930 rear flare - need help w/ a measurement

jjwood · jjwood's Garage

could a 930 owner take a measurement for me - on the rear flare, the distance from the inner fender well to the inside edge of the flare measured from the highest point in the flare. I have a 1971 911 w/ "ST" front and rear flares and am contemplating going to a 930 rear flare in search for more room under the fender. However, the ST rear flare looks almost as wide to me as a 930 flare. I currently run a 9.5 x 15" wheel w/245/50 tires with "lots" of room.

Thanks in advance!

Jack Olsen · 04-03-2004, 01:37 PM

This thread illustrates how the 'correct' ST flares were actually all over the place, offered in both steel and fiberglass from the factory, both installed and uninstalled, which means there were lots of variations.

My RSR-style fiberglass rear flares are considered 11-inch flares, like the 930. I measure 14 inches from the inside edge of the fender to the body, at the higest point of the wheel opening. It's 14.5 inches to the outside edge of the fender. I can fit 335mm (13.5-inch) tires in there, on 12" wheels. Since my flares are reproductions, and since they were installed by my shop (and not the factory), they probably aren't identical to 930 dimensions.

Generally speaking, the ST had 9-inch rear flares, which means you could run 10-inch wheels with 275mm tires on them, with a little work.

Gratuitous picture, to illustrate:

jjwood · jjwood's Garage

Thanks for the reply Jack -- your car can be held responsible for this thread. One beautiful machine! FYI the measurement on my "ST" flares is 12" so I'm guessing that BBII has about 1.5" per side more "room" than my "ST". Sure opens a lot of doors when it come to wheels & tires.

Related question --> tire height. 245/50 x 15" are prox 24.5" tall. 275/40 & 315/35 x 17" are well over 25" tall (25.68" I think). From a performance (acceleration)perspective (ignoring 'custom' gears etc). How much would I be 'giving up' with a jump from 24.5" ht to 25.5"+ ht? Seems like I really need a 275/35 x 17" to stay w/ same acceleration - a tire I've never heard of! To retain the same 'acceleration characteristics" of a 24.5" tall tire would require what modification to gear ratios (or final drive)? Hey - math wasn't my favorite subject OK! Other than the fact that we can't get "Fuchs" type centers in 18", any reason not go to an 18" wheel w/285/30 tire?