370z MEATY TIRE THREAD

[cjr1881]

Originally Posted by One_Quick_Z

Here are my new tires fresh as of today! 255/35-295/30 Yokohama AD08's these are very sticky! Its just my car looks like it needs to be lowered again....














DAN

You got the wrong size profile tires and screwed up your gearing and speedometer, you think lowering it will fix that? lol
ha

[daisuke149]

Originally Posted by cjr1881

You got the wrong size profile tires and screwed up your gearing and speedometer, you think lowering it will fix that? lol
ha

did he say lowering would fix that? he wants to lower it for the look..

good comment tho...

[Nissanboy]

Originally Posted by cjr1881

You got the wrong size profile tires and screwed up your gearing and speedometer, you think lowering it will fix that? lol
ha

wrong size? that's like a perfect combo, both side walls from front to back are about the same size.
and please enlighten me on how it will screw up the gearing, didn't know tires changed your gear ratio

[Boost_lee]

lol I think he meant effective gear ratio. Now that, tire size does come into play a bit. With the shorter tire on the 295/30, gears will be shorter, granted not by much.

Top of 4th on the 275/35 is 126.44mph
Top of 4th on the 295/30 is 123.53mph

[simota1]

hey guys.... i need a lil help.... i want to run a hella meaty tire set up on my z.... my rims right now are
*VOLK RACING GT-F RIMS
19x9.5 front +16
19x10.5 rear +24

i have a 20mm spacer in the rear... so technically wats the fattest tire i can fit on my car? for both front and the rear.... thanks guys...

[cjr1881]

Originally Posted by Nissanboy

wrong size? that's like a perfect combo, both side walls from front to back are about the same size.
and please enlighten me on how it will screw up the gearing, didn't know tires changed your gear ratio

You need to keep the total circumference of the tire the same or you will change your gearing. He has effectively shortened his gearing and will now take more rpms to achieve the same speed. The profiles for 19" tires on the 370Z should be front/40/19 rear/35/19. His are F/35/19 R/30/19 . When his speedometer says he is doing 60mph, he will actually be doing about 50mph. 17-18% off. I can't believe how many cars I see with the wrong profile tires. People are obviously oblivious to the fact that they are not just changing how the tire looks. If you plus size you need to change aspects accordingly, and if you keep same wheel size then you must keep same aspect or you will be changing gearing and your speedometer.

[FortuneLSX-TT]

Originally Posted by cjr1881

You need to keep the total circumference of the tire the same or you will change your gearing. He has effectively shortened his gearing and will now take more rpms to achieve the same speed. The profiles for 19" tires on the 370Z should be front/40/19 rear/35/19. His are F/35/19 R/30/19 . When his speedometer says he is doing 60mph, he will actually be doing about 50mph. 17-18% off. I can't believe how many cars I see with the wrong profile tires. People are obviously oblivious to the fact that they are not just changing how the tire looks. If you plus size you need to change aspects accordingly, and if you keep same wheel size then you must keep same aspect or you will be changing gearing and your speedometer.

Considering that the overall diameter of the 275/40/19 was 26.5 inches and the overall diameter of the 295/35/19 is 26 inches... not as noticeable as you're claiming

The front 245/40's was 26.7 and the 255/35's are 26.1, a bit more than the rears, but still not as noticeable as you claim.

Don't forget that while he did decrease the aspect ratio he also increased the width, which makes the change to overall diameter not as dramatic.

Also, just out of curiosity what size tire do you think he should have changed to? There aren't exactly a ton of options for changing tire size to a wider tire while maintaining the exact same overall diameter. It's only going to be "close".

And to keep the thread on track... here are some shots of my "meaty" tires
285/35/19's ... up FRONT and 305/30/19's in the rear

[Ron]

Originally Posted by cjr1881

You need to keep the total circumference of the tire the same or you will change your gearing. He has effectively shortened his gearing and will now take more rpms to achieve the same speed. The profiles for 19" tires on the 370Z should be front/40/19 rear/35/19. His are F/35/19 R/30/19 . When his speedometer says he is doing 60mph, he will actually be doing about 50mph. 17-18% off. I can't believe how many cars I see with the wrong profile tires. People are obviously oblivious to the fact that they are not just changing how the tire looks. If you plus size you need to change aspects accordingly, and if you keep same wheel size then you must keep same aspect or you will be changing gearing and your speedometer.

so u are saying that no matter how wide said 19'' tires are you should always go with 40 front and 35 rear for side profile?? You do know that those numbers are directly proportional to the tire's width, right?

305/30/19 means sidewall is 30% of 305mm.
285/35/19 means sidewall is 35% of 285mm... etc etc

[cjr1881]

yeah, you're right. I plugged in the wrong numbers (only like -3%), but still... I would never go less. Your tires are a much better fit. I'm getting some meaty tires soon and I'll have some pics up. 20" Toyo R888 285/315

[KaienZ34]

Tire Tech Information - Calculating Approximate Tire Dimensions

[daisuke149]

Originally Posted by cjr1881

yeah, you're right. I plugged in the wrong numbers (only like -3%), but still... I would never go less. Your tires are a much better fit. I'm getting some meaty tires soon and I'll have some pics up. 20" Toyo R888 285/315

based on your previous comments..

a 315/25/20 is smaller than OEM and so by your own words you shouldnt. but I think the r888 comes in 315/30/20 which would be taller than OEM.
a 285/30/20 for fronts is about perfect to oem though

[KaienZ34]

Originally Posted by cjr1881

yeah, you're right. I plugged in the wrong numbers (only like -3%), but still... I would never go less. Your tires are a much better fit. I'm getting some meaty tires soon and I'll have some pics up. 20" Toyo R888 285/315

The real question is what profile will you be running??

[daisuke149]

actually hes runnig 285/35/20 and 315/30/20 which are taller than OEM front and back... no bueno.

[W.O.W. 370Z]

Good lord tall tires

Sent from my SPH-D710 using Tapatalk

[cjr1881]

Originally Posted by daisuke149

based on your previous comments..

a 315/25/20 is smaller than OEM and so by your own words you shouldnt. but I think the r888 comes in 315/30/20 which would be taller than OEM.
a 285/30/20 for fronts is about perfect to oem though

Yeah those are the only tire options in 20" and they are just fine. I would rather go taller than smaller with performance upgrades I want first gear to be useable. 285/35/20 315/30/20