Unkle

I replaced the shocks and springs over the weekend, with Eibach springs and Bilstein HD’s dampers, and took a few photos.

Front springs are the same height to Std, but thinner and with progressive coils so it should sink a little to produce the drop and be compliant until you push it hard I am told. I cut the brake pipe bracket with a Dremel as Northway Porsche did a Brake fluid change 3 months ago.






As you can see below the front has had a healthy drop while I only dropped the rear slightly. To keep a slight nose down rake and the rears had sagged in the original pic so I new that it wasn’t healthy for damper travel to try to drop 30mm from where the car was.

Before





After (sorry no day light shots yet)






Rear looks like it now has a bit of a geo change as I swear it wasn’t pointing at that angle before.







I decided that I really want the car to be as compliant as possible and back to factory geo settings. So many things affect the setup when a car is 18 years old and potentially worn and I wasn’t sure I would really notice a RS geo setup apart from on my tires for example. So the plan was to steer clear of RS height (bump steer, drop link issues and driveshaft’s/CV’s working out of possible factory angles) and go for a VW scene OEM plus look (joke). So I have it set at 132mm at the front (RS 125mm) and 138mm rear (RS223mm) it gives me a ride that is really nice and not a great deal different from the standard ride but looks significantly lower than it was. I also cut the rear bump stops in half to have extra travel on the dampers on very big bumps at high speed, (I contacted Bilstein UK for clarification first) and no bump stops on the front of course .

Thanks to Kevin (Warmfuzzies) for the info on Colchester Porsche, I took the car to them today for alignment, it wasn’t cheap but they spent a lot of time getting it right (5 hours) from start to finish and although I was sick of day time TV by the time it was done, the drive home was great, my first bench mark was 100mph (on a private road of course) to see if the steering felt light and wandering as it did before… Gone completely, Next I turned off and heading cross country on some of the most bumpy roads in East Anglia, and the car was transformed, it felt really alert and none of the C4 original traits that came with the car when I bought it were present, I have also got the 21mm rear ARB and the previous owner had changed all the front bushes so I assume it all adds up.

I will skip the before settings as I had just fitted the suspension and knew things would need alignment, there were a lot more things but not sure what they all mean.

**The prev owners invoices came with an alignment at a non Porsche place and the sets of final results are completely different. And I feel based on specs from Porsche and Rennlist that the prev set up was wrong**

My specs:

Version: Porsche Professionell V13.00.

Front Axle
Castor 20*= 4.25 (-/+ -.30, +0.15)
KPI 20* = 20.00
Toe out on turns = -1.50 (-/+ -0.30, +0.30)
Camber = -1.00 (-/+ -0.10, +0.10)
Cross camber = 0.10
Individual Toe = +0.13 (-/+ -0.03, +0.03)
Total Toe = +0.25 (-/+ -0.05, +0.05)
Setback = -0.05
Included Angle 20*= 19.18


Rear Axle
Camber = -1.15 (-/+ -0.10, +0.10)
Cross camber = 0.20
Individual Toe = +0.15 (-/+ -0.05, +0.05)
Total Toe = +0.30 (-/+ -0.05, +0.05)
Setback = -0.05


My front camber was -1.09 and -0.54
My rear camber was -1.21 and -1.09

Both within specs of each other +/- and the target setting from Porsche.
Geometrical Driving Axes: 0.02




Will post up some more pics when gets out in daylight.


Thanks for all you help

Unkle

911Jetta

It's nice to see a Slate Grey 964 sitting right...with a "real-world" stance.

I know my stock suspension is past it's prime and definitely sits too high (4x4), but I tell you what, it just sucks up all the bumps and the car flies. I've done a bunch of "fun-runs" with guys with lowered cars and they always comment on things in the road that I didn't even see (or feel).

The track is one thing, but I'm with you, compliant travel that keeps the wheels on the ground is the way to go.

Thanks for the great pictures and your geo. specs.

StanUK951

Hey Unkle, glad you are happy with the Eibach's! I think they're great for the road which is where my car spends 99.9% of it's time. I actually tracked my car for the first time today and it handled great, perhaps a bit of body roll but that was probably tyres and roll bars more than anything else, though I have a 20mm rear bar, being a 1991, so maybe H&R bars would be a good next move... Anyway, good luck with your car Unkle.

Unkle

Thanks guys,

@ Jetta, I think i did try for a real world stance, I think thats a good way of putting it, although each to their own. I could have taken the extra off the rear perch and the same at the front but my main priority was that i actually liked the soft ride of the standard setup, and how it covers ground very quickly without fuss on bumpy country roads, so I just wanted a little more aesthetically pleasing look to go with it. If i was going to use it only at the Ring and trailer it to the Ring each year I may have decided differently, but 4 hours on Belgium roads brings tears to my eyes just thinking about it with full RS height.

The previous owner had a few problems with the geo settings from a company and had some harsh correspondents with them about what settings they applied, but after comparing what that final sheet said, and the new one from Porsche, its like night and day.

@Stan Yeah the Eibachs are great i get the looks and nearly keep the ride, win, win for me. The old dampers i took of weren't leaking but when they were compressed fully the piston rods never came back up, so much for the rebound then, and yet the suspension didn't feel like it was shot, worn yes but not an MOT issue. Eitherway I'm happy.

nidon

Looking nice, I find the Eibachs and bilsteins give a good result. Like you my front shocks would just compress with 1 finger and never come back up! and the rears had about 10mm of 'free' play before they did anything
My Eibachs where shorter than the springs that I removed though both front and rear ?

PS good colour

Unkle

Rears where much thicker less progressive and they were about 30mm lower. But the fronts as you can see where nearly the same length, the progressive coils are nearly completely compressed when on the car (from what I can see) so with a low initial spring rate based on coil diameter and coil gaps, i assume that is where they get the drop, makes you wonder how they are on a C2 and whether you get the full 40mm drop.

You are right about the colour, we don't need a special colour thread to show how good it is

boxsey911

Nice job mate

I think you'll find that getting the caster set correctly was one of the biggest factors on improving the high speed stability. I remember when my new KWs were fitted that the car was transformed from a bobbing/wandering nose to something that was rock solid. Then, for reasons I won't bore you with, the caster was reigned back a little and the wandering nose came back. We then put the caster back to the correct spec and it's rock solid again.

Unkle

Just a little update of the ride height i have and couple of pics if any other C4 owner is thinking about the change. I know the arches are 8-10mm out, but the datum points are the same so very happy with the results, as i think its as low as possible while still looking factory. The suspension is great ,turn in is greatly improved, along with the general aesthetics. Thanks for all your feedback.

This is the fitment for a C4 which is 100kg heavier, it may alter slightly on a C2. (caveat)

nidon

Looking nice !