View Single Post
Old 02-01-2012, 02:16 AM   #1 (permalink)
phunk
A True Z Fanatic
 
Join Date: Mar 2009
Location: Chicago
Posts: 3,657
Drives: 370
Rep Power: 947878
phunk has a reputation beyond reputephunk has a reputation beyond reputephunk has a reputation beyond reputephunk has a reputation beyond reputephunk has a reputation beyond reputephunk has a reputation beyond reputephunk has a reputation beyond reputephunk has a reputation beyond reputephunk has a reputation beyond reputephunk has a reputation beyond reputephunk has a reputation beyond repute
Default New front tire fail on my part

Just installed new tires. I screwed up. Here is the relevant specs and information about how I went wrong. Probably more than anyone wants to read but I'm putting it together for myself to make a decision anyway, so I'm posting it too!

Front Sport Tire Diameter: 26.8"
Rear Sport Tire Diameter: 26.5"

The car is lowered on H&R springs. I had not yet touched the alignment after lowering when....

Last year I installed TE37SL and RE11.
Front Wheel: 19 x 9.5 @ +22
Rear Wheel: 19 x 11 @ +23
Front Tire: 275/30/19
Front Diameter: 25.6"
Front Tread Width: 10.1"
Rear Tire: 305/30/19
Rear Diameter: 26.3"
Rear Tread Width: 11.1"

Notes:*
This setup changed the F/R diameter ratio a lot. VDC self adjusted after a few blocks and then performed flawlessly. I did this because for one, I wanted a 275 and the RE11 didn't come in a taller 275. I figured this would look better anyway because I am just used to a slightly shorter front like a 350z has. I am not sure why the 370 has a taller front. In retrospect, this shorter diameter did not fill the wheel wells quite enough and the front end lowered a bit and scraped more. The front looked like it could use just a little spacing and I ordered spacers but did not install yet.

As for the rear, it needed spacers ASAP. I put 15mm back there and it looked great.

My car is twin turbo and I was getting tired of poor traction. I added SPC rear camber arms and toe bolts and got the car aligned to take out some rear camber and get the toe near stock. Rear tires got closer to the fenders, but still no rubbing/contact. All was well.

Next:
Rear tires quickly became bald from spinning all the time. So I knew I had to buy new rears before spring. Winter has been real soft in Chicago this year. A month ago I took the Z out for a spin. Before I left I checked the tire pressures, all was good even after the car had been sitting for a month or more.

30 min later I had a flat, drivers front. Turns out the o-ring in the Volk valve stem cap came half out when I took it off to check pressures and I did not notice. When I reinstalled the cap, the o-ring was pressing the valve stem and letting air out rather quickly. When I was able to pull over after noticeable vibration and pulling, the tire was already cut around the inside sidewall. So now I needed new front tires too. So I ordered some.

Front Tire: Yokohama AD08; 275/35/19
Rear Tire: Toyo R888; 305/30/19
Front Diameter: 26.6"
Front Tread Width: 10.6"
Rear Diameter: 26.5"
Rear Tread Width: n/a, probably 11.6" or so.

Notes:
So I went to the Yoko in the front. Every comparison I found said its better than the RE11 (for grip, and that's all I care about), and it came in a taller 275 to get the diameter ratio back in spec and fill the wheel wells better... Yet it's only just barely taller than rear, so hopefully shouldn't look bad. The extra inch diameter should raise the front end .5" to more where it belongs so less scraping of the front lip. The tread width is .5" more than the last tire, but I was saying I needed spacers before, so the extra .25" on the outside should fit right.

NOPE: chuck testa. The front tires look massive (too tall, stupid looking) and rub on the slightest bump. The sidewalls do not protrude past the fender, they are pretty much flush. But they come in and nail the plastic lining and clips from minor dips in the road.

While Yoko has a 9.5" wide wheel as the measured specs for this tire, this tire belongs on a 10.0" inch wheel. It is too wide for 9.5", the sidewall has slight bulge. Ehh.

I am really surprised that this tire is rubbing with the rather conservative offset of the front wheels. I really thought I had more than enough room for this tire. The width, sure... Or the diameter, sure... But the increase on both was just too much.

Now I have to decide if I want to mod my front fenders to fit these things, or eat the $700 I spent on them and get them in the 265/35/19 that I should have got!
__________________
Charles @ CJ Motorsports : Website | Facebook | Instagram | YouTube
Home of the 9 second, stock longblock, stock drivetrain 6MT 370z. 9.91 @ 142mph
phunk is offline   Reply With Quote