Cold Dark Shadow

I have a set of 17x7 40+ offset wheels
Can i use these on my 89 vert without spacers or anything or will i have issues?

If i can, then instead of sellin those ill sell of my vert wheels and replace them with the 17s

Brassmonkey

iTrader: (2)

I read the first dozen pages, and the last few, and I didnt see an answer to my problem... So thanks for the help ahead of time, and dont get mad if its already been asked.

I have an 86' GX. I just got a set of 5-Zigen Copse rims, 17x7.5, with a +42 offset. I already know that its not ideal, but im wondering whats the biggest tire i can fit on the back?

They have 205's on them right now, but only 2 are good. So i want to leave the 2, 205's on the front, and then get something like 234, or (idealy) 245's on the back. Will either of these sizes fit???

Thanks again,

Dan

RacerXtreme7

iTrader: (2)

Got tired of reading through all this lol, but I did read across some misinformation. This is in reference to backspacing and wheel offset. Hers just some info and basics:


Backspacing is measured from across the outer most lip of a wheel perpendicular down to the wheels hub-mating surface were it bolts to your cars hub. Back spacing was developed so the average "Joe" could simply measure distances from his cars hub inwards to make sure the wheels he’s buying won't interfere with inner fenders or suspension parts. It’s primarily used in the US.

Offset is a measurement of off center of the wheel. If the wheels hub were it mates to the cars hub is exactly centered in the wheel, it has 0 offset. It can be positive or negative. Positive would be more of the wheel is toward the car, negative offset would be more of the wheel is outward, or further away from the car. Offset is generally given in mm. The conversion from inches to millimeters is simple. If it’s given in mm and you want inches, just divided by 25.4. Conversely if the measurement you have is in inches, multiply by 25.4 to get millimeter.

Now, a rims dimensions are NOT I repeat NOT overall rims dimensions. Go out and measure your 18" 's for yourself. You'll find that they are near 19" tall. Same for rim width, they'll typically be near an inch wider. This is because a rims dimensions are given for the rims seats were the tires beads sit.

Now, with all that being said, here are the mistakes I've seen a member or two of the forum give out as information. Taking backspace and simply subtracting half the wheels width will NOT give you offset. Here’s and example of incorrectly going from backspace to offset: 17X8 wheel. The backspace is 5.5 inches. Simply subtracting 4" (half of the wheels width would be center) equals 1.5". Then converting to mm would be 38.1mm (remember, " to mm you multiply by 25.4). I've seen members mistakenly use this method for offset when given a rim's backspacing and this DOES NOT WORK and it is INCORRECT. To find the proper offset of this wheel you will need to also know either the overall width or know how much lip there is from the bead seat to the outer most lip. It’s easier just to measure the overall width. Now lets exercise this again and make it simple. Lets say that your 17X8 wheel measures an even 9" wide and we'll keep the same backspacing of 5.5". Now, half of 9" is 4.5", subtract that from 5.5" and you get 1". You have a 1" positive offset wheel, but it’s normally given in millimeters, so multiply by 25.4 and you get a 25.4mm offset.

Hope this clears some stuff up, I didn't read all freakin 86 pages, so if someone else already cleared this up, Kudos to them and sorry for repeating info given. But in the 60 something odd pages I read, I kept seeing members (members who are veterans and praised too often) giving out the wrong info on this matters. BTW, kudos to those members who did give out the incorrect info because they still did help out MANY members with wheel offsets (though really on the low offset side).

Just some info on my ride, I have 18X9.5 35mm offset rears wrapped in a BFG KDWII in a 265/35/18 size with NO fitment issues at all. There is hardly ANY room between the wheel/tire and trailing arm. They do NOT stick out past the fenders at all with near 0 camber. Now as for the fronts, I have an 18X8 with a 38mm offset wrapped in the same BFG tires in a 235/40/18. The fronts require some modding to fit with such a high offset and a wide tire. I could have gone lower offset, but staying close to the factory offset is always better from a handling and engineering point. Too low of an offset and you get away from the engineering that went into the suspension and you can run into things like your wheels following grooves in the pavement, harder to steer at low speeds, the steering wheel being jerked out of your hands of bumps, more wear and tear on your bearing and suspension pieces etc. That and I HATE wheels sticking out of fenders. To make the front wheels work I used eccentric bolts (or commonly called "crash bolts") were the strut bolts to the hub/spindle assembly. Usually this is done to be able to dial in or out camber. So I dialed in positive camber (top of wheels tilted out) to gain clearance between the strut and wheel. Then I dialed back in negative camber using camber plates for handling.

~Mike................

RETed

7.0", +40 is the same as stock Turbo II 16" wheels.
They will fit no problem.


-Ted

Cold Dark Shadow

Sweet, Thanks

RETed

(blah blah blah)

(blah blah blah)

Dude, why don't you drop the bullshit and just use my name.

You come in here blasting me just to point out a fricken technicality.

Yes, you're right; I'm not going to deny that.

But I guess you miss all the other information of me giving out very conservative offsets which DOES NOT ******' MATTER ABOUT THE RIM PROFILE.

You can argue about "J" versus "JJ" versus "B" rim lip profiles, but we're talking maybe 1/4" extra clearance?
This is why I recommend a 7.0", +35 versus going with a 7.0", +40 or +42.
It doesn't fricken matter.

Now, usually, the rim is not what contacts the insides or the fender lip.
It's the fricken tire.
So unless you get really stupid with the offsets, it's usually the TIRE that contacts crap...unless you're running hipari, which I hate.


-Ted

RacerXtreme7

iTrader: (2)

HOLY FREAKIN SMOKES MAN!!! Dude, boy did I **** in your Cheerios. I in NO way used my post of the correct way to determine offset as an excuss to "blast you". I have nothing against you, infact I'm glad your part of the Rx-7 community. My post was for simply giving forum members the CORRECT way to determine offset by figuring it out for themselves or if they had backspacing info and wanted to convert it to offset. I in NO WAY BLASTED YOU. And for you to get so ******* defensive over someone else correcting you (and I didn't even mention your damn name) is just plain childish and OVERREACTING.


No I didn't miss that, infact, I believe I even gave out a "Kudos" for all the help you have given in my first post and this one. And..... My post was about BACKSPACING converting to offset, or determining offset of a wheel yourself with a tape measure/straight edge and math, NOT ABOUT WHAT SO AND SO RECOMMENDED FOR OFFSETS is wrong, but what a COUPLE of forum members made a mistake of determining offset using backspacing.


You’re kidding me right? 1/4" is a BIG FREAKIN deal to some people. It means it fits, or it doesn't fit. Spacers and fender pulling or rolling SUCKS and some people would rather NOT have to do that but still want the MAX tire/wheel width they can fit, or maybe they found a rim they like the looks of but the fitment is really close and its offsets are available to a limited few. That’s were this thread is useful (at least it was at one point, now someone has to go through 1,200 freakin post). 1/4" is insignificant right? 1/4" = 6.35mm yet YOU recommending a fitment only 5~7 millimeters different (17X7 35mm verses 17X7 40~42mm) is what you do to be sure the rim fits? A little hypocritical no?

Here’s a scenario and why I posted what I did: Joe blow sticks some 17X8.5 domestic wheels on his Rx with some 235/40/17 rubber and nothing rubs. All he knows is the wheels have a 5.75" backspacing, so unknowingly he uses the incorrect way to determine offset and post on here that he has a 17X8.5 wheel running a 235/40 and it has a 38.1 offset and it fits no problem with no rubbing what so ever. Well, some one reads this and thinks that this fitment works, so they go out and buy a 17X8.5 wheel with a 38 mm offset only to discover the **** runs into his spring perch. This is exactly WHY I posted this. The guy’s true offset should have been 25.4mm (granted his overall rim width is 9"). So when someone gives the RIGHT way to do things, don't let it seem as a personal attack on you. At least my post wasn’t a personal attack on you, so chill the **** out. You've gotten grumpy as hell over the last few years, dude relax.

"hipari" I don't know what this is, but I'll assume is when a dumbass runs a 235 on a 10" wheel for that "stretched" look. I agree, its stupid looking and dangerous, but that’s just my opinion.

~Mike.....................

heartofstone003

im looking at some wheels that are

F 16x7+50
R 16x8+50

with some spacers would they work? or too much of a hassle? thanks.

clubber

With spacers, yes they will work. The 8" +50's are going to need quite large spacers, like near an inch, and I wouldn't recommend it.

heartofstone003

alright thanks.

RETed

This is why information over the Internet should always be taken with a grain of salt.
I typically put disclaimers on my fitment recommendations, and if you want exacting specs then go visit a good wheel shop like Rishie at ARD.
The fronts on an FC is too damn tight for anything over 225 wide tires, and there are always people asking for the widest thing possible.
This is why I don't like recommending anything over 225...maybe 235 up front.
You're right - they still don't listen and insist stuffing 245 is a trivial matter.

This is why I need to put up my front fitment page soon, cause that should give everyone a better idea of what does and what doesn't work.
I currently have Tokico Illuminas with GC coilovers, and a set of GABs with stock-type replacement springs - this should cover most applications, short of all the numerous aftermarket coilover dampers (sorry, I don't have that kinda money to be testing fitments for ALL of those brands!).

Apologies for jumping on you like that.
You're right - my life is a bit on edge lately.
Right now, it's turning for the better.


-Ted

RacerXtreme7

iTrader: (2)

-Ted,

Glad things are turning for the better, no hard feelings. And yes, theres a lot of myths and miss information on the net. But theres also a wealth of knowledge, people just need to search and weed through the crap and decide for themselves whats legit or not. But there is a few that do try and clear things up for others. If it wasen't for this forum and other Rx-7 related ones, I would have never thought my 265 rear tires would have fit!! I mean it is freakin close both on the swing arm and no fender rolling with near 0 camber (I'll be dialing some neg. camber back in once I've gotten my suspension done). And Because of the forums, I knew my front fitmet would be close or not work. Luckily I have my little cheat for this and they fit. Another myth is coilovers in front adding clearance. I haven't yet had time to check this out, but all my wheel tire combos that come close in the front end always had issues with lower perch interferance. I now have TEIN flex coilovers but have yet to mount them (I'm currently replacing all the suspension bushings). The coil over spring on my TEINs is bigger diameter then the stock lower spring perch. So it looks as if coilovers give you LESS clearance then a stock/replacement type front strut. We'll see I guess, like I said I haven't had them mounted to the car yet nore taken the time to measure and compair coilovers against stock/replacement struts.

btw, found a typo in my last post "(granted his overall rim width is 9"). " I meant 9.5"

~Mike.............

Turbo23

iTrader: (4)

aight here we go. enkei rpf1s 17X9 +22, 17X10 +18 with a 5mm spacer in the front? Fronts have panspeed overfenders giving me about an inch in the front, and I can roll the rears if needed

RETed

9.0", +22 with a 5mm spacer makes for a 9.0", +17 effective offset.
That should work no problem, unless you get really crazy with a wide tire.

The rears could've gone another 1/4" to maybe even 1/2" inwards, but it should still fit with a little rolling.

Good luck!


-Ted

Turbo23

iTrader: (4)

is a 255 tire out of limits for the front? Or should i go with a 235?

yusoslo

OK guys here is a unique setup I would LOVE to run.

16x8.5" with offset +7

I know i need fenders I was hoping I could get away with +30mm from fenders and roll the rear fenders.

I am using hks coilovers so inner clearance should be ok.

RETed

I like how 255's look on a 9.0" wide rim.
Go for it!
This should still clear everything up front with the overfenders no problem.


-Ted

RETed

With the 30mm overfenders, it's going to be tight up front.
The rears should be okay...maybe a slight roll.
The problem with running such low low offsets is that it changes how the tire loading affects the suspension reaction.

This has nothing to do with inside clearance.

With the 8.5" width, I calculate a good offset of +25 to +27 up front.
You're like a hair under 1" off of ideal.
This means the inside clearance should be around 1"!


-Ted

yusoslo

so you think this will defintely have adverse effects on handling? This was will be auto-x and drifted.

r33

F 17x7J+5 and R 17x8+10

need fender rolled or spacer???

thanks

88t2romad

Im currently looking at 17x9 +35 (FRONT). If i go with a conservative (correct size for rim) tire size, can i get these to fit with no little to no mods?

RETed

It's hard to say...
All the Japan auto manufacturers have been going big offset so the outside edge of the tire lines up closer with the hub vertical plane.
There's gotta be something good about that.

I know huge "reverse offset" rims tend to kill wheel bearings cause of the weird loading.

I would say just try it and see how you like it?
You're only like 1" offset, so that's not too bad...


-Ted

RETed

Hmmmm...you're the guy that got his thread closed in the FC section...

Neither will work under stock fenders.
They will clear insides no problem, but they stick out too much.
Overfenders are required.


-Ted

RETed

No, a 9.0", +35 will not fit up front.
At the very least you need at least 1/2" of spacer to get it to clear up front.


-Ted

r33

thanks for your response.