Bilstein life span

[torresmd]

Back in 2009 I did a complete upgrade in suspension. I replaced pretty much everything, including shocks, bushings, torsion bars and sway bars. The rear shocks were replaced with Sport Bilstein shocks. After the upgrade was complete, the car felt like it was on rails. I drive this car daily and use the same route. I have noticed a recent change, nothing sudden but just gradual. More slop, especially cornering at high speed such as on ramps that I normally can do at 80mph now I feel much less confident. I also noticed that with some irregularities in the freeway caused my car to porpoise from front to back.

So today I was inspecting the suspension parts and everything seemed OK visually, but when I push on the rear bumper, it has quite a bit of movement up and down with little pressure. The front is very stiff. Could my sport Bilsteins gone bad that quick? It seems to be equal from left to right.

Here is a list of what I upgraded:
Rear Sport Bilsteins
Front Bilsteins
Tarett front and rear sway bars
ER adjustable spring plates
30mm hollow rear torsion bar
22mm hollow front torsion bar
Polybronze front and rear bushings

I was going to start by replacing the rear Sport Bilsteins and see if that solves the problem but I just think it is odd they have gone bad so soon. Could I be missing something else.
Thanks in advance.
Steve

[pkracer21j]

I thought I was the only one who had a set of bilsteins go bad quickly...I had my whole suspension done two years ago valved to sport/rsr specs and the car was as you say, on rails! but about a month ago I noticed it became very nervous at speeds over 60-70. sure enough. both rears had blown. I swapped them out for a pair of sports that I had on the shelf and problem solved, shes stable up to 160. So my custom shocks are on their way to Clint at Rebel racing for a proper rebuild/refurb.

[torresmd]

Maybe Bilstein's quality is not as good as it used to be. I find it odd that both shocks would go bad at the same time. Waiting for my replacements shocks to arrive and I will swap them out and see if that solves my problem.

[torresmd]

Well I replaced the rear drivers side Bilstein Sport shock and put the car on the ground to test it and found it to be just as bouncy as before. So it is not that the shocks have gone bad. Something else is allowing the car to bounce up and down. I had my son bounce the car up and down while I looked underneath and I didn't notice anything wrong or broken. I would imagine that if I had a broken torsion bar, it would sag on one side or only affect one side. I have decided to stop driving the car since something is clearly wrong. Anyone have any other suggestions? Not sure what I am missing.

[66cal912]

Did you inspect the polyurethane on the polybronze bushings?.... how old are they... Any signs of cracking squishing out or signs of wear...? If so that may lead to handling like you mentioning in your top original post... Anyone know the life expectancy of the bushings, or does anyone have mileage on the bushings they can share?

[torresmd]

Visually they look OK and I sure hope that they last longer than 5 years. Also I don't think they would have anything to do with rear up and down movement. The only thing I can think of that allows up and down movement is the shocks and torsion bars. But I am no expert. Could my spring plates cause this. Possibly a loose nut that I have overlooked?

[JFairman]

Call Chuck Moreland at Elephant Racing. You bought his bushings and he will help you out with whatever is going on.
Everyone else can only guess.
If the bushings are installed and fitting correctly I can only guess you need custom valved rear shocks with more rebound damping to go with your 30mm hollow torsion bars.

But thats just my guess from a distance and I can't give a better guess unless I was there with your car.

[torresmd]

I did call Chuck and he felt that what I described was actually normal, in regards to the rear being much softer than the front. He is probably right but I will take the car in to my mechanic on monday and have his inspect everything. I guess I never really compared the stiffness from the front to the back. I am shocked how much softer the rear is compared to the front.

[Tt surgeon]

I also have bilstein sports front snd rear, the rear is soft/front stiff.
Elephant also makes a coilovers conversion to use w your torsion bars.
Or add bigger tb's.

[torresmd]

I have been considering going to full coil overs for the front and rear. I did buy them from Chuck for my project car, have them installed but have not yet been able to drive the car. Very soon I hope. If it is truly night and day, them maybe I will make the change.