71S suspension upgrade question-

[2008SPorsche]

Ungrading from original suspension have Konis on rear bilsteins on front! Car is floating & needs focus. Thought about elephant racing 911 kit? Any thoughts???

Want this 71S to handle tight & be really nimble!!

THANKYOU FRANK

[304065]

Frank,

It depends on what you want the end result to be-- original appearance or precise control. Call Chuck Moreland at Elephant, he now offers both solutions-- can re-do the front suspension bushings as a service or sell you a patent-pending tool to install the bushings.

His Polybronze bushings are a work of art, I have them in the rear of my '71E race car. "Stiction" in the suspension is virtually eliminated, resulting in smooth suspension movement which allows the torsion bars and shocks to do their job properly. Highly recommended for DE or Racing, perhaps overkill for the street (and does carry some NVH noise vibration harshness penalty).

Two points to bear in mind that are probably more important than the choice of bushings-- for any uprated setup such as bigger torsions (22/28 would be a nice combo for your new S) having the Bilsteins revalved to match the revised spring rate makes a material difference in handling.

The other important point is this: for antiroll bars, strongly consider the Smartracing offering. They are very expensive, but the bars have the correct kinematics to avoid binding the suspension through the entire range of motion. Why this is important: if you are entering a corner and the suspension is compressing, and all of a sudden the bar binds, your effective spring rate can go very, very high, resulting in more load transferred into the tires = spin time. With the smart bars you can actually install them WITHOUT the torsion bars, then move the suspension pieces through their range of motion to observe that the suspension doesn't bind.

So to summarize, if I were you, I'd call Chuck and get complete new front and rear rubber bushings, 22/28, revalved Bilsteins (either from Chuck or the various other speed merchants, all of whom have their own proprietary secret shock valving rates) and a Smart Racing front bar, a big fat one like a 27 (I have a 31 in my race car, it's basically a steel flag pole).

Good luck!

[2008SPorsche]

Everything on this 71S is rebuilt but Trans & suspension.

It does have billstein's on Front & Koni's on back for shocks. I believe most everything is original.

The car seems to float... One front shock is leaking..

I looked on elephant web site I thought about getting total system for best street level suspension?

I just want this thing 100% on the money

front billstein & rear Koni's is a problem I believe....

So I am here

FRANK

[fryardds]

Frank,

John has posted some good info as always. I can share with you how my mechanic setup my recently aquired 2.2S.

The previous owner had installed 20mm front with 26mm rear torsion bars with adjustable 21mm front and 19mm rear sway bars which we left as is. He bought a complete set of rubber bushings from Smart Racing and installed them. The car had a good set of hydralic Konis front and rear which he set to 1 full turn from soft. He lowered, aligned and corner balanced the car. I am running 205/60s and he had them load balanced. All this has added up to a superb handling early 911.

Somewhat conservative for sure, but really sweet. I took the car out when I picked it up, ran it up over 80 and let go of the wheel. Not one bit of vibration or drift. Not only is the key to get the right mix of components but having a great mechanic is also key. Let us know which stuff you go with.

[Flieger]

Everything on this 71S is rebuilt but Trans & suspension.

It does have billstein's on Front & Koni's on back for shocks. I believe most everything is original.

The car seems to float... One front shock is leaking..

I looked on elephant web site I thought about getting total system for best street level suspension?

I just want this thing 100% on the money

front billstein & rear Koni's is a problem I believe....

So I am here

FRANK

You say the car "floats". To me this suggests an underdamped state of suspension tune. This means either your torsion bars are too strong or your car is too heavy for your dampers. This causes excess oscillations before the suspension returns to ride height after a bump.

Number 1 item is make sure the dampers/strut inserts are in proper working condition as they were originally.

Number 2 item (if float persists) is to re-valve the damping stiffness to suit your car's natural frequency of suspension oscillation. The lighter the car and the stiffer the spring, the stiffer the damper must be to control the suspension movement.

If you have a lightened car and heavy torsion bars, you can tune (with adjustable or re-valved dampers) the dampers to have less rebound damping than compression damping in order to stop the "washboard" effect.

Just some suspension dynamic theory to consider...

Cheers

[Flieger]

Mr. Cramer,

You mention sway bar binding due to bad geometry. Are you referring to the Weltmeister product?

I have a 22mm rear anti-sway bar and a corresponding (22mm?) front anti-sway bar. They are both Weltmeister items. The front is through-body and the rear is attached using the (reinforced) factory mounting brackets and hooks up to the rear spring plate eccentric bolt. The car is the 1971 911S in my signature line.

Is this geometry susceptable to the binding you mention?

The 911's rear suspension is already bad geometry because the spring plate, on which the torsion bar acts, and rear control arm are not co-linear. So it seems to me that there will not be any more binding than is already present.

[304065]

Mr. Cramer,

You mention sway bar binding due to bad geometry. Are you referring to the Weltmeister product?

I have a 22mm rear anti-sway bar and a corresponding (22mm?) front anti-sway bar. They are both Weltmeister items. The front is through-body and the rear is attached using the (reinforced) factory mounting brackets and hooks up to the rear spring plate eccentric bolt. The car is the 1971 911S in my signature line.

Is this geometry susceptable to the binding you mention?

The 911's rear suspension is already bad geometry because the spring plate, on which the torsion bar acts, and rear control arm are not co-linear. So it seems to me that there will not be any more binding than is already present.

I can't say anything good about the Weltmeister products-- I had their front and rear bars in my 911E race car-- the mounting hardware was cheap and corroded to the bar, the front bar was actually BENT when I took it out of the car (not easy to do) and their method of attachment to the rear spring plate is to tap SAE threads into the factory eccentric! I called them and asked, "why did you put SAE threads on a car that is metric" and their response was, "to make it easier to find replacement hardware." That kind of stuff just annoys me to no end, I haul to the track an entire organizer full of metric bolts and they are using hardware store fasteners! Don't get me started.

Up front it's not such a big deal, even the SRP bar has a "straight" lever arm. What's important up front is the adjustability of the drop links. The factory didn't care about that, their drop links are not adjustable, but when you are using a 13mm pencil bar (or a 15 or 16 probably) it probably doesn't induce a lot of preload.

In the rear different story. See how the SRP bar is curved, and as you loosen up the bar (move the drop link further away from the bar on the lever arm) the mounting holes move. That also allows the lever to not hit the ground.

I know what you mean about the banana and the springblade moving in different planes. It turns out that the springblade twists to provide another degree of freedom of suspension movement. Anyway, eliminating "stiction" is a good idea and the SRP stuff has unimpeachable quality-- as Bruce Anderson says "the difference in the bars is the quality of the mounting hardware."

All that said for originality I'm using a factory 13mm pencil up front and no bar in the rear, and when I AX my '66 I'll put ONE adjustable drop link to tune out the preload. (You only need one, why do they come in sets?)

Frank, back to your original question, I think Chuck's "packages" are great and he is a terrific guy to deal with, he's an engineer with a real passion for our cars. I looked at his street package and that looks like a winner for your situation.

[Flieger]

Just a quick FWIW,

The Weltmeister bar I have is curved as well. I think I got a good version of the Weltmeister product- better than the torsion tube clamp model.

At least I think my bar is Weltmeister.

Frank,

I also recommend Chuck's packages. I want to go with his factory rubber bushings when I do my suspension work. I think I will send out the A-arms for his installation service.

Does he do the rear spring plate as well? I am going to do monoballs for the front strut and rear control arm.

[fryardds]

Yes, SRP now has front and rear Factory style rubber bushings. It will be interesting to see how they hold up compared to the Netrix ones.