I've been driving my "new" 89 Silver Edition for a few weeks now, and as I'm getting more comfortable, I've noticed the shocks seem to need replacement. The car has 79K and I beleive the shocks are original. I'm assuming they are the factory Boge shocks/arms? and would like to replace them with Bilstein Sports. The car tilts slightly to the left (usually just me driving) when parked and riding down the road. (I only weigh 175 lbs - just a disclaimer for the wise guys!). The car also seems to shift rearward a lot when accelerating through the gears at a good clip - this makes sense with an engine back there - but I just wanted some advice. Is this normal or should I look into replacing them?

Thanks,

 

Todd,

The shocks don't effect body tilting, per se. If you put gas shocks in where you had non-gas shocks before, they may put some upward pressure on the body. However, it's the torsion bars that, primarily, affect how high each side of your body rides. Each bar at each wheel can be adjusted for height. Many like to reduce the ride height from US specs to European specs, roughly, measured from the road to the fender lip, 25 1/2" in front and 25" in the back.

The Bilstein sports would be an insert replacement in the front and new shocks for the rear. If you want to tighten up your suspension, upgrading the torsion bars along with the shocks will do wonders. You currently have 18.8mm torsion bars in front and 25 mm in the rear. If you went to 21/27's, you'd notice a slight tightening of the suspension, no ride degradation at all. 22/28's would be quite a bit better, approaching a stiffer suspension. Much more than that should be reserved for track usage (although you could go to 29's in the rear if you wanted). I currently have 22/29's with Bilstein Sports on my 911SC, and the daily ride is comfortable and controlled.

 

Bill,
That's exactly what I needed to know. I'll put in an order for new bars and shocks. I learn something new every day on this board!

 

Morning Face,
The Bilstein front inserts will need an adapter lock ring to fit inside your Boge strut. Easy to buy and easy to fit. Voila.
Enjoy, Regards Tom.

 

Mr. Gregory,
I was not very knowledgable when I purchased my 83 911 2 years ago. After I had the car aligned, the mechanic told me that my car is too low, and I should raise it in the back. However, he said that if I do that, he would have to re-align the car, and charge me again. Because of the cost, I did not do anything. Is it true that you have re-align every time you lower or raise the car? Thanks.

 

GeorgeMa,
Yes- changing the height will change toe settings, at least. The 911 semi-trailing arm rear suspension 'steers' the rear wheels when it moves up/down. If you're only adjusting the height by 0.2" or so, maybe it isn't that big a deal, just make sure you do both sides exactly the same-

I don't know how well Porsches hold their alignments, but I know that new alignment settings on my (unmentionable) Japanese sports car make a world of difference, especially in an auto-x.

 

Todd/Tom,

The Bilstein lock ring and adaptor to tighten it come with the Bilstein strut inserts - you don't need to buy anything separate.

George,

No, it's not a hard and fast that you have to realign it when you change the height. There are 3 cases and a caveat -

Change height in front: adjust 11mm adjuster on front torsion bars, no new alignment required.

Change height in rear: adjust adjustable swing arms (1/2" to 1" total adjustment available). I'll hedge a little here...I don't believe a new alignment required.

Change height in rear: reindex torsion bars, realignment recommended. This is because you have to disassemble the rear swing arm to pull the torsion bar cover off to reindex it. Some might mark the location of the camber eccentric bolt and reinstall it where it was before, and be real close. I don't pretend to understand how the rear suspension camber adjustment works, however. Just one of those things I let someone who knows set, and it stays that way until the next change and adjustment.

Caveat: when changing the height, I'd recommend a corner balance if you participate in drivers education, track events, or do spirited driving on the road. This is where your 911 is put on scales, and the weight on each wheel is checked to balance the diagonal weights. Makes a difference in handling, however, if yours is more a garage queen/concours machine, you probably wouldn't notice the corner weights being off.

You probably know the general euro height guideline that people seem to like of 25 1/2" road to fender lip in front and 25" in the rear.

 

Turbo Dave and Mr. Gregory,
Thanks for the advice.
I am enjoying my P, but would not have purchased this P if I had the knowledge then that I have now after reading rennlist for the last five months or so.
Too hasty, too hasty.

 

George,

Don't feel bad about the SC you have. I know my first one I paid a bit too much, but that hasn't stopped me from enjoying it to an enormous extent, and upgrading it as needed and desired for both maintenance and sport. While you could always sell it and start anew, you also have the opportunity to mould it into what you will enjoy the most. And you are in a unique club, so to speak. I like the Porsche advertisement phrase that someone pointed out the other day...along the lines of "Owning a Porsche is like having children, if you've never had one, you wouldn't understand."