BMW E9 Rims size advice...

[coupe2800cs]

Keep in mind that an 8” ET23 wheel is only 0.7mm closer to the fender than 7” ET11 wheel. Rolling the fenders gives you about .5” or 12mm of clearance. So a 3-6mm spacer with an 8” ET23 will result in 6-9mm of clearance when the fender is rolled. Camber plates would definitely help, but I haven’t figured out how much. Carl Nelson camber plates are like $80. Seems like a good investment for folks running 7” or 8” wheels with tires bigger than 185mm.

My actual concern would be clearing the strut on a 16” ET23 wheel with 225mm tires. I think you’ll need at least a 5-6mm spacer. 8x17 ET20 is a vetted size. Some members need a spacer, some don’t. It is so close that sidewall design plays a role in fitment. A 16” wheel will have even cless clearance due to the strut angle.

I've fitted the wheel on the front, it clears, but just rubs the strut a tiny bit, if I was to machine the lips on the wheel a little bit with a few mm cut off them, clearance wouldn't be a issue, however the tire deflection is a issue also, probably make sense to just run a 5mm spacer effective ET18 then.

 

[coupe2800cs]

Is the front rear track on these cars the same width or is the rear slightly smaller in width?

 

[Markos]

I've fitted the wheel on the front, it clears, but just rubs the strut a tiny bit, if I was to machine the lips on the wheel a little bit with a few mm cut off them, clearance wouldn't be a issue, however the tire deflection is a issue also, probably make sense to just run a 5mm spacer effective ET18 then.

Did the wheel have tires. If the aluminum is touching the rubber most certainly will.

Is the front rear track on these cars the same width or is the rear slightly smaller in width?

I’m not sire about actual width. Visibly you have about an inch of extra fender clearance in the rear. You also have quite a bit of inner fender clearance. Enough to run 9” wheels.

 

[rsporsche]

the important part of the discussion was that @coupe2800cs was going to use 225/50-16 tires on 8" wheels w/ et23 and add spacers. the 205/55-16 is 8.3" wide, with a tread width of 7.2". the 225/50-16 is 9" wide and has a tread width of 8". without spacers, rolled fenders or camber plates - the 205/55 rubs in most cases and will damage the tire when it catches the fender lip. using a tire that is .35" wider on each side and adding a spacer will further complicate the issue at the fender.

when i read the original post, it said that no modifications were being done ... that is what raised the flag for me. the post has been edited and says that modifying the fenders might be considered.

 

[Markos]

Doesn’t @Stan run 14x7 ET11 wheels with 225’s at all four corners?

 

[coupe2800cs]

Did the wheel have tires. If the aluminum is touching the rubber most certainly will.

No tires mounted yet to the rims yet, but I have a set of used 225 50 16 tires that came off my Mustang for test fit. Pretty sure the tires would fit with the 5mm spacer in there up front, though there might be a bit rubbing with tire deflection on the the strut housing, as well the front inner fender lip. I'd feel safer running the 215 55 16 tire size all around, with the front fender lips rolled. The main thing with the 215 55 16 tire size will help keep the tire from deflecting on the rim, effectively stretching the tire across the rim width, and make the car feel tighter in road response, as well 55 profile will help with ride quality...


I’m not sire about actual width. Visibly you have about an inch of extra fender clearance in the rear. You also have quite a bit of inner fender clearance. Enough to run 9” wheels.

I shaved the inner lips on my Mustang with a die grinder both font, and rear, instead of rolling the lip, might use that approach with the race car E9 also....