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Discussion Starter · #1 ·
OK. I like most of us would like to upgrade my rims and tires.

Now I got 215/60R15 on all four corners, on original 15/7" Turbo rim with 0 offset. This package woiuld be 25.20" in diameter. I would like to move on to:

Rear: 245/50R16 Diameter=25.59" Widht=9.61
Front: 225/55R16 Diameter=25.67' Width=9.06

For both sizes they recomend 6-9.5" rim. Whorever I think If I just get 16/7" rim it might be a bit too tight for a tire. So, I was thinking towards 16/8" combo.

So, what do you think offset would become then? Any ideas about this topic all together? Throw me a bone here, been wrestling with this issue on/off for a long time now.

Hope together we can figure it out.

BTW. Tires I want are 460 NITTO.

Thanks

Eugene '83ZXT
 

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Discussion Starter · #2 ·
<b>RE: Lets do some wheel math.</b>

Z's are a bitch to find decent wheels for . I beat this subject to death a while ago, and found these conclusions .
1) do not go much over 3.5" backspacing 7/2=3.5 to centerline 0" offset gives you 3.5" backspacing .
2) 8 inch rims are too wide for a stock ZX 8/2=4" to centerline 0" offset gives you 4" backspacing too much it will hit on your spring perch if you try and go more -ve offset the tire will rub on the fender lip.
3) I would get the 225 all around with 16x7 0 offset, the 245's may fit but might rub dunno .

Euguene do you have your webpage going it showed real promise, and it was focused on performance . I really liked it
 

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Discussion Starter · #3 ·
RE: Lets do some wheel math.

Cant speak for the offset, but as far as width goes, I had 235/60 14s on my 72 and they rubbed the fender lip on the back. Fit ok on front though, just looked stupid with 235/60 front and 215/60 back, so I bought 2 new 215s.
 

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Discussion Starter · #4 ·
<b>Do not care for fender lip. (More)</b>

I really do not. I wanted to go flared anyhow.

Clint - my I dea was kinda same. If I go wider wheel then offset needs to be changed towards negative side. Right?
But how far? Maybe, since I want to put flares up anyways, I can go even wider than 245. 265 Maybe?
Did you ever find a compaly who is making/selling NICE Z rims? What other cars have similar to Zs offsets, may be it would be easier to find a rim for those cars and reuse it on Z?

Thanks to all.

Eugene

PS. Site is going little by little. Lots of work, and very little satisfaction. Instead of dozens e-mails with bunch of info and pics I would be lucky to get 5-7. Plus most unfortunte crush wiped my PC out of those e-mails. But, regardless of everything I am still working on it. I do not want to open a site with nothing on it. And it is kinda not that easy to gather info. But!!!!!! Links section is done, and I am working on article part of the site. Wiht gods help we all MIGHT see site up and shining some time towards our main holiday.

THanks for your interest.

Eugene
 

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For Eugene

Eugene,
The geometries between the 280Z & ZX are close but still a bit different. I know from first hand experience that the widest tire you can run in the back with 0 offset (3.5" backspacing on a 7" wheel) is a 225. If you flare the fender you can start adding tire and wheel width. You'll still need to stay with the 3.5", maybe 3 5/8", to keep the wheel/tire out of the suspension. That means a 1" flare would get you to 245, a 2" flare might get you to 275. The problem at this point is that your either have to stick with 225's in the front or deal with handling problems if you flare the fronts too and go with significantly wider wheels that extend well beyond the hub. Z's tend to get darty when this is done. My 77 had 6" rims with a 2.5" back spacing for a while and it's handling suffered and I had to do a lot of front suspension fixes to eliminate some resulting vibrations. I don't have that with the 16x7's with the 3.5" backspacing.
Phantom
 

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Discussion Starter · #6 ·
Nod Nod, Agree with Phantom...

I am running 225 60-14. Yokohama A509s. They look mean, and when put on a Z you really need flares unless you like cleaning road grime off you rockers. The response I have out of the tire is WONDERFUL. As it is I have more tire on the road than the car needs. Unless you plan on drag-racing you might not need anything larger. And if you need more stick, for the same (sometimes less) price you would get a 245 you could get a better compound 225. As for your brand tire choice, you should look at Yokohama. C&D, Consumer Reports, and HUNDREDS of SCCA people will attest that you can't get a better bang for you buck than Yoks. You will find that one brand or another will beat Yokohama in 1 out of 10 categories. Enough rambling, don't take my word for it, go check it out. There are lots of tire reports in C&D and CR.

Sorry for the long post...
Bean Bandit
280ZTR
 

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Discussion Starter · #7 ·
wheel sources

If you are going to use flares, I agree with Phantom,
3 1/2 or 3 5/8 inch backspacing. You can try these custom wheel makers, in order of price:
Centerline
Billet Specialties
Colorado Customs.
All make custom wheels for any application. If you want some ideas, just pick up a Truckin' or Sport Truck magazine and check out their ads.
Unfortunately, trucks are about the only vehicles aren't positive offset, so their aftermarket companies are the place to look first. They do have some really cool designs however. (I have a 97 Blazer with 17" Boyds ((no longer in bus.)) and 275/40 235/45 tires)
 

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Discussion Starter · #8 ·
<b>RE: backspacing correction</b>

Wheel width is measured between the inside edges of the bead. Backspacing is measured from the outside of the bead to the inside face of the mounting flange. IOW, a 7" wide wheel will be a total of 8" from outside bead to outside bead. Thus with a '0' offset it will have a 4" backspacing.

A 16x7 w/'0' offset will work well with a 225x50-16 tire (slight fender trimming required). A 16x8 with 1" positive offset (5" backspacing) work in the rear with a 245x45-16 tire.

this is all on a '70 to '78 z-car.

Rrc X
 

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Discussion Starter · #9 ·
<b>RE: backspacing correction</b>

True yes I did have all this sorted out before,my brain must have forgot sorry there is enough confusion on this subject without me adding to it . Postive offset is tucked under the car and negative is sticking out from the car . Good luck BTW Eugene I will be doing my turbo transplant and writeup with a T3/T4OE-57mm turbo and intercooler in my 78z . I want you webpage to be the one to have it first, that should spike some intrest in the site and get people going .
 
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