Refreshing suspension

[PaulHere]

A little while ago I was treated to a hot lap in a 924 Turbo around Bruntingthorpe - one thing I noticed was how well it soaked up the poor road surface before the main straight.

However when I took the same corner in my own 83 2.0 the ride was much bumpier and noisier.

Are there any tips for improving what I have, or what do I need to replace to refresh the suspension?

Thanks []

 

[usermjg]

hi Paul


Not 100percent sure on the 924 but i have had my car lowered by 35mm, by adding new lower stiffer sports springs on the front, the back of the car has also been lowered but no additional equpiment or parts are needed just time. This has the effect of sitting harder over the shocks fooling them into beleaving there sports shocks, much stiffer. It really has made a large difference in handling and road holding, a really big difference, the car is no longer twichy under heavy load.

I didnt do this job myself as i thought i might lose a finger or too when undoing the front springs, so the PorscheShop undertook the work for me and have done a fantastic job, i am very pleased one of the best upgrades i have done so far. The price for the job was around £350 if my memory surve, if you want a true figure i will find out my receipt.

Marc

 

[924nutter]

I would respectfully suggest that all of the handling improvements come from the stiffer springs (more resistance to roll), and the fact that the c of g is somewhat lower, but not 35mm as you might think, as the unsprung weight, ie wheels, tyres suspension arms, discs and callipers are still where they were. Factor in a dose of extra confidence and the improvement is tangiable. I would beg to differ about the shocker and feel you must have been unintentionally misled, or perhaps have mis-understood the way a shock absorber works.
Making a shocker work in a different portion of the stroke, ie 35 mm further down, cannot change the carachteristics of the damping medium, or the settings of the bounce and rebound valves, but I will concede that the shocker may bottom out, and then the suspension will become very stiff indeed

 

[924nutter]

ORIGINAL: PaulHere

A little while ago I was treated to a hot lap in a 924 Turbo around Bruntingthorpe - one thing I noticed was how well it soaked up the poor road surface before the main straight.

However when I took the same corner in my own 83 2.0 the ride was much bumpier and noisier.

Are there any tips for improving what I have, or what do I need to replace to refresh the suspension?

Thanks []

 

[usermjg]

Hi Mr nutter

I'm not an expert or anything or offer my experience as the right way of things, just posted what i have and what i have done, and i understand about the shocks and now you have commented on it, it does bear out, however its not my imagination about how much better the car feels and the handling compared, wheres my to do list, (New shocks)got it.

i feel told off []

Marc[][]

 

[924nutter]

There is no need to feel 'told off', usermjg, NO offence was intended, and the shock-absorber is an often overlooked component, and comes into the category of 'Black Art'. It is always incredibly difficult to gainsay someone's comments and let them retain their dignity.

The difference betwen old and new shocks can be quite astounding as you say; when I was a callow youth, I went to the Motorshow, (the N.E.C. hadn't even been thought of) where Armstrong had a rig to demonstrate the difference.
It had a pair of handles, each connected to a different spring/shock set up. On compressing the springs with the handles, you could then witness the differing return rates, new against old, upon releasing the handles.

A shock absorber is, in essence, a piston connected to the outside world by a rod or lever, which has two opposed one-way valves built into it. The piston moves in a sealed cylinder filled with hydraulic fluid on either side of the piston. As the spring is compressed the shocker piston is forced through the fluid, and as a fluid can only be compressed to its maximum density, (to all intents and purposes no compression at all) in order for the piston to move at all the fluid must get to the other side of the piston, which is does via the one way valve. The rate at which the piston moves through the fliud is determined by the cross-sectional area of the bore of the valve, the force applied to the piston rod, and the viscosity of the fluid. Two valves are necessary because of the different requirements of bump and rebound.

The spring stores the energy of the bump, the shocker controls the rate at which it is stored and released.

I have two 931s (924 turbos to the uninitiated) one totally original, and one that has been retrimmed repsrayed rebuilt and generally tarted up. Admittedly it has 16" Boxster S wheels but the tarted version rides like an ironing board with wheels, whereas the 'original'car has much more body roll. I think this is down to more than new versus old shockers as the tarted car has covered twice the mileage and has the stiffer ride.

 

[usermjg]

Hi Mr Nutter

No No, u mis-understood me, i am greatful for your advise i want the best for my little car, and what you say rings true and im going to replace the shocks, but at the time i was told that i didnt, clearly this was incorrect information and i dont mind being told off or getting good advice, and lord nows you know your onions [][][]

Marc
Ps thank you Mr Nutter i truly welcome any advise /support on my car

 

[usermjg]

Hello Mr Nutter again


Just alittle of topic but i thought i would ask you first, what is is there a model number for the 924s, I know its 924s but is that its real number eg. a944turbo is a 951,so therefore my thinks does the 924s have a true model number ???

Marc

 

[924nutter]

For starters fit the turbo anti roll bar (from a breaker's) but you will need two off bushes 477 411 053 N. My Turbo also has a roll bar on the back, but I don't know whether this can be retro fitted to the Lux.
There used to be Koni front suspension strut inserts available from Porsche for the Lux and probably an even stiffer one for the turbo as the part numbers are different, and the Turbo has lower (10 mm) stiffer springs too. There are also listed Koni and Fitchel & Saschs telescopic shocks listed on PET. Email me if you would like the P Nos.