Think I made wrong suspension choice

[CL767]

I have just finished a complete suspension renewal on my 1986 3.2. Everything changed to new, except for torsion bars and stabs. I chose the Bilstein B6 sportlich strasse(street performance).
For the setup i used the standard Porsche values for the model. Set slightly lower than standard, but not really low.
Now back from the test drive, and I am a bit disappointed. There is much more body roll than expected, weight shifts feel very soft and wobbly, and after initial turn in it feels as if I am rolling onto oute edge of the tyre.
I thought I wanted it to drive like it did in 1986, but if this is it, I am quite disappointed.
My question is: Would it have made a difference if I had chosen the Bilstein B6 Clubsport instead? Can the Torsion bars and Sway bars have become softer with age? Would changing to thicker sway bars help even if not changing dampers or torsion bars?
I want the car to be a street/track compromise. Like a standard 964 Clubsport or similar.

[stlrj]

Failed to mention alignment?

[JBSC]

Originally Posted by stlrj

Failed to mention alignment?

In addition to alignment/corner balance, I'd recommend larger torsion bars before you touch the sways. Not sure if you had those shocks re-valved, but digressive valving will help as well.

Also, did you replace all of your bushings? That alone made the biggest difference in my setup. I just got done with a complete suspension refresh/upgrade on my 3.0.

[CL767]

Originally Posted by stlrj

Failed to mention alignment?

Used the standard alignment that was on file at the shop I used. For a 1978–1989 911

All bushings, spring plates, control arms, ball joints, turbo tie rods replaced

Don’t get me wrong. It was a massive improvement, but maybe not the firmness i expected from a sports car.
I have seen a lot of guys having fun on track with what looks like fairly standard 911’s, but they may have had more track focused setups.

I have another car just for racing, so wanted this to be a trackable road car. But as it is, I think I will get sea sick on track...

Rear: Camber -1’22’ and -1’25’
Toe +0’11 and +0’15’
Front: Castor +5’26’ and +5’42’
Camber -0’55’ and 0’43’
Toe +0’09 and +0’09

[coomo]

Wasnt 1986 the "one year" larger sway bars anyway,iirc? There must be something wrong set up wise.Unless of course your lowering activities has caused geometry issues.As a standard car,it should handle far better than you say.Ive used B6 Bilsteins in other Porsches.The response has always been neutral & precise.Waiting for a suspension guru,hopefully along soon.

[manbridge 74]

Too low with standard t-bars makes them roll even more.... has to do with roll centers.

[Paulporsche]

What tires/pressures are you running? How old are they?

I just had the same things done to my car, incl replacement B6s and I'm loving the improvement.

[Bill Verburg]

'86 oe has the largest t-bar ever used on a stock street 911 also largest roll bars
what you have is
t-bar 18.8 & 26
rollbar 22 & 21

The shocks slow but do not limit roll response,

The most common performance related issue w/ a stock 911 is the large amount of body roll

That said I've got to wonder if the roll bars may be were changed or disconnected or possibly tire pressures were down


After checking that everything you have is right then a move to 20/26 or 21/28 might be desirable

It is true that when the car is lowered the lever arm responsible for roll is lengthened and you do get more roll for the same input but it's not that big a factor until you get to really low heights. A first step to shorten that lever arm is a steering rack spacer and then for even lower heights raise the spindles.

[manbridge 74]

....until you get to really low heights.”

Like all the stance bros in that other thread.

[john walker's workshop]

Stiff sidewalls or mushy?

[Kraftwerk]

When I switched tires many years ago the sidewalls were...disappointing. It really took the wind out if the overall performance my car. I went from the great Bridgestone SO-3 's to something with a less stiff sidewall. Pretty much every tire has a less-stiff than sidewall than those SO-3's.. handling was crappy to say the least.

[rattlsnak]

Every early 911 I have ever had went immediately went to 23/30 T-Bars.. Zero roll- but you will feel every pine needle you run over... I'll take that trade any day on these cars..

[wayner]

Ive got 23/30 and was surprised how it handled flat yet didn't feel bone crushing either.

I wood have thought 30 was too big but I really like it.
(I am running 9" and 11' x17 rims and tires though, so Im not sure how all that extra wheel weight factors in.)

My car is a 73 and weight 2360lbs

My aftermarket adjustable rear sway bar is on a softer setting. That did make a difference in comfort from my track setting.

[T77911S]

Originally Posted by Bill Verburg

The shocks slow but do not limit roll response,

.

I don't think most people realize that the shocks only effect the transitions of the car.
as said, that is how fast or slow the body reaches its roll angle.
shocks also have a big effect on initial steering input.


you did not say what or how the car was set up before.
mainly in alignment.
if all you changed was shocks, then it must have had a bit more of an "aggressive" alignment before, and/or some things could have been off.
if things like front and/or rear toe were set wrong or even caster was wrong and they are now correct those can have a big effect on how the car feels.

[AG81]

Originally Posted by Paulporsche

What tires/pressures are you running? How old are they?
.

^
This is also my question.......

I too had the same things done to my car and love it......My tires are new and a bit stiffer than I had anticipated. Probably will use a softer compound in the future.

[Driven97]

Roll is not necessarily bad, means the car is generating lateral acceleration. Eliminating roll is not a good goal, I mean you could just drive on ice all the time and have zero body roll.

These cars are super softly sprung by modern standards. They're going to roll, pitch, squat, and dive. It's a rare thing in modern sports cars, really only the Miata and Alpine A110 give you that time to feel the weight transfer process these days, and we don't get the latter in the US.

So yeah, you may have an issue with setup or tires or something, but there's also a chance you want to turn the car into something other than stock.

[racer]

Looking and recalling "in period" pictures of stock 911s of this era and older, they all have incredible amounts of body lean compared to both modern cars and especially vs modern Porsches. Its part of what makes them such versatile cars. It also makes it tolerable to ride over harsh impacts and rough city streets and not feel beat up.

I would guess that what you really want/desire is a slightly stiffer ride. I'd suggest 21/28 torsion bars. If possible, make sure the shocks are valved to match the torsion bars.

[CL767]

Thanks for all your input. You have raised a lot of questions, and I will try to elaborate.

Car is my first Porsche. I have never driven a well sorted example, so no idea what it felt like in 1986.
It had 100k miles on it when I bought it, and suspension felt awful. I didn’t mind, because I knew I was going to restore it. Everything was original, and it took some effort to get everything taken apart. The bushings where completely gone, balljoints stiff, etc.
So i changed everything. My approach was to get it to drive like in 1986, with a hint of sport to it. I thought that since this was a sports car, it would be firm enough to take to the track once a while.
So I installed standard bushings, Bilstein B6 sport dampers, new spring plates, new control arms and balljoints, new top mounts and tie rods from Turbo.
Tyres are brand new Michelin Pilot Exaltos on 16”
The setup values i used were values stored in the computer program at the setup place.

I know the dampers don’t control the amount of roll. It is when changing directions quickly, left right left right, that I find it somewhat wobbly. When doing “skid pad” around a roundabout, at full roll, it actually feels quite neutral and has a lot of grip.

I think that mostly my expectations are to blame. I have previously driven a bike engined seven on track, and I now use a 700kg Lotus for the track. The Porsche I bought mainly because I wanted a classic that I could enjoy on the road, and as such should not be turned into another track car. But in my opinion you need to track any sports car once in a while, just to know and experience what they are all about. Since I was only 12 years old at the time my car was built, I have never driven a sportscar from that era. Closest I got was my dad’s E36 M3 in the 90s, and my own Peugeot 205 Gti. Both were a lot of fun, so I expected this car to be similar.
As it is now, I don’t think I would enjoy it on track.

I would really appreciate if the guys who have similar cars set up for occasional track use, would share their setup (t-bars, dampers, s-bars). Like i mentioned, I would like to go for something like 964 club sport feel. Essentially a car that can be used every day, but is no stranger to the track.

[CL767]

[KTL]

Even with larger torsion bars, the car is going to exhibit some body roll. You have to get really stiff with torsion bars and sway bars to arrest most of the body roll. Ride quality suffers greatly

I posted some pictures many years ago of my car and a friend's car in the same place on a track. His was factory torsion bar sizes and mine was upsized torsion bars (22 front, 29 rear) and the amount of roll still appeared the same. See post #17 in this thread

Tracking 86 or newer Carrera w stock susp?

That said, don't let the body roll influence you too much. They may lean over quite a bit but they still handle quite good. Certainly not as good as modern multi-link suspension cars. But they hold their own pretty good for a dinosaur that dates back to 1950s chassis design?