tire size issues

[reegs01]

i have a 71 240z lowered about a inch and i have on it now 245/60/14 all around the front tires rub . i need to put a different set of tires on the front that wont rub and give me maximum height because i have clearence issues with my exhaust .will 205/75/14 or 195/75/14 work

[zguitar71]

The 205/75 will work but they will be sloppy handeling. If you can afford to switch to a larger diameter wheel like a 15 (205/60) or 16 (205/55).

[=Enigma=]

How about just getting a better tuck job on the exhaust?

[Arne]

The 245/60-14 size you now have is already two sizes taller than stock, and much wider. The normal 60 series equivalent to the stock 175SR14 is/was 225/60-14 on a 7" wheel.

What tire size you should now consider depends on where and when the tire rubs. If it rubs when turning, you might get away with a narrower tire. In this case try a 215/70-14 which should be close to the same height as you have now.

If it rubs when you hit a bump while driving straight, then the tire is already too tall. In that case, you're hosed. Either raise the car back up, or change the exhaust.

[reegs01]

thanks ill check into that tire size , it only rubs when i turn .the exhaust cost too much to replace id rather get new tires , or change my springs .but i need new tires any way

[EScanlon]

Be careful of major shifts in tire sizes though.

If you get them too wide, you may find that the front end rolls around ok....until you go for a hard curve while going downhill, and then the tire contacts the lower front valance. This occurs from the flexing of the tire. More often than not, however, the problem is when you are backing up OUT of your slightly inclined driveway and the tire now grabs the valance and folds it.

This is a common problem due to the curve of the valance AND it's proximity to the tire. I've seen guys with as little as 1/4" of clearance while stopped...you do the math. There are things you can do to reduce this, all of them involve playing with the alignment of the fenders to the hood, sugarscoops, bumper etc, but that would take hours to explain out properly.

In the meantime, I found this formula for determining actual tire dimensions at www.tirerack.com (don't know whom to credit) :

Width x Aspect Ratio = Section Height

Section Height x 2 = Combined Section Height

Combined Section Height + Wheel Diameter = Tire Diameter

The example they give: 185/60R 14 85H or 185/60HR14

185mm x .60 = 111mm

111mm x 2.0 = 222mm

222mm + 355.6mm(14") = 577.6mm or 22.74"

Now, with a little bit of playing you can sit in your driveway and find out what your max tire size is, or at least get a good idea.

I went to the tirerack and punched in a 71 with the example rating, and here are their 30 picks for tires.

http://www.tirerack.com/tires/Compare1.jsp?width=185%2F&ratio=60&diameter=14&vehicleSearch=true&startIndex=0&search=true&pagelen=20&pagenum=1&pagemark=1&speed_rating=SR&speed_rating=TR&speed_rating=UR&speed_rating=HR&speed_rating=VR&speed_rating=ZR&speed_rating=WR&speed_rating=YR&RunFlat=All&x=75&y=7

FWIW

E

[RB30DE240Z]

215 65 14 with P10 would be my choice.

Alternativly, run 225 50 16 with P5, no worries then.

[romeo_30906]

on the stock 14 in rims run 235 60 14ther wide enough looks wise but dont scrub and that is tha i have a custom front bumber and i can clear it also

[funz1z]

here is a link to a good tire calculator

http://gs.tolan-hoechst.com/tirecalc.htm

We are trying to determine what size tires to install on our stock 71 240 with 14" wheels.

[Arne]

here is a link to a good tire calculator

http://gs.tolan-hoechst.com/tirecalc.htm

We are trying to determine what size tires to install on our stock 71 240 with 14" wheels.

Toni, since I have seen your car (and it's wheels) in person, and also because I have almost 25 years of tire selling experience behind me (prior career), I can probably help. What is it that you want in new tires? Stock height? How wide?

[zztom]

I have 205/70r14 with stock height springs installed this month on my 71Z.

[ZSaint]

Arne is the guy to talk to on these tire issues. He identified my spare by looking at the tread in a pic. Wow. These old guys really know their stuff!