Those aren't the best prices, but Volks are expensive. CE28Ns are extremely light and I think RE030s are as well.

 

Again, do all these wheels fit or are people just throwing out 'possibles'.

IMHO, I would think a thread with facts in what REALLY fits would work out much better. Just sayin'.

 

I put a note on the ones I'm not sure about, but I honestly don't think the RX8 calipers are big enough to have clearance issues on any 18" racing-oriented wheels. If you call TireRack, they may be able to confirm caliper clearance, but I'm not sure how else to garuntee fitment.

 

Usually, threads like this one on most other forums are for confirmed fitment. As in 'we bought them, they fit' or 'tried them, don't fit'.

Just throwing out possibiles will lead to a rather large thread with hardly any conclusions. That's of no help to those wanting wheels that will work for STX that find the thread. Wheels that 'may' fit can be found on any other website, including tirerack, discounttiredirect, etc... but of those, which actually 'do' work for STX?

See what I'm getting at?

--KC

 

There is a "what-fits" thread in the wheels section.

I understand your point, but I think at this point its difficult to just find potential choices given that there just do not seem to be that many choices in 18x9. So, we have almost been brainstorming the possibilities out there.

 

In order to better define "what fits" for the RX-8, STX application I mounted a 265/35R18 Yokohama Advan Neova AD07 on a 18"x 9" wheel with a 60mm offset. I then compressed the suspension until the rear tire shoulder was next to the fenderlip at it's widest point. Using the 60mm offset wheel, this combination presented no clearance issues with stock fenderlips and -1.9 degrees of rear camber. Using wheel spacers, I then moved the wheel outboard to simulate lower offset wheels/wider track. It appears 44-46mm is about the limit before minor rubbing will begin with this tire and negative camber combination. If you plan to use a lower offset than 44mm, you should be prepared to deal with tire rub by rolling the rear fenderlips and possibly adding additional negative camber to gain clearance at full compression.

As others have indicated, you will find that at least 90% of the 18"x 9" wheels on the market will clear the RX8 brake calipers.

As a note of caution, I am unable to simulate bushing compliance under cornering load with out testing the car on course. Build variance between vehicles and section width differences between different tire brands/models also may affect these numbers slightly.

Chris H
The Tire Rack
06' RX-8, B-stock

 

Thanks for the great info Chris! Were those measurements taken at the front or rear? Or both?

 

Rear. Because of the width of the rear fenderlip, it will be the first interference point when trying to maximize the tire fitment.

Chris H

 

Just bought a set of the SSR Type F 18x9 +50. 18.6 pounds and SSR was selling them for half price. Not sure how many are left now.

 

Just mounted up the 17x9 (ET 45) RP-F1s and they clear the brake caliper less than the thickness of a stick on wheel weight.... after a few blocks the wheel weights clear too.

255/40x17s were the largest ST class tire I could find and there is lots of gap between them and the fender lip; certainly more than I'm accustom to with 285/35x18 V710s on 18x9.5 (ET 45) wheels

I'm thinking I could fit a 20mm spacer without the tire contacting the fender lip, although the rear's going to be the issue.

One thing's for sure, all that extra sidewall and tread sure makes street duty more civil.

 

if it will help your reference any I ran 265/35-18 AD07s on 10.5 @ 45mm SSR Comp wheels in STU trim and just cleared the factory rear lip

pics of the fully compressed suspension with wheel/tire mounted are on here somewhere, maybe the "goodies" thread

 

I had one of my front wheels off today so I threw one of my 17X9 ET42 Weds Sport TC005 on to double check. Tons of clearance, I could fit the entire width of my hand between the caliper and the rim. And my hands aren't small.

 

How was clearance to the outside lip of the fender? What about on the back of the car?

 

I didn't check those things, I don't have tires yet, just threw up the bare rim to check the brake clearance. I got a little nervous after reading how tight 4D-Sport's Enkie's were and others had been asking about brake clearance with the 17's so I was sharing that the Weds Sport's clear with room to spare.

For fender lip clearance, based off of what TeamRX8 used, in a 17X9 rim any thing with a reasonable offset should fit, my set up has more clearance both inside and outside than what he used.

I didn't check the rear brakes because the fronts are bigger, if they clear in the front they'll clear in the rear.

 

Chris, I must say I'm surprised that you think it will rub at 44-46mm.

FWIW, I use 255/40-17 RA-1s mounted on 17"x9" track wheels. These should be very close in overall diameter and mounted width to a 265/35-18 Advan.

My wheels have a +35 offset. On a slightly lowered car (RB springs and Koni yellows) with two degrees of static camber front and rear, I have had absolutely zero rubbing over 1000+ track miles. None. My fender lips are completely unmodified as well.

Just a data point. Pictures of the setup mounted on my car are here. Your mileage may vary.

 

Iain,

Couple questions:

1) Do you need to run hub centric rings with the 5Zigens?

2) I imagine the +43 Fn01r-c's would fit better than the +35 on an RX-8. Did you go with the +35 just for price or do they have some other benefit?

The 5Zigens are on my short-list of wheels to purchase for STX. I love the ones in bronze!!!

 

Hi Iain -

I am a bit surprised as well, it may be the combination of slightly more negative camber and the shoulder profile of the 255 RA1 versus the 265 AD07 that allows you just enough clearance or you may not be completely compressing the rear suspension on the tracks you run to get the rub. My process for checking the tire clearance was pretty straightforward, jack-up the left rear of the car and slide two 2x4's under one rear tire. Lower the car and take the jack around to the opposite side front jacking point. Jack the car up until the right front tire almost leaves the ground, the rear tire is now compressed 90% of the way into the fenderwell and probably not yet touching the lip. Now open the trunk and use your body weight to bounce through remaining rear travel. You may want to uses some chalk or other substance on the tire/fenderlip contact point that will transfer to the fenderlip if you don't have a spotter working with you. This simulates max cornering load with full weight transfer plus bounding over FIA curbing etc. The other common method is to pull the rear shock and spring out and cycle the suspension/wheel tire assembly with a jack under the tire. This takes a lot more labor though.

Using the first method and the 265 AD07 and simulated 40mm offset wheel, my set-up was hitting the fenderlip just short of full compression. I like to leave 4mm to 5mm static clearance to compensate for bushing compliance, tire deflection etc when the car is actually cornering, which is how I arrived at the 44-46mm estimate.

I am not trying to contradict what your are stating, just clarifying the test method I used if you and others want to test a fitment this way.

Chris H

 

Chris,

No problem. I hope you don't think I'm trying to contradict your input either.

I have fully compressed the suspension on several occasions with this wheel/tire setup on the car, both on the track with a 200# student in the right seat and a full fuel load, and on the street with a spare set of wheels in the back seat and 150# of tools in the trunk. In addition, my car has much shorter bumpstops than your B Stock car, so the suspension can travel further physically. I haven't scraped the spats at the leading edge of the rear wheel wells yet, but I get pretty close.

However, I haven't mounted up a set of AD07s, so I can't say if they would clear or not. I just wanted to offer another data point for this discussion.

Chike, if I were to do it all over again with STX in mind, I'd probably opt for the +43 wheels. In my case, I was trying to maximize the track width, and I will also admit I was curious to see if the +35 would fit. It does, at least in my application.

 

Thanks Iain. I think +43 is as low as I'd go on a 17x9" wheel. Ideally I wouldn't want to roll my fenders unless I was running in SP on 305's.

 

Btw Iain, do the 5Zigens fit the RX-8 hubs?

 

They definitely fit over the hubs without machine work, but I honestly can't remember off the top of my head if they're hubcentric or not.

However, I've never really been that concerned with hubcentricity. In reality, a properly torqued wheel that is not hubcentric will still be lugcentric, since your lugnuts have tapered seats. They're designed that way for a reason.

In over ten years of autocrossing and track days, I've never bothered with hubcentric rings, and I've piloted cars on the track to over 140 mph without balance problems (my old FD was capable of higher terminal velocities than the RX-8 is ). I am however a big advocate of having competition wheels/tires balanced. I find it funny that some people who are fanatic about using hubcentric rings balk at the extra expense of balancing their race tires.

That's my $.02. YMMV.

 

I just found out that the 17x9 +45 RPF1 will not clear the Racing Brake BBK.

 

Also, a new addition to the list:

Enkei RP03
18x9.0 +40
18.3 lbs

 

^ How much are the Enkei RP03's? Are they available from Edge Racing?

 

Damn. Where were those last year? Definitely would have gotten them over the 18x9.5 RPF1s if they're the same price.

I know the 18x8s are $300 a pop on Tirerack. Shouldn't be that much more for 18x9s.

EDIT: Wait. Tirerack has the 18x8 RP03s at 20lbs. Where are you getting 18.3lbs on a bigger wheel? And TR has the 18x9.5 RPF1s at 18.6lbs.