One resource I use religiously help to determine wheel fitment is willtheyfit.com (not a sponsor, just love the site). It has crushed many dreams of running a set of wheels I just found for sale. I highly recommend using that site before forking down your money on a set of wheels only to find out they won’t fit.
The site is pretty straightforward; punch in your current specs and, hopefully, your new ones. In this case, I am using the OEM Bugeye wheels vs my current set, the Rota Tarmac II wheels.
Press calculate and you will some info about both setups. The most interesting info here is probably the speedo error. My speedo is off by -1.77% which is something I need to keep in mind when driving down the road.
However, the most important part for most of us is the info below that. It tells you how much the new setup will poke out or if you have tight strut clearance like the GD chassis, how much closer you are to the struts/coilovers. On the Bugeye, I have to mind both of these items closely.
Up front, on my current setup, there is just over half an inch in clearance from the struts and just under an inch from the fender.
In the rear things are much tighter. I have less than half an inch between the wheel and the strut and a little over half an inch between the wheel and the fender.
The graphic showing how much pinch or stretch your tires will have is handy too. I like to run the widest tire I can without too much pinch.
Now let’s compare the Tarmac IIs to my new inbound setup.
The new setup has the same offset but is an inch wider. So, I will lose clearance on each side by half an inch. This should be about perfect; depending on my tire selection. I have 255s listed, but since I will probably go with all-seasons, due to how much driving I am doing (work, school, kids, etc…), I will probably go with 245s. UHPAS tires usually have soft sidewalls so I want to be conservative here with the tight clearances. So I will probably go with a 245-series tire just to be safe.
So what is the new setup? Well, friends, it is a surprise. Actually, I don’t want to get too far ahead of myself. I’ve been burned before so I will wait until I have them on hand before revealing them. I can say that even though they are wider, they are, supposedly, three pounds lighter than my current wheels. And they are not RPF1s, aka, the greatest wheel of all time (GWOAT).
One thing the site can’t do is tell you how much camber you can run to clear the fenders. For that, I would try to find people with similar setups and try something similar. Keep in mind spring rates, damper settings, wheel offset (spacers included), tires, camber, and caster all play a role in wheel fitment. At some point, it becomes a method of trial and error to get the right amount of clearance. Camber plates will add negative camber without decreasing wheel clearance to the strut; however, adjusting camber via the camber bolt will affect the strut/wheel spacing. So keep all of this in mind when considering high offset wheels.
I have STi LCAs and Lateral Links. These supposedly add around 10mm to the WRX track. So, I have less fender clearance than a stock Bugeye sedan. So keep that in mind when using my setup in comparison.
In the meantime, while the new wheels are in transit, I need to finish rolling my fenders. I need to look into getting my lost caster back as well. I think I am going to flip the LCA bushing pin; maybe add some spacers through trial and error. It would be nice to track my progress with alignment readouts but I don’t think that’s going to be practical with my current schedule.