Perfect S13 Wheels & Tires

[nismofly]

People bash Eibach because they are popular.

i honestly dont think ive ever heard someone bash eibach because theyre popular

eibach for other cars are great, eibach springs are used in ground control sleeve overs

its just, as i said, you are one of two people i know that actually liked the handling their eibachs gave them, and didnt think they were as soft as if not softer than stock

i never said you had to get coilovers, heck im not, but something a little stiffer maybe

but if your happy with the eibachs then by all means leave them

[Edub1]

if youve got 270hp its an extremely bad idea to get cheap tires

if you cant afford a $500 set of tires every 6-9000 miles you cant get staggered

youd be much better with a set of 17x8 wheels, and getting sticky rubber

Dude, "tires cheep" not "cheep tires." I can get them wholesale as with the rims I'm ordering. I've got a cousin in the tire business.

[Edub1]

But like what I'm going to do is just get 17x8 and put a 235/45 on it, no really need for a wider tire. Now for looks and being a show car then go for it but I dont think thats what your after here.

I know you have a picture of these on a car. Would you be so kind as to post them?

What offsets are you going with?

[youngmanvr4]

Well I dont have the wheels yet but I should in about 2 weeks or so (pay check). But I'll be taking before and after pics. I'll post them up along with the fitment. Note I have stock suspension for another couple months (want to get some drifting down before I mod suspension much. I'll be getting KTS coil-overs.

Offset will be +35 since thats the only size offered in 4 lug (17x8 +35). Well their is +42 but dont even think about fitting that on a 240.

I'll try to find a pic of a 17x8 with a 235/45, but I dont have one on hand though. I'll see what I can do. I might be able to find a 17x8 225/45 then that will give you some what of a idea, then just try to picture it only just 10mm wider.

[Edub1]

I took some measurements. My car has an Eiback Pro Kit with KYB GR2s and stock wheels & tires.

Front:

Tire 205/65/15 is only 5/8" (15.9mm) from the stock strut. The outside of the tire has about 1." (25.4mm) of clearence from the plastic wheel well while turning.

So, it looks like a 235 +35 will celar the stut by 5.9mm and miss the wheel well by 5.4mm. This assumes there is no change in the diameter of the tire.

235 +35 seems like an ideal front tire.

Rear:

Tire 205/65/15 is 1.5" (38.1mm) from the spring and about 1" (25.4mm) from the midline of the stock fender lip. It is 2" below the stock lip on my car.

So, up to a 265 +40 will clear the spring. To be at least as wide as the front, 20mm must be added to the outside. A 245 +40 offset will accomplish this. A 255 +40 will give 5mm more and droping offset will add to that.

The problem in the rear is with wheel travel and fender clearence. If we allow enough wheel travel to put the tire into the well, (2" on my car) we only have about 12-15mm of clearance.

So, it seems that for anything wider than a 225 +40 some fender rolling is required unless we go into a higher offset. 245 +50 clears the inside & sticks out 10mm more than stock. I'm not sure why I'm getting this when everyone says to go with a lower offset. This might work with rolled fenders but will rub stock ones if my math is correct.

Anyway, it seems that 255 +40 is ideal. That's 25mm or 1" added to each side of the tire. Clears inside & out with modest fender roll.

Front: 235 +35Rear: 255 +40

I welcome comments.

[nismofly]

not quite sure how you arrived at your numbers

offset and tire size are two different things

tell me this...what wheels do you want to get? ill get you the sizes, 17x8 / 17x9 is your preference i see, and depending on available offsets for the wheels i can tell you what tire size youll be able to run

if what im thinking youre thinking is right, you think you can run a 235 on a 17x8 +35, which wont happen

youngman here is getting 17x8 +35, because thats all thats available, but he also wants to run a 235, and hell be running at least a 10mm and possibly a 15mm spacer to clear it, but he knows hell at least need a spacer and hes going to test the fit to see what size spacer he needs

[Edub1]

I didn't see any wheel clearance issues. My measurements reffer to the tire width. Since the tire moves with the wheel I measured from the tire. Say a tire is 30mm wider and the wheel is positioned as stock (+40). The end result is a tire that is 15mm wider in each direction. Shift the wheel out with a +35 and the tire moves 5mm outward with the wheel. So, 10mm inside and 20mm outside.

Are you saying a 235 will not fit an 8" rim?

I will be having my rims made custom and I do not have coilovers. I can use any size/offset I want. If you have info on sizes, please share.

As for spacers - there is about 1" (25.4mm) from the stock tire to the wheel well when turning. A 235 will take up 15mm and the offset will push it out another 5mm (the tire moves with the wheel). That leaves 5.4mm - there will be no room for a specer unless the plastic wheel well is modified.

[nismofly]

235 will fit on the wheel, convert the tire sizes to millimeters and the 235 on an 8 has less overhang than the 205 on a 6...but it probably wont clear the shock/spring, because your offset has the wheel to close, and as you said the tire moves with the wheel, therefore with the wheel being too far in it has the tire too close

offset is just the postition of the mounting pad on the wheel relative to the centerline of the wheels width

the +40 stock is on a 6 in wide wheel, to have the same clearance to the shock/spring on the inside youd need a x8 +15

try this:

http://marksink.com/tire_wheel_offset/offset.html

you put your current wheel size in, this will tell you how much farther in and out it will stick, with a 235 youll actually have better clearance in terms of the tire overhang on the wheel

[youngmanvr4]

From the given infomation that 17x8 +35 with a 215/45 clears front with coil-overs without a roll if my math is right a 17x8 +35 with a 235/45 with coil-overs with a roll with a 5-8mm spacer. If it doesn't fit then what I might do is run a 225/45 and just keep the 2 extra 235's for the rear.

[nismofly]

it *should* clear with a 10, because thats how much farther a 235 sticks out on either side from a 215

the reason by the way i keep using multiples of 5 is because ive never seen a spacer that isnt, like youre not going to find an 8mm space, so just get a 10

[Juujai]

this is pretty confusing. what does 235 have to do with a single offset? ooo you mean tire series... / not +. toss all you know out the door. i think you're misinformed tire size itself is irrevelent it depends on wheel width/offset also.

only time tire size would matter is if it is bigger than the wheel width like when it bulges out.

theres no way for him to be able 17x9 +15 and 17x10 +25 with his current shockspring setup. you need to be pretty low for that (coilovers, fender roll, camber arms)

custom wheel sizes sound cool but doesn't mean much if it isn't flush or atleast proper. what type of look are you going for? if you don't want to roll or adjust camber settings/hit springs and don't care about flush too much...

i'd recommend 17x8 +25~+/- STARTING point to liking with tire sizes from 215/45 to anywhere like 245/40. or 17x9 +30~ since lower would mean fender roll/a lot of camber. mcrusselpants sizing would be a lot manlier but less function not for fast laptimes more show.
Modified by Juujai at 11:17 PM 2/19/2006

[nismofly]

this is pretty confusing. what does 235 have to do with a single offset? ooo you mean tire series... / not +. toss all you know out the door. i think you're misinformed tire size itself is irrevelent it depends on wheel width/offset also.

haha welcome to the club, i think weve got that addressed between us

as for the wheel tire combo, if you can get custom

17x8 +25, 235/45/17 ; 17x9 +35, 255/40/17

[Jookmasta]

i think with shocks and springs he will clear.............i run +47 or +44 17x7 with a 215/45/17 and i have no rubbing or fender rolling or whatever. been like this for about 3 or 4 years now and yes im lowered with shocks and springs.....

[McRussellPants]

i think with shocks and springs he will clear.............i run +47 or +44 17x7 with a 215/45/17 and i have no rubbing or fender rolling or whatever. been like this for about 3 or 4 years now and yes im lowered with shocks and springs.....

No fender rolling???!?!!?!?!? HOW DOES THAT NOT RUB@?@/@?@/2222@!!1

[Edub1]

I can see a few people aren't following me so I'll try to explain it better. First, I do not have coil overs. My measurements are for struts.

I measured the tire and not the wheel because on my car it is the tire that will rub, not the wheel. Some of you might have coil over issues. Other than that it is the tire that ultimatly determines clearance since they protrude farther than the wheel.

Offset determines where the center of the wheel, and hence the tire will be with relation to the hub. If tire width increases by 30mm 1/2 of this (15mm) adds to each side of the stock tire. So, with the same offset, your new tire is 15mm closer to the shock and 15mm closer to the fender no matter what size rims they are on. A 235mm tire is 235mm wide excluding streaching.

Now, if 15mm is too much on one side, you change the offset of the wheel to shift it and the tire in either direction. Say you move it out 5mm with a +35 offset. Now your 15mm on each side has shifted to give you 10mm inside and twenty to the outside. This is relative to the original size and position of the stock tire.

Look at it this way; figure tire width increase/2. That is added to each side. Then take the change in wheel offset (5,10,15mm...) and shift this measure in the appropriate direction.

I should also mention that the s14 has different clearance. Just measure your clearance from where the tire will likely rub and apply a little geometry.

Again - I do not have coilovers!

[Juujai]

yes we understand but why do you need oversized buldging tires? you're making it sort of complicated. we understand that fitting a tire is going to be divided fatness on both sides left and right.

2 ways to change offset, wheel spacer or get new wheels.

you are going to get new wheels so unless you plan to buldge tires then measure tire width but i'd recommend square [ ]/stretch <> tires over ><.

having coilovers or not doesn't have to do with wheel fitment unless you are fitting unproper wheels... with super high offset. which i don't see why you would go that route as you can custom any offset/width.

you don't sound like a flush conscious kind of guy so go with something like 17x8 +25~+/- all around and you'll be fine. you'll be able to fit any size tire thats proper for it... buldge or stretch.

[nismofly]

of course we know what offset is, its just before you were relating it to tires so we werent sure if you knew what it was

how about this, disregard clearance...run what i told you (17x8 +25, 235/45/17 ; 17x9 +35, 255/40/17) and youll be fine

if youre still worried about clearance run a 225/45/17 front and 245/40/17, this will also be nice and square...or even a 215/45/17 front 235/40/17 rear for an ever so slight stretch

or as Juujai said dont even stagger, just get the 17x8 +25 all around and call it a day, you can run any of the front sizes i listed, 215, 225, or 235

[Edub1]

Which of these sizes have you personally seen on an S13?

Because a 235 tire on a +25 offset wheel gives 30mm outward. This should hit the inside of the wheel well when turning according to my measuements.

[nismofly]

ok i think i may have just found a flaw in your calculations

youre saying theres an inch of clearance, but this is an approximation when its sitting uncompressed right? so youre worried that it would rub when the suspension compressed?

[Juujai]

i think your calculations are completely off and i'm too lost to find where you are wrong at.

let me clarify. wheel width/offset are measured together. tire size is irrevelent unless it is bigger than the wheel... like i have said a few times.

again offset does not mean anything at all without wheel width. for example: an 8" +25 vs say a 9" +25 is way different atleast half an inch more outwards.

THE sizes you are looking at are way too wimpy to even get close to the coilover or the fender. those sizes aren't flush or pushing the limits in any way or form... compared to fitting 18x9.5/19x10.5 on an s13 those x8 x9 sizes are a walk in the park. which was what me and nismofly were aiming for recommending "EASY" to fit sizes without hassles/troubles of fenderwork/camber/modding other stuff

[nismofly]

the thing also to remember is, you may not have coilovers, but that wont have an effect on your outside clearance, only the inside

also, what i was getting at with the clearance, remember that when the suspension compresses the wheel tucks, it doesnt go straight into the fender

you should be fine on the fender side, and certainly on the shock side

[Edub1]

The car is sitting on level ground. I turn the wheel to about 45 deg.

If you measure from the rear most edge of the tread (perpendicular to the plane of the wheel) to the wheel well you get about 25mm.

You can not seperate the wheel offset from the tire position because the tire is mounted on the wheel. If the wheel is pushed out 10mm so is the tire. What is there not to understand?

A 235 tire on any wheel has 30mm wider tread than a 205 tire. That makes it 15mm closer to the well on any size wheel - as long as the offset is +40 the wheel can be of any width and the tire will still have the exact same center line and thus still stick out 15mm more.

Move the wheel out another 5mm and the wheel, tire and tread edge is now 15+5 = 20mm closer to the well. You have 5mm left.

Say your wheel size increases from 6" to 8" and a +35 offset. That is 20mm on the inside and 30mm on the outside. The wheel grew more than the tread (30mm) but the tread is still centered on the wheel which is shifted 5mm outward. The center line of the tread moves with the offset and the extra width is added from the center. The fact that the tire bead is streatched out a little doesn't come into it. Here is why...

The wheel rotates left and right about an axis and produces a radius. So it is the outer most edge of the tire that produces the largest radius when cornering (think in 3 dimensions). I can fit any size wheel I want - it's the tire that won't fit.

Get a tape measure, go outside and experiment. Measure 20mm from the outer most edge of the tire, straight out from the plane of the tire. This is where a 235 on any wheel with a +35 offset will be. Now turn your wheel about 45 deg and note that it will just miss the wheel well along the trailing edge.

Go try it.

Modified by Edub1 at 9:35 PM 2/20/2006
Modified by Edub1 at 9:38 PM 2/20/2006

[nismofly]

if youre that worried about it run the 225

i have a 225 and it works fine, plenty of clearance, i know people have cleared 235

youre leaving a lot of variables out in your calculations, but if you dont want to take the chance run something smaller

if you dont want to stagger run 17x8 +25 all around with 225/45/17

[Edub1]

if youre that worried about it run the 225

i have a 225 and it works fine, plenty of clearance, i know people have cleared 235

youre leaving a lot of variables out in your calculations, but if you dont want to take the chance run something smaller

if you dont want to stagger run 17x8 +25 all around with 225/45/17

A 235 with a +35 should just barely clear. A 235 +25 should hit the wheel well. A 225 with +25 is close. If you have 225s on a +25 rim, perhaps you would try to measure clearance with the wheel turned. Just see how close it comes to the inside of the front wheel well and let us know.

I bet it clears by a CH.

[nismofly]

I bet it clears by a CH.

not sure what a ch is, you mean cm?

anyway i can fit 2 fingers in there, tight squeeze but i can, and i can guarantee you my fingers are more than 5mm wide

as i already said, youre not including all the variables in your equation

[Juujai]

not bashing or flaming at all but just trying to make it clear.

"You can not seperate the wheel offset from the tire position because the tire is mounted on the wheel. If the wheel is pushed out 10mm so is the tire. What is there not to understand?"

that is correct but as i have said unless you plan to run fat tires it is irrevelent. wheel WIDTH/OFFSET are always together... DO not measure offset without accounting width. that's why forget about the tire size you can work on that later.

"A 235 tire on any wheel has 30mm wider tread than a 205 tire. That makes it 15mm closer to the well on any size wheel - as long as the offset is +40 the wheel can be of any width and the tire will still have the exact same center line and thus still stick out 15mm more."

that only happens if the tire is being forced on a properly square setup or bigger. if it is being put on a stretched setup then it is irrevelent. say for instance the 205 is being stretched on an 8 width wheel and you decide to upgrade to a 235. the overall tire/wheel will still be square in other words measuring the wheel for clearance vs tire for clearance would be almost identical.

i have no idea what type of fit you are trying to do but seriously unless you are getting towards x8 +40+offset or closer to x7 +0 offset you won't have to worry about tire selection. width/offset doesn't start getting very specific until you reach 9.5/10.5~ widths. that's where you need offsets within range.

if you want to do it yourself use the wheel offset calculator. measure how sunk your wheels currently are ~2" or ~50mm fender side, ~1" or ~25mm spring side and type in 6 +40 and play with it.
Modified by Juujai at 12:43 PM 2/21/2006

[nismofly]

i think i may have just found a critical flaw

you said here:

I took some measurements. My car has an Eiback Pro Kit with KYB GR2s and stock wheels & tires.

Front:

Tire 205/65/15

Rear:

Tire 205/65/15

youre saying your tires are 205/65/15? like you actually see this on the sidewall, or you just think thats what stock is?

if thats what size your tires are, thats not stock size, so all your clearances are going to be much tighter than they normally would be

[Edub1]

Just double checked. That is what's on my car so the measurments stand. You had me all exited there for a moment - I was hoping it was a mistake.

What is the stock size?

Wheel and offset sizes can be confusing. It helps to think of the offset in terms of where the middle of the wheel/tire will be.

Consider that no matter what size your wheel is, the center will always be in the same place unless the offset is changed. A 12" wide +40 wheel will have a center that is 40mm from the hub. So will a 8" wheel or a 2" wheel.

Because the tire is centered on the wheel, wheel size is irrelivant. The new tire will have the same center line as the old - unless the offset is changed. Then, it corresponds in absolute measure.

Just picture the tire growing in each direction, then shift it Xmm. The tire is centered on the wheel. Everything takes place from the center line. So measuring from the tread will give an acurate measure. Xmm wider and kick it over Ymm. That is where your new tread edge will be.

Have I managed to explain this effectivly yet?

[Edub1]

The width and offset are completely independant. The offset is the distance from the center of the rim to the hub. A +40 mounts 40mm from center regardless of width. Calculate from the center and you will see what I mean.

As for being square, I'm planning on running a normal setup, 225/45/17 or 235/45/17 with +35 offset on a 8" rim.

A 235/45/17 with a +35 should clear. I don't think it will with a +25

A 225/45/17 with a +25 should just clear as well.

[nismofly]

you do have 205/65/15?

stock are 205/60/15

all your measurements are probably an inch off or more, hard to tell without the right tire sizes

theres our mistake