rota rb

[280chisel]

So my wheels came in yesterday and I was doing some dry fitting. I will need a spacer for sure being that my wheels have a 20 mm offset. I am putting 7.5's on the front with 225/45/17's and the back will be 8.5's with 245/45/17's. My question is will the 245's fit back ther without coilovers? or should I just go with say a 235 or 225? I know some of this has been covered but this issue for me is still unclear and I want to go get some rubber on these things! also do any of you reccomend a 20mm spacer or 10mm for the rear? it is going to be close! Thanks for any advice! It is very helpful to have experienced people to go to for answers! Paul

[twsutt]

Paul,

Don't be too surprised if you don't get too many answers to your post. As you should know by now, the topics of back-spacing, wheel width, coilovers, tiresize, spacers, etc. have been covered extensively. The "Wheels, Tires and Brakes" sub-category is overflowing with info on this subject.

Now it's time for you to use the info given here to find the proper mounting of your wheels/tires (and body modification depending on how wide you want to go.) Chances are, your going to have to physically take many, many measurements and then look for, or special order, the spacers/adapters that fit your specific needs.

I wish you the best of luck and look forward to seeing pictures once you get your Rota RB's mounted.

p.s. - If I come off as rude (which is unintentional) is just because I wish I had a set of Rota RB's on my Z.

[srbigbutt]

What color did you get? Can't wait to see pics. Also what year 280z do you have and is it stock suspension. I'm interested in getting a set of 17x8.5 RB-R. Where did you get yours from?

[ktm]

Why.....why do people jump in with both feet and buy something without doing research first, and then come and ask if they will fit?! You deserve every hour of aggravation you are about to face. Chalk this up to a lesson learned in life. Seriously, research before you buy.

Now that I've said that, I am going provide you with your answer.

You are hosed with the 8.5 in the rear unless you are running stock suspension or coilovers. Even with the stock suspension, you are going to rub the fenders on bumps.

S30s need about 4.5-inches of backspace for clearance. Your 8.5-in. wide, +20 offset wheels have (8.5+1)/2+20/25.4 = 5.5-inches of backspace. Rubbing will occur between the tire and the spring perch, regardless of the tire width unless you run spacers. However, your spacers will push the face of the wheel out towards the fender lip.

Cool you say, well, yes, it fills out the wheel well, but now your tires are going to rub the fender lip. Time to roll the fender, but I have a feeling that this will not help as the wheel may be protruding too far out.

At a minimum, you are looking at running 15mm spacers, maybe even 20 mm. The spacer width is also determined by the tire width. A 225 in the back may only require 15 mm, a 245 may require 20 mm. Now you are going to need longer studs. Anything over 3 to 4 mm spacer will require longer studs if you want your wheels to stay on the car.

Your fronts are going to rub as well and will require spacers. Again, you will need longer studs. Also, the front tires will rub on the valence unless you are running an airdam.

I am running 16x8 +10 Rota Grids with 245/50s all the way around. I am running a 10mm spacer up front and no spacer in the rear. I had to trim a little bit of the spring perch for clearance in both cases. I rolled my fenders but still rub on severe bumps. However, I am running the Tokico HPs and their progressive springs. Next year is coilovers and camber plates which should help.

[blue 72]

I've seen 17x7.5 20 offset RBs on a 280Z and they fit with a 1/4 inch spacer in the front. Rolling the fender lip is usually required to fit these as well. Might be time for some flares or metal work to make the rear ones work without rubbing.

[srbigbutt]

I'm thinking of getting 17x8.5 with +4 offset. I should be fine in the back but the front is what worries me. I may just need a 5mm spacer and probably run 225 45 17 in the front. I would just like to see some good pictures and different color options before I buy.

[280chisel]

I have read all of the threads here and on hybrid z pertaining to this subject but I would still like to see a duplicate of the install I am doing. No matter what it takes I am willing to fit them in. I lined up a friend in the body business to roll my rear fenders for 100 bucks. and I already put a 240 air dam on it. If I have to get the coil overs I will but it would be nice if i can get away without it. I knew going into this that I would need some spacing. I have heard 20mm and that may be the right fit.. Another question, How low can I lower my car with coil overs? I would love to drop it down a bit.. Thanks for the input! Oh and my car is a 1976 280z that I have been putting 240 trim on. love those little bumpers!

[280chisel]

What color did you get? Can't wait to see pics. Also what year 280z do you have and is it stock suspension. I'm interested in getting a set of 17x8.5 RB-R. Where did you get yours from?

I got the rb's silver with the polished lip from 18racing and they look really nice! my car has stock suspension for now.

[srbigbutt]

Are they both 20mm offset? Any reason you didn't go with the +4?

[280chisel]

These were all they would have for at least three months. too long for me to wait..