924S Wheels, Backspacing, Offset, Yipes!

[rwsams]

Folks,
I've been researching 924/944 wheels now and I got a nice set of 16x7 trash lids to replace the phone dials on my 87 924S. With 205/50X16 Nitto 450's, the car really turns.
Here's my problem.
Jim Pasha's great article in Excellence and quoted on the web at the 924 Garage site says that 924S's (15 and 16 in wheels) had backspacing or 153.9MM and an offset of 52 MM. First problem - my phone dials (15x6) have a backspacing of 5 5/8 in (142.9 mm).
Second problem - Pasha's table says that both 6 and 7 inch wide rims have the same offset and backspacing. Now I'm no math genius, but if offset is the distance between the wheel width centerline and the mounting face and backspacing is the distance from the inside edge of the wheel to the mounting face, you can't have the same offset and backspacing for different wheel widths. One of them has to change!
Problem three - The best I can get for a camber adjustment is 0 degrees. -3/4 degree results in tire rub, even on slow turns. Did I miss something here?

Thanks.

Bob S.

[wolfrpi]

More camber should mean less rubbing. Where are your tires rubbing - front or back? Also, I've put 15" phonedials from a 944 on my 924S and they fit fine. Where are the trashlids from?

Erick

87 924S
86 951

[Porsche 951 Fanatic]

trashcan?..... heh.. just joking.. what is a trashlid anyway? - well the rim

[e_nough]

please post a link to a picture of a trashlid rim

[rwsams]

Here's a link to a photo of the wheels I got. Wheel Enhancement was a fine place to work with, by the way.
http://www.wheelenhancement.com/DiscSpl.htm
The tires are rubbing on the coil springs on the stuts. No trouble rubbing front, back, or top...even at full lock. Go figure.
Anybody want to comment on the backspacing/offset arithmetic?

Bob S.

[marksportcts]

Won't you need those to cover your garbage cans from animals? Kidding, I think those were called the "928 Flats".