thats whay I have sorta. How many others are using this setup? I've been thinking about going up in tire size but not sure if the cost is worth it?


Sorry dont mean to jack this thread,. just curious

And yea dont do what I did.. Over mod then not be able to drive it fast, it sucks!

 

thanx for all the help guys...all this info and advice helps alot..u all rock!

 

what about cooling? Do our cars need a radiator upgrade to be handle track days? especially in the summer....

 

as for cooling, i dont use any after market cooling "mods", but in the summer in louisiana i jus have the boost set at 21psi and use 0W50 amsoil.. also for above posts, 255's on the stock wheels are perfect to start out with. Just get some stickies, like the Z1* or equivilant. Hell, even when i return to the states ill be on 255's with my Motons and lots of power

 

Not in WA. My stock radiator does fine. I use straight water and Redline water wetter.

 

what about aero stuff.. lips, wings, etc.. do they make alot of difference?

say like a apr wing compared to oem wing

 

Seems like most tire specs for 255/40 17's say that the rim width range is 8.5-10, so the 17x8's still work?

 

Yeah they work fine, I know lots of people who have done it. But a 235 or 245 is fine also.

Don't add any aero at first, the car is balanced from the factory. It you put a big wing on the back you need a big splitter on the front to balance it out. The same is true vise-versa, a splitter needs a bigger wing.

 

Awesome! I had been planning on a set of 235/45 AD08's, but if the 255/40's will fit, then I'll definitely go with that size instead. That's almost an inch more tread width and only 2 more lbs. of weight at each corner!!!! Thanks!!!

 

I'm running Enkei NT03+M's. 17x8.5 with a 255,40,17.. Lowered quite a bit. No scrubbing or rubbing. Car handles great and with the NT03's I dont have to add weights to the wheels, they always balance out perfect with a 255.

I'm currently working on a fiberglass front splitter. I'm doing this to offset the huge Tanabe swaybar I put on the car. I'm also running a set of canards on the APR GT front bumper with the integrated lip. I hope it works out good

 

Aero should be used to balance aero, not mechanical parts like springs, and swaybars - at least when possible. Aero loads vary with speed and are not constant, thus the balance they provide can not be relied on.

 

aero should be last on the list... i run wingless at the moment even, once the coilovers get put on i'll throw the stock wing on and a splitter and call it a day

 

255/40ZR17 Z1 Star Specs on stock BBS rims FTW! work great for me and i have no rubbing issues with my coilover setup

 

I started HPDEs on Buddy Club 17x9s with 255/40/17 Dunlop Z1*. Works great, car was very balanced. After almost a year of running those, I pulled out my old Gram Light 18x9.5 and put some 275/35/18 NT01s on there. What a pain. Car understeers pretty badly now, and took some sorting out to clear the fenders.

 

Are the wheels/tires the only change in your set-up? Hard to imagine that you'd lose front end grip like that with a 275/35 compared to a 255/40. A 9.5" rim is on the small side for a 275/35 tire, so maybe the NT01's are rolling over on the sidewalls due to a lack of support, and therefore causing your understeer issue. Just speculating.