I'm going to chime in on this as I just went through a very lengthy exercise to source a new set of tires and wheels for my car.

So for reference, mine is a late manufacture 260Z (read that as 280Z).  I run Eibach lowering springs and Tokiko illuminas.  My present setup uses 16 x 7" Konig Rewinds (0 offset) on Michelin Pilot Sport 225-50X16.  I have zero clearance problems on the front and some very minor rubbing on the rear when I go over hard bumps at speed.  Rolling the rear fenders solved 90% of that problem.  My only regret is that I did not do the rolling before the car was painted which made the task a lot more challenging.  I would suggest that if you are going to go with a more aggressive setup that you have your fenders rolled prior to paint.

My initial motivation was to get a set of real summer tires that would provide a stickier grip for summer driving.  I really liked the Michelins I have on the car now, but they are more of an all season tire and I really wanted to switch to a summer tire.  In discussing this with my son Alex (and for those of you who know him, his feedback will not be surprising), his input was "Hey dad, if you are going to get new tires, you may as well get a new set of wheels as well so you have the option of switching tires and wheels and achieving a different look".  Extra expense aside, his feedback made sense to me so I was off to the races seeking a new set of wheels and tires for my car.

On the wheels, I really wanted something that was different from the most common wheels used on the S30's (ie Watanabe's, Konig's, Enkei's, etc) but I had no idea that finding something a little out of the ordinary was going to be so difficult.  The big issue here is finding a wheels with the right bolt pattern and the right offset with a width that will not interfere.  For the front, I found that a 0 offset was ideal but try finding a modern, non-standard Z wheel that is visually appealing and meets all of the specs.  I spent weeks looking for something suitable and frankly only came up with a couple of options and almost all of them were wider than what I was already running (either 8 or 8.25" wide) and this raised concern about clearance in the front.  As it turns out, a 0 offset will clear the strut and spring and will also clear the fenders.  The strut clearance is acceptable but it does not provide a lot of room for error, so in my opinion any wheels with a positive offset would potentially interfere with the strut / spring and a negative offset would likely result in fender clearance problems.  The rears are a lot more forgiving on the strut side but I wanted wheels to match the front so I also decided to go with 0 offset for the rears as well.  So in the end I decided on a set of XXR's in Chromium Black, 16 x 8.25, 0 offset.

Unfortunately I did not find a lot of summer tires that would fit this wheel, but ended up with Pirelli Trofeo R's.  They are basically track tires meant to be used on the street, and are pretty aggressive, very soft compound, and sticky as hell.  I also decided that I wanted to try a staggered tire setup as I do like the visual look of slightly larger tires on the rear than on the front.  Totally understand the downside of doing this (ie can't rotate, etc) but my main motivation was visual appearance along with acceptable performance. So in the end, I went with 225-50x16 up front and 245-45x16 in the rear. 

Finally, I am not a huge fan of black wheels and had a high level of concern about how these were going to look, but my son convinced me to go for it, which I did.  Fortunately, these are powercoated in chromium black and so look more chrome than black depending on the lighting, so I am quite happy with the end result. 

In any case a long winded story to a simple question, but I do hope it helps those trying to find something that's a little different than the ordinary.  I will say that the easiest way to solve this problem would have been to go for a set of complete custom wheels made to my exact specs, but in checking into this as an option the cost was through the roof.  For what it would have cost for one custom wheel, I got a complete set of 4 with money left over to put towards my tires.  So that is definitely an option, but you better have deep pockets if you plan to go that route. 

Here's a few pictures with the final result.

 

3 hours ago, Mike W said:

I'm going to chime in on this as I just went through a very lengthy exercise to source a new set of tires and wheels for my car…

 

Man that looks nice. I’m not normally a fan of that style of wheel for S30s when I see them on a website or off the car, but these look soooooo good mounted.

Thanks for the comment on rolling the fender, too. I'm glad to hear someone successfully runs 8.5" rear wheels, although I wasn't clear what you ended up using in the front.

I’m going to the body shop today, so I’ll discuss it with them. Is the rubbing issue always on the outer lip or is there an issue on the inside as well?

Edited August 23, 20186 yr by Matthew Abate

Thanks for the nice words!!

All four corners are the same wheels.  16 x 8.25.  Weird size but that's what they are.  Rubbing in the rear occurred on the outer lip.  At 0 offset there are no issues on the inside at all.  Plenty of clearance with the strut and spring.

Mike.

I read a lot of rubbing issues on the outer lip, but not much is mentioned about the rear inner fender well. I found that I could clear the lip but the rear tire would rub up inside the well on hard bumps with the car loaded. I cheated in every way to get my 17x8.5 +4 offsets to clear. Including in the cheating was actually changing rear camber by slotting the strut mounting holes. I run 225/45/17 and I bet I could get 235/45/17 in there too. So I can see how if the diameter is kept down you can get 245 in the rear. I actually ran 245 all the way around first time and the fronts cleared - barely. The 245’s just rubbed too much in the rear to keep on there. 

Camber in the back will gain you some room. Positive offset on the rear would allow for bigger meats , but too much positive up front it will rub the strut . I actually flattened the strut perch on the wheel side to clear my WHEELS. 

Being 17” the wheel rim is on the same height as the spring perch, so adjusting spring perch( with hammer) actually helped. A smaller wheel would have a tire lined up with the perch and it would flex, so might not work

Okay, all of this was valuable feedback, so thanks. I've decided to not risk jumping on wheels right now and to wait until I have the whole thing back together. There was a sale on the Group4 wheels I've been looking at, but it won't be their last one.

In other news…

Edited August 24, 20186 yr by Matthew Abate

Problem solved:

Are all 240z front struts the same? NO! Those two struts have different sized bolt holes.

 

On the left you see m12x1.25 holes, and on the right you see m11x1.5 holes.

 

I think this was done by a previous owner. Either the bigger holes were retapped or one of the struts came from a different year car. There was suspicious overspray of body color on these parts when I pulled them, so something definitely happened here.

BUT! The bolts I got with my bump steer spacer kit are m12x1.25, which means the manufacturer of those probably match them to a bigger size, so maybe m12x1.25 is right on some cars.

 

***

 

Regardless, I have a drill and a tap coming in the mail. Now I’m going to find some grade 8 or higher bolts to replace the stainless ones that came with my spacers.

Are you sure those M11 threads are native? Are you sure they are cut directly into the strut housing and it's not some sort of an insert or helicoil or something?

M11 is a real thread, but it's a little unusual.

Not sure of anything, but I didn’t notice any inserts when I inspected them before refinishing them.

I used a micrometer on them and I’m starting to think it is poor machining tolerance rather than a totally different size. There’s a very wide range across the four holes.

I *might* be able to force a 12mm bolt into the small ones, but I think I’ll just run taps through them to make them even so I don’t break a bolt. The 11mm tap goes in pretty easily, but it’s not sloppy like you would expect from a 1mm diameter difference.

 

¯\_(ツ)_/¯

 

 

It should be pretty easy to determine what size bolts are supposed to be used there. If I had to guess, I would say they should all be M12.

There was a drawing floating around here somewhere that called out all the sizes for the suspension bolts. Have you seen that?

I believe I have some of those bolts sitting on the bench. I can check them after church

This is a set of strut to knuckle bolts. Bolts appear to be 12mm dia and the shorter bolt is 30mm on the shank. The longer bolt is 35mm on the shank and goes in the front hole of the strut. 1.25 pitch