Whats my spring rate?

Hey there, I've been running my Fox 2.5" Extended travel Coilovers for a few months now. LOVE them. Theyre model #

$1,607 880-02-418 Coilover and Upper Control Arm Kit

880-02-418

I recently ordered a new bumper (~100lbs). I've noticed to attain my current lift height, i have placed quite a bit of preload on the springs. I'm worried the new bumper will be pushing those poor springs and my preload to the max. So, the question is.... whats the spring rate are my springs? i can't find the info ANYWHERE. I've looked for a few hours, and even called fox. I've searched all i can think of. Im guessing my spring rate is too low though... SO which springs should i get? Taller, or stiffer?



A good idea of how much preload I have



Suspension off the truck


the bumper that will be installed next week. ~100lbs

 

The springs are probably around 650lbs, like the "stock" ones from ICON (and other manufacturers).

100lbs won't make much of a difference. Certainly not enough to justify putting stiffer springs in.

I saw my front-end dip by 1/8" when I installed my low-pro bumper and winch (130-150lbs total); ICON 2.5 coilovers up front w/ 650lb springs.

As far as how much preload you currently have - quite a bit. I'd be careful with that as there are limits to how much you can/should crank it. You need to find the max that FOX recommends and ensure you're not over it.

 

According to @Downsouth Motorsports's posts in this thread, the coilover part number you listed comes with 13" long and 600lb spring-rate springs. In that case, you may want to step up to 650lb springs. You can probably get them from Eibach.

 

Good to know, this is a good start to my search. I've def noticed the amount of preload I have and it worries me too....Ii have them set at 2.5" over stock lift height. Fox advertises i can get 3" (I'm accounting that 3rd gen is 1" higher stock)

Thank you, for your time and help. i honesty appreciate any help you guys offer.

 

Ahh! Yes... I've been having an idea that they were pretty "light" springs.

 

Right, so if Fox says 3", then that translates to 2" for the third gen. If you're sitting at 2.5", they are probably cranked a bit higher than they should be. Probably as in, it will vary from truck to truck. FOX can give you a simple measurement of how much coil thread can be exposed at max setting (something like 2", or 2 1/4"), and you can then compare that against the visible thread on your setup.

 

perfect. I'm gonna place a few more calls tomorrow. If the rate is truly a 600lb rate, ill be going up to a 650lb for sure.

I'm sure the body roll will be much less noticeable too as i have no swaybar

 

Lighter spring rate will make for a softer ride. A 50lb increase in spring rate can make a very big difference in ride quality. Note that with heavier-duty springs, the max amount of preload you can run will change. Again, using ICON as an example, I vaguely remember that on 650lb springs you can have about 2 1/4" of preload, but on 700lb springs, the max is about 1 1/4". So it's a pretty big difference, and there's likely to be a similar one if you step up from 600lb to 650lb coils on your FOX setup. Best to confirm specifics with FOX.

 

I'd wait until your bumper is installed before ordering replacement springs. See how much things change and whether you like the new setup or not, then make the call.

 

Makes sense. I'm gonna give that route a go.
I truly appreciate the time you spent to help a guy out.

 

How do you like the fox kit so far OP?

 

I love it. Worth every penny so far!

 

I have the same set up with my All-Pro UCA with sway bar delete. I was already going to increase spring rate to 700 but curious if 650 is enough. Currently no front bumper but was eying the all pro 2.0 bumper soon. I too have quite a bit of preload to achieve the 3" or 2" net lift. As far as Fox providing thread length they only tell you to keep adjusting collar height to achieve net lift.

 

Nice! I can't wait for my 2.0 bumper to arrive. Should be any day now.

I'll be calling fox today to get some better answers hopefully. Then I think I'll make a decision from there on getting some heavier springs.

 

I was waiting on the bumper to be provided with a hoop bar but awesome looking bumper and on the lighter side which I like. Please post spring details once you figure it out. I assume you might have to contact Eibach for new springs.

 

I have FOX IFP non-reservoir. You can look on the springs themselves, there should be a part number. On mine it was 039-26-004A. This is FOX's number for a 3", 13" long, 600 lb/in coil. Eibach makes them AFAIK.

I found that it was plenty and I run an ARB bull bar front bumper. I did end up putting 650 lb/in 14" springs in anticipation of putting in my winch but my project to restore it (it's an old XD9500 that needs to be painted and new grease put in) stalled. The ride with 650 lb/in springs is a little stiff. It rode really well with the 600 lb/in.

 

Will do!
I'm looking at eibachs or a set of king springs. I'll post here when I decide!

 

Good to know!

I'm gonna give it a shot with the 600lb springs. I plan on keeping the All-Pro winchless for a few months while I save my pennies

 

There are a couple of good threads about this. My $0.02 is with 2nd gen 700 lb/in springs are getting up there but this may not be the case with 3rd gen since you started with a higher spring rate from Toyota.

https://www.tacomaworld.com/threads...-springs-and-aftermarket-plate-bumper.214013/

https://www.tacomaworld.com/threads/icon-2-5-c-os-king-14x700-springs.212046/

 

@brendanwebster911 any updates on possible 650 # springs?