Advice with suspension / wheel setup


  • Advice with suspension / wheel setup

    Hello everyone! I'm still fairly new to working on cars and I've been studying like a mad man over the last couple of weeks. I'm doing some basic mods to my 86 na Z31 and would really like the feed back and advice. Critique is welcomed. Anywho, I'm gonna just lay out what I'm planning on doing in the next month.

    Currently 86 NA complete stock. What I'm adding / considering. Note: This is my daily, and has been for the last 4 years. Figured I'd give her a new dress and shoes.

    I'm aware that the current wheel set up is 15x6.5 with +10 mm offset.

    What I'm planning on getting are Tokico blues + eibach springs. I hear these make one of the better bang for your buck daily set ups. Any other suggestions welcomed as I have not purchased anything yet.

    I'm set on getting 17x9.5 +15mm all the way around. 225/45 fronts and (this is just what i've been suggested) 255/45 rears. I've been to an online calculator that shows that it should clear but is 43.1mm closer to the strut.

    So the question is; Do I / Should I need spacers? Will there be any fitment issues? Again, I'm a novice at this stuff at best but I work best with advice. Even if it's just a point in the direction of learning how to figure it out. Any and all advice is appreciated. Thanks.
    Last edited by BruiZer; 02-26-2017, 07:20 PM.

  • #2
    Eibachs and Tokicos are a great combo for a street driver and don't let anybody tell you different… I have put Eibach pro kit series springs on two z31s, two s197s, and an altima 3.5 coupe and they always look and drive exactly as advertised. Wheels… ummm… can't say I have much experience as all my z31s have been zenkis and you have to be really careful with wheels on zenkis - the look doesn't 'update' well, you gotta stay pretty classic.

  • #3
    Originally posted by BruiZer View Post
    I've been to an online calculator that shows that it should clear but is 43.1mm closer to the strut.
    Measure your current clearance in that spot. 43 mm closer in the front sounds a bit fishy, but I'm not sure.

  • #4
    I have an 86 with eibach and tockico HPs = awesome combination. This is what the car should have always felt like.

    Be sure to look at your bushings since you are upgrading suspension. At minimum I would recommend doing the rear subframe bushings, inspect and/or upgrade differential bushing in the rear. Tension rod and lower control arm in the front.

    Wheel size will be more on the aggressive side for this kind of setup, you really would need more camber adjustment to pull off 9.5 with 225 in the front without looking weird. I would look at 17x9+15 area knowing you are going to need a 15mm spacer in the front to clear the spring perch (17x9+0 is what you want effectively). For tires I like the 245/45 combination on 17x9 with eibachs, you could even look at 255/40 combination as well but may need to roll the front fenders (super easy).
    86na - BlueZ
    Shiro #366 - Kouki Monster
    85t - Mr Tickles

  • #5
    Thanks for all the replys. Yeah I think it'd be in my best interest to set up an appointment with my local tire shop to see what they think after i get the suspension installed. I've seen on another forum that the specs 17x9.5 +15 were z31 Friendly, but it just seems a little wide. There are 17x9 +30 and I don't mind spacers at all, I'm just still learning all the numbers and whatnot. Thanks again.

  • #6
    Just to be clear, you're going for the stretched look, right?
    Justin
    1986 NA 2-seater
    SCCA Solo E-Street Prepared #31
    Race Videos
    Build Thread

  • #7
    Essentially yeah but I think due to fitting issues that i keep running into in the calc and not quite yet being comfortable using spacers, I think i'm just gonna go with a more proper fit. Since we're talkin about it, I wonder if you wouldn't mind giving me some advice on my current idea set up for the wheels.

    16x8 +15 (very close to the na stock offset) with the suspension i'm considering should drop it about 1.25 all the way around. I'm very novice at tires and I wonder what would look good on these.

    I'm just trying to plan everything ahead of time, so any advice/opinion is helpful.

  • #8
    I'm a fan of 16's since 225/50/16 tires are really, really cheap. On the downside, 225 is the widest you'll get on the best of compounds for 16" (there are some so-so 245s out there). Of course, 225 on a 8" wide wheel is not going to be stretched if that's what you were after.

    If you're going with 16x8, I would do a 16x8+0 and you can even go negative offset on the rear (something like a -10).

    As far as the 17" fitment goes, I fit 17x8.5 +7 up front with 275/40/17 with no problems and did not need to roll my fenders.

    EDIT: Actually, I may have forgotten which spacers I used with the 17x8.5 … it is possible the effective offset was +0, not +7.
    Last edited by frostvectron; 03-03-2017, 02:43 AM.
    Justin
    1986 NA 2-seater
    SCCA Solo E-Street Prepared #31
    Race Videos
    Build Thread

  • #9
    Your main issue with the 'stetch look' is the lack of adjustment with the suspension setup you are going after. You would really need coilovers, spacers, fender rolling if you wanted it to look correctly.

    I echo frostvectron recommendations:
    -- 16x8 with 225/50 is a great and affordable setup. You would want effective 0 offset in the front and 0 to -10 in the rear. Rarely any wheel company is going to offer anything that aggressive, probably more along the lines of +15 -- so you are going to have to get comfortable with spacers to dial everything in

    -- 17x9 is a very common wheel size you can find around. Similar you are going to need to run effective offset of 0 in the front to clear the spring perches. Not many companies are going to offer +12 to +18 so you are going to need to run a spacer to get everything where you need it. I still thing 255/40 is a great fitting combination for 9" wheel and will look great.

    16x9 with 0 offset in the front with 225/50. This is running a lot of suspension adjustment with s13 rear but you can gather what the wheel and tire setup would look similar on a 16x8 with 225



    86na - BlueZ
    Shiro #366 - Kouki Monster
    85t - Mr Tickles

  • #10
    With eibach springs, you are also going to need to remember you are probably not going to drop your ride height more than 0.5". This is because the OEM springs are old and probably sagging (more than you think in the rear). This is still a very beneficial upgrade, but it is not going to provide a dramatic height difference.

    I finally found some pictures of my 86. This is eibach + tokico HPs with new poly spring seats (and a bunch of other bushings) The wheels are 17x9+12 with 245/45. I am running a 10mm spacer in the front and none in the rear. I will upgrade to 255/40 tires in the future and get larger spacers to push the wheels out. Adding a rear spacer would minimize the wheel gap space in the rear visually since the wheels are a little sunk from camber.



    86na - BlueZ
    Shiro #366 - Kouki Monster
    85t - Mr Tickles

  • #11
    Thanks very much for the info and shots. Helped me out quite a bit. Those setups look great. I'll get some pics of mine once I get some time and weather allows.

  • #12
    I would recommend running square tire sizes to be able to rotate tires to maximize tire life. No sense in running different tire sizes on square wheel setup.
    17x9.5 +15 will not require fender pull. I run 18x9.5 +12 wheels and 265/35R18 tires front and rear with 10mm front spacer to get wheels flush. No tire rub.

    1986 300ZX Turbo…sold
    1990 Skyline GT-R…new money pit
    2014 Juke Nismo RS 6-speed…daily

  • #13
    Just measured the back up on the '87T for 10x18's, they will require an offset of 5 to clear the inside, tyres will be 275/35 semis. If the guard needs work then race car, same for the front. Link to a excellent calculator http://www.tyresizecalculator.com/ty…ace-calculator

  • #14
    Incidentially I have ordered 18x10 wheels all round for the race car project, from what I've learnt here 275/35 tyres should be OK at the back with a bit of guard rolling, the fronts will be a bit more, umm, interesting. Any pics/experiences with over sizes at the front?

  • #15
    if you want flush with a **x9" wheel run nothing shy of ~ -5 to +0mm