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Gallery - Craig Forrest's 911T

73_911_rear.jpg


Craig writes in part:
Dave,

Congratulations on an outstanding Porsche web site! Your's has to be one of the most enjoyable web sites regarding Porsche that I've yet seen on the web....

I bought an unmolested 1973 911T coupe in December of 1998 (I've attached a shot of the car from the rear.). I got lucky and found a car that has never been modified. (except it does have rear splash guards.) Seems that most of the early ones have been turned into race cars....

The reason I was investigating torsion bars is due to the fact that my car is about 1 inch lower on the right side than the left. I have talked to Jason Burkett at Paragon regarding this and he suspects the spring plate bushings have weakened as yours did. (Incidentally, what is your opinion of adjustable spring plates?)

I notice when I have the front of the car on jack stands the rear bumper is perfectly level. Could it be that the driver's side front torsion bar might possibly need adjusting to lower the left front some? Might this bring up the right rear? It doesn't seem that a weak bushing could cause a 1 inch difference in height from side to side. At any rate all bushings need replacing due to the car's age.

Craig Forrest Sleepy Hollow Studio Cullowhee, NC (not so much a town as a state of mind) http://www.sleepyhollowstudio.net


There is some great art on your site!

Have you weighed the car one wheel at a time? Bruce Anderson in Up-Fixin der Porsche from PCA has a lot to say about twisted Porsches being way off on one wheel or another. I've not done that with my car. I guess some shops can do it, or perhaps a truck weighing scale.

Is you car lower on the right when you are sitting in it?

The factory method of leveling the car involves measurements when sprung - off the jacks. The quick and dirty method is to measure the spring plate angle (one way or another - see below) with the car off the ground. This is true for the front as well as the back. It may actually be more work to do this on the front than the rear - the front is harder to take apart for me because of the tie rods and sway bar. I don't have a pickle fork.

See the alignment article on Pelican Parts for some more tips including corner balancing. Check out the other suspension articles on that site.

You can measure the actual spring plate angle - I bought a protractor giz from Sears to do this. But another way that I intend to try the next time is to measure with a tape measure to various points on the body and the suspension. I think it will be more accurate. To first order both sides of the car should be symmetrical for both front an rear. I'm hoping small adjustments should measure to better accuracy with this method.

I think the bushings are a first step if the carrier is off center. Be aware that some models have the rubber bushing and the spring plate bonded together. However, you have a lot more freedom than I because the '73 is better supported than the '66 for parts - both after market and factory. In addition the racers you mention have created some new designs such as the adjustable spring plates. I recommend you call Gabe at Strasse (877) 944-9911 about this stuff. He knows these cars pretty well. Little of it is available to the earlier SWB cars like mine so I don't have much choice for changes other than bushings.

It seems to me that the advantage to the adjustable spring plates is to be make small changes easily, but you still have to get them installed in the first place. I'm not sure they save much effort in the long run because you should only have to do all this once.

Another possibility is one or another torsion bar may be weak. I have no idea how you test for that problem, but again Gabe probably does.
Last modified: Sat, 08 Feb 2003

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