NitrOmm

iTrader: (1)

We know a OEM C5Z 18x10.5 has a +58 (documented online) offset that TYPICALLY needs around 12-15mm spacer in the front to fit...making it a +43mm offset wheel. Which is why OP's F14's with a +40 offset fits with no issues. I suspect his fitment is the same as running a C5Z wheel with a 18mm spacer.[/QUOTE]

Exactly !
On my WS6 I have OEwheels C6 deep dish 18x 10.5 on four corners (+58 with 17mm spacers). Effectively making this 41 offset. So we are all on point here with these specs.

OP: car looks impressive.

For me: I am interested in super concave on all corners. I need about 1/4" to clear my big brakes. I'm calculating a 47-48 offset with 7mm spacer.
Can anyone comment on this ? Is there anything that prohibits this combo.

SS#1531

iTrader: (4)

OP has an 11" wheel, not 10.5, so the offsets are not directly comparable. There are calculators online that consider different width wheels.

stp001

People make it harder to comprehend by mixing metric dimensions with "inch" dimensions. Personally, I think in terms of inches and automatically convert mm to inches. 25.4 mm per inch. For wheels sizes you can convert exactly or use 25 in your head. Pretty easy really!

dojob

Offsets are comparable... wheel offset is based off the center of the wheel. So a 315/30 on an 11" or 10.5" with the same offset will sit in the wheel well in the exact same spot

SS#1531

iTrader: (4)

I suppose it matters exactly where you're trying to make fit. You are right the centerline of the wheel will be the same, which is helpful for comparing caliper clearance if it's the same wheel design. And the position of the tire will be the same if the same size is used. But the inner and outer wheel edges will be different, which is important when working with wide wheels and clearing our front spindles and rear bump stops.

http://www.1010tires.com/Tools/Wheel-Offset-Calculator#

NitrOmm

iTrader: (1)

Correct. I guess I should have asked the question differently,
Will a 7mm spacer be enough to clear the big brake calipers on a Super Concave wheel ?

SS: thanks for the calculator, great tool.

dojob

tough to say. spoke shape matters not just offset. forgestar might be able to send you a paper template to print that you can place on your hub to check brake clearance

it's a game though with 315s.... has to sit perfect for the inner and outter clearance. 7mm for the brakes clearance could get you into the fenders/qtrs

SS#1531

iTrader: (4)

I was afraid to go super concave as well. My dealer said he wouldn't suggest more than a 42mm offset (11" wheel), but I don't think he was an expert at 4th gen fitment either. I will say with my deep concave and a 47mm offset, I have more caliper clearance than expected. I've seen a template for deep concave before, so like dojob suggested, Forgestar can probably send you a template to print out so you can check.

Nick Haines

where did you buy the wheels from??

M4N14C

iTrader: (3)

PM sent.

delta3

Looks really good! They almost look like my Miro 111s. I went with the same size/offset all around. I posted mine on here too. It's the Black SS.

blackbyrd

iTrader: (14)

ive got C5dd wheels on all 4 corners but didnt run spacers, I have just a tiny rub mark on the spindle just barely took the black paint off. I'll probably add a spacer at some point just so im a bit more comfortable. Been thinking about ctsv brakes also, but man the wide tire up front makes it feel like its on rails in the turn.

Love that shot with the wheel turned out up front its bad ***

WS6 #3392

Do you have a video of you at the road course or auto cross? I would love to see it if you do. Nice ride, and wheels excellent job!

M4N14C

iTrader: (3)

Last one I went to below, started raining right before I went so I got a little more sideways that I anticipated


Last dry event I went to:

Saturn5

Not saying Forgestars are bad - only it's important to remove and check your wheels, front and back, before track days. Espeically important if the failure mode on these wheels normally begins from the back side of the wheel.

Parts break. Knowing what to look for is the key to catching it early.

dojob

Friend of mine has them as his street wheels on his c6z. Refuses to use them on the track for the same reason.

smitty2919

WOW. Glad he was OK but that was hilarious to see his reaction LOL

Saturn5

Takes a while for the adrenaline to wear off.
I'm considering a set of Forgestars for my 2000 ragtop, but I don't track/autox it. After seeing this, I think I'd be doing regular wheel inspections (among other things) before and after *any* serious track outing - regardless of the manufacturer. No matter how good a brand is, parts fatigue and sometimes defects get out the door. Better safe than sorry.

Chased

I read this whole thread and not one person gave the specs for a basic fbody 18x10 setup.. did I miss something?

Id like a set of 18x10 in the rear and 18x8 up front my cars lowered also.

I also PMed Sam and it’s pretty upsetting that he won’t help with specs, sizes!!!

dojob

i run 18x10.5 +38 285/35. Perfect clearances.

Sam will help you. Just has to be money in it for him though.