Anybody considered using 16" wheels for the track?

[ft86Fan]

Originally Posted by Dave-ROR

I've been looking or 17x8.5s for 235/40/17s. Only food a few there plenty of 17x8 though.

I just bought a set of Kosei K4R 17x8.5 for my Bimmer and they are extremely light (15.4 lbs) for $199 but its for 5X120. Not sure if they make it in 5X100. I only found 17X7 in 5X100 and its only 14 lbs.
Kosei K4R

[Dave-ROR]

Originally Posted by ft86Fan

I just bought a set of Kosei K4R 17x8.5 for my Bimmer and they are extremely light (15.4 lbs) for $199 but its for 5X120. Not sure if they make it in 5X100. I only found 17X7 in 5X100 and its only 14 lbs.
Kosei K4R

17x7 only, already checked

PLENTY of 17x8.5 options in 5x114.3 though

[ft86Fan]

Originally Posted by Dave-ROR

17x7 only, already checked

PLENTY of 17x8.5 options in 5x114.3 though

Wow, you guys are good :-)

I bought the 17X8 and 17X8.5 Kosei K4R. Both of them has 5X114.3 stamped on them even though its 5X120. I asked TireRack about it and was told that most likely the mold for the blanks was for 5X114.3 but then they drill the holes for whatever bolt pattern they want. I'm sure they can do the same for 5X100. I guess they are not doing it now because its not popular but wait until our cars come out :-)

[SUB-FT86]

Originally Posted by Dave-ROR

17x7 only, already checked

PLENTY of 17x8.5 options in 5x114.3 though

I was just looking up rims with the 5x100 and they all suck ass to me.

[Kostamojen]

Originally Posted by Dave-ROR

Do the math. It'll increase diameter unfavorably enough. If you want street tires 235/40/17s will lower the diameter and therefore shorten the gearing. Since the op is talking track use I made the assumption that he cared more about performance impacts over street tire availability. There's a chart in the tire width thread showing these sizes (with diameter changes) and prices of good tires that I threw together last week.

Combine the worse gearing with the additional sidewall flex and the only slight bump in width.. I see it as pointless. Unless you are trying to save money, tires will be about ~30 (or 50 for re11s) cheaper per tire for the good street tires versas 235/40/17s. Sadly RS-3s are not sold in 235/40/17 but I plan on contacting them to see if they'd consider the size. Compared to stock tire pricing is 1-23 bucks per tire cheaper.

A) Shortening the diameter for tighter gearing isn't what I'd want. That means you have to shift out of second gear sooner, and that can be an issue for auto-x.

B) Sidewall flex is not an issue. And actually, the tread pattern is better with the 225/50/16's versus a narrower 16, where the tire doesn't have a rough edge to the tread so it rolls over better under hard cornering.

I ran 205/55/16's, 215/45/17's, 225/40/17's, and 225/50/16's on my Impreza (which only has ~170hp mind you, and weighs 2600lbs, very simular to the BRZ/FRS and with the Macpherson front suspension setup too) and the 225/50/16's were BY FAR the best for every scenario (track, auto-x, mountain roads, and daily driving).

[quik1987]

Hey sorry, I'm not familiar with racing and wheel size.

I understand the weight saving benefits of a smaller tire, unsprung weight, and better cornering,

but why do sports cars such as the Cayman R or Ferrari California come with large tires if smaller tires are better for racing?

[DuMa]

porsche and ferraris run larger wheels and tires because they need to clear their massive brakes which are often 15"+ with supersized calipers

[Dave-ROR]

Originally Posted by SUB-FT86

I was just looking up rims with the 5x100 and they all suck ass to me.

There are plenty of good wheels in 17x8 though..

Volk, etc make wheels that will work too even at 17x8.5, but I have no intention of buying wheels like that unless they are used (I buy wheels for function and the functional difference is just not worth the price to me).

[Dave-ROR]

Originally Posted by Kostamojen

A) Shortening the diameter for tighter gearing isn't what I'd want. That means you have to shift out of second gear sooner, and that can be an issue for auto-x.

B) Sidewall flex is not an issue. And actually, the tread pattern is better with the 225/50/16's versus a narrower 16, where the tire doesn't have a rough edge to the tread so it rolls over better under hard cornering.

I ran 205/55/16's, 215/45/17's, 225/40/17's, and 225/50/16's on my Impreza (which only has ~170hp mind you, and weighs 2600lbs, very simular to the BRZ/FRS and with the Macpherson front suspension setup too) and the 225/50/16's were BY FAR the best for every scenario (track, auto-x, mountain roads, and daily driving).

As proven by GRM and others, the gearing will make up that once or maybe twice per run shift. I don't hit 60mph in second and I rarely ever have an autocross that requires me to shift into third.

Sidewall flex can definately be an issue.

Laptimes?

I like the Rotas though

[quik1987]

Originally Posted by DuMa

porsche and ferraris run larger wheels and tires because they need to clear their massive brakes which are often 15"+ with supersized calipers

This car has a big brake option 6/4 pot brembos though, requiring 18 inch wheels.

We know 18s and 19s fit

So what set up is better?

Big Brake Kit with ULTRALIGHTWEIGHT 18/19

or 16s with 2/1 pot brakes?

[Dave-ROR]

Test it and find out. I'll be running 235/40/17s myself. I'll take the extra width and slightly shorter gearing myself. I have no intention of ever putting 18" or larger wheels on this car and would only consider 16s if I were running R comps in 245/45/16.

Others opinions and experience will vary so you probably just need to find which you like the most.

[Kostamojen]

Originally Posted by Dave-ROR

As proven by GRM and others, the gearing will make up that once or maybe twice per run shift. I don't hit 60mph in second and I rarely ever have an autocross that requires me to shift into third.

Really? I've had a few that require 3rd or I bounce off the rev limiter... But I have a 6200rpm redline too.

Sidewall flex can definately be an issue.

I worry more about tires that DON'T have sidewall flex. Although that might be better for drifting.

[fatoni]

Originally Posted by quik1987

This car has a big brake option 6/4 pot brembos though, requiring 18 inch wheels.

We know 18s and 19s fit

So what set up is better?

Big Brake Kit with ULTRALIGHTWEIGHT 18/19

or 16s with 2/1 pot brakes?

i dont think the big brakes are going to stop any faster. they are just going to be able to stop better for longer

[DuMa]

Originally Posted by Dave-ROR

Test it and find out. I'll be running 235/40/17s myself. I'll take the extra width and slightly shorter gearing myself. I have no intention of ever putting 18" or larger wheels on this car and would only consider 16s if I were running R comps in 245/45/16.

Others opinions and experience will vary so you probably just need to find which you like the most.

agreed. biggest i would ever run is maybe 245/40/17. the prices for 18" tires and wheels disgust me