Polman

Instead of flying to a 3 day meeting, I did a nice trip from Sweden to Belgium with my Cabrio. To stretch out on the Autoban with no speed limit is nice. The only problem was that I felt like a Kamikaze pilot. When the speed was around 250 km/h (almost top speed) the car didn’t feel safe anymore. Okay it is 12 years old, but has “only” run 92000 kilometres, the tires is okay with the right pressure, suspension was changed at 60000…..but still…In my Audi, I can travel in that speed and still pick my nose
What shall I do to get it right? What bushes wears out on the 964 ?

springer3

One thing I like about any 911 is you can't ever feel sleepy when driving it. If the car felt dangerous, however, I would head for the best suspension shop I could find and have a diagnosis. Are the tires correct and not badly worn? 4-wheel alignment checked? Shocks in good shape? Sway bar bushings are prone to wear, and that will make the on-center feel a little unstable. If you just had the suspension changed, it is possible that something is amiss from that operation.

R6XTERRA

I never ever had a quiver out of my 911 C4 at those speeds and above with the proper suspension setup. Sounds like something is not right or your roads are absolutley horrible.

Jeff

Millemiglia

I've driven my '90 964 Cabrio flat-out on the Autobahn and Yes, the sound-level in the cabin was deafening, but it never felt unstable.
So I agree, sounds like something is wrong with your cars suspension setup.

Btw, flat out was 285 km/h on the speedo.

Superunknown

Thats something like 177mph!

Seight

285 Kmh? Your speedo must be way out, a 964 is not geared to do that speed, even if it had the power to pull to it.

R6XTERRA

hmmmmm, then my speedo must have been out too. I had it wrapped around.

boxsey911

If they're all supposed to be 10% out then the actual v-max is about 160 mph which is about right isn't it?

Well done Peter and Jeff

barney55

I often do the Autobahn storming (i live 25 mins from Germany) and see 280

on the speedo, is it accurate, who cares,nothing and i mean nothing has over taken me at that speed.

Lack of ***** rather than slow cars i'd say,but over 250 it's as solid as a rock.

But if it's a bit windy then thats a whole different ball-game,then you need to watch for the side winds.

I even do 250 in the rain,and love it,you hardly have to slow down at all.

Best cars in the world...bar none.

Polman

Thanks for your suggestions, I will go by a shop and do a proper suspension setup right away.....
Then I must test again....

rennmax

How do your soft tops cope at that speed, my ones starts flapping at 140km/h.
Do you have the vents shut so the cabin doesn't pressurise?

Polman

Hi Rennmax,
In that speed the top was up, and of course it´s very much noisier that a ordinary 964 coupe. Any flapping ….-no I didn’t notice that. A/C was on and closed windows.
With the top down and the cover in place..220 km/h was absolutely no problems. I have the wind stopper mounted at all times, but a sweeter around your shoulders’ is a god thing against a very stiff neck the following evening!
A god thing to reduce the noise at high speed is the form shaped plastic spoiler that you mount in the rain gutter on the windshield frame. I found it at a RUF dealer in Germany. Since it’s a RUF part… it looks god and doesn’t suck at all when mounted. I don’t have it on my Cab, but put them on my 993 4S. You can see it on the picture.

Otherwise on your problems…check your window seals…

rennmax

Thanks, I'll have to find some quiet country roads to see how it is at the speeds you're talking about.
I'm probably exaggerating a bit when I say flapping but the top starts to get a little noisey at 140km/h.

Anatol

You should check your tie rods (arms from steering box to wheel carriers) whether the bushings are worn. Mine were and that caused the car to wander on the road heavily.

Furthermore, all the bushes in the suspension may well be shot by now. Either you go for new suspension parts (Porsche does not sell the bushings) or you have a specialist replace them for rubber or better uniball bushes. I went for uniball and the effect is dramatic: more precision, less fear, no sudden and unpredictable movement under heavy cornerning.

And no need to fear excessive noise or harshness levels from uniball joints: our cars are not softly sprung or silent anyway, so you won´t feel a difference here.

Last suggestion: go for splitters under the front bumper. They are available as easy to fit parts for each front corner and work wonder at high speed.

Hope that helps!

Polman

Thanks Anatol,
I have a very good Porsche mechanic shop around the corner that can fix my problem. How many "dollares" do you think I have to spend on an total "bushing overhaul"