jw996

This is a new issue. Only has 29k. Cars seems to have become a litlle squirrely at 70-80. Feels like I have a trailor behind me in tow,kind of front doesn't seems to be connected to rear. Opinions thx.

chsu74

check tire pressure first then alignment then new shocks/suspension.

Ubermensch

If this issues just cropped up, I agree with checking pressure and alignment, but isn't this sort of a known issue with the US spec suspension? Common fixes have always included lowering the front end height from the US spec to the Euro spec, or using the aerokit to reduce front end lift.

Macster

By 'new issue' I assume you've owned the car since new and it is stock in its suspension and aero hardware and this squirrely feel has just appeared?

Then my first suggestion would be tire pressures.

At 29K miles (even at zero miles given the hit or miss aspect of new car alignment) an alignment would not be out of the question.

Yet another factor might be tire wear.

Not sure how well this maps to the 996 but I my 02 Boxster's Michelin tires were shot. The rears were worn down in the center through the wear bars to the point lighter colored material was showing through. The car had such a downright squirreliness feel to it that I was pricing new struts/bushings/etc. But I decided to hold off until after the tires were replaced. After new Pirelli tires were installed (I had ordered Michelin tires but I found out they are currently unavailable in my car's size/etc.) the car's squirreliness feeling went away.

As is my habit when 4 new tires are installed I talked about having the car aligned, but the tech told me that his experience was the center wear was not due to any alignment problem simply a characteristic of the car/tires. Save for the extremely heavy center wear the rear tires did not show any wear sign arising from misalignment issues and the fronts likewise showed no signs of any misalignment issues. The tech said further that at some point Michelin tires wear quick fast, the wear is not linear as I had thought. Oh, the rear tires had about 30K miles on them while the fronts had around 50K miles.

Sincerely,

Macster.

jw996

Car lowered 1",with gt3 front end. I forgot to mention that I replaced rear tires with Hankook v12,285's . front tires are in great shape but different manufacturer. Tread design very similar. Reason for change, besides being worn, wanted wider tire that older tire didn't come in 285 size. Have noticed a clunk in front end when going over payment change of say 1" difference. Made app. with dealer to investigate, and I am aware of the listed things to check. Curious I didn't find anyware that a little tread pattern would make car track differently. Anyone done this and had similar experiences? Thx.

jw996

Sorry, "pavement" changes. I also haven't been 70-80 recently until tire change.

San Rensho

Sounds like the mismatched tires is the cause.

Macster

Mismatched tires always come in for suspicion. I can't offer any direct experience for I've never run mismatched tires, not even mismatched N-rated numbers, but I've read posts by some who have mixed tire types/brands and I can recall some owners were unhappy with the feeling of the car.

What I have done is I have run partially worn front tires (the front tires had plenty of tread left) with new rear tires without any odd handling behavior though.

Kind of drastic to replace a pair of tires just to find out in your car's case this is the cause of the symptoms/behavior but unless you can find some other reason I think you're facing a pair of tires.

Sincerely,

Macster.

trapperdog

I've had my car for 8 years and it has always felt "floaty" at highway speeds. Over the years it's had new tires and an alignment but still feels the same. I also have the GT3 front bumper. I don't have a rear wing and wonder if the aerodynamics are messed up because of the front bumper. It is stock suspension. I read about that "hunkered down" sensation some guys say their cars have and wish mine was like that but it doesn't.

jw996

Will do process of elimination, getting suspension checked out next week and probably an allignment. If that doesn't work then I guess I'm buying two tires. The old tires were near wear bars and were a little slick. I did have the feeling of hunkered down at higher speeds before. I am curious that since I went with a wider tire if that might have messed up the allignment. I will post my findings. Thx.

philooo

I think the car always floated for me, with new tires or not, the only way to get rid of it is lower the car. no need to go drastic, simple pss9 stock high will completely eliminate the floating problem, but considering Us highway speed.. I don't see the need. I prefer the everyday convenience of higher ride height.

jw996

The car is lowered 1" with eibach springs, this is a new feeling. I'm leaning toward mismatched tires. what do you guys pay for allignments, thx.

Macster

it is very possible the presence of the GT3 front bumper and the absence of the matched rear wing has upset the car's aerodynamics.

I can't call up a good mental pic of the GT3 front bumper but I just replaced the air dam of my 03 Turbo and this air dam has a distinct lip/ledge jutting out from its bottom edge that acts to generate front down force. The rear wing is of course factory (and raises at 75mph (indicated).

At very high speed speed the car feels quite planted.

Sincerely,

Macster.

AndyK

I'm wondering if the high factory recommended tire pressures can cause floaty performance at high speeds? From what several of you have said, your cars have always been floaty?? That probably means that unless everyone has worn suspensions, or alignment that's off, it's got to be something else!

It's "Porsche, there is no substitute", not "Porsche - floaty at high speeds"!

Gaspasser19

When I first bought my cab. I too felt that the front end was "floaty" at higher speeds. Some research on this and other forums revealed that many were using a lowered suspension to mitigate the floatiness. I had the R0W M030 installed and indeed the floatiness was resolved. The 20mm lower front was sufficient to change the feel of the car on the highway.
The ride height of the 911 sold in the US is higher than those sold in the rest of the world due to US regulations on bumper height. Porsche had to compromise their design to meet US regs. and it made a difference in how the car handled.