king vs. icon vs. fox racing coilovers

Again, race trucks are not a fair comparison because they get rebuild before a race. Take thermal expansion out of the discussion, I've mic'd both Fox and king resi's. The IFP in Kings had 4 one thousanths of an inch larger tolerance than Fox according to my Starrett.

As for the hose...King probably knows my number on caller ID by now. A simple phone call will confirm it for you. But a quick google search came up with this:

http://www.offroad-engineering.com/foxvsking.html

And for the record, I'm not advocating fox over king. Just stating what I've found, measured, and tuned over the years. I'm a King fan through and through.

 

Also, the hose does not see the highest pressure. The shock body and resi see higher pressure. Simple fluid dynamics will tell u that. If you use Bernoulli’s Equation (Conservation of Energy) you can see that larger diameter cylinders (the shock body and resi) have slower fluid velocity. The resi tube is significantly smaller and the velocity is faster. In transitioning from a larger diameter to a smaller diameter the velocity increases. This represents an acceleration of the fluid. Acceleration requires an unbalanced force, which in what we are discussing, is generated by the pressure on the fluid by the walls. The pressure in a larger diameter cylinder (shock body) is greater than the pressure in resi tube to accelerate the fluid. And once again in the resi itself, the pressure must be larger in the larger diameter of the resi due to fluid deceleration.

 

Right on man. I've been mobile so no I didn't read your bio.

1) I've overcharged as well. Rating doesn't mean that they can't handle more, it's a working pressure, not max pressure. Feel free to make a phone call to Aeroquip to confirm the pressure ratings, but the last time I called King, that's what I was told.

2) I'm not trying to be a dick here, but it physically and mathmatically impossible for fluid to flow from a larger diameter cylinder to a smaller diameter cylinder and maintain the same pressure. This would counter Newton's second law of motion and Bernoulli's principle if you assume the flow is laminar and fluid is in-compressable in a sealed container...as in no matter how much you compress a liquid, it doesn't consume less volume). Steady state (as in no fluid movement) yes, you are absolutely correct. The pressure is identical. But during shock shaft compression, the shaft displaces fluid in the shock body and the fluid has to flow somewhere...it goes through the resi tube and into the resi. The pressure's exerted within the resi tube is lower than that of the shock body and resi. I think I went drunken math geek enough for one night, but here's a decent overview of pressure differences if you want to know more about the math.

http://en.wikipedia.org/wiki/Bernoulli%27s_principle



In the end, I'm just some asshole on the internet currently running 3 pairs of King shocks, a pair of Fox bumps, a box of shims, and a complete disregard for my personal well being. But it works.

http://www.youtube.com/watch?v=mne65embTZ4

 

Right on. Thanks for double checking, but for which hose? I know you guys you different size hoses for different shocks.

My buzz has worn off and I found my King scribbles. My bypasses use an GH194-8 hose which is rated (operating pressure) at 2500 psi. I forgot a zero.

 

What's your goal? Go fast or crawling?

I'd avoid a shackle flip for anything remotely pre-running/go fast. The factory inverted shackle will allow more bump travel without putting the leaf pack at a wicked negative arch. The flip itself will also give you some marginal additional lift regardless of what leaf pack you end up with.

The j66 is shit. Even my skinny 155lb ass can flex those things just by jumping on it. The AP standards are a claimed 3" lift, but it's an 11 leaf pack with a military wrap and (what AP calls) a "torque leaf" to combat axle wrap.

 

Of the off the shelf packs, I like the AP pack. But for custom packs I'd go with Deaver or Alcan.
I personally don't see the need for a traction bar with a good aftermarket leaf pack.
Obviously I'm biased to SUA, but that's for my particular driving style and terrain. SUA gives great uptravel which is obviously what you want for hi speed. But I rock crawl the hell out of my truck as well. Have to pick your lines a little better to not get the springs/ubolt plates hung up, but the extra uptravel flex works well for me...and locked front and rear.

 

Yes. But it's easiest to buy a shock up front that fits the profile you want. Icons piston is a two piece piston that's dished which makes it trickier to get a progressive profile.
If you want a linear/progressive profile, start with a flat piston like King, fox, ads, etc. If you want a digressive profile, start with Icon.

 

Haha. Yep exactly.
There's a few companies on the market that also make a preload shim with raised lips that can change change the dampening curve of a flat piston digressive.
You can use a small thin shim the same depth of the dish on a dished piston so the rest of the shims are not preloaded to move the curve progressive. Several companies sell specific digressive pistons as well (such as bilstein) that will fit pretty much any 2.5" shock body. But all this costs money. Best to just start with what you want.