Do I Need Suspension Upgrade for GX460 Front Bumper? (1 Viewer)

[TwinTipFlip]

Hi Everyone,

Just got a 2014 Lexus GX460. I would like to put an ARB or Ironman bumper on the front end, but am a little strapped on cash to go all in on suspesnsion at the same time. Does anyone know if I would be able to put the bumper plus a few lights on the front without modifying the suspension? The vehicle has coils up front and airbags out back.

Thank you in advance!

 

[Tex68w]

I don't know for sure but if you have anything larger than factory size tires I am willing to wager that you might have rubbing issues especially if you add a winch too. The added weight out front will certainly cause to the suspension to sag some. I am sure someone will chime in here soon that knows for sure.

 

[r2m]

I'm thinking that you would want to upgrade your suspension. The reasons:

• You'll be hitting your bump stops more often.
• If you add a winch, that's another 50 lbs plus hanging off your front end.
• You may start getting that "stink-bug" look. e.g. your rear is higher than the front, enough to look odd...

So the short answer is no you don't need to upgrade your suspension, but the consequences are noted above.
Just my 2 cents.

 

[ChiTown]

If you don't want to do full suspension right off the bat you can do the Bilstein 6112 (47-281202 Lift 1.5"-3.2" / +150-200 lbs) up front and leave the rear stock.

 

[TX GX460]

I'm thinking that you would want to upgrade your suspension. The reasons:

• You'll be hitting your bump stops more often.
• If you add a winch, that's another 50 lbs plus hanging off your front end.
• You may start getting that "stink-bug" look. e.g. your rear is higher than the front, enough to look odd...

So the short answer is no you don't need to upgrade your suspension, but the consequences are noted above.
Just my 2 cents.

r2m is correct here. The extra weight of a steel bumper that far out front will have a significant effect on your front suspension and vehicle dynamics. An additional issue would be increased nose-dive on braking. Personally, I would recommend suspension before bumper if you could only do one for now. But there is no physical limitation preventing you from adding a bumper without upgrading suspension.

 

[Armed in Utah]

ARB on my '14 Tacoma was 135#

plus the 87# winch....replaced the front coils to OME 886

 

[tortoiseracing]

A Google search turned up 550 lb/in spring rates in the front.
The total weight of the added components is approximately 225 lbs (bumper + winch + lights - OEM bumper). Assumption is 100% of the additional weight is applied to the front suspension.
The wheelbase of the car is 110"
My estimate is the front bumper is ~24" in front of the front axle, creating a slight lever effect.

Some quick math:
225 lbs * ((110" + 24")/(110")) = ~275 additional pounds applied to the front suspension

That weight is split over both front springs, so it's about 137.5 lbs per spring. That additional weight will drop the front end 1/4" when the vehicle is static. (There are a lot of estimated numbers here, so buyer beware.)

As r2m and TX GX460 pointed out, though, the additional weight will mess with vehicle dynamics when the suspension is moving. The dampers will not be able to control the additional mass so well, and the springs will compress more than normal under braking and going over bumps.

 

[manpurse]

^^^ Looking at those numbers it doesn't seem to me to be a huge issue if you wait to upgrade springs later. The suspension is made for dynamic loads that are constantly changing: I regularly add a bike rack to the hitch with four bikes. The fuel in the tank goes up and down from a few pounds to over a hundred when full. I have a friend who sometimes sits in the front passenger seat that weighs 250 lbs. Kids in the back sometimes, heavy loads in and out of the trunk and on the roof rack, etc. All of those changing weight variables are taken into consideration when engineers design the suspension.

 

[Tex68w]

^^^ Looking at those numbers it doesn't seem to me to be a huge issue if you wait to upgrade springs later. The suspension is made for dynamic loads that are constantly changing: I regularly add a bike rack to the hitch with four bikes. The fuel in the tank goes up and down from a few pounds to over a hundred when full. I have a friend who sometimes sits in the front passenger seat that weighs 250 lbs. Kids in the back sometimes, heavy loads in and out of the trunk and on the roof rack, etc. All of those changing weight variables are taken into consideration when engineers design the suspension.

Yea but those dynamic loads are factored into the design and distribution of the suspension and within the fixed box of the shocks/springs. Adding 250+ pounds some two or more feet out in front of the engine isn't something that the engineers factored into those ever changing loads. It will certainly impact the load level and handling dynamics of the vehicle.

 

[r2m]

Just a suggestion, go ahead and do the bumpers and all, AND if your suspension performance/ride quality becomes a little wanky, just be sure to have enough left over from the bumper purchase to dump into suspension also.

 

[ChiTown]

Having just installed my Ironman bumper and a winch I will say there is a noticable difference in handling and the way the front end of the truck feels.