18x9 on front?

I was looking at the 18” GNX reps and wanted 8” in front and 9” rear however Gbody parts is showing the 18x8‘s as being out of stock.
is any running 18x9” all around , if so any issues?
The suggested tire size is Suggested Tire size 255/40 18 F and 275/40 18 R.
Thanks!
 

conn84gn

Well-Known Member
I think you will have issues with the 9" in the front
I'm running 7" wide 17" with 242/45/17 on the front and they rub the UMI tubes
Running a 8" wide rim on the back with 245/40/17 and had to put a 5mm spacer on the driver side
 

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Reggie West

Well-Known Member
TurboBuick.Com Supporter!
You can get away with a 18x9 in the front but you need to have aftermarket uppers and lowers to make that work. I know the Ridetech arms have that much clearance and maybe the SC&C arms. I can't vouch for UMI or others.

You can run a 255/40/18 in the front and a 285/40/18 in the rear. Some rears are not so squared up so a safe bet is 275/40/18s on the rear.
 

1986 Buick GX1

GX1 #001 [The One and Only]
I had 17x 8.5 with 4.63 backspacing on the front, all stock suspension. The tires (255/40-17’s) were very close to the rear of the lower A-arm.
A 9 in. wide wheel with the same backspacing would have pulled the tire away from the A-arm a bit and still had room on the outside.
A 26 in tall tire will probably rub a bit on the inner fender by the firewall when fully turned.
 

1986 Buick GX1

GX1 #001 [The One and Only]
The 255/40-17, 8.5 wide, 4.63 backspace wheel on the front. The rear is 275/40-17, 9.0 wide, 4.63 backspace wheel with the extra thickness of a rear disc brake kit.

6CBFE004-BEC4-448E-B5E2-F75175CC5F3C.jpeg
 
I'm surprised that nobody mentioned that running wide tires up front increases the chances of your car following every crack or defect in the asphalt making it unpleasant to drive...
Claude.
 

conn84gn

Well-Known Member
Since I have put on the 17" tires on the car it has never been as good for handling
UMI all the way around and QA1 Coil over.
I have had cars, Camero SS, Mustang GT that did handle poorly WHEN the tires got old and worn
Goodyears were the worst
 

Turbo6inKY

Short Guy
I'm surprised that nobody mentioned that running wide tires up front increases the chances of your car following every crack or defect in the asphalt making it unpleasant to drive...
Claude.
Because tramlining really doesn't get bad until you're above 300mm, unless your alignment guy sucks.

But you're not gettiing 305s in the front of these without a massive amount of work, like replacing the entire frame forward of the firewall.
 

TType85

Well-Known Member
Because tramlining really doesn't get bad until you're above 300mm, unless your alignment guy sucks.
This. Running 255's on the front and have had no real issue with tramlining. I have had it happen a little but no worse than my daily driver.
 

turbojay

Active Member
My GN has 18x9 GNX rep wheels on the front. Tires are 255/35R-18. My car does have full Ridetech suspension(coilivers/upper/lower arms) and the front passenger tire will rub very rarely on big dips in the road.
 

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TType85

Well-Known Member
My GN has 18x9 GNX rep wheels on the front. Tires are 255/35R-18. My car does have full Ridetech suspension(coilivers/upper/lower arms) and the front passenger tire will rub very rarely on big dips in the road.
That's good to know. I am running the same suspension setup and don't have an issue with the 18x8 rubbing with the same size tire.

What brakes are you running?

I did have the occasional rubbing issues like that when the car had the 16" GTA wheels, 245 tires and Baer brakes (.400" added to each side of the track width I think). I currently have CPP spindles that use C5-C7 hubs and C6 brakes. I don't know if they changed the track width at all.
 

turbojay

Active Member
That's good to know. I am running the same suspension setup and don't have an issue with the 18x8 rubbing with the same size tire.

What brakes are you running?

I did have the occasional rubbing issues like that when the car had the 16" GTA wheels, 245 tires and Baer brakes (.400" added to each side of the track width I think). I currently have CPP spindles that use C5-C7 hubs and C6 brakes. I don't know if they changed the track width at all.
Stock brakes for now. I have the hardware for upgrading to Blazer brakes in the front but haven't done the install yet. My GN definitely needs a brake upgrade.
 
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