It's been a months long process to get this figured out, but thanks to many of the members (Cloud9, Neema, cp85gt, Wingrider, VooDooBoss and I am sure others I have missed) here along with some of our own measurements we have come up with the formula for wheels to get as much tire as possible under the car without a wide body kit or extensive modifications. Shout out and thanks to James Jeffers with Pinnacle Performance Motorsports as well.
But what I really wanted was a set of 18x11" wheels that I could run as a square setup and rotate front to rear, to get as much life out of my track rubber as possible without having to deal with taking the tires off the rims to rotate tires. We found the formula to an 18x11" rim that you can run square and rotate because they are all the same offset if you are willing to do some minor mods and run a hub centric spacer up front.
Album on Flickr with all the pictures: https://www.flickr.com/photos/surfergeek/albums/72157660194695686
What's Required:
Hub centric spacers
Extended Length Racing Studs (ARP/Ford Racing)
Negative Camber up front
We test fit on 2 configurations:
1. Cortex Racing Extreme Grip Coilovers w/ 14" Brembo, Maximum Motorsports Camber plates, Ford Racing Hubs / Extended Length Studs
2. Koni Struts, Lowering Springs, 15" 6 Piston Brembo brakes, Maximum Motorsports Camber Plates, Ford Racing Hubs / Extended Length Studs
The wheels
Forgestar CF5, custom ordered from Auto RnD (http://www.autornd.com) Rishie is the owner there and I have worked with him for 15 years, extremely knowledgeable.
After reading and researching, talking to people, and taking our own measurements we finally settled in on an offset to use. I went with the Forgestar CF5 for their relative affordability, strength (don't read about a lot of failures on these), competitive pricing, the fact that the clear 15" 6 piston brakes for future upgrades and ability to order in any offset we wanted.
After seeing them on my car, I am ready to get a second set and make them my daily driver wheel as well as my track wheel, clearing the path for me to go 6 piston brakes in the future if I wanted to. Bonus, the factory Forgestar center caps fit!
We settled in on an 18"x11" CF5 wheel with a +52MM offset.
Wheel Test Fit Day by Jared Elson, on Flickr
We wrapped these wheels in NT01 Tires with a 305/35R18 tire (Pictured compared to RS3 285/35R18 tire on 18x10 wheel)
Wheel Test Fit Day by Jared Elson, on Flickr
The Fitment I am Going With:
My car is on the Cortex Setup. The full flickr album has more photos with descriptions for each one, but this is what I am ultimately going with.
Using an 8MM hub centric spacer in the front. The wheels fit with no spacer, but clearance from the offset strut, was unacceptable. A 5MM spacer left plenty of clearance, but we opted for a little more spacer to get some scrub radius back and give me more room for turning with my brake cooling ducts. It doesn't look like steering stops will be required, but I'll be installing them as a precaution.
With my ARP extended length studs, there is still plenty of stud to support this spacer.
I am running about -1.8 - -1.9 degrees of camber in the front.
There are no other clearance issues in the front or the rear. It looks great in both spots, and looks like fender rolling won't even be required in the front.
Some photos with the 8MM spacers:
Wheel Test Fit Day by Jared Elson, on Flickr
Wheel Test Fit Day by Jared Elson, on Flickr
Wheel Test Fit Day by Jared Elson, on Flickr
Wheel Test Fit Day by Jared Elson, on Flickr
Wheel Test Fit Day by Jared Elson, on Flickr
Wheel Test Fit Day by Jared Elson, on Flickr
Wheel Test Fit Day by Jared Elson, on Flickr
Wheel Test Fit Day by Jared Elson, on Flickr
Additional Test Fit For Vehicle 2:
We had a 2010 GT with Konis / Springs most importantly 6 piston brembo 15" calipers. This let us check clearance on a strut strut / spring set-up and with the big brakes.
The CF5 has no problems clearing the 15" 6 piston Brembo. Plenty of space even in the 18" wheel size.
It takes more spacer to get the front rims to fit (as expected), but it's not completely unreasonable to do. With our +52MM offset, we tried no spacer (no go, 5MM spacer, no go, 10MM spacer damn close to going, and 15MM spacer, going with a decent amount of clearance. If you aren't going to go coilovers and are going to stick with struts/springs you may want to consider as others have, a +55MM offset and you can run a little less spacer (most likely an 8MM or 10MM). If you are okay with a 15MM spacer, the +52 offset worked for us in our test fit.
Here are the pictures from the second car, note the pictures of the wheel/tire/strut didn't come out great in this case, but there was plenty of room in there.
Wheel Test Fit Day by Jared Elson, on Flickr
Wheel Test Fit Day by Jared Elson, on Flickr
Wheel Test Fit Day by Jared Elson, on Flickr
Paint Transfer is from testing 5MM spacer and no spacer:
Wheel Test Fit Day by Jared Elson, on Flickr
Wheel Test Fit Day by Jared Elson, on Flickr
I hope this and the full album of Flickr images is helpful!
First day at the track on the new wheels and tires will be in November and I can't wait to give them a go.
But what I really wanted was a set of 18x11" wheels that I could run as a square setup and rotate front to rear, to get as much life out of my track rubber as possible without having to deal with taking the tires off the rims to rotate tires. We found the formula to an 18x11" rim that you can run square and rotate because they are all the same offset if you are willing to do some minor mods and run a hub centric spacer up front.
Album on Flickr with all the pictures: https://www.flickr.com/photos/surfergeek/albums/72157660194695686
What's Required:
Hub centric spacers
Extended Length Racing Studs (ARP/Ford Racing)
Negative Camber up front
We test fit on 2 configurations:
1. Cortex Racing Extreme Grip Coilovers w/ 14" Brembo, Maximum Motorsports Camber plates, Ford Racing Hubs / Extended Length Studs
2. Koni Struts, Lowering Springs, 15" 6 Piston Brembo brakes, Maximum Motorsports Camber Plates, Ford Racing Hubs / Extended Length Studs
The wheels
Forgestar CF5, custom ordered from Auto RnD (http://www.autornd.com) Rishie is the owner there and I have worked with him for 15 years, extremely knowledgeable.
After reading and researching, talking to people, and taking our own measurements we finally settled in on an offset to use. I went with the Forgestar CF5 for their relative affordability, strength (don't read about a lot of failures on these), competitive pricing, the fact that the clear 15" 6 piston brakes for future upgrades and ability to order in any offset we wanted.
After seeing them on my car, I am ready to get a second set and make them my daily driver wheel as well as my track wheel, clearing the path for me to go 6 piston brakes in the future if I wanted to. Bonus, the factory Forgestar center caps fit!
We settled in on an 18"x11" CF5 wheel with a +52MM offset.
Wheel Test Fit Day by Jared Elson, on FlickrWe wrapped these wheels in NT01 Tires with a 305/35R18 tire (Pictured compared to RS3 285/35R18 tire on 18x10 wheel)
Wheel Test Fit Day by Jared Elson, on FlickrThe Fitment I am Going With:
My car is on the Cortex Setup. The full flickr album has more photos with descriptions for each one, but this is what I am ultimately going with.
Using an 8MM hub centric spacer in the front. The wheels fit with no spacer, but clearance from the offset strut, was unacceptable. A 5MM spacer left plenty of clearance, but we opted for a little more spacer to get some scrub radius back and give me more room for turning with my brake cooling ducts. It doesn't look like steering stops will be required, but I'll be installing them as a precaution.
With my ARP extended length studs, there is still plenty of stud to support this spacer.
I am running about -1.8 - -1.9 degrees of camber in the front.
There are no other clearance issues in the front or the rear. It looks great in both spots, and looks like fender rolling won't even be required in the front.
Some photos with the 8MM spacers:
Wheel Test Fit Day by Jared Elson, on Flickr
Wheel Test Fit Day by Jared Elson, on Flickr
Wheel Test Fit Day by Jared Elson, on Flickr
Wheel Test Fit Day by Jared Elson, on Flickr
Wheel Test Fit Day by Jared Elson, on Flickr
Wheel Test Fit Day by Jared Elson, on Flickr
Wheel Test Fit Day by Jared Elson, on Flickr
Wheel Test Fit Day by Jared Elson, on FlickrAdditional Test Fit For Vehicle 2:
We had a 2010 GT with Konis / Springs most importantly 6 piston brembo 15" calipers. This let us check clearance on a strut strut / spring set-up and with the big brakes.
The CF5 has no problems clearing the 15" 6 piston Brembo. Plenty of space even in the 18" wheel size.
It takes more spacer to get the front rims to fit (as expected), but it's not completely unreasonable to do. With our +52MM offset, we tried no spacer (no go, 5MM spacer, no go, 10MM spacer damn close to going, and 15MM spacer, going with a decent amount of clearance. If you aren't going to go coilovers and are going to stick with struts/springs you may want to consider as others have, a +55MM offset and you can run a little less spacer (most likely an 8MM or 10MM). If you are okay with a 15MM spacer, the +52 offset worked for us in our test fit.
Here are the pictures from the second car, note the pictures of the wheel/tire/strut didn't come out great in this case, but there was plenty of room in there.
Wheel Test Fit Day by Jared Elson, on Flickr
Wheel Test Fit Day by Jared Elson, on Flickr
Wheel Test Fit Day by Jared Elson, on FlickrPaint Transfer is from testing 5MM spacer and no spacer:
Wheel Test Fit Day by Jared Elson, on Flickr
Wheel Test Fit Day by Jared Elson, on FlickrI hope this and the full album of Flickr images is helpful!
First day at the track on the new wheels and tires will be in November and I can't wait to give them a go.
