15x9 Rota RKR

[saladin]

Anyone know if this will fit with lowering springs on the stock spring perch? I'm assuming you need 0 offset.

Something that looks like this

Thanks

[BluDestiny]

More like -10 to -15 offset and stretched tires. But they will fit. 

Edited September 25, 2015 by BluDestiny

[Dat73z]

Curious about pic above. Have 15x8 0 offset RKR's and with AZC knuckles will probably need ~10mm spacers to clear. If the OP pic is something like a 15x8/15x9 -10 to -15 offset then I'm assuming 225's fitting under the factory arches without negative camber + roll + pull is out of the question?

 

I've attached a pic when I threw a 15x8 0 offset RKR on the other day for a quick visual. Granted there is no load on the suspension, things aren't looking too peachy if a 10mm spacer gets thrown into the mix although 15x8 0 offset looks like it'll fit excellent to the fenders with good clearance on the back.  

Edited September 25, 2015 by Dat73z

[saladin]

I think the tires in the OP are 205/50 stretched on the 9. Looking at your picture, I think if you're trying to do 225 you will have to roll at least. Looking good though! The 15x9 only comes in 0 and -15 so I'm still not sure if I should get the 0 and spacers or just get the -15.
 

[casper9182]

I have a set of rotas, 15x9 at -15 offset and I will tell you that they don't clear the AZC knuckles.

My plan to fix this is get some 16" wheels.

[Michael]

Front, rear, or both?

 

My measurements in the rear (well, my 1978 280Z's measurements - not mine personally) with a 14x7 wheel and 225/60-14 tires: approximately 1.25" clearance between the rim and the spring-perch, for a wheel with 3 7/8" backspacing.  In a 15x8 with 0 offset, that's 4.5" backspacing, taking up 0.625" clearance between rim lip and spring perch --> should fit.  This is what I am contemplating for my car.  But with a 15x9 and 0 offset, that's 5" backspacing, and perhaps 1/8" of clearance... not enough, in my opinion... especially if tolerances stack up.

 

This is the inboard clearance.  Outboard, I'm not starkly worried about the tire rubbing the fender, as my car is "elevated" (unintentionally) and space is ample.

 

This is all assuming stock camber and reasonable comportment between tire width and wheel width.  For a 15x8, I'd prefer a 245 or 255 tire, but only 235 is available in semi-streetable compounds, and only 225 in truly streetable compounds.  For a 15x9, if I were to have attempted such a thing, I would have preferred a 275 tire - which for 15" diameter does not exist.

 

For the front, I am aiming for a 15x7 wheel, with zero offset.  This should fit comfortably with stock brakes and suspension, supporting a 215 or 225 tire.

[Dat73z]

Just to confirm and a bit sidetracked from the OP's original question, I have 15x8 0 offset RKR's and with a square sidewalled tire they will fit both inboard and outboard speaking from my own physical mockups with full T3 suspension and brakes/OEM F/R hubs (e.g. F/R control arms, full coilovers, caster arms, wilwood disks). 

 

With AZC knuckles and outboard/fender clearance that is a different story and something I had not considered when picking up the 15x8 0 offset RKR's. I spaced things out with washers and you'll need something between 5-10mm spacers to clear at a minimum. I'm thinking closer to 10mm but memory is a bit fuzzy. Note however I want to run sticky 225's. If you are willing to run a stretched tire and/or lots of negative camber the dynamics change entirely. From my measurements and as casper9182 alluded to above, simple solution is to upsize to 16's or 17's so the AZC knuckles will clear in the barrel. That is, unless you want to stick with 15's (which is my case). 

 

Edit: I should also note I know a local z owner with AZC knuckles and 15x7's on the front in I believe 0 offset and no spacers. Last time I looked barrel doesn't extend inboard enough to hit the AZC knuckles. No tire stretch but can't remember the width. I know the rears are 15x7 running 225's. Clears inboard/outboard front and rear just fine. 

Edited September 30, 2015 by Dat73z

[Michael]

Just to clarify - by "AZC knuckles", is the reference to the aluminum contraption in the bottom photograph of http://www.arizonazcar.com/lowarms.html ?  As the photo opening this thread is of the rear, I'd assumed that the question is mainly about the rear wheel/tire fitment.

 

Also, to Dat73z's point, there is ample evidence that 15x7 wheels sporting 225-width tires indeed clear in the rear (sorry for unintentional puerile rhyme).  The matter is less certain for 15x8, let alone 15x9, especially if we assume stock springs, instead of coilovers.

 

The question of wider 15" wheels also begs the question of tires. If we limit ourselves to 225-width tires, why bother with wider than 7" wheels?  But what are the offerings in tires of 15" inner diameter and widths wider than 225?

Edited September 30, 2015 by Michael