[jinnrice]

Which is better for tracking? 18" wheels or 19" wheels. Taking all aspects into consideration.

My situation. I ordered Michelin pss on tirerack (245/40r18) they are on back order. So I got some time to think of what I should do.
Go run rim and tire combo to 19" or stay with with 400m wheels with 245/40r18s.

All feedback is welcomed.

[drob23]

Originally Posted by jinnrice

Which is better for tracking? 18" wheels or 19" wheels. Taking all aspects into consideration.

My situation. I ordered Michelin pss on tirerack (245/40r18) they are on back order. So I got some time to think of what I should do.
Go run rim and tire combo to 19" or stay with with 400m wheels with 245/40r18s.

All feedback is welcomed.

I just went through this analysis myself. I wanted a dedicated setup, so I could stop killing my PSS street tires at the track (I have forgestar cf5-v's for the street). I was destroying the sidewall, I'll prob get a more aggressive alignment, but the PSS is not a great track tire. Gets very gummy once heated up, even if you keep hot pressures in check. It is the ultimate street tire, but not a great track tire.

I considered going with some CH-R's in 19", but that's a lot of money to spend on track wheels. But I suppose they will hold their value for the used market. But the cost of 19" tires is just soooooo much more. *Especially* for r-comps.

So I ended up with a set of VMR V810s 18x9.5 from mod bargains for 1140 shipped, which is pretty good for a flow formed wheel in my opinion. Now I can mount a lot of different R-comp tires or get killer deals on street tires. I ordered a set of Dunlap ZII's in 245/40R18 for ~750/set installed, which run extremely wide in that size, 9.5" tread width according to tirerack. Once I want to step up to R-comps, I can get a set of NT01's for about 1000, or go all out for A048's for around 1300. The 19" options will be a shit load more expensive, especially for fancy tires like PSC2 or PZero Corsa.

Edit - my analysis is purely from a cost perspective. In terms of performance, 19" tires will give you shorter sidewalls, which means stiffer for the same tire. This will make your transient response tighter and I suppose your slip angles will be smaller. You'll probably have better steering feel. You'll eat a little performance in terms of larger wheels => higher inertia.

[jinnrice]

Originally Posted by drob23

I just went through this analysis myself. I wanted a dedicated setup, so I could stop killing my PSS street tires at the track (I have forgestar cf5-v's for the street). I was destroying the sidewall, I'll prob get a more aggressive alignment, but the PSS is not a great track tire. Gets very gummy once heated up, even if you keep hot pressures in check. It is the ultimate street tire, but not a great track tire.

I considered going with some CH-R's in 19", but that's a lot of money to spend on track wheels. But I suppose they will hold their value for the used market. But the cost of 19" tires is just soooooo much more. *Especially* for r-comps.

So I ended up with a set of VMR V810s 18x9.5 from mod bargains for 1140 shipped, which is pretty good for a flow formed wheel in my opinion. Now I can mount a lot of different R-comp tires or get killer deals on street tires. I ordered a set of Dunlap ZII's in 245/40R18 for ~750/set installed, which run extremely wide in that size, 9.5" tread width according to tirerack. Once I want to step up to R-comps, I can get a set of NT01's for about 1000, or go all out for A048's for around 1300. The 19" options will be a shit load more expensive, especially for fancy tires like PSC2 or PZero Corsa.

Edit - my analysis is purely from a cost perspective. In terms of performance, 19" tires will give you shorter sidewalls, which means stiffer for the same tire. This will make your transient response tighter and I suppose your slip angles will be smaller. You'll probably have better steering feel. You'll eat a little performance in terms of larger wheels => higher inertia.

Agreed- difference in price of tires is 300 or more... I only track maybe once or twice a season. So shaving quarter of a second with extra cost in tires doesn't really justify it for me. I am kind of glad now that my tire order was back ordered. My friend (master Forman at BMW...DIDNOT KNOW TILL NOW!!!) expressed to me today that the PSS are not good for the track like you said. I asked for a set price for conti extreme contact dw. He came back with 945 (245/40r18)his cost. I asked why even his cost compaired to tirerack the price is almost 250 or so more. What he told me was something new to me. He said that bmw and other car company gets first dibs off the tire production line. BMW gets any "StAr" rated tire and the rest goes to tirerack or other chains hence the price difference. Since I was tracking only few times a year he suggest that I should get my tires from tirerack n get the cheap good ones and he will install. What he said next made made me feel like a noob. Ur not a pro anyways. Drop it with dinans an get the tires n u should gain a half a second... Hahaha.