So these system 4's are bolt on and will work with the fronts? No shaking or vibration to worry about?

with system 4 you just need to attach the spacer on your factory wheel hub with the provided nuts and use your factory lug nuts:

http://d5otzd52uv6zz.cloudfront.net/...507c19-800.jpg

with system 6 you will have to take the factory studs out and install provided longer studs with the spacer and still use your factory lug nuts:

http://d5otzd52uv6zz.cloudfront.net/...cc47c3-800.jpg

if you compare the pictures for both options you can decide which one to go with easier. I would go with system 4 just because it seems to be easier and safer to me. I dont think there will be any vibration issues as long as you go with 15-20mm. if you go with 25-30mm on the front chances are you will have some vibration.

^^^ Thanks!

Yes, I was planning on 15 mm front and rear, and would definitley want to stick with bolt on if possible, for ease of installation.

However, it seems that several people recommend against a bolt on application for the fronts -- are you sure these will work? Do you have bolt ons on your fronts?

omg... looks AMAZING! :tup:

I dont have any spacers at the moment but I used Eibach system 4 before, 15-20mm without having any issues. I would suggest you to take a look at the following thread if you are planning to get spacers since you will find so many people using them with no problem ;)

FAQ: Official wheel "SPACER" thread! - Page 26 - MY350Z.COM Forums

There are clearance issues with any bolt on spacer that is 15mm or smaller due to the factory studs contacting the wheel. It depends on how deep the 'pockets' are in the Nismo wheels as to whether you will be able to bolt on 15mm spacers without any issues.

Yeah, I don't think the factory studs will clear with less than like a 25mm bolt on.

Yes the pocket depth and width on your new wheels will determine if those 15mm spacer will work. On factory sport 19s, 20mm is the smallest bolt on spacer that will fit I believe.

I don't understand -- so it's the dimensions of the wheels themselves that determine whether bolt-on spacers will fit?

The S-tune wheels have the same dimensions as the OEM Rays as far as I know...

If you look at the backside of the wheel, the spacing between the 5 lug holes is what will determine if the bolt on spacers will fit. This is where the stock studs and open ended lug nuts (which come with the spacers) will fit. If the holes are too small or too shallow, then the wheel will not be able to sit flush against the spacer face.

This is more common on spacers smaller than 20mm, because the stock lugs will protrude more on a 15mm spacer than on a 20mm spacer of course. The less they protrude past the spacer face, the less room needed for them to fit inside of the wheel's mounting surface.

Argh... I see. So it fits on the rears on on the fronts it simply won't.

Okay, thanks for clairfying -- looks like I need to do replacement studs for the front.

Depends on the backside of the wheel still lol. 15mm might work on those nismos if the gaps are large enough for the stud stud and open ended lug nut to fit.. I would guess no and if u don't want to take the risk, get the stud replacements.

What do you guys think about 20 vs 15 cosmetically?

Which is more flush with factory offset?

with factory rays 20mm looks better, no rubbing

After much consideration, a set of 15mm HR's have been purchased.

Pics once they are installed :tup:

Thanks for everyone's input and suggestions :tiphat: