increase the amount of crash that you will feel through your seat and magnify any squeaks/rattles/creaks that may not have been noticed before. The brace really does add a more solid feel to the car plus makes cornering a far more precise affair. I am sure others will disagree with me and as you say, it is perhaps purely subjective.

nidon

attached are some pictures of last track outing, one is of slow hairpin after 90MPH stright , the other may give you some idea of the height.
I have also fitted front strut brace, which has sharpened up the front considerably

Unkle

Pics look good nidon, best car in the line up too

If the spring hadn't sagged at the rear due to age on our car, I would probably just put on a strut brace coupled with the 21mm rear roll bar I have, and be done with it as I like the compliant factory suspension. But if its got to change...

So really I am looking for the most compliant suspension, and irrelevant of the data on the list in my first post I think you fellas have helped my decide.

Any more comments are more than welcome

Dwane

Around town and on the highway, the ride is better...
The suspension was 16 yrs old....sooo

StanUK951

If you are looking for a compliant setup the Bilstein HD and Eibach combo is very good IMHO. I have had quite a few cars with lowered suspension setups including a 944 turbo on Koni adjustables and lowering springs (not sure of make) and this setup is by far the best I have had. The ride is much better than my 100k mile standard setup and there is no more wallow or dipping front and back under acceleration or braking yet it is firm enough to handle well in the twisties. As I say I haven't been on track yet so am waiting to see if H&R bars are necessary... I have a day booked at the Porsche Experience Centre at Silverstone and I am taking my car on the car control course so might be interesting!

Unkle

Thanks for the replies so far.

I have ordered Bilstein HD from Shox.com and am waiting for them to arrive. I am not in any particular hurry as they car will be off the road over the winter, but will possibly go for the softer option of Eibach springs, I don't believe they will be softer than the standard set up despite the spec in my first post . I want soft compliant suspension - over track performance so If anymore has a good clean set to sell let me know although a new set is £250 only these days.

Brian 96C2

Hi Ian,

Your car looks great.

Can you provide the C4 lightweight set up or a source for those figures? Thanks.