WHeel Size Advice
 

I have 7 & 8 X 16 wheels on my 84 Carrera. I want a sceond set for track use, and have available a set of Fuchs 7&8 X 16. I was hoping to find a set of 9" for the rear, but they are harder to find. Alternatively I was thinking of going to 17" for either the street of track.
Aesthetics aside, how big a deal is the gain fom the extra inch of width?
Similarly, is the gain from the 17" upgrade significant?
The car has been lowered and stiffened. My track expectaions are such that I probably won't go for R compund tires for another year or so.
Any comments/advice appreciated

Couple of comments. With 7's and 8's you can go with the stock sizes of 205's and 225's. On the 8's, if you want, you can install the next size up, 245/45x16's. Club Racers in G stock class run these on 8" rims. 9" rims move the sidewalls out for a bit stiffer sidewall, and fit real nicely under the 89 and earlier body (I had them on my SC). If you look carefully, you can probably find a racer who is moving to 17" tires. I think I paid $700 for the pair of 9x16" Fuchs. 17" tires buy you a shorter, hence stiffer, sidewall, and possibly more choices in tire sizes. Last comment, if you've updated your suspension already and are going to have track wheels/tires, unless you have extra tires, why not mount "R" compound tires now when you buy new? They make a tremendous difference in grip, and most work well as street tires, so you can drive to the track.