I have two questions....

well first off my car got keyed so my rim money or about a thousand of it is out the window... so now im left with about a thousand and some bad rims cause they also were destroyed... they're still in good enough shape to be powdercoated though but there only 17's so my questions are will a 245 size tire fit on the back rims instead of the standard 235's and how big of a diffrence will the 275's make cause i was gonna originally get the nismo's before this incident... what im thinking of doing is powdercoating my rims black and putting as big a tire i can fit to gain some performance till i save another grand back up... just dont wanna look like garbage driving around... any ideas ... i got about 1500 right now....


also how much do the stock 17's and 18's weigh???

 

I have stock 17" and I'm running 235/45/17 fronts and 275/40/17 rears. I put these on when I got the car and have attended 6 different HPDE over the summer with no problems. Weigth for the 17"s is about 25 lbs ea. (rims.)

 

how does ur Z look with tires that wide on the back???

 

Clyde

Be glad your car doesn't have VDC, it would not like what you've done. Also, you have upset the handling setup that Nissan wanted us to have. You have upset the factory built in stagger, as your front and rear tire outside diameters are now the same. Your front diameter is OK, but your rear is about an inch to small. Unless you've lowered the car, you gap in the rear should be quite large

In addition, you should have severe tire buldge. the 275/40 tire is ment to be run on a 9.5" wide rim, not an 8" rim. The rim width range is from 9" to 11". What you're doing is unsafe.

Lou

 

Ditto, tire manufactures would highly recommend AGAINST that. They have specs for a reason.

 

When choosing this setup I purposely checked stock setting and came as close as possible to matching them with the set up I'm running.

note:

stock (225/50 f 235/50 r) Width .39 dif , Side wall height .20, Overall height .39, and circumference 1.24

my setup (235/45 f 275/40 r) width 1.57, sidewall height .17, overall height .33, circumference 1.05.

Yes I have VDC and you'll notice I'm well within a 1/2" spread of the measurements that affect VDC.

Yes, I hve lowered the car by about 3/4" with JIC a2's.

 

What "Z" comes with 17" wheels and VDC? The front's are now 25.7" vs a stock 25.9" Outer diameter - No problem. The rears are now 25.7" vs a stock 26.3". This is is a problem. The front's and rear's are the same, no stagger. On 18" wheeled cars, the rears are 26.7", not sure why the smaller diamerer on 17s. However, you want to maintain the stagger, you haven't.

As stated above, the bigger problem is severe tire buldge on the rear wheel/tire combo, you are flirting with danger here.

Lou

 

I disagree with the danger aspect.

I do agree that the setup is sub-optimal, but evey competitive AutoXer runs outside of MFG specs, and on all types of cars.

I am personally running 265's on 8" rims, and I know other members are running 275's on 7.5" rims. I've never had a problem on the course, or on the road to and from an event.

I do agree that the VDC issue may arise (if it is actually present on the car), although again, I have the same size tires all around for racing - 265/35-18, and have not had a problem with VDC on the way to or from an event.

Anyhow, as far as the original question goes, I would just go with 245's or the stock 235's on the back in order to keep the handling as neutral as possible. Adding a wide tire in back may look cool, but it may also make the car understeer even more than it already does in the stock form (plus you wouldn't need to worry about any potential safety concerns, no matter how slight they might be). I'd think hard about putting on 275's.

-D'oh!