that floaty feeling with Hankook tire is well documented

https://www.6speedonline.com/forums/...x-ps2-v12.html

https://www.6speedonline.com/forums/...xperience.html and more..

although many have great experience with v12's, plenty also had awful experience where the car feels 'floaty' and unsafe.

it can be simply due to that mixing any different tire brand on front/rear is disastrous.. but i personally wrote this off to bad batches of weak sidewall and bad quality control on Hankook..

bol and let us know what the 'fix' was

 

I have the same feeling on mine, and have been told it's a common 911 feeling. I've got a buddy who has had 4 or 5 911's, and he said he's had that on all of his. That said, I'm going to adjust the PSI and see if that makes any difference. Stock suspension on mine as well.

 

the floating feeling is normal. It is a trait of the 911. I thought there was something up with my car when i first felt it, then two days later I was watching top gear and they were doing an episode with sharkworks lime green gt3 and they talked about the floating and said how it is common and expected out of all 911's. You can look this up on youtube and watch the video.

 

Only the American 911 floats, American buys complained to Porsche that the car rode to rough and most Porsche Owners are older, they prefer a slight more comfort, so American 911's where fitted with a softer suspension set up. Switch to the M030 or a Aftermarket Suspension properly set up, you can tune the suspension perfect. People lower there car 1" and wonder why it handles like sh*t, one thing changes another. Lowering your car changes your Caster and Camber. The M030 comes with lower strut height, lower springs, different sway bars. And a good after market set up will also include or recommend thrust bearings, adjustable control arms, adjustable tie rods, adjustable dog bone, even adjustable sway bars so you can balance how much load the suspension receives under acceleration and braking. I have the M030 Full Set Up on my car and i have had it at @160mph and she handled nice and smooth, no floating, very firm and well planted.

 

I just replaced my back tires with matching Hankooks and had the car aligned. Fronts were in too good a shape to buy 4 pzeros. Prior to this no float at speeds up to 140. Now the car floats. I had thought I was just being too sensitive until I saw this thread. So you guys think it is the tires versus the alignment? I was thinking the prior owner had the alignment set a certain way that burns through tires faster but kept the car tighter to the pavement. Tires or impact of a quality alignment?

 

Once again, it is not.

 

I am experiencing a similar issue after getting 4 new tires and a 4 wheel alignment and have to agree with DenverSteve.

I recently had 4 OEM size Michelin PS2's replaced with 4 new OEM tires, and had a 4 wheel alignment done. Shortly after I started noticing a vibration at 80 mph that was not there previously, and noticed the floaty sort of feeling at high speed that the OP described. My car is on stock suspension, stock ride height, and this feeling was not there prior to the new tires and alignment. I have played around with tire pressures with minor changes noted, but am getting ready to bring it into the dealer to have them take a look because it is not getting any better.

 

Just checked my tires cold this AM. I was at 36 rear and 34 front. I filled to 42 rear and 36 front. It seems to be more prone to "pitching out" on small bumps and feels like it is "squirrelier" when driving fast. I'm going to start backing off the air at 2 lbs per tire and see what works. I'm running Goodyear F1's on 19" DCR rims. They are quiet, but I don't like the new float at higher pressure.

 

Normal trait for 911's, I have 18" Kinesis wheels w Hankook V12"s and when I got the car it floated like crazy at high speeds. I put a set of Champion Motorsports lowering springs on and it got worse.
I pulled that set up off and put a set of adjustable coilovers on and started playing with ride height and dampening til it went away.
So it can be done but I'm pretty sure it has nothing to do with tires cause I didn't change tires or wheels.

 

Hi Phantom- Yes, I have PSS9's and they used to be slammed. Raised it about 3/4" to clear some tough spots and not bottom out. Better now. It is still pretty firm and I don't think float or porpoise is the right word. My is just more squirrelly with the higher PSI. I'm trying to find the sweet formula for 19's with my suspension. It is not what the door says...I know that. What pressures are you running?

 

This is my first 996 (Turbo). I felt the same way. Got alignment checked, all was to spec, yet could not feel confident. Tech told me to lower the rear pressure a bit, but still within specs, and was amazed at how something so simple could inspire confidence and change dynamics of car. I mean really, just air pressure?! The car has its own feel, granted, and it takes some getting used to, but I did a HPDE a couple of weekends ago, expecting to be timid and reserved, but once I got the 'Feel" of the float and the inherent understeer feel, I was amazed at my lap times. Sorry, but for me it was just learning the cars inherent style, and losing a few poujnds in air pressure. I am relieved, because I was thinking I had made a huge mistake with buying the car.

 

I'm dropping the rear 2 lbs. I'll drive and drop another 2 if it does not feel better. I'll re post my results and where I ended up.

 

I maintained & test drove Porsche's western region press fleet 2000-2003. All cars test driven at factory spec tire air pressure settings. Never experienced anything like this at any speed.

 

It's rather strange that those who experience this so-called "floaty" feeling have all strayed from the P-approved setups and recommended inflation pressures.
PC recommends N rated tires with inflation 36 front and 44 rear. There is a reason for that: the geometry of the rear engine. Any time one strays from the recommended and/or apporoved setup, you will alter the car's handling characteristics. You do so at your own risks. 'Nuff said.

 

I'm running 40lbs front and 38lbs rear but that's on 18in 235/40 f and 295/30 r, tire pressures for your 19in tire size will probably be different.