dclin

iTrader: (4)

choatica7's rolling 18s, yummy.

JoeD

****! thats nice!

FastX7

What kind of wheels are those?

Jsquared

JeffShoots your 7 looks NICE. what kind of hood is that?

P.S. Volk TE37s are some light stinkin' wheels

and that black 7 with the JDM wing looks sweet as well...

Toadman

I took off these 18"s when I had a couple lugs strip out, and put on the stock set. I was surprised that the car is so "tail-happy" with the 16's. A bit too aggressive a turn at the edge of boost and the *** comes swinging around and snaps back like a 911.
Fun as hell, but a total different feel than with the 18's and the fat rubber.

JoeD

Fastpac CF hood...i think.

JoeD

285/35-18 are too tall as opposed to stock. get 285/30-18s. they are the same exact diameter as opposed to the stock 225/50-16.

weaklink

OK I'm confused...since the 255/35 is so close to the 285/30 then why isn't it mentioned as an optimum size? Also do I need a 10" wheel to run 285s? And, will 255s rub in the front? Oh yeah, DCLIN seems you could get pzero direcs up front and run assims in the back and they are all in stock.

FD3S

I found that most people put 265/35 on the rear, but 255/35 is so close to the 24.8" diameter because 255/35 is 25" diameter and 265/35 is 25.3" diameter. Why? Please give me some information.

Flybye

I assume you are talking about 285/35 vs 285/30? Well, the 30 series tire costs a **** load of more money, and there are only a FEW manufacturers that make em.

Go to www.tirerack.com and search for 285/30 18s. Not a lot of tires will come up and then look at their price.

weaklink

actually I was comparing mounted wheel and tire OD's. The 255/35 is pretty close, closer than some of the sizes JoeD recommended. I just wondered if they would rub in the front. I also still need to know if I need 10" rims in the back to run the 285's.

weaklink

ok so what about 235/40/18 up front and 265/35/18 in back. The OD on these is 25.4 and 25.3 respectively, compared to 24.8 or 24.9 stock?

pp13bnos

iTrader: (1)

I was playing with one of those Les Schwab tire sim. the other day, and was looking at some wheels for my FD. (I was there for work related tires.) I was wondering if anyone has any pics of the there FD with some 17 or 18 Antera type 181 on it? I like the clean and simple look. On the machine with my black FD lowerd an inch and some 18" Type 181s it looked so awesome. CJ

JoeD

the 2 closest tire sizes made are 245-35/18 and 285-30/18. those are THE CLOSEST tires to stock in terms of diameter. you can not find any size tire, for any size rim, closer than that.

the diameter difference between a 245-35/18 and 285-30/18 is around one hundreth of an inch. in other words, those 2 sizes are the exact same diameter. those 2 sizes, (pretend they are one size since they are the same) are within one tenth of an inch compared to a stock 225/50-16.

there is no closer tire size produced.

JoeD

BTW, you need 10 inch rims to run 285s.

weaklink

I hear you Joe, and I agree. And in a perfect world where matched sets of those sizes were plentiful and cheap, I'd be first in line. But that's just not reality...

JoeD

tirerack does not list ALL the tire sizes for ALL the tires they carry. go to Pirelli's website and youll see that P Zeros and P7000s both come in both of those sizes.

the_glass_man

iTrader: (2)

So should I get new rims and run 285/30/18's all around? Would this work good for street setup?
I have 275/40/17's in the rear now and 235/45's up front, you can never have enough rubber!

JoeD

you could. you would just need rolled fenders, coilovers, and custom wheels.

dclin

iTrader: (4)

Short answer:

Depends on tire manufacturer. 255/35/18 from Brand A will actually measure differently from Brand B. Shorter in diameter (front only) means less chance of rub. 245/35/18s would be a safer bet, fitment wise.

If Bridgestone has/will have 245/35/18s, I would choose that to give me a margin of error, especially considering I've lowered the car. I'm less concerned with maintaining the same diameter front to rear, but the actual diameter itself.

Mounting 285s depends on the tire manufacturer what rim sizes are approved. Most recommend 9.5"-11".

I would cancel my order a few days before they come in, my typical luck. Oh well - I want Bridgestones anyways,hehe.

Long answer:

I've found that the smaller the overall diameter in front, the better it avoids rubbing. Obviously, tire width, wheel width, wheel offset, camber settings, and tires' manufacturer (same rated sizes vary in actual size and profile) effects fit.

But suprisingly enough when I put together my wheel buy, my experimentation with sizes showed that overall diameter played a big part in fit as well (remember, we're just talking about front).

My first set of aftermarket wheels (the SSRs on chaotica7's brilliant black above) had 18X8.5 +40 with Kumho Ecsta Supra 235/40/18s. I had rubbing under one condition only: turning onto an inclined driveway with the wheels turned at faster then normal speed. What is happening is when the front wheels hit the drive, it compresses the suspension and the thread of the tire makes contact with the fender lip. I hit a drive once going WAY to fast, and the tire ripped the fender lip out.

This is not my car, but illustrates what happened:



Under any other circumstances - hard cornering, speedbumps, whatever - I did not have this problem.

Another way to look at this phenomenon - stand over one of the front fender looking down with the wheels turned. Obviously, you can see the top of the tire tread, with the tire pointing out at an angle. When hitting a driveway too fast, the suspension compresses, and some part of this tread contacts the fender lip, and pulls it out. When the tires are straight, they tuck neatly in to the wheel well under full suspension compression - no contact. (At least, for my wheels. Obviously, if you had a wheel that was offset so that it sits 5 in past the fender, it would be another matter - so those that choose to mount heavy offset Daytons would have problems no matter what, hehe).

As that I came across an excellent deal on Borbets in 18X9 +42, I was concerned on the fitment of this wheel given that it is 1) wider and 2) sits further out then my SSRs.

Ignoring tire sizes for the moment, we can see that 18X9 +42 would sit 8.35mm further out then a 18X8.5 +40. I was obviously concerned that it would not fit, given that I was having problems with the SSRs above. (Note: BTW, the simple solution is to NOT enter driveways too fast - but we should not be doing that anyways, right? )

Looking at number of other wheel combinations of other RX7 owners though, I noticed that many had 18X9 with about the same offset, with no reports of rubbing etc. It took awhiles, but I finally figured out the common factor was that all had a overall diameter of shorter then my Kumho 235/40/18s (which incidentally spec at 25.4" overall diameter when mounted on a 8.5" width rim)

I choose to mount 255/35/18s (of Kumho Ecstas again to eliminate the tire manufacturer/profile/etc variances) as that it was wider BUT shorter in overall diameter (25" dia on 9" width rim). Supension height and camber settings were kept the same to elimnate other variables. This was the widest I was comfortable with, at least for a 9" width wheel.

Cutting to the chase ( I can hear snoring in the background), even though my new combination of a wider wheel with more offset, a wider tire BUT a shorter overall diameter resulted in the disappearance of the fender rub. This backed my theory.

There are many other factors that contirbute to fitment though. There are variances between tire manufacturers, for the same size. There are even variances in tires of different models, but by the same manufacturer.

If you compare Pirelli's PZero and PZero Rosso lines, the 285/30/18s have an overall diameter of 24.9' and 25.2" respectively.

http://www.tirerack.com/tires/Spec.j...so+Asimmetrico

and

http://www.tirerack.com/tires/Spec.j...em+Asimmetrico

(note also the two 'different' sizes of 285/30/18s within the same model line of the regular Assimetricals - big difference)

Camber settings, lowering height also contrbute to fit.

So, assuming a correct wheel width and offset range is choosen, it is safer to recommend 245/35/18s in the front.

weaklink

thanks Daniel

weaklink

I went to the pirelli north america site where I noticed that only the assims and rossos were offered in those sizes. None of that size in directionals or p7000.

Tire rack does list both the assims and rossos, but the assims are on backorder, or were.

http://www.us.pirelli.com/en_US/tyre...productid=2626

http://www.us.pirelli.com/en_US/tyre...productid=2606

single o 7

rx7-2jock... I lllloooooovvvvveeeee your car... Maybe one day mine will look close, but you must have at least 30 grand in parts and labor there ! And I must say that I love the chamelian paint, I never knew it looked do good til I saw it on a 7. You have done well, and I am sure we all appreciate your taste in good looks, as well as taste in style. well done, thanks- Brian,
single-o-seven