just_drive

Yet another question on ride height. Sorry in advance if this has been covered.

1989 S4 100K miles, well kept. Unsure history of any adjustments in the shocks/springs.…maybe purposely lowered by PO or just sagging from age, or bad shocks?? However I don’t feel the ride is out of sorts, or very sloppy. I believe the Boge blue shocks to be original although not 100 percent sure.

The front sits low (approx. 152 mm on both sides.) The rear is better but uneven, at 160mm right side and 170 left side. Bonus question! Do the WSM numbers for height include the weight of fuel and/or passengers?

I should mention I have installed Engine Protection Plates from 928MS and both belly pans. The car is only driven occasionally and on highways mostly.

The question is: In what order, considering ease and potential price, should I approach the issue. Adjustments, new parts, do nothing, other? Thanks.

Front shocks

Rear shocks

FredR

That is pretty typical of what happens to these cars as they age- the front springs sag- that or someone deliberately lowers them. The front needs lifting and then when settled check the alignment as that will change with ride height.

Bash plates are a must irrespective of ride height. I reckon keeping the front to rear differential of 7mm is a must aerodynamically then work within the allowable range of ride heights. If there are a lot of pot holes in your location set it as max ride height- it will look a little strange. I run at the lower end of the allowable range but then I have stiffer springs and bash plates.

Running at your front height and no bash plates is just a crap shoot as to when either the alternator or air conditioning compressor is snapped off and then whether it takes the crankcase with it. Even with bash plates I am not so sure they can guarantee non of that attrition as it probably depends on the shape form of what you hit.

Wisconsin Joe

I'd try adjusting it first.

They don't look too 'crudded up'. I'd soak them in penetrating oil for a while before trying to move them.

There's a spread sheet in the "New Visitor" sticky that tells you how much each turn of the adjuster will change the height.

Don't forget that the front end takes a bit to 'settle down' after it's been up in the air.

Bertrand Daoust

Bonus question! Do the WSM numbers for height include the weight of fuel and/or passengers?
If I recall correctly, it's with a full tank and no passenger.

I would try to adjust first.
Like mentioned, soak them in penetrating oil first.

Speedtoys

Link Below @just_drive ..you'll see it.

It should be in the sticky thread too, some day...

dr bob

Jeff --

Make a dedicated post for it in the "new visitors" thread. Will consume seconds....

Wisconsin Joe

Ummm...

The ride height adjustment is already in the New Visitor sticky.

Page 4, post 61.

Randy posted a link to the post that has the link to Speedtoy's spreadsheet.

Speedtoys

W00T, was doing a 2nd edit locally before posting...sorry I missed that.

Mrmerlin

Well based on pictures you have original 30 YO Boge shocks,
now that its cleaned up, things look good here please consider this suggestion.

I would suggest you buy a set of Bilstien shocks,
and 4 white discs and the front and rear bump stops and refurbish your suspension.
NOTE the Bilstiens come with new lower perches and adjusting collars so the swap over is pretty easy
A fresh suspension along with a ride height adjustment and alignment will make the car ride perfect again.

NOTE for ride heights match your new shocks lower perches to the old ones then add 4 turns up.
install them, let the car settle to do that drive for 50 miles then check the ride height.
Use Speedtoys flow chart to set the heights.
NOTE its easier to lower the perches than it is to raise them, you will have to have the wheels off the ground
NOTE also buy a collar adjuster wrench Ohlins makes a good one

just_drive

Thanks for all the terrific info. I will attempt to raise the front if I can break the collars free while checking around for pricing on replacements for the Boges. I wasn't sure of the expected life of these factory shocks but I'm sure they are close to the end. I do not currently have a garage or flat driveway work area so this job may have to be outsourced as much as I hate that.

The RL members have truly been a great resource to this new Porsche owner. Thanks again
Mark

Mrmerlin

My estimate including Bilstien shocks and bumpers and other parts, alignment and ride height resetting and installing labor,
figure about 2400.00 to have the job done
for a Boge shocks install with the same bumpers and parts and alignment 1900.00

An Ohlins collar wrench is about 45.00
Can of PB blaster 5.50
wear leather gloves so you dont hurt your hands

Wisconsin Joe

Well, in theory you could jack up one wheel at a time and do each corner individually.
Not the way I'd choose (not the way I actually did it either).

There are some 'tricks and techniques' for getting the stuff apart and back together. The rears can be a huge pain, or not that bad. Depends on corrosion on the big pin.

Roger had the Boge (Sachs) on sale a while back. I'd guess they aren't anymore, but he's still the best price around for a lot of stuff.

Get the bump stops too. You will almost certainly need new ones.

And Stan - I found a collar adjusting wrench at the local motorcycle shop for less than $30. Maybe not quite as nice as the Ohlins, but it works fine

GregBBRD

There's not a snowball's chance in hell that the car has "settled" this far...someone lowered the front.

At 152mm, the car has been riding on the front bump stops (Porsche calls them a supplementary spring, which is what the actually are)...and they will probably be very deteriorated. You will probably need to replace them. The shocks could be in excellent shape...they haven't been doing much, the entire time the car was this low.
Raise the car to reasonable ride heights....160 minimum in the front....and at that height you will should do some modifications to increase the shock travel....something that almost no one ever realizes or has a clue on how to do.

Make sure that the lower control arm rubber bushings are still intact and still vulcanized to the control arm/outer mount on the front. (You may have to lower them to find this out.) At 152mm,. those rubbers have been super twisted and they might break when you raise the car and drive it, in a very short amount of miles. (The rubbers in the lower control arms are a huge percentage of the front spring rate and are frequently overlooked, when people are working on these cars.)

The front spring adjusters will end up about the same, from side to side, if the springs are still good. The rear will end up with the adjusters quite a bit different, from side to side. 170mm rear height works fine...

3/4 full of fuel works best, when making changes/aligning.

Get the car aligned and see how it drives.