Floaty Front End - Already Replaced Whole Suspension

Hi All, I recently purchased an 02 996 Cabriolet with 69k. The front end is "floaty" - the wheel doesnt shake, but it feels like - a) The car never takes a "set" or "squat" in sweepers b) the steering feels numb on center and has a tiny bit of play c) In a sweeper, when it feels vague, if I try to correct into the turn, it feels like the front end goes loose and then I go back and forth overcorrecting. I basically just don't "TRUST" the steering, especially at higher speeds. Here's the thing - I think I've eliminated most of the suspects, but here's what I have going on - and this was happing before I replaced the whole suspension, which is what I chalked it up to. - Replaced entire suspension... all tie rods, arms, bushings, top mounts, etc. Installed Koni Active struts (also, the rear seems like it's sitting a little high, but that's another issue). All other components "stock" or "OEM Equivalent" - Meyle, Lumfoerder, etc, some genuine Porsche - Aligned the car with a Hunter Machine (at America's Tire) - Running on original, stock, non-M030 springs - Running on original MY02 5-Spole rims on 18's (yes, could have a little understeer due to larger-spec, I believe 225/40 and 295/30 What am I missing? Need new steering rack? I've read that there's some "nut" that bolts to the steering rack which can get loose...... Ideas!? Driving me nuts. I'm way more $ into the car than it's worth, and I just want to enjoy it. Thx!!

Quotes source post: 19082561

That nut is probably the nut that sets the pressure with which the rack is pushed against the pinion. Nothing you can adjust or repair yourself, really. If the pressure piece is too loose the rack itself tends to get noisy on coble stones and the like. If you don't experience that, I doubt it is loose. How old are your tyres and are front and rear of the same brand and type?

And what tires are you running and what tire pressures? All the 996s came straight from the factory with understeer. Add in tires that are over inflated and not grippy you have another set of problems. Add in a suspension set-up that is too stiff in the front in relation to the rear and it enhances the understeer. Wrong alignment specs can also create problems. For sure, improper replacement of parts or wrong parts can do it as well. Don't know if you have any prior experience with driving a 964, 993 or 996, but the steering feels "alive". It tracks the road and every nook and cranny. More so if you have an overabundance of camber. The 997 has it too a lessor extent. The 991 and 992 steering is more neutral amd doesn't really have it.

God I hope that but is all it is, that nut. Just drove on freeway and there�s wind in Los Angeles today. Thought it was the wind tossing me around but even when it stopped, I was still flopping left and right. tires are new. Less than 500 miles. All matching. when I take a sweeper there comes a point where instead of the steering getting higher effort as the car sets, it just get weaker and then I oversteer unless I immediately decrease the effort. this car is bleeding me to death. have had a Boxster before and drove a 996 extensively 20 yrs ago so I�m familiar with the weight distribution and how the steering should feel alive. this is scary.

Also I don�t hear any noise from the rack over road textures. I�ve sunk so much into this car, not to mention being without it all the time, makes me want to cry right now. And I even knew what I was getting into but it shouldn�t be this bad. (Did the full suspension, clutch, brake discs and pads, put in 996 shifter, prior owner did coolant tank, low temp thermostat, AOS, IMS, hoses and some other misc. i put on the stock wheels, was running ****ty aftermarket 19s when I got it. like 50% if the car is new at this point� still having this steering issue which is scary. FML FML FML

Here the good news, suspension problems are fixable. Was the shop that did the work a Porsche Indy? What do they have to say about it. Quite frankly, if it's as bad as you say, you probably shouldn't be driving it and get it into the shop that did the work so they can go over it and make sure something hasn't come loose or snapped. If it's not a shop that specializes in Porsches, you would be well served to find one. The 996 suspension is pretty damn tough amd durable, so once you get it right, you really don't have anything to worry about for a good long time.

Post a pic of your alighnment.

Thanks everyone for the kind help. I�ll post a picture of my alignment in a few hours. Mechanic is a supposedly well regarded 50 year German Indy shop. Porsche is maybe 20% of their business but they only do German and 996 has been around long enough that they have experience. that said, my reverse gear stopped working 2x when I went to pick it up (but I understand this can happen at times. They did eventually fix it.)

When you post your alignment specs, let us know what tires you have on it and the front and rear tire pressures. Might as well fill more variables. Post a side picture of the car as well. More the better.

You didn't mention the speeds at which you start to feel the car getting loose or start to float. Being a .2, you do have some better aerodynamics up front, but at higher speeds, with a stock body, you may still experience some front end float. My .1 Cab can get a little floaty at speeds "in excess" of the speed limit, but it means I just have to pay more attention to what I, the car and others are doing around me. In addition to checking your alignment, have you checked to see if your rear spoiler is working? Make sure all your belly pans are there and properly fastened too. Just my .02$.

OP, just to confirm, is this your first 911, or are you comparing it to other Porsches you�ve driven? The light front end at speed is inherent to the design of the car, and you�ll (well, at least I�ve never been able to) make it track as smoothly over things like elevated freeway curves as a front engine car. It doesn�t mean you can�t attack them, but does require an adjustment to driving style.

OP - Datapoints for speed when front end seems to lose some tire patch reduction and speeds when you tend to feel push (understeer) when braking and turning in? What is your ride height f and r? Rake? Tire pressures (#1 suspect)? Does your spoiler work (#2 suspect)? If you have a slightly taller rear, and that added rake, it should put more weight on fronts. My initial suggestion is check air pressure for fronts at 36 psi and rears at 40 psi for starters. If you are using maintenance throttle in sweepers and understeer is present, when you correct with throttle, does the car overreact in the expected direction?

Have the Alignment Shop adjust the alignment to give you the MAX "toe-in" front and rear, but still within the Factory Specs... Having the Max toe-in will be the most stable feel of the car...

No, this is not my 1st 911. I've had plenty of seat time (a while ago) in a 996 Cabriolet and a 996 TT Cabriolet. I've also owned a Boxster before. I know what 911 steering should feel like, and what steering should feel like in general, and they're both wrong here.

I don't think it's so much float as loose steering causing float. I just had the car aligned last week. Yes, my rear spoiler works. Everything looks clean under the belly.

I have a 99 cab and I had the front and rear suspension replaced when i got the car just about a year ago by a dedicated Porsche suspension shop. Bilstein B4s. I had a horrible 500-700 miles of driving. The car felt all over the place. Dangerous. Loose. It took a much longer while for the shocks to settle. But also, the air pressure was set way to high for Pilot Sport 4s's (sticker) I since lowered to 34/38. After the miles and the drop in pressures, the ride is dynamically different than it was before. BTW, what shop did you go to (I'm in LA too).

Hi Everyone - THANKS FOR YOUR HELP. In answer to a few questions and to repeat - - Car was aligned last week. - My tire pressure gauge is busted, so I can't check, but assume the tire shop did and put car within spec a week ago - Tires are General G-Max RS Ultra High Performance Tires (pls don't lecture me about my tire choice because I should have spent more, thanks) - I think the mechanic that did the suspension DID NOT torque the arms UNDER LOAD! - However, before I replaced the entire suspension, I still had this problem. There's play off center, it seems, and it becomes more floaty at freeway speeds. And on a sweeper, the steering SHOULD sort of take a set and then have a constant level of effort, but it feels like instead the amount of effort just randomly lightens up mid sweeper (yes, I'm still on the gas) - The new struts are Koni Actives (saw lots of love in 993 community. wanted a more GT feel since it's my DD right now) However, the rear end looks like it sits a little high (keep mind these are not YELLOWS, so they are not adjustable). On stock springs. FYI - Front does have high quality 7mm spacers. Believe Porsche made factory 5mm spacers for some wheels, so I'm gonna doubt that 7mm makes a huge difference. Here's my alignment specs and some pictures. Thx again all!!!!!!!!!!

Is that normal to have so many problems for so long with a new suspension!? I'm out on the border of Ventura County. Went to German Independent Specialist in Simi Valley. You?

NM my prior post. I see you got after market suspension. I would take the alignment to a Porsche shop. Also, the sticker pressures for the 996 is way off. The center of my tires are worn from canyon driving before I dropped them. It was since adjusted lower by Porsche because the sticker accounts for a full load. I would go get a pressure gauge. And the front does feel floaty, you have to dig it in.

Quotes source post: 19083217

I'm in Glendale. Went to Pro Motor Sports. I had a bit of an odd experience, but they are a Porsche racing shop. And I have no idea if it was normal to break in that long. But the thing drives like rails now, even with B4 non-adjustable base suspension. Read through this and see if sounds familar: https://rennlist.com/forums/996-foru...sties-now.html

OP - Even experienced Porsche wrenches make mistakes. Check for pretensioned sway bars, adjust tire pressures. Check your connections up front with a Mark I eyeball. Be very suspicious. Incorrectly installed control arms.

What's a Koni active strut? If the rear is higher, I'm wondering if the struts/shocks are too long/hard for the car so it never settles. Then bump steer adds in. Just a thought...

Quotes source post: 19083434

Plus if they preloaded the bushings by torquing them at full suspension droop... hmmm. OP do you have access to a ramp lift? (4 post lift.) Drive it up there and loosen/retorque stuff. These are Koni Actives. They are designed to self-adjust according to driving conditions. https://koni-shocks.com/products/kon...id-porsche-911

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If the car is being held up by the strut, you got real problems. Springs carry weight, struts control spring movement.

Quotes source post: 19083213

New tires you say ? What brand and what pressures are you running ? Tire shops often read the tire pressure figures quoted in the door jamb, and merrily hose 38-40psi into the fronts (which with four people in the car and a full trunk, at 150mph on the Autobahn, is fine, but not if there's only one of you with zero luggage and you're only travelling at 70mph. Have you done good few miles on them to remove the release compound ?

Take it to a shop that specializes in Porsche track/race cars. They'll have a better understanding of possible problems/fixes. Explain the problem and let them drive the car at speed. Don't just throw money at it. Get a mechanic involved that knows how these cars should feel/work on track. That mechanic, after driving it, should have a good idea of where to start.

I would NEVER accept an alignment from a "professional" that had 1/2 degree of cross camber. That's just sloppy work. You would normally want the max camber that is attainable, I'd want at least 1 degree on both sides AND have the exact same value on both sides. Caster is on the low side, more caster gives better stability and heavier steering. Changing camber also changes caster; the stock setup does not have caster adjustment. Toe looks good, assuming that it's toe IN and not toe OUT. You wrote the steering feels loose even when stopped. That is not how it should be. There is a flex joint in the steering shaft that has been known to get loose so might want to check that. Don't go crazy adjusting the pinion mesh. The rack wears more on center, so cranking up the pinion mesh cam make the steering had to turn, or even jam, at the edges.

I do not. Would have to go to mechanic. I emailed Koni about the height of the rear and they said -- he rear KONI dampers themselves should not raise or change the vehicle ride height, as the lower spring seat location matches that of the original OE shock location. The only way the shock itself would raise the ride height would be is this lower spring seat location was mounted higher up on the shock body compared to the original damper. It is possible depending on what all other parts were replaced at the time of the install that he suspension could sit slightly higher especially if worn and compressed rubber spring isolators, shock mount were also replaced. Another possibility for the rear sitting higher could also be related to how the control arm bushings and lower shock mount bolts were tightened. If the control arms and lower shock mounts were tightened and torqued down with the suspension hanging at full droop (suspension not being supported) the bushing could be binding up and keeping the suspension sitting up higher in the rear, and needed to be relocked. The control arm bushings and lower shock mount bolts need to be tightened will the suspension being supported. Though I dont think any of this will address the steering issue?

Thx. I thought I was done bleeding but will have to find a porsche specific performance mechanic to check this over. More blood....FML. Unfortunately I live a little ways out of town, and would have to basically wait around all day while they checked the car so I could drive him. Any recs on Porsche shops in LA (especially west San Fernando Valley or Ventura County would be appreciated)

Does this apply to simply street driving? Will never track or push this car beyond 7 or 8 tenths canyon runs rarely

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Fixed The alignment shop probably didn't look at the top mounts to see the slotted holes for camber.

Don't believe there are any

Quotes source post: 19084618

Pop off the plasic in the frunk, the sheet metal is slotted. In the back its an ecsentric washers and a bolt. Also the last time this topic came up it was a simple tire pressure change that fixed most of the issue. I personally think the alignment is too neutral and the car is too high for the aero. Look up the european alignment specs for the car.

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Thanks Brad. Think faster than I type.

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Trust but verify. When I run 2psi too high, my car handles like yours.

2psi? That seems crazy

Please note the pressures you measure after you got yourself a gauge and post them here. I'm very curious what they are. Did the ride height change in your view after the Koni actives had been installed? If yes, then perhaps something was assembled incorrectly when the springs, spring pads etc. were put on and the ride height ended up too high. Picture shows correct position of the spring coil's end. An incorrect position immediately increases ride height. The Koni actives are twin tube gas pressurised but the gas pressure (about 100 psi) is too little to lift that end of the car significantly.

Quotes source post: 19085454

I might be wrong. Maybe it�s 4� I would overfill my tires a bit in the fall to avoid losing too much pressure over winter, and/or having to refill again in only a month. But then my handling was noticeably worse.

Quotes source post: 19085696

I�m pretty sure I can feel 2psi under/over. Usually the car starts feeling a bit off, then tire pressure gage comes out, and the values are off. Easy fix Also, make sure you�ve drive your tires for a good 500 miles before fully pushing. They�re fairly slippery before that.

Front 37, Rear 40

Try 34 for your front.

I think i feel more comfortable with Porsche specs (yes, I know they assume load), but I don't think 3PSI would radically solve this major issue.

I run 25 psi cold front.... you'll be fine with 35.

36F 44R are porsche specs for the 18 carera 5 spokes. Dont knkw the specs on the skinnier rims or 17 inch rims. That was back in 1999-2004, when very few tires had strong sidewalls. Different story today. FWIW, keep in the back of your mind that those who track their 996s may start off with 25/26 F and 27/28 rear cold so when they are hot after 2-3 laps, they expand by 7-8 lbs to get then to 32/33 F hot and 34-36 R. Point is the tires can handle playing with pressures 2-4 lbs under the 36/44 on the street. Its part science and part trial and error. But I would never suggest anyone should run 25-28 lbs on the street. They will never get hot enough and you will experience rim damage as soon as you hit a large bump. Tire pressures do matter with handling characteristics. So does a properly set up suspension.

Quotes source post: 19086275

Come on, just try it. It won't kill the car, and you'll have more information. I'm at 30/38 with ps4s tires in the same size. I'm glued to the road. eta: '02 c2 cab

OP - Isn’t the whole point of asking this forum to get ideas on how and what to investigate as a cause? If you don’t you’ll be kicking at a moving goal post. Do your tires have a contact patch mark to give you info on where your tire is wearing vs where it should be wearing? Your pressures at 37/40 are fine, but try 35 front and see. Do you happen to have any way to compare before and after ride heights? Yes, two psi over, depending on the tire, will make a big difference. If you bump your rears to 46 (two psi over Porsche recco) you can drift the crap out of a C2 996. At 40 psi, good luck getting the rear to kick out much at all.

Yeah, I have been running a 7 year old set of bridgestone pole positions summer tires at 32F and 38R. Started off running them at 30/36 and I got a little too much wear on the sides. Whereas I was running most of the summer on a set of Bridgestone RE71RS at 30F 36R and they stuck like superglue to the street.

I do run the NT01's at 25-27 on the street. I also run 3.8 degrees of camber... need the low pressures to get a decent contact patch. Tire wear is not a consideration, I am thrilled if they last 3000 miles.

Me too.

I set mine at 36F/44R when I first got the car. Horrible. Harsh ride, felt like it was on tiptoes in corners. I run 33/39 now. Michelin PS4S.

The 36F-44R Cold psi Porsche recommendation is to safely carry 4 Passengers + luggage and a full tank of gas at 172 mph on the Autobahn for hours at a time. YMMV

i run 32/40 cold and usually drive alone. this is on 18s with the same general g-max rs and i don't have any issues with the front end feeling

I am also running General G-Max tires. Two track days and ten autocross's and there have been no issues. I have tried many different combo's of air pressure front and rear with no bad habits. Hope this helps.

Dang, after reading this thread, I may try dropping my pressures even though I�m not having any issues just to see.

Yeah, it's tire by tire. The newer versions of tires seem to have much stiffer sidewalls in comparison to the past. Not to mention better rubber compounds and design. So we can play with pressures more on the street. Its good to see we have more choices today. 10 years ago we had very little choice with our 18s as the performance cars were moving to 19s and then 20s. Seems tire companies realize there is a big market for 18s again.

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LOL!! Me too !

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I understand this. But I have seen dozens of instances in my BMW world(that' I've been part of since the 80's) where people have installed HD struts because they're cheaper and they raise the ride height significantly.

This is a great conversation. I have Koni actives on my cabriolet and they did NOT sit that high with stock springs. I've since lowered it and the steering hasn't changed. If anything it's snappier, like my GT2 tuned TT. 1.25" H&R lowering springs, 10mm spacer with Koni Actives.

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That would indicate to me a damper that is acting (stiffer) as the spring. I�m not sure why anyone would want to do that. Maybe the fact that the spring sits in the control arm bucket apart from the damper has something to do with it or the maybe the dampers are just too long, I don�t know enough about how BMW suspension works but I can say with high confidence, on a 911 the weight of the car should not be held up by a damper, and with the weight of the car, so goes the ride height.

Quotes source posts: 19090446, 19090476, 19090477

Gas charged :::: not all shock/strut brands have the same gas charge. And old worn out struts/shocks usually have lost their gas charge so installing new ones will sit a little higher.. I have seen some shock set-ups ( especially on racing Dirt Bikes) that didn't even have springs, just adjust the gas pressures, and still has rebound and damping adjustments..

Quotes source post: 19090762

Cool story bro.... I'm just saying, if your shocks are holding the car up, which is what would be happening in your example of a new shock making the car sit a little higher... your shocks aren't designed to do that, your springs aren't designed for that, the chassis isn't designed for that... so, you are doing it wrong and if you change your shocks and the ride height is wonky and your car is handling like ****... well, maybe those 2 things are related.

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I was explaining why a car would sit higher after replacing the shocks only, nothing else..... I wasn't speaking to any other problem with the car..... Gas Charged vs no gas charge

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The ride height should be the same with only a spring and and empty dummy shock or even no shock at all as it would be with a functional charged shock. The shocks ONLY job is to moderate the oscillation of the spring... If you change your shocks and the ride height changes - there is an issue... again, for the hundredth time.

Quotes source post: 19083216

Your ride height seems a bit tall. Is it possible that the PO replaced the front springs meant for a C4, coupe, etc. There are different part numbers for the springs so assume there are different spring rates.

Quotes source post: 19091272

Where do you get that **** from?? Would be true for a hydraulic shock, but for gas charged strut/shock the 75-90 psi per shock is pushing up on the car and will raise the ride height about as much as a full tank of gas and a Race car driver will push down and lower the ride height...

Quotes source posts: 19091272, 19091370

If you've ever tried to compress a Bilstein shock you'd see how hard some of them are to move even a little, then they push right back. Even a KYB low pressure 'Gas Adjust' gas pressure shocks will add to the spring rate thus lifting the car. Now granted its not a lot, maybe 1/8..? 1/4" idk, but it will raise up, how much depending on the shock. An old style Koni hydraulic non gas pressure shock won't raise the ride height. It actually slightly lowers ride height if its replacing high pressure gas shocks. Any shock that pushes' back when compressed will raise the car slightly. jmo

Dude.... Seriously. The only way the gas shock raises the ride height is if it has a higher effective spring rate than the actual spring thats supposed to be holding the car up. Where I get it is because the only way your scenario works is if you put the wrong parts on the car. In mine, yes, should not matter if the shocks are charged or not, because they have a lower effective spring rate than the main spring regardless. I don't even get why we can't just agree on this. And ​​​​ @allcool - try compressing the spring by whatever method you're talking about compressing the shock and let me know how it works.

Quotes source post: 19091392

We can't agree because your "theories" just doesn't work in the real world... Or you just like to argue... You can prove it to your self very easy, go to your car and lift up on the fender and see how much effort it takes to move up 1/4" ....Does it take 75-90 lbs like I say...or 600-800 lbs ( your spring rate) like you say???

Quotes source post: 19091392

This is entirely pedantic, but adding extra pressure to a Bilstein will raise the ride height and affect the corner weights. It's not always a tiny change either - in stock class AutoX this trick is abused all the time to artificially get higher spring rates. Higher spring rate = higher ride height. That's not to say any of that is related to the thread topic. Based on OP's described symptoms (steering effort changing mid-corner) I would start looking at the power steering components. I've had a bad rack on a different car before and the wandering and inconsistent assist lines up. When I finally disassembled the old rack, what came out was basically glitter.

Quotes source post: 19091392

If you're interested, I can explain. The outcome will not be debatable, however. If anything, only the way I'd explain it would, in case it fails to give you the correct understanding.

Before going down a separate rabbit hole that has many twists and turns, measure the ride height of your vehicle from the points delineated in the Bentley's manual. If it is higher, (almost always lower when measured with older springs), then try to tackle the problem one step at a time. Suspension setup has so many variables, each change has second and third order effects that may foul up the original problem.

Quotes source post: 19091392

Yep, I don't think your'e thinking here. Gas pressure is an additional spring adding to the spring rate so a gas shock will raise the car compared to no shock

BTW, if the toe is way off the car will climb up it's suspension as the wheels try to come together and the height will be all messed up

Quotes source post: 19091425

option # 3) He's just trying to 'pull ur chain' and we both fell for it. Z is much smarter than that, he knows exactly what happens when a gas pressure shock is installed in place of a hydraulic damper, for sure...

Quotes source post: 19092084

Maybe........ but probably option #2) you just like to argue... .caused by. option #4 option #4 ) too many Budweisers on a Friday night...