Zathras

I just bought a Silverstone Enthusiast model. The Enthusiast comes with 225/50-17 front tires on 17x7.5 rims with a 30mm offset and 235/50-17 rears on 17x8 rims with a 33mm offset. The wheels weigh 23.3 pounds for the fronts and 24.1 pounds for the rears.

I got the wheel info from www.wheelspecs.com.

I want to do a modest upgrade to the tires and wheels. From what I've read on the board the combo I think I want is 245/45-18's on 18x8 rims with a 30mm offset. The rim specs are straight from the Performance Z model, so I'm sure I'm safe there.

My goals are:

1. Reduce understeer, balance the handling
2. Allow front to rear tire rotation
3. Lighten car

Does this combination sound like a good one? What would you all recommend for wheels and stores where to get them? I'd like for the wheels to be as light as possible without sacrificing strength. I won't be racing the car.

Will running 245/45-18's all around mess up the TCS or ABS? I could run 245/40-18's up front if a height stagger had to be maintained.

Would I want to use runflats and ditch the spare? Runflats are an option with the Bridgestone RE040's.

Would 245/45-18's all around look funny? Would a spacer be desireable on either the front or rear?

Your thoughts and suggestions would be appreciated. If anyone is running a set up like this please include pictures.

Zathras

Nobody? Too dumb of a question? I promise I searched

8" wide rims don't look like too popular of an option at www.tirerack.com. 18x8.5 looks like a more common wheel size. What offset would I use with an 8.5 rim?

245/45-17 looks like an option too. Judging by the SSR GT2 wheels, going to 17" rims saves 2.2 pounds over 18" rims (15.9 pounds versus 18.1 pounds). If you go smaller rims, doesn't that mean bigger, heavier tires?

ether

i'll answer the TCS ?.. i have 255/40-18 all around on 8.5 +23 wheels.. tcs is affected, basically a bit more sensitive in that less wheel spin is needed to trigger the tcs, same size all around the ecu thinks a bit of wheel spin is all ready occuring... but easy to fix by pressing the tcs off button.. not a problem here

ether

run flats?.. you would take a perfomance hit by using those.. get tripple AAA and ditch the spare.. +30 offsets on 8.5 will start looking a bit odd try around +25 on 8.5 wheels that should look decent all around

Zathras

Thanks Ether.

Did you notice any less understeer running 255/40-18's all around?

I don't know if it is understeer I'm feeling, but my car feels less than right when taking a corkscrew (270 degree?) freeway onramp at a brisk pace, say 45mph plus on a 15mph onramp. I hate to say this, but I'm trying to get my 350Z to feel like a RX-8 I test drove. I took that the same onramp at 45+ with the RX-8 and felt like I wasn't approaching its limits yet. The 8 runs 225/45R18's on 18x8 wheels.

Ether, are you running spacers?

lowrider

iTrader: (3)

IMO

you should maintain the stagger by putting the 245/40s in front and 245/45s in back.

Lou

ajk4

to stagger he would need a different series not profile. however, you might feel a slight difference between 45/40 profile but i seriously doubt it. also, if you plan to autox you might want think twice about staggering.

lowrider

iTrader: (3)

Not True ajk4

The stock 18" sizes are 225/45/18 and 245/45/18. The the height of 225/45s is 25.8", the height of 245/40s is 25.8" and the 245/45/18s are 26.8". That's how we get the stagger. BTW, these are for the Michelin Pilot Sport. You see that the 225/45 and 245/40s are exactly the same height. 225/45/18 is a hard size to find. My initial post is correct.

Lou

ether

i'm not running spacers, the wheels are 8.5 +23 offset. the car definately has less understeer than stock and less than when i run 245 Fronts and 275 rears. i like the 255 setup quite a lot, the only thing i would change is to get the new pilot sports 2s, those would allow full rotation from front and rear and side to side, they still weren't available when i got the rims.

If tcs is important to you, then definately stick with stock diameter differences, if not then just push the button and get the tire sizes that you want, bye the way abs is not affected, although the car has sensors at all four wheels the ecu dumbs it down by just looking at the front versus the rear, so as long as you have the same size on both sides its fine (take this with a grain of salt - this is not in the service manual - was told to me by someone who knows our car's ecu like the back of their hand)

Zathras

Hehe. So far I'm not impressed with TCS. I figured it would allow for some wheelspin, but seems like it just flat turns the engine off when it senses wheelspin. Is TCS supposed to act so abruptly?

What do you think about running 17's Ether? What do racers run? I haven't figured out yet if 18's are for handling or looks.

ether

17 would probably be best if you are looking for pure a performance setup - I run 14" brakes that fit 18s and bigger only..

wheel choices.. have you looked at the advan tc2s or the BRS REs.. was considering those before i settled on the pro-drives.. both of those are relatively light.. for 18 and smaller wheels, designs without lips IMO look a bit better by using the entire size for the wheel spoke design

Zathras

By from a pure performance setup do you mean handling too?

I don't know squat about wheels. This is my first new car in 12 years. I tend to keep my cars a long time. The names I hear mentioned the most are Volk, Rays, SSR, and BBS which has been around forever.

Aha, I'm glad you mentioned lip. What is a lip on a wheel and what are the pros and cons of having a lip? Would having one or not help keep some idiot from marring the rims when they change my tires?

ajk4

i know but most people refer to width when staggering not height, but yea either width or height could be staggered.

Loren04G35

I run basically the setup you are looking at. The first week I got the coupe I swapped the front tires. I am still running the stock OEM Infiniti 18x8.0" 30mm offset wheels with 245/40-18's Pilot Sports up front and the OEM 245/45-18's Pilot Sports out back. To be honest, I think the 245/40 fits the rim better than the OEM 225/45. With the narrower tires, the tread almost comes in from the sidewall. The 245/40 looks very square on the rim and there are no wandering or tramlining problems. It does slow turn-in just a tad, but you will notice a gain in front grip. With the sway bars set for the front soft and the rear medium, the car is incredibly neutral and has great turn-in with this setup, unlike the plowing pig it was the day it arrived at the dealer.

Definitely stagger heights for 2 reasons. First, it keeps the VDC from freaking out. Second, the car won't look right with the same height tires all the way around. If you look at the wheel well openings and heights, they are designed for staggered tires heights. You are actually raising the front end of the car, making it look pitched back. We have a guy on the G board who bought a set of 18" ADR M-Sports from a Maxima owner. They were 18x8.0" or 18x8.5" with 225/40 tires all the way around. They looked great on a Maxima, but there was somthing definitely off on his car. The short tires looked somewhat OK in the front because the wheel gap wasn't far off. In the rear, the tire height was reduced by over and inch and the gap looked unsightly like a 4x4.

ether

don't diasgree that it raises the front, but by a very small amount. i have pictures of my ride with 19s with a stagger and 18s without stagger.. on the TCS, if you someone needs/wants the computer to help them drive this car then by all means keep the stagger it will affect it, i'm just used to having sports cars without computers helping me drive and always turn off the TCS and avoided getting a model with the full VDC system

19s 245/35 Fronts and 275/35 Rears

ether

18s without a stagger

stumpmj

iTrader: (1)

I'm running 5 Zigen FN01R-C's 18x8.5 +30 offset with 245/45-18 all around. The wheels aren't as light as a forged wheel (BBS, Volk, etc.) but they are a lot cheaper. I bought mine from Kevin at Discount tire. Looks wise, I think it looks good but I'm thinking of getting a spacer for the back wheels (maybe 10mm) to bring the edge of wheels closer to the fenders. For now, its good enough. I took the money I saved over forged wheels and bought a second set of wheels with R compound tires for the track.

Zathras

Ether, thanks for the side views. That doesn't look bad at all with 255/40-18's all around.

stumpmj, what brand and model of tire are you running? Did you notice any difference going to 245/45-18's all around versus the stockers on your Enthusiast? Do you notice the traction control system behaving any differently?

Strife350z

iTrader: (4)

i completely agree... run 245/40s in the front and 245/45s in the back if your goal is to dial out understeer unless you plan on driving without TCS all the time

i use same heights all around on my winter setup... it's fine for winter since I actually WANT my TCS to turn on in advance, but come spring, the car's acceleration and everyday driveability turns to mush

Zathras

Loren04G35, you mentioned adjusting your sways. What sway bars do you have?

I'm thinking of going 245/40-18's on 18x8.5 rims for now. This gives lots of tires to choose from, is close to the stock diameters, and gives room to change the rears to 245/45-18 later if I want to stagger the heights.

I can't seem to get 17" tires to match the stock tire heights with sizes that have lots of choices at Tirerack.

I used this site to calculate tire diameters:

http://www.miata.net/garage/tirecalc.html