One more tire question

[arabbit]

Okay actually two more tire questions, I need some advice before I order a set. I bought some Forgestar F14s, 19x10 up front and 19x11 rear. I need to order tires, and I was planning on getting a set of 285/30r19 for the front and 305/30r19 for the rear. However, the more I think about it, Im wondering if that is going to be too small of a tire height. What are the disadvantages to having a 30 height tire? Im worried that it will leave a stupid looking wheel gap because I am only lowered on T springs, will the difference between 30 height and 40 height be noticeable?

Second question: stock tires have a setup in which the fronts are 45 height and the rear are 40...is there a reason for that? Should I have the front tires have a taller height than the rears?

Im a wheel and tire noob so Im trying to find the best setup for my Boss, and advice would be appreciated. Bonus points for anyone with pics if they have a relavant setup. Thanks!

 

[Grant 302]

Aspect ratio doesn't 'determine' height'. For example I have Super Sports in 265/35-19 in the front and 295/30-19 in the back and they are the exact same height despite the different aspect ratio. I suggest looking up the specific tire diameters, until you get used to using the aspect ratio to figure out total tire height.

Off the cuff, I think the 285/35 would work better.

I hope you're fronts are less than the typical +42 offset for F14 19x10s, which may not clear the brakes.

Most stock tires, even with aspect ratios of 40 or 45 are between 26.9" and 27.2" or so. one exception is the 15' GT performance pack which has a 27.7" tall rear.

Hope that helps!

 

[Jabooh]

I have a 305/30/19 on 11" cf5v



Personally I think it looks weird. I will be doing a 325/30 next time.

I wish I got 20's, at least in the rear.

 

[arabbit]

Grant 302, thanks I did not know that.

Jabooh1, what makes it weird? The width or the aspect ratio? And are you lowered? It doesn't look too bad to me.

I wish I could just get 305/35r19 but that size doesn't exist yet

 

[Jabooh]

There is a decent gap. I am lowered on Steeda Boss springs.

Here is a better pic illuminating the gap.


Interestingly the GT350 (or R) CED with 305/35/19 I read. They might one day be available.

You can get a 325/30 which is about 0.5" taller diameter so it would fill 0.25" more of the gap.

 

[superhero]

I see what your saying. the tire / wheel combo looks small for the wheel well opening on the car. Your right about the 20's. It would fill the opening better. Bottom line is it still looks good.

 

[arabbit]

Yeah supposedly the 305/35r19 PSS are going to be released on June 15. But I don't have that much time to wait, and who knows how much they'll cost. I could go with 295/35 PSS but I wanted wider tires, that would miss the point. But im not sure 325s will fit.

 

[arabbit]

Well shiznit. Just played with a diameter calculator, I think I'm screwed. It said the stock diameter is 28". There is no tire made that can achieve that in the rear. The closest I can get is 295/35/19 for the rear, which is a 27.1 diameter. So basically I am going to go one size up for width on front and rear, and lose an inch of diameter. Should've bought 20s. How does everyone else with 19x10 and 19x11 do it?

 

[Grant 302]

Stock Boss diameters are 27.1" front and 26.9" rear.

 

[arabbit]

Ugh I just plugged the stock tire numbers into a diameter calculator. Is there another factor aside from width, aspect ratio, and wheel size that I'm supposed to input? Or is the diameter calculator I'm using wrong?

 

[VoodooBoss]

Ugh I just plugged the stock tire numbers into a diameter calculator. Is there another factor aside from width, aspect ratio, and wheel size that I'm supposed to input? Or is the diameter calculator I'm using wrong?

Post a link to what you're using. The stock sizes are:

255/40/19 F
285/35/19 R

 

[arabbit]

Nah I figured out what I was doing wrong! Thanks for correcting me. That's a little more manageable than I thought it was.

 

[cp85gt]

19 x 10 & 19 x 11 F14's with 295 30 19 & 305 30 19 Michelin PSS. Lowered on AST 4150's.

 

[Jabooh]

I know a 325 will fit for me. However a 325/30 PSS is quite a bit more than a 305/30.

 

[arabbit]

Cp85gt, how lowered are you? Your stance looks great but I'm guessing you are lower than my t-springs.

 

[cp85gt]

I did raise the back of the car a bit last year for bump stop clearance. Right now the car sits at 27 - 1/4" in the rear and 26 - 1/2" in the front. That's measuring from the ground to the middle of the fender. I would guess that is close to the drop a set of Eibach Sportlines would provide. If you're wheel/tire set-up is a street only set-up (not worried about a perfect handling balance) a set of 325 30 19 and 275 35 19 Michelin PSS are almost exactly the same height at 26.7 and 26.6. So .2" shorter in the rear and .5" shorter in the front.

 

[arabbit]

So what is the better choice for track use? I chose 19's because 20's just seemed too big for a track wheel on a Boss. Are there any advantages to doing either size over the other? I'm trying to get as close to stock diameter as possible, but should I worry about doing that? I don't want tiny wheels and big wheel gap, but I do want something good for race use.

 

[Flyboygsxr]

This is just my opinion but I think 18's are the best choice and here are a few reasons why:

Less weight, the mass is closer to the center (think newton's second law when applied to a rotational mass), more tire sizes available, tires are cheaper, lower center of gravity (unless you match the diameter of the OE wheels), and the list goes on. I am pretty sure even the Boss 302S/R cars were running 18's. With the car lowered properly a good set of 18's fills the wheels gap and fender perfectly. Just my opinion

 

[Jabooh]

Agree 100% with above.

I'll add that if they are track only wheels a little bigger gap isn't that much of an issue.

 

[THRAPY]

Grant 302, thanks I did not know that.

Jabooh1, what makes it weird? The width or the aspect ratio? And are you lowered? It doesn't look too bad to me.

I wish I could just get 305/35r19 but that size doesn't exist yet

Nitto NT05's come in a 305/35-19