Okay... after getting the 4-wheel aligment, new wheels, GT2 ride height on PSS9s... I guess I was hoping for better handling than I am getting.

First, the brakes are shaking under certain situations which could be pad deposits, could be ****ty stock pads... okay I will replace them.

Second, is the lack of complete confidence at higher speeds. The wheel shakes at aroun 75-80mph and eventually smooths out... but not all the time. One theory is that the wheels are not snugly fitting the hubs so the hubcentricity is off. Theory two is that the tire are not mounted on the wheel with the heavy side alligned with the valve stem. Theory three is poor front wheel balance however this can;t be because I had them roadforce balanced this morning and corrected. Theory four concerns the suspension being so low that the bump-stops are being engaged causing problems (see KPVs post concerning GT2 ride-height on PSS9s)

Third, in the turns the car seems a bit uncontrolable at times. This may be due to the fact that the understeer amount has changed once again do to the fact that I just lowered the car and I am just not used to it. Once again, bump-stops may be the cause.

Any ideas on how to get better stability out of this $135,000+ car?

 

Britt

Listen closely:

GT2 ride height with PSS9's = BUMP STOPS
As far as the shake that is wheel balance and brake problems

KPV and I have been over this a million times

JIC, Moton and JRZ are they only way to go for low down ride height and suspension travel at the same time

Sorry buddy and I feel your pain, been there done that

 

Sorry to hear about the problems Britt. Didn't Rob go with the GT2 ride height with his PSS9's? Rob???

 

Britt, i have the same wheels and tires and mine do not shake at all at any speed; it has to be a balancing issue. As far as the brakes you may be exceding the temperature rating of your pads.
Suspension wise , i had the same problem with the H & R coilovers but when i switched to the moton suspension , it was all taken care of.

 

Not that it helps you in your situation, Britt, but i have to say that the JRZs with Bilstein springs provide a great setup. I havent had any problems with them at all, the only thing/change i noticed was that you experience a bit more road noise through the front. I believe this is due to some of the sound deadening/insulation material being taken out to accomodate the reservoirs.

Food for thought should you decide to change it in the future. GOOD LUCK

 

The wheels are balanced, I watched them do this myself. The wheel is not 100% snug on the hub... this was illustrated to me by the alignment tech. He said that they make shims that might help this but I have no clue where to get them.

As far as bump stops go, what symptoms are produced when these come into play.

 

Plus... motons are out of the question. Too much money. I guess I could raise the ride height a bit... but how much is the minimum to get satisfactory results?

The car looks great as is but the performance is suffering! It's all a balance isn't it?

 

Britt, call me when you get a chance, I had a problem with this and may be able to help.....

 

Ah... Thats the problem.... Only 135K !!! These cars do not get to where you want them until you put in 160K or so....



Sorry to hear about your issues... For the driving you and I do I still think X73 is the way to go... We don't track and you will achieve the lower ride height and improved handling over stock.

At least that is what I am thinking about doing.. Oh, and any issues... let Porsche figure them out as they are OEM parts.

 

If its a wheel issue, I'm certain Wheel Rob will take care of you. They should fit snug without an adapter.

 

Raise the pss9 to row specs and take it from there.

 

After driving it to work this morning I made the following observations:

1. Brakes did not shimmy once.
2. Vibration is around 70 mph... sometimes. Can't figure this out.

I think that I need to become more familiar with driving at this ride height. You really feel alot more of what's going on at these ride heights.

If the vibration problems persist I will raise the suspension 5-10 mm and see if that helps. Also, as a troubleshooter, I will swap the wheels and tire for the factory equipment and see if that makes a difference.

Thanks to everyone for their advice and insights.

 

I have seen brake pad embed in the rotors. This will do what you have described. This will occured when the brakes were not broken in properly. If so it can be fixed easily.

 

Britt,
Call me when you get a chance and we can discuss.

 

Sounds like your wheels are not hubcentric. Put your stock wheels back on and see if the problem goes away. The brake vibration could be the wheels shaking on the hubs under load. I have experienced this problem before. You may need hub rings. If this is the case, I would promptly return the wheels for a hubcentric set. I am guessing you have after market wheels.

Craig