Coilover springs and spring rates, weight, lift, ride quality and how they relate.

Yes! that's something I didn't touch upon and will be adding to the OP next...

 

I don't think you can have this discussion without wheel rate; given that many that lift will use spacers or high offset wheels.

Wheel rate=spring rate x motion ratio^2.

Moving the tire out decreases the motion ratio.
Motion ratio is also suspension travel vs wheel travel.
0.8 motion means 0.8" suspension travel vs 1" wheel travel.

As an example, a 1.5" wheel spacer reduces the motion ratio by about 0.1 and reduces the wheel rate by about 10 lbs.

 

I just wanted to post a little update, I did install 14" king coils on the icon COs and the result was as predicted, I got more lift and softer ride without changing the nut height. I actually got too much lift so I had to drop it a little bit so even with all the added weight, I was able to regain my lift and I didnt have to use higher rated springs which would have made the ride harsh. I did the exact opposite.

 

You are wrong. "Preload" only changes your ride height by traveling the suspension. The length of the coil spring itself at ride height doesn't change, it's not more or less compressed, it's carrying the same load thus steering the same energy.

When "preload" causes your ride to suck it can be a topping out condition because you have less droop travel but typically it's the increased downward angle in the a-arms that sends more of the contact patch loads directly into the chassis since the wheel isn't tracking as vertical as before.

 

You have this pretty well figured out. Ride height is adjusted by spring length and spring mounting locations. Spring rate (as it affects wheel rate) dictates your ride frequencies, handling, and dynamically loaded travels.

 

Hi there, I know it’s been a couple of years but I’m kinda facing the same dilemma. I need to get more preload in order to get more lift and the reason being I need to get more clearance for my 33” tires which rub on some occasions. It was fine when I initially installed my coilovers but truck has sagged about 3/4”-1” since. So I want to regain my lift height but I’m maxed out on my Fox 2.5s. Springs are stock 13” 600 lb/inch. So I have 3 options- get 14” 600 springs or 13” 650s or 14” 650s. Obviously I do care about ride quality. Thanks

 

https://accutuneoffroad.com/articles/coilover-spring-rates-for-toyota-tacoma-4runner/

 

I have read Accutunes suspension articles many times over, including the fine print max preload setting below each example and summary from this article.
I believe the relationship of longer 15" to near 16" length coils from Dobinsons and OME, is to approximate/mimic preload settings.
I am not aware that either offers a mid- spring rate option, only 586-590#, straight to 700+#.

 

I’ve read those articles as well. IMO I think anyone with questions should contact @AccuTune Offroad or any other vendors that offer great advice on set ups. For me I’m 1000 lbs over stock with full steel armor , front bumper , winch etc. Why when talking with Accutune I went with 700lb coils on my kings. I’m super happy with set up.

 

I am willing to bet there are many heavy 3rd gens on sub 600 rate springs, effectively preloaded to the tilt, that could benefit by a heavier rate spring option without sacrificing ride quality, and maybe even improving.

 

I‘ve read those articles before they don’t give definitive answer. Everything varies from truck to truck depending on etc.
So I guess I just need to go ahead and see what happens and I’m going to try 14” 600lb/in springs as Accutune declares that I can get up to 2 5/8” preload on those. Also I don’t run any extra weight in the front except the LED bar but it always nice to have some room in case I decide to add equipment. Thanks everyone

 

I'd go with Accutune's rec on your Fox for sure. They are dialed in tight.

 

What makes you think your Fox 2.5s are maxed out?

How much added weight do you have up front over stock?

Ride quality will come with proper spring rate and valving. We definitely need to get the correct spring on there first, then we would typically revalve the shocks to work the best with that rate and vehicle.

 

Preload is at the max recommended by Fox - ( I believe it’s 21” top to bottom) which is about 1.93” of exposed threads. Not much of an extra weight- just a LED bar - so I don’t need heavier spring.
I’m thinking to replace factory 13” 600lb/in springs with 14” 600lb/in ones to have some room to play with the ride height.
Thanks