Aggressive Wheel Offset - Not-so-apparent Issues?

[Junior357]

I plan on running a fairly aggressive (or maybe mildly aggressive) wheel setup when I build my GX. The wheels will be 18x8.5 with a -18 offset. By my calculations, the outside face of the tire will be exactly where it would be with a 9" wheel and a -12 offset. The tire and wheel would be 1/4" further away from the suspension.

I fully expect to have to do a BMC to it. No problems there. I plan to run the Ironman Pro forged UCA's...which require a maximum 4.75" backspacing - the setup above has about 4.04" backspacing. Don't think that will be a problem. I'll have a high-clearance bumper (probably MT's Goblin bumper)...so I think this will clear easily on that.

Is there something that I am missing? I have looked through the Wheel & Tire pic thread...but only found a couple of GX's running that much negative offset. Am I asking for trouble (other than slinging mud/dirt all over the truck)?

 

[OCGX]

It will change the scrub angle. I don't think it affects it too much. I'm running 18x9 +0 with a .75" wheel spacer so about -18mm offset. Truck handles different, but fine. I don't have pulling problems when braking hard.

 

[Junior357]

It will change the scrub angle. I don't think it affects it too much. I'm running 18x9 +0 with a .75" wheel spacer so about -18mm offset. Truck handles different, but fine. I don't have pulling problems when braking hard.

Thanks...that's why I posted this on here. I understand about the scrub angle, and the change in vehicle dynamics. But your setup is really close to what I intend to run...albeit 1/4" wide each side. Did you find it necessary to flatten the pinch weld? Any other rub points I should keep in mind?

 

[yeos]

I ran 17x9 -12 with 285/70/17 and currently 18x9 +0 with 275/70/18 with a BMC and stock bumper with fender liner pushed forward. The only time that I may have rubbed was under full compression and turning it would just graze the fender liner by the flare.

 

[OCGX]

On my setup I am running 275/70R18 KM3's. I did the BMC, but nothing with the pinch welds. I've trimmed and heated the fender liner above the BMC. The tire did catch part of the rocker molding when I was flexing, so on the spot I just whipped out a knife and trimmed it.

 

[Junior357]

Great info...and much appreciated. More than likely the running boards will be gone and the front bumper will be changed out before these wheels go on...so maybe that will minimize the chances of rubbing. Will probably do the BMC between taking the running boards off and installing rock sliders. No need in doubling the work by having to remove the sliders to do the chop.

I'll also be sitting on a 3"/2.5" lift by the time the wheels go on. Sure that makes some difference...although probably part of what will necessitate the BMC in the first place. Not my first rodeo with modifying vehicles...just my first Toyota-based 4x4 since about 1998.

Thanks for the input...sounds like the setup will work based on your combined experiences.