DrewGS4

I will be ordering up some new tires for my 18inch OZ Salina wheels.

Here is my question:
The current rims are Fronts: 18x8 and Rears are 18x9.5

I have the supra LSD in the rear so I am looking to get the maximum rubber in the rear without loosing performance.

My current tires on the rims are 235/40/18 and 265/35/18. I really like how I can now slide the car around a turn and break the car loose predictably. The tires are pilots and there is really no thread left on them.

I was thinking of going to 245/40/18 and 275/35/18. Do you think a taller tire might be better considering the LSD. The supra turbo has a recommended tire size of 255/40 in rear. I am trying to get the right combination for the supra LSD and tire size. I was thinking of going a bit taller in the rear say even 275/40/18 to match the supra specs. From searching the old forums I found only 2 people running this setup in the rear (jacobt and captain bone) This will increase the height of the overall tire by 1.3 inches from the current setup. It would give me a slightly better ride and more rubber in the rear which looks better and helps in traction. What does everyone think.
Should I stay with the 275/35/18 or opt for the 275/40/18??

RMMGS4

iTrader: (5)

Drew,
a higher profile is helpful in straight line traction. Going up to a 275 tire might help, but because your rim width is narrow, the tire will tend to bow in the middle during hard acceleration, meaning that the outer tread is not in full contact with the surface. Even with my 285/30-19 set up and 19x 10 rims, and now that I have done my share of 0 - 60 launches, it is apparent that the center of the tire has worn out much more than the sides. If I did normal driving (no burn outs), I believe the wear would have been even across the tread. In your case, I'm not saying the 275 wouldn't help, but it's not probably going to contribute as much as if you had a 10 or 10.5 in. wide rim. A 285 is probably not recommended.

Since you have worn down your current tires, how does the wear look on the rears, even? If you have done a lot of drifting / burn outs and are getting even wear, I'd say your set up is ideal, so going only 10mm wider might not be worth much.

That said I would factor in tire diameter more and how the width and profile selecion will affect that. Our cars have different mods and power, so your decision on increasing diameter has to factor what you are experiencing. In my case, I feel the power I have is not getting to the ground. My launch rpm on my NorCal slippery dragstrip is a very low 1200 rpm. Beyond that I am just spinning tires standing still. So in my case I feel I have too much gear. Adding more gear will make this worse, so shortening the final drive ratio by adding a taller tire is probably going to be something worth trying.

I am ordering my 295/25-20 rear tires TODAY. So this will be wider, taller and the Michelin PS2 will be stickier. I hope to report some 0- 60 times by the end of next month (wheather permitting).

Last note, we can talk tire size all day long, but unless one is using the stickiest tire available, it's useless discussion. Selecting a decent tire brand is important. Example: Selecting Bridgestone SO3's is going to be a significant factor compared to using Kuhmo All-season tires. No matter how wide the Kumho's are, they won't beat the SO3's.

It's sounds like you are already using a decent brand tire. I'd suggest the PS2's as a worthy replacement and either a 265 or 275- 40 tire size.

My usual disclaimer: I 'm not considering drag radials or slicks in my response, since my discussion here is for a street tire that has treadwear better than 500 miles.

rominl

iTrader: (4)

hey drew,

personally i would do 245 and 275 for sure. you want wider tires for the rear as much as you can. for 9.5 i think 275 is perfect

285 would be too wide imho

flossn

I would agree that 275's are just fine for a 9.5 rim. Back in my Mustang days, everyone was (and probably still is) running 275/40's radials on the 17x9 Cobra R rims. I'm sure 285's would work too, but I don't know if you care about trying to keep close to the stock diameter. Of course if you did want a drag radial, Nitto makes a 285 that would probably fit more like a 275 (they are sized a little high).

Now hurry up and get something ordered so we can see some pics

FutureGS400

Drew, I am running 285/35 18 Goodyear GS-D3 on the rear and it works great! With my offset (45 I think) on a 9.5 inch rim there is NO rubbing at all and it does help with traction somewhat. This tire fits on the rim just fine-it is not really that much wider than a 275. I had my old 275 next to the new 285 and there was VERY little difference. Slightly wider of course, and slightly taller too.
I have wondered how a "fat" setup in 19" would work to gain the extra height and a 285 section width tire. I would be interested in hearing how your proposed "fat" 18 setup works out!

RMMGS4

iTrader: (5)

Yes Drew, do post some 0-60 times. We can all talk what we "think" helps, but the numbers won't lie.

I just spoke to Brandon @ TireRack today and he said my tires will be in this Thursday.

I'll definitely be posting my launch times in the next few weeks. (Wheather permitting)

redgs4

Arghhhh, I suppose I should get around to ordering my tires.

redgs4

As for the best tires on 18's, I have been running 18/275/35 myself - first Bridgestone S03 and now the Goodyear GS-D3. I think the increase to a 40 series in the rear would help but IMO the brand and type of tire is probably a bigger impact. Face it, short of re-calibrating the traction control you will likely have to get by on better technique.

rominl

iTrader: (4)

few weeks? you ordered your wheels already?

DrewGS4

Thanks for all the advice and suggestions:

I think I will order up the 275/35 rears on my car. I am going to go with toyo T1-s. I am getting a fantastic deal on the tires so I couldn't refuse.

My car orginally came with 16 inch tires. Replaced them to 245/45/17 all the way around. With the addition of LSD and TC these tires equipped with GS-D3 were not sufficient. WIth the TC alone this would of been okay setup. When you throw the LSD into the mix the car behaved very differently on launches.
My best 0-60mph launch with TC and SRT intake alone was 5.38 seconds
I was convinced that I would be able to get better times when I put in the LSD. I was wrong and my times actually dropped down to 5.8-5.9seconds. With the LSD installed the rear of the car would shake when I accelerated from a stop. This was really evident when I turned from a stop.
My conclusion was the change in gearing from LSD and my rear tire sizes where not matched to right ratio to effectively utilize the LSD. So thanks to Neo, I was able to get these newer L-tuned rims with the staggered setup.

What a Bitc* to change tires when the car is lowered with body kit. I was only able to swap out the rear tires. Currently, the car is running the 17inch up front and the 18inch rears in the back. Oh, I had the 25mm spaceres in the rear as well on my 17inch setup. Had to remove those to intall the 18's. Once the swap was done, I could instantly feel the difference in launch. The car did not shake as much but the rear tires would spin much easier, because of the fact they really did not have much tread to begin with. Hoping the T1-s will solve that issue.
The current rear tire size is 265-35-18. I think the 275-35 would be a good combo and a better suited tire to get the max bang out of the LSD. If I went 275-40 or 285-35 in the rears these sizes would be a bit to big.

Hoping to get all rims and new tires installed by next weeks time. It really looks funny driving with L-tuned rims in the rear and my 5-spoke 17inch tire up front.

Neo

iTrader: (3)

Well, you already know my suggestions.