t-o_double_d

What tire pressure is best for the RE-11A's? I have a square set up 245/40/17 on 17x8.5 wheels. I'm running a saner front bar (softest setting at the moment) with stock shocks and tein springs.

Anyone have any recommendations for tire pressures?

iamxpl

well its really dependent on conditions and driving style.i would pick a baseline and adjust from there.

viccath5

it depends as iamxpl says, conditions, driver style, also spring rates, ambient temperature, wet/dry, alignment, course design, pavement type and condition.

it also depends on how warm your tires are from the previous run. Are you co-driving

I suggest you start higher than you think you will need then start dropping it after each run keeping an eye on how far on the outside of the tire you are scrubbing. Some say you should be using all your treaded portion of the tire, then some, if the car is still working for you.

ask what others that are doing well are running. FYI I run BS, 225/255 street tires with a Gendron hollow bar set on second to softest with max camber on front and back...all else stock. I had been running 37f and 34b but a very competitive friend of mind with an almost identical set up (although he runs 245s on the front) is running 32/32 and doing quite well at the same events. Lately I have been playing with slighly lower pressures, as low as 35/33 and it feels great. I won't go any lower than that for now.

iamxpl

^ well he went very into it. seeing from your upgrades you will be in STR

do you have a sway bar on?

Most tires will have a Pyramid on the side wall showing how much of the "shoulder" of the tire should be used. you dont want to fold the tire over. if you are scrubbing past the tip of the pyramid or triangle add more pressure. under hard cornering you might rub the fenders (depending on the offset of your wheels. if memory serves me right most 8.5 in wheels will be out of STR compliance. but dont worry about it if are just going to have fun anyways.)

procedure to find out what works.

pick a tire pressure to start. 35 usually works best to get a baseline. drive 2 laps with it. check the wear on the tire. you can clearly see where the tire is meeting the road. if the wear is too far in on the treads drop the PSI. too low triangle will be getting rubbed off. also consider the temperature. colder weather you might want to run higher than normal pressure due to denser air and the tires will not heat up as quickly. during hot days bring a water sprayer with you to keep the tires cool ( especially if you have a co driver )


theres more to follow but i want to hear what you say first.

disclaimer*

i have no experience with RE-11A, im not sure on their characteristics. some tires love heat, some dont. im not sure how much heat they can handle before drop off point ( get slimey and lose grip )

Croc

at auto-x with R1Rs and AD08s high pressure always felt better for me.
i guess because tyres are too cold...

iamxpl

^^ i had the R1R and i also ran them higher pressures since the sidewalls were not as stiff. from experience the ZII's have a beefy sidewall so i tend to run them at softer pressure.

ViperASR

What would make an 8.5" wheel out of STR compliance?
STR only restricts wheel size to 9", offesets are free game, they just have to fit under the fender with no modification.

iamxpl

most of the wheels that are 17x8 or 8.5 mainly one that i know of would be the RPF1 and they dont come in higher offset than 45. from his picture it looks like he has RPF01 and in 8.5 i think they come in +40?

only other wheel i know of 17x8.5 that is a +60 would be NSX NA2 wheels or squared ap2 wheels. with these i dont see him running into a problem with clearance.

EDIT. you can have any offset. but fitting 245 on a low offset wheel he will chew up his fender or have to mod it. sorry i should have been more clear. i dont think im still being clear anyways lol. and with his current suspension set up i think the shocks with tein springs might be too soft to keep him away from his fender. and from what ive seen the RE11A has some pretty beefy looking shoulders. anyone take measurements?

ViperASR

Haha.
I know what you are saying, just wanted to clarify that 8.5" doesn't necessarily mean illegal. I've seen and drivin his car, the OZ wheels are perfectly legal.

iamxpl

lol derp!! had a brain fart moment. it made sense in my head but i forgot to write down my reasoning. thats why i did horrible in class . but yeah id like to know more about RE-11A. just havent seen anyone run them at autocross.