Ideal width/offset CCW's for 285/30/18 tires?
 

Hello All,

I'm set on getting a set of CCW Classics for my FD. I've got a set of 285/30/18 tires sitting here waiting for a set of wheels to call home. I've been reading that 18"x10" seems to be the ideal wheel diameter/width for this tire size. Though, I am seeing a lot of mixed info on whether a +50 or +52 offset is ideal.

I don't mind rolling my fenders at all, since I already have the tools. Also, I'm running on Tein Flex coilovers. So what is exactly the ideal offset and wheel width for this setup? Thanks in advance, guys!

I have CCW Classics 18x10.5 with 275's pictured here:

https://cimg4.ibsrv.net/gimg/www.rx7...4c99a59fba.jpg

I also have TEIN Flex coilovers. I'm also selling my set. 18x8.5 in the front pictured here with 245's on the front.

I jumped a curb and damaged all four rims but I have a quote from CCW themselves for repair cost.

If youre interested, shoot me a PM and we can discuss.

Nick

What offset are those?

The ideal offset depends on how much camber you run since this influences there between the suspension and fender edge the tire is.

*ideal offset meaning centers tire between coilover and rolled fender lip*

Every 1 degree of camber moves the edge of the tire ~ 5.5mm at the tread.

0 to -1.5 deg camber up front and you want 50mm offset to center the tire.

-1.5 to -2.5 deg camber up front and you want 45mm offset to center the tire.

-2.5 to -3.5 deg camber up front and you want 40mm offset to center the tire.

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In the rear there is the additional element of rear toe.

If you run rear toe the tire rubs the unibody on the inside front of the fender well and also may hit the trailing arm. There is a bit more room to the fender compared to the front- so add 5mm to the rear.

My example is that I run 18x11 +45 front and rear with 295/30-18 tires.
I have-
rolled front fenders with slight pull and lightly rolled rear fenders.
-2.4 deg front camber, -1.3 degrees rear camber.
Stock trailing arms
Tripoint front swaybar with tube shortened 1" for full steering lock.

https://cimg1.ibsrv.net/gimg/www.rx7...7d9faa921e.jpg

Thank you for the detailed post. So if I plan on running stock or near stock alignment settings w/ 285/30/18's, I should probably run an 18"x10" (or 10.5"?) +52mm offset wheel?

Blue TII assumes you never decide to change your camber after you decide on a wheel offset :)

Both the 50 and 52 mm offset should work. The 50 mm offset will give you another 2mm of space at the fender lip obviously.

Gotcha - I guess I'll go with the 18"x10" +52 over the 18"x10.5" +50. This will still allow me to run up to a 305mm width tires if I so chose and still saves some weight over the wider wheeel option. Is anyone opposed to that?

gracer7-rx7

Blue TII assumes you never decide to change your camber after you decide on a wheel offset

Nah, I assume one can reason out that if you ever think you want less camber one goes with the higher offset and adds a spacer to decrease the offset because you can't increase wheel offset with spacers...

Gotcha - I guess I'll go with the 18"x10" +52 over the 18"x10.5" +50. This will still allow me to run up to a 305mm width tires if I so chose and still saves some weight over the wider wheeel option. Is anyone opposed to that?

Wheel width won't affect how wide tire you can fit (just offset does) and 2mm offset isn't enough to worry about.

I would definitely do the 18x10.5 +50 given the choice between those two.

With a +50 or +52 offset-
for a 305 in the back you will have to run a 5-10mm spacer (and roll the rear fender) as the tire will rub the unibody in the front top of the wheel well.

18x10.5 +50, huh? I'll definitely go that route then. Do you believe I would have to do any fender rolling if I'm going with 285/30/18 tires?

You will have to roll the front fender lip under with 18x10 +52 or 18x10.5 +50 to run 285s.

They will actually clear in a straight line without rolling the fenders if you max the camber- except turning hard up an incline or racing will cause the sidewall to grab the unrolled fender lip and f*&k it up.

It is better to roll the lip under ahead of time so you don't mess up the part of the fender you can see (like what happens when the tire grabs the lip).

If you don't want to roll the fenders at all then use a 265/35-18 tire.

I had 265/35-18 on 18x10.5 and loved it.

Good to know -- I'll get them rolled before the wheels come in. Thanks for the help!

To be honest, I don't know. I gave the serial number to CCW when getting the quote and since they were bought by Weds Wheels, they don't have the "old records". My guess is they are either +50 or +52 even. When looking at the setup I had, my back spacing was "perfect" by several people's estimations. I never did the measurements to figure it all out. All I know is, I had a modest drop, fat tires and zero rubbing.

These are the CCW Classic Race by the way, which are honed out and lightened versions of the traditional Classic's.

If you're interested let me know. I had contemplated keeping them as track wheels and getting them fixed, but I don't know if that's reasonable at this stage.

If you're looking for a more robust front end package, like TII's setup, you can change the inner and outter lip/barrel to go wider as they are a true three piece wheel.

Nick

Thanks for the offer -- I'll definitely keep you in mind.

I'm running 18X10 +50 on all four corners with 285/30 rubber. My fenders are rolled.

https://c2.staticflickr.com/6/5753/3...7a4226a1_b.jpg
https://c6.staticflickr.com/6/5782/2...46d67f27_b.jpg

Great looking setup -- thanks for posting that. Are those the Sumitomo HTR Z III's? If so, how do you like them compared to other tires you've had?

What bumper is that? looks great!

[QUOTE=gracer7-rx7;12131133]
:score:

Yes, they are Sumitomo HTR Z IIIs. I like the tires; however, I don't have any other experience with tires this wide. I have Nitto NT555R rubber that is slightly narrower on another set of rims. Both are responsive and I do admit that I don't drive the car too hard...at the moment :)

Not to detract from the thread, but it is a Leg Motorsports bumper. You can search the forum and you will find a thread on it.

So I talked to the CCW guy. he said the 10.5" has ~.750 lbs/wheel over the 10" unit. Do you think it's worth it to go the 10.5" route, given the choice between the two?

Does a crack baby shake?

Nick

I would say the 10.5 wide at 3/4lb more over the 10" wide is worth it if you are planning on running a tire wider than 255mm.

I did 18x10 +38 Enkei PF01 with 265/35-18 before my 18x11 and it got me addicted to wide wheels. Such awesome tire response.



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If wheel weight is a priority to you there are lighter cheaper wheels out there than CCW.

My 18x11 +45 Forgestar F14 pictured are just under 22lbs (or the same weight as 18x10 CCWs) and cost around $1,500 a set.

Well, CCW has the 1 piece wheels that are lighter but more expensive than their 3 piece wheels as well.

Of course, the nice thing about 3 piece wheels is you can replace the barrels if you bend them or put wide fenders on your car.

Haha -- duly noted!

Yeah, or just some 18x10 RPF1's would have been way lighter. It seems like everyone agrees, 18x10.5" +50 it is -- it seems more suitable for 285/30/18's anyways.

You should look at tire section width as well. A cheapo tire like the Sumitomo HTR Z III is almost a full inch narrower than the same sized PS2. 18x10+51 all round for a square setup. When CCW specs the 18x10's they use a 7.5" backspace which I believe comes out to +51mm offset. That's absolutely perfect for the front but too inset for the rear. With rolled fenders you'll need a 10-15mm spacer.

This assumes alignment within factory specs. I have the CCW SP 500's at 18x10 +51 and they work out exactly like I stated above. Front's perfect, rear is too far inset. I'm not rolled in the rear and still have a healthy gap between the tire and lip with a 5mm spacer. My tires are between the Sumi's and PS2s in section width. 285/30-18.

As a side note. The 18x10+45 should be able to fit a narrow 315 in the rear like the 615r or similar. A PS2 will not even come close to fitting without a healthy pull.

Ahh, ty for the info. I was thinking of going with the 18"x10.5" +50mm (with a full fender roll, slight pull), which should get rid of that "extra" space between the rolled fender and wheel lip.