Fatty Tires Question: putting a 265 on a 9" rim?

[archaeic_bloke]

Hey,

Been doing some thinking again... wondering all your opinions on this:

car is a 91 GTR. heres the setup on the wheels at the moment:
Rear: 18" x 9.5" SSR Type-C RS with 265/35 Bridgestone Potenza RE-01R
Front: 18" x 9" SSR Type-C RS with 235/40 Bridgestone Potenza RE-01R

Before someone jumps on it, yes the rolling diameter of the 2 front to back are within less than 1% difference, so this setup does not cause ATTESA issues.

Anyone ever fit a 265/35 on a 9" rim?... would you guys recommend it?

see, my thought is that it will be very buldged out the sides over the rim, but this might be a good thing because a little more cushion and flex in the front tires, when inflated to like 28 PSI for trackdays, might be a good thing, as it would increase the contact patch relative to the rear tires, which would help grip and control more.


From google searches the most common answer is it depends on brand of tire, but it has been done often. I just wonder specifically with the AWD and the GTR setup, how do you figure it will behave with 4 tires at 265/35 but the rims being different 9.0" Vs. 9.5" rear.... follow?

[Bignoga]

As for bulge, I use 255 all around on R33 gtr wheels which are 9 inchs and it could easily fit a 265 or 275

[doc]

on my 300c i have 265/30/22 on a 22x9 rim
here is a link to pics of it

http://www.300cforumz.com/showthread.php?t=78766

i know its not the same type of rim or overall size but its a 9 inch rim with a 265 nitto invo tire

[cobrAA]

yeah I was told I could go up to 275 with a 9 inch rims. but now do you think you will be able to fit that size without having to roll the fender ?

[archaeic_bloke]

yeah I was told I could go up to 275 with a 9 inch rims. but now do you think you will be able to fit that size without having to roll the fender ?

See thats 1 of the 2 things concerning me: right now with 235/40 I don't rub, but just barely, on a hard corner or a bump it may rub a tiny little bit... I'm not at all keen on rolling my fenders lol.

so, what do you think about the difference in handling/stability?

[frankiman]

theres no problem fitting a 265 on a 9" rim
eck, i'm putting 275s on my 9" rims

the racing guys even put 275s on 8" rims

its no different then running 225s on 9" rims

on the track you actually want less flex from the sidewalls, so there is less overall deflection from all the steering components

when stretching tires, outward or inward, you limit the ability of the sidewall to flex further more


your wheel offset and ride height will determine if/how much fender rolling / pulling you'll need

the rear fenders are easy to roll, not so fun to pull,
but to roll and/or pull the front fenders you'll have to sacrifice the inner-fenders

[archaeic_bloke]

Frank whats your front alignment settings? and ride height?... will you be pulling/rolling your front fenders to fit the 275's?

Hey wait... I could probably test fit the 265's by swapping my rear set onto my fronts couldn't I? the rim the tire is on doesnt make a huge difference for where the tire sits relative to the body as long as offset is the same right?

[cobrAA]

I have 245 and I'm not rubbing but it also depends how low your sky is. I want to sell my rims so i can buy my new rims. however they only comes in 18. so I was thinking 255-265 but I'm sure they will rob after the drop and wider tires so maybe I will just stick to 245-18.

No way I will be rolling my fender

[frankiman]

Frank whats your front alignment settings? and ride height?... will you be pulling/rolling your front fenders to fit the 275's?

Hey wait... I could probably test fit the 265's by swapping my rear set onto my fronts couldn't I? the rim the tire is on doesnt make a huge difference for where the tire sits relative to the body as long as offset is the same right?

if the offset is the same, the center of the tire will be the same, so yeah theres no problem test fitting your rear pair


my alignment right now is;

FRONT;
caster 7,5deg
camber -2,1deg
toe 0.0

REAR;
camber -1,6deg
toe 0.2 in

ride height i not too low

this is how it sat with 255s with +13 offset front and rear

rear fenders have been rolled already





not looking to take the front fender liners off, so if it doesnt fit i'll just raise the car a bit

function > form

[archaeic_bloke]

hrmmm... 255 @ + 13 offset, I think the -2.1 camber up front helps u a lot! how the Eff did u dial up so much negative camber frank? My fronts are -1.6 and they are maxed out.

like both frank and cobraa said, I guess if it rubs I could raise the car up a little bit.
ok when i get home later on I'll jack the car up and swap rears to front and see hwo 265 +20 fits on the front. will snap some photos for those who are interested

[gtrjon]

hrmmm... 255 @ + 13 offset, I think the -2.1 camber up front helps u a lot! how the Eff did u dial up so much negative camber frank? My fronts are -1.6 and they are maxed out.


like both frank and cobraa said, I guess if it rubs I could raise the car up a little bit.
ok when i get home later on I'll jack the car up and swap rears to front and see hwo 265 +20 fits on the front. will snap some photos for those who are interested

id like to see some photos. im running 18 x 9.5 +22 all around and i was thinking of running 265s all around :s

[frankiman]

hrmmm... 255 @ + 13 offset, I think the -2.1 camber up front helps u a lot! how the Eff did u dial up so much negative camber frank? My fronts are -1.6 and they are maxed out.

like both frank and cobraa said, I guess if it rubs I could raise the car up a little bit.
ok when i get home later on I'll jack the car up and swap rears to front and see hwo 265 +20 fits on the front. will snap some photos for those who are interested

not sure why yours are maxed, i can still go to ~ -2,8 with mine
maybe because of the roll center adjusters?

and i'd like to see pics yes!

[DJ]

I had 17x9's with 275/40/17 and it rubbed the inner lip on the rear when going over bump or taking hard turns! I liked it much better with the 255!

[cobrAA]

Thanks DJ.. but how about the front? what was your spec? 275 too?

I want to see pictures too because I'M about to order tires and I'm thinking between 255-275

[DJ]

all around.