Interested in everyones thoughts on the cost vs benefit of 18s (vs 17s) on road courses. Right now the car is used for DE events and I plan to start some light competition with in a year. I realize that at some level it comes down to "how fast do you want to go".....

I realize that 14-15" brakes can be stuffed under the 18s, but the stock Brembos seem to be more than capable of stopping the car with my current setup and skill.

So aside from more room for brakes, do 'yall' find that the benefits of 18s out weight the increased cost of tires? Why or why not.

If their 11 inches wide and you cut your fenders they are.

What wheels you run are dictated by the tires and the brakes you want to run...

If their 11 inches wide and you cut your fenders they are.

Although I am still on stockers, both the front (chargespeed +20mm fenders) and rear (rolled and stretched over and inch from stock) have more space. In a few weeks 255/40 on top of 17x9s will go on, these will be the rain tires. I plan on 275s for the dry.

Although I am still on stockers, both the front (chargespeed +20mm fenders) and rear (rolled and stretched over and inch from stock) have more space. In a few weeks 255/40 on top of 17x9s will go on, these will be the rain tires. I plan on 275s for the dry.

DAM....Now that's some meats!!!!!!!!!!!!!!!! :eek:

I would cast my vote for the 285/30/18. Those are quite a good tire and there are plenty of manufacturers that have that size in a wide variety of tire "types"

-Tom

hey javid?

would you be interested in a set of 17x8.5 57S's?

Right now the car is used for DE events and I plan to start some light competition with in a year.Check the rule book for whatever you plan on competing in. It might specify what wheel size is allowed.

There was an article in Grassroots Motorsports a couple years back comparing lap times with the same width and make of tire on different diameter wheels. 17" was the cutoff point before lap times slowed down. The problem is weight. If you are worried about cost check prices of a 17" setup vs an 18" setup using the width tire you want.

While big brakes look cool, if the ones you have now work fine but you start getting them hot try adding brake ducting to get some air to cool the brakes. It is not only more effective it is much cheaper.

There was an article in Grassroots Motorsports a couple years back comparing lap times with the same width and make of tire on different diameter wheels. 17" was the cutoff point before lap times slowed down. The problem is weight. If you are worried about cost check prices of a 17" setup vs an 18" setup using the width tire you want.


Bingo..

reducing unsprung weight is one of the biggest performance enhancements you can make to the car (it significantly effects braking/acceleration/corning).. Which is why people spend so much money on lightweight 2 piece alumnum rotors/hats, and forged/magnesium wheels...

I realize that 14-15" brakes can be stuffed under the 18s, but the stock Brembos seem to be more than capable of stopping the car with my current setup and skill.

It doesn't sound like you're abusing the brakes that badly yet, if you're not boiling fluid or smearing pads you need to push your braking points up :D

Seriously though i'd cut off the factory dust shields on the front rotors before anything else (my next little project), run some real high temp fluid (Motul RBF600, Castrol SRF, or Ford HD), and see how that works. Ducting is definately the next reasonable step, with a BFBK being a larger and less reasonable step after that... :p

some threads I've stumbled across for ducting..
http://www.clubwrx.net/forums/showthread.php?t=90383
http://forums.nasioc.com/forums/showpost.php?p=7657834&postcount=18

I know people that run 15s with a awesome brake setup. one guy has some TE 37s that are 15x 7.5 and they weigh like 8 or 9 lbs. these are great for Auto-X and out in the canyons and im pretty sure they hold up on the track. just look at the WRC cars. they can get a lot of brake to the ground using a 15, and as for your car i wouldnt recomend anything over a 17, rims and tires just get too heavy.

The only reason to get 18's is to fit the bigger brakes (for track use). If you're not go to run bigger brakes, don't get 18's. Simple as that.

As someone that had to shop for 18's for Stock class in my 8... 18" lightweight wheels are NOT cheap. You'd be better served finding lighter and cheaper 17s. If $$ is not object, then go for it... but even the Kodiak 18 x 8s, which are strong, fairly light wheels, would be around 16 lbs each... and cost *bling*.

Not to mention, 18" tires are also much more expensive than 17s.

So, if cost were a factor, you'd be better served going with as small a wheel/tire you can get for your $$. ;)

--kC

Thanks for the imput guys.

jmolaver: The XP9s on the Brembos are stout, I could easily push braking point back if I had more tire, right now they can get into ABS at any ol speed. They run hot and are hard on fluid but never give up, ironically I have ducting sitting in the back seat right now. :lol:

STiTuner: are they 114.3 or 100?

Do you run R-Compound tires? XP9's will outpower any "regular" street tire.

I have been running on 070s. The XP9s were definitely too much for them but they were nice cause they never give up and they forced me to learn to brake and not just stomp on the pedal in the middle.

255/40 RA-1s arrived a few days ago. :)

Interested in everyones thoughts on the cost vs benefit of 18s (vs 17s) on road courses. Right now the car is used for DE events and I plan to start some light competition with in a year. I realize that at some level it comes down to "how fast do you want to go".....

I realize that 14-15" brakes can be stuffed under the 18s, but the stock Brembos seem to be more than capable of stopping the car with my current setup and skill.

So aside from more room for brakes, do 'yall' find that the benefits of 18s out weight the increased cost of tires? Why or why not.

skill? what skill? is that like computer hacking skills, or numchuck skills? oh yeah, can't forget beer drinking skills :lol: ;) :p

I'd say keep the 17's. no point in getting a potentially heavier wheel

skill? what skill? is that like computer hacking skills, or numchuck skills? oh yeah, can't forget beer drinking skills :lol: ;) :p

I'd say keep the 17's. no point in getting a potentially heavier wheel

It was an eloquent way of saying slowness. :) Using 'skill' rather than 'slow' and still getting the point across is why they pay me the big bucks.... :lol: Any race teams looking for a PR guy?

you get paid the big bucks for doing a LOT :lol: ;)

Any race teams looking for a PR guy? *ahemcough* YES

-Tom
who will also require Lindsay/Nicky as the umbrella girls

*ahemcough* YES

-Tom
who will also require Lindsay/Nicky as the umbrella girls

12345!

jmolaver ... cut brake shields ... mine (WRX) just unbolted ?

One advantage to the 18's is the lower profile tires available. Which of course translates to better transtional response.

mine are 5x100
its a fairly cheap wheel if you want the 5x114, I can make some arrangements ;)

will 17x9.5 et38 fit over the brembos?

I was looking at RPF1s but the word on the street is that the 17x9.5 is a deep dish made for the Z and wont clear the brakes.