TrackJunke

This is my first 911 and recently put pss9's on my car. The front end of my car when going faster feels a bit floaty. It seems to kind of pull back and forth on the road. It seem to be worse on undulating or bumpy roads. The front end just does not seem as planted as it should. I do have about 1.4 degrees negative camber up front and RS toe settings. I ask this question as I have seen all the recent threads about damaging pss9's when using an impact wrench on them. The front top bolts were tightened with an impact wrench pretty good, and am wondering if it damaged them which is causing this. Or is this a normal feeling? How can I diagnose if they are perhaps blown? No oil is seen on any of the shocks and the adjustment ***** work properly. I set the shocks to a lower number and it did not seem to affect the issue. Thanks

Matt Vaughan

That's not "floaty" by definition. Your car can be wandering, or darty, due to alignment changes such as camber or toe. More aggressive alignment settings will be better on the track, but not so good for the street. Also sounds like your tires are tramlining, which can be happening with certain tire tread designs or significant tire wear.

TrackJunke

I figured the alignment is what is causing the pulling and am not really to worried about it but it does still feel floaty. Atleast that is the best I can describe it, it is almost as if the front and does not really want to cooperate. The rear feels fine and once in a turn it will take a set but the front does not feel the same. Perhaps it is just me not being used to a rear engine car (coming from a boxster).

viperbob

I run -2.3 camber upfront, and 1/32" of toe in and the cars is plated solidly on the rode with no wandering (caster is around 5.8 on both sides). What is your toe in and caster setting in the front?? What are your settings in the rear?

KOAN

The feeling that you are experiencing is NOT typical, and something is probably wrong. Is "floaty" like pogo stick bouncing, which could reflect a broken shock? Sometimes one broken shock will cause the front end of the car to wobble after a bounce. Are you sure that all of the shocks are dialed correctly, that is, could one be full stiff and the other full soft? What tires are you using? Has the car been corner balanced? That can make a huge difference. Did the problem occur with the same tires, and only become evident with the new suspension?
SO3s have a tendency to "tram", that is, if the road has worn tire paths, making the road crowned, then the car can be a little darty ( any car with SO3s, not just 993s). Does it happen with newly paved bouncy roads, or with old or more uneven ones?
Those are some ideas.

Chuck

Matt Vaughan

It will be really noticeable on grooved or uneven pavement. Add some water to that equation and it's downright scary!

Check to see that your drop links are still on the front sway. If the car does not feel right, even on the firmest setting, there could be a chance of a failed shock. I'd have it checked out to be certain.

TrackJunke

My alignment settings are .05 degrees toe in up front, 1.4 degrees neg camber, 5.6 degress caster on both sides. Rear is 1.8 degrees neg camber, .15 degrees toe in, and kinematic toe is maxed out. I am going to get the kinematic toe set properly next week. If I hit a bump straight ahead in the road it absorbes and rebounds fine, no pogo sticking. However just driving along and turning it feels a little unplanted. The car has been cornerbalanced and I am running Michelin Pilot Sports N1. How can I check if the shock is failed?

Phil

Have you checked tire pressures?

TrackJunke

Yes, the tire pressures are fine.

kary993

TrankJunkie,

Can you talk more about "pulls back and forth" ?

CP

Track,

Check your rear alignment again. Mine was a little floaty (front end seems to wonder at high speed, it may not actually wonder, just feels that way). Tony did an alignment/corner balance, and noticed that the rears were off, by a combined 1 degree. He zeroed that out, and now the car is as planted as ever.

I was quite surprised how sensitive the car was to such minor adjustments. The PSS9s are perfect now.

CP

TrackJunke

Thanks for all of the input guys. I went and drove another guys 993 today and he drove mine and he said felt like the steering might feel a little lighter but in his opinion there did not seem to be anything wrong. I drove his car and it felt similar to the way mine does, I guess it is normal. I think another thing that may be contributing is the kinematic toe not being set perfectly.

bet

As others have said a 993 should not feel "floaty". I know you indicated that it is probably "normal" but I have a couple of thoughts you may wish to investigate or think about.

Since you have the PSS-9's which are ride height adjustable, did you have a corner balance done on the car when the PSS-9's were installed? This is an important and often over looked factor to installing ride height adjustable coilovers.

Did the shop check the "rake", or the relation of the front height to the rear height. The front of the car should sit just slightly lower than the rear so there is a 1-2 degree slope if you drew an imaginary line. If the installers did not get the ride height set correctly then this could cause a "floaty" feeling or not planted feeling to the front of the car, especially as speeds increase.

I have the PSS-9's and have my alignment settings and ride height settings set to a little less agressive than the RS. I do not have any "floating" sensations while driving. The car is really planted to the ground. In fact much more so than the standard suspension 993s I have driven. On certain road conditions I do get some “tramlining” that is more a side to side “wandering” versus a “floating” or non planted feel.

I would suggest taking it to an alignment shop that really knows how to set up a car and let them drive it. The 993 is extremely sensitive to alignment settings. Not every shop can align the 993 properly, they have to have experience with the 993 and not just other Porsches.

User 4621

If your car with PSS-9's, increased neg. bamber and corner balance felt about the same as a stock 993, then there is definitely something off.

"Floaty" is a common term that refers to the front end pogoing, typically because the damping circuits are shot or overpowered by the springs. What you described is not floaty, it sounds more like tramlining, which as others have pointed out is worse the more negative front camber you have and is tire dependent.

TrackJunke

Peter,
The 993 I drove was setup with pss9's.

bet,
The car was corner balanced and set up with 1 degree rake. The rear, however, looks like it has settled more than the front so it may be off now.