Car feels a bit "floaty"?

I do not typically drive over 100mph, but I have been over 100mph (100-125mph or so) in at least two cars on a few occasions, my 2003 VW GTI and my 2000 996. I have the full factory aero kit, and pilot sports with good meat on them. It seems that over 100mph the front end seems very floaty. Not sure if its just me and my inexperience at high speeds or what. I guess I was hoping the car would feel solid like on rails at 120mph, but its just nervous ground for me. This would be on the Florida Turnpike aka Autobahn, during spirited runs where I couldnt see any cars in perfect light, and like I said, its only happened a few times. Brian

+1, I have an aero also.

Is the front lip installed on the front bumper?

check your tire condition and pressure

Front lip is installed. Tires were just balanced, so I assumed pressure was good but will check. I had new pilot sports in back, put 200 or so miles on them before testing at high speed. Can someone describe what the car should feel like at 120mph? At what speed does it start to feel a little freaky to you?

Put the M030 suspension on (mk I 996's) or x74 (mk II 996's). That will button it up.

What are you tires sizes, front and back?

225 in front I beleive, 265 in the rear, 18"...........so I guess just regular 18" setup. As for M030, would that really make a difference going straight at high speed as far as the floatyness feeling?

With same tire sizes as you and the same aerokit, without the front lip, I get floating above 120. With it, floating is gone.

I have a C4S style front bumber + lower lip on my C2 (yeah, custom fit the bumper) - no floaty stuff. No other aero work (no side skirts, no fixed rear spoiler). But I do recollect that on stock bumpers I was feeling a bit floaty on the front.

I noticed the front end would get light and wander on my 02' when I originally got it above 130 mph. Keep in mind that there were substantual changes that reduced the 02'+ front lift 25% and rear lift 40%. When I swapped to a ROW M030 suspension, it completely tightened up and I can say confidentally that it is extremely stable above 160 mph.

Your tires are fine and so is your aerokit. I would be surprised if a front lip would make that big of a difference. Two questions - Is your car lowered? When did you do an alignment last on your front wheels?

IMO, your suspension and front spoiler setup has everything to do with how the car feels at speed. I believe I would be a bit nervous driving at 130+ mph without the full aero kit plus front splitter and a lowered suspension. The base 996 will, of course, handle triple digit speeds quite easily, but the car's feel will be a little more . . . . shall we say . . . . light if you do not have the proper aero and suspension setup. And for good reason, as the volume of air entering the car at those speeds generates exponentially higher lift than at say, 70 mph. I'm sure there are many much more technical guys who can give you exact formulas using downforce, lift, volume of air, speed, etc. Also, please note the crosswinds will have a tremendous effect on how the car feels at high speed. Since there is ordinarily more lift on the car at high speed, the crosswinds tend to have a greater effect on the car's straight line tracking thus highlighting the "light" feel of the car. As for my 996 (see below for specs/mods), I feel well planted at up to around 160mph. I have had the car at an indicated 181 mph once and the car did begin to feel like I was getting a little light, but it was too tough to focus on any one thing at that speed. At 181 mph I ran out of straight road, but believe it would have finished the pull to a rev-limited 187 mph if I had more pavement. I routinely have the car to 140 -160 mph with no problems including shallow banked, broad cornering at 150 mph without much drama; however, if there are more than 5 - 10 mph crosswinds the car will dart around at 120+ mph and I will slow my butt down in a hurry. Crosswinds are not to be played with or taken lightly when performing high speed runs, not by me anyway. Crosswinds and stray puppy dogs are the enemy at high speeds. Come to think of it, at high speeds you have many more enemies, birds, stray tire treads from big trucks (a.k.a. alligators), nails, and the list goes on and on. You will notice I do not include other cars as an enemy because you should not be running those speeds in the U.S. with other cars present, since you never know what "grandma" or "the distracted driver" in the other vehicle is going to do next and the speed differential between you and the other cars is too great for relatively safe driving.

I had a 1995 'vette Z07. That car felt 10 X's more stable at speeds than my 996. Once I was doing about 140 and you almost couldnt turn the steering wheel it had so much downforce. My 996's steering gets lighter at speeds over 100, I placed the blame on the wing, I wanted to take it off.

My '99 Cab feels great as fast as I've had it which has been at 155 with the hardtop on and my wife in the car. This was on a 2 lane country road in Kansas. I've been at 140-150 a few times with the soft top up and it always feels good, 140 top down feel really good, 125-130 one handed taking pic of the speedo and view thru the windshield, felt fine. Over 20 years ago I raced a motorcycle at Bonneville Salt Flats and got wheel spin up to about 80 on the wet slippery salt and a few strong side wind gusts that try to blow you off course at speed. The long course is 5 miles of full throttle acceleration and a couple of miles for slowing down. My 2 way average was 148.546 and compared to my '85 ill-handling motorcycle on a soft slippery surface the Porsche feels wonderful.

For a reference point, my stock '02 C2 felt good at a GPS-calibrated 141mph, but I'd had it carefully aligned three days earlier and I'd checked the tyre pressures about five times that morning The car felt very stable up to about 120mph, then started to feel a little "dartier" but I wouldn't call it floaty, just that the steering was getting very responsive indeed, and I definitely didn't want to sneeze I'd definitely check the alignment first, then see how it feels.

My bone stock 02 C4S feels firm and planted at 120-130mph. Steering feels tight and heavy as well, I guess due to the all-wheel drive. The only floaty feeling I have during those speeds are my licence and $$$ at high risk of floating away...

I have a '01 C2 with the stock bodywork, and I've driven it up to 135 with both stock suspension and PSS9s (on track). The car feels better lowered, but fine either way, and turns just fine at about 120mph (gentle kink in the straight). It feels much better than my S2000 at those speeds. This coulsd all be a matter of personal preference/experience, but I would recommend trying it without a rear wing (of you have one).

Blame it on US regulations that require Porsche to raise the front bumper 10-20mm in order to come into proper bumper height safety compliance. No word yet on when domestic SUVs and trucks will have to 'lower' their bumpers in order to keep from scraping sedan and coupes windshields in every fender bender.

Your rate of acceleration has a big effect on the front end float too as your front end is raised even more allowing air to get under the car.

My car has never felt "floaty" in the front, before or after the aero kit and suspension mods. Up to 145, nothing but a good solid feel to it.

Assuming you have corrected the no brainer stuff like alignment and tire pressure, the floating sensation is caused by the fact that your car is essentially a wing. Just like Wilber and Orville's wing the air passing under your car travels a shorter distance than the air traveling over your car which produces lift. Ever wonder why a spoiler is called a spoiler. It's because is messes up the airflow over the car reducing the lift effect. It "spoils" the airflow. The solution, as many have mentioned, is to reduce the amount of air that gets under the car. You can do than by adding an airdam of some sort on the front, by lowering the car, changing the rake of the car or all three. A couple suggestions, if you have a full areo package you must have the front lip on. It makes a huge difference. Leave your rear wing flat. Especially if you are at stock ride height. Downforce in back will just make the problem worse. If you have adjustable ride height dampers, lower the car and rake it a bit to the front. Just my 2 cents and worth both pennies. Jim

It could very well be my alignment. I have had the car only 4 or so months, and have not had an alignment or the alignment checked. There are diferent kinds of alignments that can be done correct? Any special instructions I should give the alignment shop as to how to setup the car, or do they just punch "2000 996 C2" in their computer and let it do all the magic? Also should I get the alignment at a Porsche Dealer or am I safe with a normal Alignment shop? The car tracks straight, but in looking thru the service history it had gone thru a few alignment adjustments in the past to try to correct for some pull the previous driver was having. It followed the tires however, and was not a mechanical problem, but they may have tried to correct for it.