924Board.org

[goose]

OK there's been discussions about wheel sizes on here before. But from what I can see, these are based around the offset figure. To me, stating the offset on a wheel which is wider than the stock wheel is a waste of time. What's more important is to know the backspacing (and it's equivalent overhang on the bodywork side of the wheel).
This measurement is the distance from the mounting plate of the wheel to the inner rim. In other words how far back the wheel will reach into the car (towards the suspension strut etc). The equivalent "overhang" will determine how much the wheel will stick out towards or under the fender. These figures can be worked out from the wheel width and offset (unless there's something I have missed). I guess the optimum backspace to aim for is 111mm which is the measurement on the stock wheel.

Phew !
So my questions are,
1. did Porsche ever produce a 6x15 rim (4 bolt) for the 924, if so what was the offset ?
2.What is the acceptable deviation from the stock 111mm offset that a) will not interfer with suspension or brake calipers etc, b) will not produce unacceptable pressures on the wheel bearings. I've seen road and track cars with spacers that look aroun 50mm deep on the rear!

[64Corvair]

Yes, Porsche did make a set of 15" x 6" wheels for the 4 bolt 924. They are called the spiderweb, or aluminum honeycomb wheels. check the tech section here.

http://www.924.org/techsection/technical.htm

Also here regarding a previous discussion about the offset and backspacing.

http://www.924board.org/viewtopic.php?offset=&topic=3679&forum=1

Also, see here if you want to try to find some aftermarket rims that will fit.

http://www.924board.org/viewtopic.php?offset=&topic=3707&forum=11