650# 700# or 750# springs on Fox 2.5 Elite Series?

Is that your current truck weight? What is your spring height when parked level? If your springs are 14” free height, I’m guessing parked height is ~10.75-10.8”(average both sides) but would be curious to know, to confirm my thoughts about factoring in motion ratio to estimate truck weight by spring height. (I just realized I can’t accurately confirm my formula on my own truck because my current weight has changed since I last weighed it, but I have a general idea.)

 

It is current truck weight. Can't say for sure on measurements since I've trimmed ~2.5" off the fenders/flares. I think I can confirm it's not more than like 2" of lift given my CV angles. Springs are King 14" 700# variety.

 

It doesn’t matter what the lift height is. I’m curious what the spring length is while the truck is parked level. (Average between the two sides.) That measurement is always static, unless the truck weight changes or unless you change out the springs.

 

Gotcha yeah I'll take a look tomorrow

 

https://youtu.be/uiADcthIDyo?si=cyHxQTpJKWAkILS1

 

Just went out and measured. Driver side is about 10.25 and passenger 10.375.

 

This is all very helpful information. At this point, the coil overs are installed on my truck. I guess I’ll wait till the bumper comes in put the lights, winch, and accessories on it… and see how she sits/handles. At that point, I will have a better idea of the CV angle, and lift it’s going to provide, as well as how it handles. At that point, I can always bump up to the 700 pound spring, if need be, Or decrease the preload on my current set up. Here’s a question. Do I need to take apart the coil over in order to decrease the preload or can I just jack the truck with the wheels off the ground and turn the preload collar with a spanner wrench?

 

you appear to have a C4 bumper that has been powder coated is that correct? I ordered my bumper powder coated from the factory, it’s my understanding that this is a new offering that they are offering since they were purchased by a larger parent company. If yours is powder coated, how is it holding up I’m thinking about just running it with the factory powder coat, but I’m also thinking about having LineX sprayed over the Powdercoat for extra durability in rust prevention… How’s yours holding up ?

 

So C4 didn't offer powder coating when I got the bumper like 4 years ago and I got it coated at a place in Danbury, CT called https://chem-tron.com/ that was fantastic. They did my front and rear bumpers back in 2021 and they're both still flawless in places not directly stripped by rocks and trees.

It's a ways from Maine but if you're in the area I would trust them to PC absolutely anything I wanted to last.

Edit: one thing I don't like about the C4 bumper is the position of the recovery points. They should be positioned on the front of the bumper by the light bar, but as they're positioned downward now they wind up becoming an obstacle on the approach angle. I had this happen multiple times in Moab.

 

Thanks for the response… I will make sure to come back to this thread after a year and give everyone an update on the in-house powder coating done by C4 now

 

Tons of great info here.

I have similar mods on my truck. C4 bumper, lights, winch etc.

I am running nearly zero or 1" of lift (as measured from hub to cut fender) and my kings have 600lb springs. It rides like a couch, I love it. I have adjustable shocks so turning up the compression damping helps when I am on the road, and turning down when I am on the trail.

600lb x 14" springs measure 10-5/8 & 10" (huh, found that lean I was trying to fix)

 

Stock length control arms (i.e. not long travel) ? What wheels and tires? (Wheel offset?)

 

Everything is a trade-off. C4 positioned the recovery points to be in line with the frame and bumper mounts, so they don’t create an unnecessary moment arm for recovery forces that could end up bending things. I forget who does it, but some company recesses their shackle mounts so they don’t take away from the approach angle. Notably, pretty much every off-road bumper for Tacomas creates a moment arm against the bumper mounts when the winch is used. The difference there is that force applied by winching is usually slow and steady, unlike a quick pull from a kinetic rope or (worse) a tow strap or chain.

My bumper sticks out so far I end up dragging the corners up steep climbs, e.g. coming out of the last hole on the escalator, on the passenger side of the line to keep the truck fairly level. (But also, I’m on positive offset skinny 33’s without long travel, which is probably the absolute minimum build for trying that obstacle in a midsize truck.)

 

I don’t have personal experience with this, but I’ve seen some people on here say truck bed coating (on sliders especially) tends to come off in long strips when dragged against rocks. I’m think I’m about to try a truck bed coating on my sliders but I’m going to use a rattle can variety so it can be touched up. I might spray a test piece first and scratch it with something sharp to see how it holds up.

 

Yeah stock length arms - 17x8 -10et wheels and 35x10.5 Kenda Klever RT tires.

 

Okay, so really rough estimates here:

Each front corner of your truck weighs ~1,500 lbs. That’s about 1,300 lbs. in unsuspended weight at each front corner after subtracting 100 lbs. for the wheel and tire, and another 100 for the rotor, caliper, spindle, etc. (Like I said, rough.)

Your 14” 700 lb. springs compress 1 inch per 700 lbs. of force. With no motion ratio considered, 1,300 lbs. would compress them ~1.86 inches. Your measurements show they are compressing ~3.7 inches (average).

That means they are compressing 1.99 times their rate for the estimated unsuspended weight of your truck — which seems to make sense when we think of the generalization that adding a .5 inch tophat spacer (e.g.) adds about twice the amount of lift at the tires.

That would mean we can make a VERY general formula that a non-long-travel 2nd or 3rd gen Tacoma front end weight can be calculated by measuring spring height like this:

(Spring free length - spring length while parked level) x (Spring rate /1.99) + (weight of one wheel and tire + 100) = corner weight of truck. Do the same on each side and combine the corner weights to get the weight of the front end.

This doesn’t account for a few variables, so is a ballpark estimate. For instance, spring rate is not perfectly linear, and nominal spring rate is only a generalization of actual spring rate. Also, higher lift and more positive wheel offset would reduce that number of 1.99. (The tires move inward in an arc as the vehicle is lifted, reducing the leverage that the contact patch — thus, the vehicle weight — has against the spring, and more positive wheel offset also reduces the amount that vehicle weight is leveraged against the spring, unlike the motion ratio of suspension travel, which does not change with wheel offset on independent suspension.)

@TacoTuesday603 what am I missing?

 

I think that is pretty good for some bar napkin (ignore all frictional losses) type math