Mark VIII & Thunderbird Custom Wheel Spec's

Welcome Aric !

I find it difficult to understand your math. The specs you give seem to be off a bit since the actual width of the wheel is always greater than given 8 or 9". Thus, providing a figure of 2.xx" of front space is far from what is the actual clearance to lip.

It's very well known, that if a 9" (10" actual) wheel is used, the max BS is 6.42, and max FS is 3.58" for the front. The rear has the same front space, but approx 7.18" back space until things start to rub.

Of course all of these specs go out the window once you start running tires that are greatly wider than the actual rim width.
 
Thought I would add some visuals to compliment Aric's numbers :)

Tires:

Front - Toyo Proxes T1R 255/40ZR18

Rear - Toyo Proxes T1R 285/35ZR18





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Well, one thing for certain, that's taking it to the max!

The end result was spectacular Mike. Congrats.

It's very well known, that if a 9" (10" actual) wheel is used, the max BS is 6.42, and max FS is 3.58" for the front. The rear has the same front space, but approx 7.18" back space until things start to rub.
Click to expand...

If written another way, 6.42 max BS + 3.58 max FS = 10", that means a max 9" wheel?

So for the rear, 7.18 max BS + 3.58 max FS = 10.76", that means a 10" wheel won't fit?

Also, if your running cobra front brakes, add 1.00” to the front spacing and subtract 1.00” to the rear spacing. That would allow an additional 1” to the front wheel “lip” and still clear the front brakes.
Click to expand...

So does the 6.42"BS/3.58"FS now become 5.42"BS/4.58"FS? I don't know why I find this wheel fitment issue so confusing. :confused:
 
Mike, you're missing the point.:cool: Of course the wheels worked, but the numbers as stated won't help anyone. They will actually cause a lot of confussion.


driller said:
If written another way, 6.42 max BS + 3.58 max FS = 10", that means a max 9" wheel?


So for the rear, 7.18 max BS + 3.58 max FS = 10.76", that means a 10" wheel won't fit?
Click to expand...

Yes, max 9" wheel can be run on the front.

For the rear, 10" (11" actual) wheel won't fit if you run a tire that was meant for a 10" wheel (not some wimpy 275 :D).

However, you can easily modify the sway bar and the quarter panel lip to allow for a 10" wheel and 315 ... maybe even 325 tire.
 
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OK, I think I understand better now. I'm still a bit confused on the brakes.

Mad1stGen said:
However, you can easily modify the sway bar and the quarter panel lip to allow for a 10" wheel and 315 ... maybe even 325 tire.
Click to expand...

I understand modifying the wheel lip, but how do you "easily" modify the sway bar?
 
The brakes used on Mike's car require a little more clearance to the wheel spokes due to size of four piston calipers. Brembo caused problems for people for as long as I can rememeber (not that much ;)) If you're after a big lip (mustang craze aka steam rollers) then it only adds to the problem. Spoke design plays a big role here. If you stick with dual piston calipers, none of these problems exist in reality.

Modify the sway bar ? cut in half, cut off 1/2"( or whatever extra room you need) off each end, slip a piece of pipe over both ends, weld it all together. It worked great on a local m8 that runs 315 BFG Drags. The ends where the end links attach, might need to be bent outward if you making the bar a lot narrower.

It shouldn't be to difficult to make a new swaybar either. Especially if you're looking for a solid bar.
 
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Mad1stGen said:
Welcome Aric !

I find it difficult to understand your math. The specs you give seem to be off a bit since the actual width of the wheel is always greater than given 8 or 9". Thus, providing a figure of 2.xx" of front space is far from what is the actual clearance to lip.

It's very well known, that if a 9" (10" actual) wheel is used, the max BS is 6.42, and max FS is 3.58" for the front. The rear has the same front space, but approx 7.18" back space until things start to rub.

Of course all of these specs go out the window once you start running tires that are greatly wider than the actual rim width.
Click to expand...

OK, you were 100% correct on my math being wrong. This is what a-d-d and 16 hour days do to ya;). No accuses tho, I need to provide good info for you guys, especially for the amount of time I vested in this project. I have updated the post on my site with the correct dimensions. I apologize for any confusion guys and gals.
 
Hey, we all make mistakes. If everything was a bolt on and go deal, it wouldn't be as much fun ;)

One last thing.
Front wheel dimensions: 18x8 w/ 6.375 back spacing

Rear wheel dimensions: 18x9 w/ 7.500 back spacing

Do these measurements take the front and rear (different thickness right?) spacers into account ? Or ar they actual wheel measurements ?
 
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Those are the dimensions without the wheel spacers. I'll make another change to my post to help clear it up. That was the original measurements from Boze. The spec's below(in my post) are what everyone should be concerned with. I hope this helps, let me know.

-Aric
 
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