I have been working this out for some time now and feel like I've come up with an easy method of figuring wheel sizes and offset. This will not work for all wheels since spoke design and brake setups can affect the outcome.
First and formost Wheel Tech-
http://www.tirerack.com/wheels/tech/index.jspWheel weights-
www.wheelweights.netOffset calculator (plug in stock wheel width and offset s13=6.5 +40 offset)-
http://marksink.com/tire_wheel_offset/offset.html For the S13 I used terboboost from clubfr's wheel sizes as a baseline since his wheels fit IMO perfect with a fender roll + possibly slight fender pull.
1" = 25.4mm (25mm)
.5" = 12.7mm (13mm)
This is the conversion so if your trying to fit wider wheels, but keep them in the same inside location over stock and assuming 50mm front and 66mm rear is your goal, you can decide what size and offset you want to run. Remember that when choosing widths for every inch you add to the wheel it adds .5" to both sides of the wheel.
Front: 17x9 +22 Which means over the stock wheel width (6.5") the inside of the wheel will be 14mm less or in other words closer to the strut housing and the outside of the wheel will be 50mm closer to the fender. Using 14mm and 50mm as a baseline, you can plug in numbers to try and match 50mm for flushness. I would be weary of anything more than 14mm less (closer) since I do not know how much clearence is back there.
Rear: 17x10 +18 Which means over stock the inside of the wheel will be 22mm less or in other words closer to the strut housing and the outside of the wheel will be 66mm closer to the fender. Again, using 22mm and 66mm as a baseline, you can plug in numbers to try and match 66mm for flushness. Again, I would be weary of anything more than 22mm less (closer) since I do not know how much clearence is back there.
Here is another example using edgar's (d*star) setup:
Front and Rear 15x8 -15
The clearance from stut housing to the inside of the wheel will be 36mm MORE
The outside edge of the wheel will EXTEND an extra 74mm
This setup gives plenty of clearence from the struts but sticks the wheels out 8mm more in the rear and 24mm in the rear. This is a super agressive setup that is IMO overflush and requires a lot of work to fit.
Now don't think this is the perfect setup or that you can just use these numbers and just slap wheels on your car. This is just a basic guideline so you can figure out what width and offset you would like to run. To do this right, you would have to measure and measure and measure to get your perfect fitment.
Ziptied wheel offset thread is the best.
http://www.ziptied.com/forums/index.php?topic=2542.0Finally ClubFR's offset thread-
http://www.clubfr.net/forums/index.php?showtopic=4213Here you can see pictures of other peoples setups and get their wheel sizes and offsets. They haven't cleaned it up much so to find the setups it takes quite a while. This is why I have chosen to make this post to try and get all the helpful information into one easy to read place.
If you would like to contribute to the post, please list (using clubfr's guideline) your size/offset/etc. and post a picture showing the flushness. Please keep these pictures available because looking through old posts to see a bunch of red X's is annoying to say the least.
Also, please don't comment on peoples wheel sizes and designs. If you have a question in relation to a post, please use our PM feature. All questions/comments will be deleted.
:::example:::
Car: S13 coupe
Wheel Front: 16x8 +15
Wheel Rear: 16x8 +15
Body Front: 25mm overfender
Body Rear: Pulled
Spacers Front: 30mm
Spacers Rear: 20mm
Camber Front: -3*
Camber Rear: -6*
Castor: 6.5
Other Info: Lowered 3". Rubs fender on bumps. This setup clears coilover and z32 brakes
picture1
picture2
Car:
Wheel Front:
Wheel Rear:
Body Front:
Body Rear:
Spacers Front:
Spacers Rear:
Camber Front:
Camber Rear:
Castor:
Other Info:
_________________
I have no idea what I'm talking about. I'm only here for suggestion.
Subject: Wheel Information 
December 18th 2007, 1:25 pm
