altiain

iTrader: (3)

Title says it all. I'd like to run a set of 275/40-17 RA-1s or R888s on the car next year for track days. The car has RB springs and Konis. I'm assuming a 9" or 9.5" width, but what offset should I be looking for?

Thanks in advance.

Juice

iTrader: (1)

9.5 +45

TrochoidMagic

try my set-up: RB springs, 17x9.5 +38 enkei rpf1's (from endless rotary auto rnd), falken azenis, and to complete the pkg; some nice sways.

thats what i'd like to run when i track sometime next year...just hope to have all the stuff mentioned above by then.

altiain

iTrader: (3)

So have you actually mounted the RPF1s with that offset and 275s, or is that what you're hoping to use?

c41250n

iTrader: (5)

17x9.5 +40

Endless Rotaries

iTrader: (6)

I have a pretty good selection of Enkei Japan wheels that should fit with that setup.

Enkei NT03+M makes a 17x9.5 +44 offset, clears big brakes too.

That's what I was going to run for track.

Rishie

TrochoidMagic

not yet. i was debating 17x9. but was strongly recommended to go with 17x9.5 with +38. and as i looked and researched for tire selections... i found that this is the medium range in what i want to compromise for a shorter tire. the stock tires run 25.9 and the 275/40/17 is 25.6. so if running 17x9, 255/45 will get me a really short tire at 25 o.d.

and i was forewarned of slight, but only "slight" fender rolling to get those baby massaged in there... the rears only. which won't scare me off.

so waiting for rims to arrive. seems like rishie is the man to be getting ur enkei's from...

TrochoidMagic

and it looks very aggressive on ur car sir. i may not need worry as the RB drop is hardly a "drop".

but DAMN, those offset and SSR's look HOT! i've always had/love ssr's, but too bad its too damn rich for my blood brand new.

c41250n

iTrader: (5)

naw....the one on my car now are 18X10 +24 front and 18X10 +21 rear

this is 18X9.5 +40 all around on the track!


and thanks for liking my wheels!

Endless Rotaries

iTrader: (6)

Hi Trochoid,

i'll check with Enkei on WEds to get your tracking #.

woot woot, can't wait to see that fitment.

It's gotta be incredible. I dropped to 17's and i saw a 15% increase in fuel economy with 245 wide tires. Not too mention the car accelerated much faster.

Rishie

BigOLundh

iTrader: (1)

THATS A MEAN PIC!!!!

TrochoidMagic

if ur seeing 15%, then i should see less than that on assumption. it is only .3inch off from the factory tire o.d.

but i guess that size would be the most useful if running in autox. i can't really complain here as i am getting the added width and still a lil bit shorter tire... it should still be lighter than the oem wheel/tire setup no?

Razz1

I hear you can get better times with the 18" x9.5 than a 17x8.5

TrochoidMagic

what about 17x9.5 instead of 8.5...

turborx8

iTrader: (1)

so whats the advantage of going 17x9.5 over 18x9.5 ??

I was going to order these in a few months.

http://www.good-win-racing.com/Mazda...21-1051FD.html

mac11

iTrader: (1)

the cost of 17" wheels and tires is less.
the rotational wiehgt is closer to the hubs.

TrochoidMagic

^^+1. well, there are benefit in many ways if you look at it.

some of it are very basic if you really think about it. lets set the example to be the same in terms of tire... in 18s, picture the road as the mechanical leverage on ur tires and the same for 17s. the larger diameter will have a greater mechanical force on the rotors and therefore will make it harder on the pads to lock the rotors... but too small of a rim can easily "lock" the rotors up.

so having smaller rim and tire pkg will just maximize ur tire potential given less diameter to have to stop.

and of course the obvious: less diameter and rolling mass. a decrease in % or a "shorter" tire will accelerate faster along with engine speed.

to make it easier, the concept with a bicycle are practically the same. its all in gearing selection...

and yeah, like what mac11 said too... tire selection are wider and its also cheaper.
there really isn't a definite rule that mazda chooses 18s over 17s cuz its better. they're just following the trend in modern cars look "classier" with bigger wheels and less tire.

TrochoidMagic

hard to explain fully in detail as there are many ways to find whats right for ur usage.

it'll be better if you have a specific question or concern that will land you what will go right with ur car.

Endless Rotaries

iTrader: (6)

Ditto on troichoids words and troic your wheels should have left enkei today.

I should have tracking by tomorrow. You'll have em next week regardless.

rishie

TrochoidMagic

^^woo-hoo!

thanks rish. and i'll give you a call sometime in the future for the center caps when i have enough to pick up that luxury piece.

any chance that those pieces will go up in price?