Suspension upgrade not as fab as hoped....?

[kiwi 911]

OK, just changed out my tired stock suspension rubbers and torsion bars for some 21/28 torsion bars and superpro urthane bushes all round.

I was hoping for wonderful things and lap times to tumble.............

Instead I appear to have a car that is too stiff and has chronic wheel spin in 2nd and 3rd gear corners all over the track.

On the open road the car fine - not to stiff at all, and the car surges stonger with the reduced pitching under braking and acceleration.

With the previous 'stock suspension, I could floor it out of corners and never incurred wheel spin.

Today I was feathering big time to avoid wheel spin and losing 3-4 sections a lap over my previous stock set up.

The car will go into the Porsche shop this week and given the simple instructions to 'fix' - but what should I be looking to do?

It is as simple as now needing an LSD to cope or am I missing something..........?

I would really appreciate some help here please.............

Thanks in advance.

Paul

[equality72521]

Did you align and corner balance after the work? If not, you need too.

[Shaun @ Tru6]

Suspensions are systems, you can't just change one or two parts and achieve optimum results. You will most likely need to match your shocks to the bars, what tires are you running? check tire pressures, test and adjust, sway bars? and as Mark suggested, an alignment and corner balance are critical in getting the most out of your suspension.

[Grady Clay]

Paul,

Remove the rear torsion bars and the adjusting lever in front.
Disconnect the F&R sway bars.
Check that the suspension corners are free throughout their entire travel.
Confirm that the disconnected sway bars are free to travel the entire range of suspension movement.
Note if any loading could put something in a bind.

Do these bushing require a lubricant?

What size sway bars? What bushings? Stock mounting points?

What do you know about the shocks?
Hand operate the shocks through entire travel.

Install a LSD. I use the OE ZF, set to 'tight' 80%.

I assume your ’76 3.0 has 108 mm CV joints. If you have 100 mm CV joints, consider change for your use.

You may want adjustable sway bars F&R. The LSD will introduce a bit of ‘push’ – normally a good thing but you want to adjust to the track and your driving.
Be sure to reinforce the sway bar chassis mounting points.


Great looking 911.
You will get those seconds back – in spades.

Best,
Grady