RPG's "Stage 2 Kit": Rear frame support and Fox Air Bumps

[RPG]

If I remember this right its tapered like 1/4 or 5/16 in... And you should make sure that it keeps the factory angle or the pinion bearing will prematurely wear out and start singing... I seen them take 40 or 50k miles before it starts ... If the springs are not tapered that a is easy to piece to make...

Correct, the blocks are different height front to back. Not a good idea to switch them up for the reasons you mentioned.

 

[BigJ]

BigJ, great write-up. Can't wait to install my RPG kit this spring.

Curious though. You mention installing the Stage 2 kit, but then your pictures show National Springs. Did you already have the springs or did you actually get the complete Stage 3 kit?

Sorry for the confusion! Yes we installed the stage 3 kit, but I wanted to break up the discussion into two parts because, really, they're two separate issues that are being addressed. I know this part, aka the Stage 1 and Stage 2 kits, are of big time interest to lots of folks and that the questions/answers about it are going to be quite specific. The springs, aka Stage 3 are equally as interesting, but pretty different in terms of the why, how and what when all is said and done, so they'll have their own specific questions/answers. I didn't want one getting confused/muddled by the other. Does that make sense?

I'm gonna try and get the springs writeup done and up this evening, although it will need to evolve a bit since I haven't had them off road yet (I do have some thoughts after 400miles on road though). Stay tuned!

 

[f16YODA]

Rock on!

 

[BigJ]

BigJ - Which springs did you install? The HD version?

Yepyep! Details comin soon

 

[debate]

If I remember this right its tapered like 1/4 or 5/16 in... And you should make sure that it keeps the factory angle or the pinion bearing will prematurely wear out and start singing... I seen them take 40 or 50k miles before it starts ... If the springs are not tapered that a is easy to piece to make...

So, swapping the OE blocks from driver side to passenger side and from passenger side to driver side would still have exactly the same pinion angle as when my Raptor rolled out of Dearborn?

 

[pirate air]

Another awesome write up! You got me thinkin about my frame. All though I've eyeballed it, maybe its time to pull the factory bump stops off and check it with a straight edge. If its bent then I'm deff going to need to address it before it gets worse and needs major repair. I know my thrust angle stays pretty consistant every time I align it so I dunno

RPG, the stage 3 kit look to take about 300 bucks or so off the springs as a package deal. If someone were to buy the stage 2 kit, then later bought the springs to help spread the cost, would the springs be full retail?

Also, what's needed to charge/adjust the fox bumpstops?

 

[BIRDMAN]

nice write up J! i spy new wheels and tires too!

 

[BigJ]

nice write up J! i spy new wheels and tires too!

Aye that you do! Outlaw Raptor set me up big time, mounting and balancing them for me too. They even let me borrow a set of sensors! bstoner was nice enough to pick them up for me, bringing them two hours north to meet me at RaptorAddict's shop, saving over 4 hrs off my round trip to and from SoCal from NorCal. Very very cool stuff all around.

 

[RPG]

Another awesome write up! You got me thinkin about my frame. All though I've eyeballed it, maybe its time to pull the factory bump stops off and check it with a straight edge. If its bent then I'm deff going to need to address it before it gets worse and needs major repair. I know my thrust angle stays pretty consistant every time I align it so I dunno

RPG, the stage 3 kit look to take about 300 bucks or so off the springs as a package deal. If someone were to buy the stage 2 kit, then later bought the springs to help spread the cost, would the springs be full retail?

Also, what's needed to charge/adjust the fox bumpstops?

Pirate Air,

I'm sure we can work something out for ya

The bumps come setup from Fox so they shouldn't need much adjusting. However, if you do want to play with psi levels then you will need to use nitrogen, NOT air.

One question I seem to get a lot lately is why did we choose the size Air Bump we did, and do I keep the stock block when going Stage 2?

When installing the RPG Stage 2 Kit, you will retain the factory block. There is no need to flip the blocks from side to side. You simply just slide the impact pad in under the factory blocks and proceed as normal.

We supply a longer pad on the shaft to compensate when keeping the OE spring.

Second, the frame support is the cookie on top so to speak when doing the stage 2 or 3 kit. The real benefit lies in the performance gains you will get over a stock or 2.0" setup, not just the added security of the frame bending issue, which is a plus.

We opted to run a 2.5” Air Bump for the following reasons.

The main purpose of using an Air Bump is to help slow down the compression of the suspension that normally would result in bottoming out. Think of it as helping out its big brother (the Shock). The larger the Air Bump, the less valving is needed to control compression energy. This is why you see big heavy TT, Class 1 cars and the like run 4.0-4.4 inch shocks. The larger the shock, the more effective that shock is at controlling the heat and energy required to slow down the compression and rebound of the spring. This very same concept applies to Air Bumps as well.

Raptor’s tip the scales around 6000 pounds, and when the truck starts to hit the dirt and get some movement in the bump, the larger 2.5” Air Bump is better equipped to handle the greater amount of energy in question. This means the bump itself can run longer periods of time with less fade resulting in longer life of your suspension components. I like to look at this in a simple way. Let’s assume a 150 pound guy and a 300 pound guy need to push a 300 pound box the same distance. The amount of effort needed by the 150lb guy is far greater than that of the 300lb guy to move the same object. This same principle applies to a 2.0” vs. a 2.5” Air Bump.

In a mid size truck like a Ranger or Tacoma, the Fox 2.0” Air Bump does the job perfectly. However, in a full size truck the larger 2.5” Air Bump is better suited to slow down the compression with less shaft travel needed (2.5” of travel vs. 4.0” of travel). This results in a quieter ride around town with less impact over the average speed bump and pothole, yet yields better performance results when hitting the dirt.

 

[justthebest]

Great write-up AND Q&A session!