So I know a lot of folk go 4x c5z rear rims for tracking in square setup, and I know a number of people have migrated to c6z staggered on c5z with a spacer on the rear, but has any one used 4x c6z FRONT rims for square? I'm afraid the smaller offset value (+40 vs +58) and shallower backspace (6.82" vs 8.03") may lead to either A) excess poke/fender rub or B) adverse change in handling? To be honest, I'm looking NOT for track but for daily driver....I would like to put all-seasons on these rims so I have extended travel / cold season tires that I can rotate as needed; possibly Michelin PS A/S3+ in 285/35R18 or Advan Sport A/S, etc. Since I'm looking to make this happen by purchasing two full c6z rim sets used, I might as well ask if anyone is using the 19x12 c6z rears in a c5z square setup? If so, I'd have to imagine that involves all kinds of widebody work and excessive spacer use...but I'd be curious how it was done. I'd be MUCH more likely to sell the 19s on the cheap.

For track days, I have CCW 18x10.5 front + 18x12 rear that came with the car (grain of salt...I haven't unmounted and checked specs on either, so I could be off 0.5 either way honestly) -and- I managed to pickup a pair of CCW 18x10 off this forum, with the notion of trying true square [exact same tires all around] vs narrow/wide (+/- staggered height; I can near square via diameter but no rotation options). COVID prevented me from burning off the remainder of the current 'meh' tires at the track, so I've not yet been forced to pull the trigger on new Ultra Summer and make my final decisions. Having an all-season clad square setup would give me even more opportunity to make the right choice before next year's track schedule.

Thanks

 

Well, that's an interesting idea. The wheels are 9.5" on the front of C6Z.

I imagine they could work, but the less offset on them leads me to believe there might be excessive poke in the front. But alternatively since they are narrower than square rear C5Z, you might be ok.

Theoretically would make a nice winter setup. You would have to know the offsets though of all 3 (stock, rear C5Z, front C6Z), to know for sure. Since the rear C5Z poke some in front, you could mathematically figure out where front C6Z would land.

 

Both ends would poke, with C6Z fronts all around.

 

Yeah, I was hoping the offset difference of 18mm (just over 3/4 of an inch further away from car center) would get minimized by the inch difference in width. But thinking it through, 3/4 of an inch further out minus a half inch (9.5 vs 10.5 is split between inner rim and outer rim) still puts the outer wheel edge a quarter of an inch plus further out than c5z rears....which already poke as fronts. Thus the desire to see someone having done it, to see just how bad the poke looks ..... as well as if there are any front fender rub issues with that extra extend. Unfortunately, no one makes an anti-spacer. <grin>

Thanks Hitman and USAZR1.

ETA: Maybe I need to consider c5z fronts all around for square winter. I just really want a set of all-seasons and a set of track tires so I can swap (and store) as needed. Lord knows, collecting a 4pk of 17 fronts should be a bit easier with all the 18 rear square runners out there.