Will a 20x8.5 fit?

Discussion on wheel & tire issues
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Will a 20x8.5 fit?

Post by 79sevillecoupe » Wed Oct 04, 2017 8:29 pm

So I have a set of 2017 alpha camaro rims(pn#23434342) and they are in a squared setup of 20x8.5(25mm offset) with 245/40r20 goodyear eagle f1 asymmetric runonflats installed. Will these bolt up without any rubbing? Would I need spacers? I saw a few posts for camaro rims but nothing that specified whether these 8.5" wide rims would pose any clearance issues. Suspension and ride height are factory. Anyone have a setup like this or something similar?
Camaro rims.jpg
Camaro rims.jpg (43.32 KiB) Viewed 4251 times
Size and offset.jpg
Size and offset.jpg (25.65 KiB) Viewed 4251 times
Part number.jpg
Part number.jpg (21.58 KiB) Viewed 4251 times

s/c'd cav
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Re: Will a 20x8.5 fit?

Post by s/c'd cav » Wed Oct 04, 2017 11:31 pm

thought those were the staggered set ?

ive seen them on the g8's before , dont remember if anything was done though

s/c'd cav
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Re: Will a 20x8.5 fit?

Post by s/c'd cav » Thu Oct 05, 2017 1:32 am

here is 2 pics of them on a SS
ss camaro wheels.jpg
ss camaro wheels.jpg (78.3 KiB) Viewed 4235 times
ss camaro wheels 2.jpg
ss camaro wheels 2.jpg (93.44 KiB) Viewed 4235 times

Navy Lifer
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Re: Will a 20x8.5 fit?

Post by Navy Lifer » Thu Oct 05, 2017 2:42 am

I refer to this thread: viewtopic.php?f=19&t=2316" onclick="window.open(this.href);return false;

Clearly the wheel in question will "fit". That does not make it OK for fitment on the Zeta platform--G8, SS, 2010-2015 Camaro, or PPV.

The 8.5" wheel with 25mm offset pushes the wheel outward--as mentioned in the link, a stock SS sedan (19" stock or 20" accessory versions) are 8.5 front with 48mm offset and 9.0 rear with 57mm offset. These wheels consider proper suspension geometry and bearing/hub loading.

The difference in offset between the Alpha Camaro 8.5" wheel and the stock (Zeta) SS sedan wheel, the closest equivalent Zeta wheel, is 23mm--nearly an inch. The positioning of the Alpha wheel laterally outward by nearly an inch brings the tire into a position where it is very likely going to project beyond the body wheel opening when viewed vertically from above. Tire contact with the edge of the wheel opening is inevitable, and it would not surprise me if rolling fenders would still not correct this.

The differences in the Zeta and Alpha chassis suspension geometry dictate why the wheel offsets are what they are--using the Alpha wheels affects scrub radius, bearing loading, and it will affect the way the car feels/drives, and not in a good way.

It's just an opinion, of course--so I offer this only as food for thought.

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Re: Will a 20x8.5 fit?

Post by mercialogo » Thu Oct 12, 2017 7:58 pm

I agree with Navy Lifter. with an 8.5 wheel, I would absolutely not go more then +30mm offset. ( dont laugh ) but my current set up is 7 inch Equinox wheels originally +46mm offset with 20mm spacers. That puts me at +26mm of offset with only a 7 inch wheel. Add another 3/4 of an inch from the 1 side of the wheel and I can tell you that will be too much. My wheels were free and look better then the cop wheels, but I have added the spacers to get a better feel for the offset I want for my wheels. I plan on 9 inch wheels with a 35mm offset. That is going to be pretty extreme especially if you lower the car much but will fit. Keep in mind that I will be auto crossing my PPV and will be changing the Wheel alignment drastically from stock, so my scrub, caster and camber will all be different and will allow for the +35 offset better. The Cadillac CT6 ( which is almost identical to the PPV in suspension geometry) has a 8.5 x 20 wheel with a 33mm offset. They are almost perfect.
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