king vs. icon vs. fox racing coilovers

They've used different pistons over the years and model splits. But current generation stuff from Fox and King leaves lots of room for improvement. Their tunes are great for washboard, but anyone who is comfortable in their trucks will find they are bouncy and that they bottom out too quickly on rutted out roads and while crawling.

 

As compared to stock? To me, stock is really bouncy

 

I haven't got a ton of experience with King, Icon, FOX. I have had several iterations of OME suspensions to compare. I may understand what you're talking about, though. My '08 came with stock suspension that was 42K old when I got it. Ride was alright on pavement, terrible off highway. Completely uncontrolled on washboard and high speed (35+) on dirt roads. Crawling it was acceptable.

With the FOX 2.5 IFP (no reservoir, stock tune) and 650# springs in front and OME CS047R/FOX IFP 2.0 rear the truck floats over washboard and feels great on rutted dirt but does seem bouncy (which I mean it wants to rebound too quickly, it's not bouncing as in oscillation) on rocks. Mind you it's superior to stock and probably about the same as OME, but does seem either underdamped or over sprung. I tend to think I might be marginal with 650# springs (ARB bumper, XD9000 w/ synthetic line, dual batteries, stock skid plates).

I also get a little bit of back end oscillation at certain speeds on the highway if the crack joints are spaced just right and if I put the bike rack in the hitch, so figure 100ish lbs hung a foot or two from the hitch, it will be really bouncy.

 

Stock is VERY bouncy. It's much bouncier and less controlled than necessary so there's a lot of room to get rid of the bounce and gain control without giving up much on washboard.

You basically nailed it. They lack control which gives you bounciness. It's especially bad when you start tackling rougher terrain and adding weight.

 

Not sure if this has been covered in 60+ pages but does anyone have any input on running Kings in the front/Icons in the rear? Will the difference in valving front/rear make for a unpleasant ride when used for their intended purpose?

I have standard travel 2.5 non-resi Kings up front currently and have the opportunity to score some new rear 2.0 Icons w/ resi for a good price, curious to hear if it's worth taking the leap or not.

 

What do you have in the rear now? You should be able to valve the rear however you want

 

For anyone with Fox, are there different valving options from the factory? If so? what?

 

5100s. Was running them front and back but switched to Kings last week, trying to decide on what to do with the rear now. Came up on the Icons for a good deal but I know they're valved differently than the Kings are (progressive vs digressive)...this is my first experience with actual performance coilovers so I just want to make sure I'm not putting together an unrecommended setup by doing so.

 

I had Icon 2.0 rear shocks running with ADS coilovers and I could feel the difference. I ended up ordering matching 2.5 ADS rear shocks.

 

I've got king fronts and icon rears, pending install of the king rears.

You can definitely tell there is a different valving in play, it's not necessarily bad, but it's different.

 

Cool thanks for the input, I think I might jump on them. I'm more of a 4lo and slow kind of guy anyway, only really do the high speed stuff when I'm trying to keep up with the others I wheel with (wasn't/isn't easy with the 5100s, lol). I'm leaning toward pulling the trigger on them, regardless it will be much better than my previous setup I think.

 

Good question. Leaf springs tend to be progressive rate, so how does that change damping profile when compared to a coil that's usually mostly linear?

 

Fox only has one valving option. We take every shock apart and tune it for your vehicle and your terrain at no extra cost.

 

That's an extremely complex question because it depends on whether it's front or rear, where the rate changes in the travel, and how aggressive the rate change is. Things like this are why I created AccuTune equations, to handle the extreme complexity and variety that can happen even on the same platform. It took 4+ years of testing in the desert and in the lab to be able to accurately figure that out. Suspension is fun, hahaha.

 

Did you upgrade springs? I thought the 2.5" came with 600 lb coils? If someone isn't running any weight up front with the 600# coils, it should be much less like you are describing.

 

My coil overs came with silver 13", 600 lbs Eibach springs. I replaced them with 14", 650 lbs King springs to compensate for an ARB bull bar, winch, dual batteries, sliders.

With a stock truck the FOX springs were sufficient and maybe slightly stiff but once I started adding things I was turning the collar pretty far down the body to keep the ride height >2" over stock.

I will say the stock set up rode like really nice with the extra battery and bumper, like a Cadillac. Parking lot speed bumps disappeared. I didn't run it long like that so I doubt it would have been a very stable ride, but it sure was cushy.

Overall I'm happy with the ride now. It probably needs a little more rebound damping for slow speeds, that's about it.

 

A lot of people mix up the need for more spring and the need for more damping. On the front of a Tacoma I would run as little spring rate as possible to get the desired ride height without the spring going coil bind (a real concern). Then I'd make it ride well by fixing the damping.

Any stiffness from stock valving on Fox and King Reservoir shocks is coming from the heavy spring which could give you some harshness on gravel type surfaces. But it really depends on your tire/wheel/air pressure.

 

It's interesting you mention spring rate vs damping. What's your $0.02 on everyone getting 700 lb/in springs?

Over gravel and graded dirt my truck rides fantastic, very happy with that ride. Well controlled and can drink your hot coffee without worry smooth. It's crawling where it wants to rebound too fast. That's why I wished I could get 625 lb/in, 14" springs but that's not a typical configuration so I err'd on the high side to prevent bind, as you mention.

FWIW, I run 235/85R16 load range E BFG AT KO2 usually at ~32 psi both front and rear.

 

I think it's way too much spring rate and should only be used if ride height can't be achieved by adding preload due to coil bind height constraints. Unfortunately heavier springs have less travel so as you go up in rate you can't add as much preload without running the spring solid. So I see how some people need a 700 lb/in spring to get ride height, but I wouldn't just immediately go there.

 

They will be an upgrade to your current set for sure, so probably a good idea if it's a good deal.

You can always a) revalve them or b) sell for what you paid and buy kings. Or decide that you like the Icon ride better and sell the fronts...