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Custom wheels for race rubber?


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I'm looking for a set of wheels to mimic my current ones so I can put race rubber on them and use them for track only. I don't want to break the bank, doesn't have to be pretty - just functional (and lightweight preferably).

 

I've not found anything at Summit, and don't know where to look. These are really odd sized wheels, as I have coilovers and flares.

 

FRONT = 17x10 5 5/8" backspace, which would be a +16 offset (roughly)

 

REAR = 17x12 5 3/8" backspace, which yields a -16 offset (roughly)

 

I "think" I have the calculations correct. Please correct me if I'm wrong.

 

So - I need to find a set of 17's in a 4x114.3 bolt offset to put race rubber on.

 

ANY ideas??

 

Also - when measuring wheel width, does one measure from outer lip to inner lip (extreme most portions of the wheel) or from where the bead seats? Haven't been able to figure that one out yet. If so - my measurements above will differ.

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Check out http://diamondracingwheels.com/drwcustom.html

 

They make steel racing wheels and will make them with custom bolt patterns and offsets. I thought about getting some from them and probably still will in the future for track use. I bought Kodiak racing wheels recently which are very pricey. It's very difficult to find wheels with the deep offsets and 4 lug bolt pattern. Look through the products on the website and give them a call and they'll help you out. The diamond wheels are very reasonably priced although, they don't look all that great. Very plain wheels but very functional.

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Give Zak a call or email Boze/ZE forged wheels. I have 17 x11 and 17 x 9.5 Pro touring wheels on the way- should be here by Thursday. I still have 4 -lugs , tokico springs,shocks (no coilovers) specs to fit Arizona z car brakes. I order them just after Xmas $1900.00 plus shipping. CCW have some great wheels and great service, I wanted to try something different.

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OK - help me out here guys. If I'm measuring from bead seat to bead seat (which I can't do b/c the tires are mounted currently) to calculate width, then would it be safe to say I'd subtract an inch from the overall wheel width? (1/2" per bead lip) to surmise the proper wheel width?

 

That being the case (if true), that would make my wheels 17x9 up front and 17x11 out back. Backspace is still measured from the mounting pad to the innermost lip, so it hasn't changed, but what HAS changed is my offset. Help me out and make sure my calculations are correct.

 

Offset = backspace minus the centerline of wheel.

 

Front = 9", so 4.5" would be the centerline. Backspace of 5.625". So 5.625-4.5= 1.125" correct? Multiply by 25.4 to get mm = 28.575 offset.

 

Rear = 11", 5.5" is centerline, backspace 5.375", so 5.5-5.375=0.125" or 3.175 offset.

 

So, since my fronts are wider on the inside, that makes the offset negative - correct? That would make my rears a positive offset, yes??

 

Maybe I have this whole thing bassackwards. I'm just trying to nail down what I need to tell the folks at the custom wheel shop...

 

Any help is greatly appreciated.

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Looks like you got it. It is a basic calculation and the relationship does not change. You really only need to give the wheel maker either the offset and width or the backspacing and the width (besides the diameter of course). They will take care of the rest.

wheel_measurements_thumb.jpg

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When you are using a backspace measurement to find your offset you need to use the overall width of the wheel for the calculation.

17x9 = 10" overall so

centerline = 5.0= 127mm

(I work in Millimeters)

BS= 142.875

BS-CL= 142.875-127= 15.875 offset on a 9" wheel

 

Rear

BS-CL= 136.525-152.4= -15.875 on an 11" wheel

 

If you need a detailed explanation PM me and I call you.

 

Roy

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Roy - that explains things perfectly! Thank you.

 

Well - I find out now that Diamond Racing Wheels does not make a 17" for cars (trucks only), and the 16" wheels they make are in 8" and 10", and 12". I need a 9" and an 11". Guess I'll be looking elsewhere. I just can't justify nearly $2500 for a set of CCW wheels. Spin Werkes looks like they only have drag wheels, so I don't know what to do at this juncture. I have a very specific fitment need that looks like it will be hard to fulfill..any other suggestions would be greatly appreciated..:icon14:

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Why do you need 17"s if you're using them for race rubber anyway? If you drop down to 16"s then you can get a set of Real's for relatively cheap in any width/offset you want:

 

https://www.rsracing.com/rscatalog/asppages/rrw-pro616.asp

 

I've been running 16x10 Real wheels from RS on my FP car for 7-years now with no issues.

 

Also, when I was looking around for 15"s I ran across these:

 

http://www.bogartracingwheels.com/wheels/rt4lug.jpg

 

They will custom build any width/offset you want but I suspect the cost to be similar to the CCWs.

 

-Rick

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I checked into them. Real only does backspacing in inch increments. I need roughly a 5.5" backspace. I also don't know if 16's will clear my calipers. I have the 4 pot Z32 calipers up front. I will pull one of the wheels off my DD (16x7) tonight and see if it will fit and clear the caliper....however, the backspacing issue could be a problem.

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I will say that you really need to be careful at this point and make sure you can find rubber for the wheels your getting. It's very difficult to find rubber for that wide of a tire on a 16" wheel. I was told early on when buying my wheels that 16" wheels would perform better, but it was really hard to find tires for 16x12 wheels. So, check into the tires real fast and make sure that won't change anything before you go a whole lot further.

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http://www.bobwoodmantires.com/bwttires.php

 

They have plenty to fit 16x9 and 16x11. That's not the hard part. The hard part seems to be finding wheels in 16x9 and 16x11 with the proper 5 1/2" backspace without spending over $500 a wheel. I was just quoted nearly $600 a wheel from Bogart racing wheels....top that off with a +/-$300 piece of rubber......daaaaaaaammmmmm!!!

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