Swapping Coils from 600lb to 650 or 700?

I am getting ready to pull the trigger on swapping out the 600lb coils on my 2.5 extended travel Kings with adjusters and going up to 650 or 700lb coils. Seems like most people are going to 700lbs, regardless of their setup, but I am not trying to make the on road manners complete garbage.

I currently have an AGM battery, a steel plate front bumper (140lbs) and some sliders (130lbs) with no other significant weight added towards the front of the truck outside of that-- and no plans to add anything else in the near term.

I know this is all preference, but since my setup is so common I assume there will be some opinionated answers. Thanks in advance for any info/opinions!

 

I have Kings as well but no weight. You already have weight added and I hear with the 700lb spring the truck feels a lot firmer and handles well. I would go with the 700lb spring if I were you.

 

I have the same coil overs and I might be adding front and rear bumpers in the near future. I choose the 600 lb springs because I wasn’t sure if I was going to add a bumper and if I did I planned to add an aluminum one.

When and if I add bumpers and I don’t like the ride height I plan to increase the preload. If it feels underdamped I will consider sending the coils off for tuning. As a last resort I will go to 650lb springs.

More information here:

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

And this video:
https://m.youtube.com/watch?v=-MsKf1lIYI0

 

I love all the info Accutune has put out and read/watched it all I think. If I were to do it all over again, I would pay the little extra cost to have gotten my shocks from them tuned from the get go... but I didnt and seems all little too intense to do a rebuild on 8k mile coilovers-- maybe in another 20k miles that will be the solution.

In the meantime however, I do want another 1/4" - 1/2" of lift, however that is not my main objective of swapping out the coils as I found out via Accutune that preload isn't asssssss bad as everyone on this forum preaches. Its definitely still feeling a little too soft/under dampened.


....but f@Ck it, maybe I will just drop the truck off for a couple days at Accutune.

Circular thought process continues.

 

Kind of my thought process as well... just trying to hear some personal experience from somebody with a similar set up. Only been in two other tacomas with kings, both had zero added weight and had 600lbs coils.

 

I’m currently running 650lbs coils on my
Kings with a bumper, winch and skids. I’m going up to 700 pound coils as soon as I get a chance to swap them. They’re just sitting on the bench waiting to go in the truck. I thought the ride was great with 650s and no extra weight. Didn’t have much nose dive with the sway bar off, not too stiff with it on. But once I added everything else, the 650s no longer cut it for me. I’d just go straight to 700s so you don’t become the owner of 2 sets of springs, like me. Also think about what you’ll be running in the rear. It’s weird to have a super stiff rear and nose diving front or vice versa

 

Well.... if you feel like getting rid of those 650lbs springs to take some of the sting out of the second set-- let me know

Thanks for the input, without the skids and winch I feel a little uneasy though. As for the rear end, I just have the Icon progressive 3 leaf AAL with the stock overload taken out. It rides okay, but plan on getting hammer hangars and some medium duty leafpack in the next year or so to get a little more travel without changing up the ride height/stiffness.

 

Good info! Thanks, I probably will reach out to them to get a quote and turnaround time anyways just to help some of my circular thought process.

 

In general preload doesn’t directly cause problems until the point the coils are binding before the bump stop is reached. All you are really doing is changing the ride height. The spring rate remains the same. If it is a 600 lb/in coil spring it will compress 1in for every 600lbs of load regardless of preload. Hooks law is linear.

F = -kx

https://en.m.wikipedia.org/wiki/Hooke's_law

Indirectly, using preload to increase ride height can get you into trouble if you end up with too little down travel. Increased ride height also messes with your alignment but that is easily correctable as you probably already know.

 

I’ll let you know but @whatstcp got me thinking I’m crazy going to 700s haha. Just trying to stiffen things up for pulling the camper.

 

In my opinion, most people don't need 700 lb coils but do it anyway because they see other people doing it. You'll be very happy with 650.

 

I think in general that if you are looking to improve your ride quality you should be thinking about your shocks (i.e. damping) and suspension travel; not your springs. For example, if you are bottoming out too easily, you should first think about increasing your damping rather than your spring rate. It’s damping that converts the kinetic energy to heat; not the spring. The spring alone is only capable of storing and then releasing the energy. It’s more complicated than this, but that’s the general idea

If you have ever ridden a dirt bike, you may have observed that the springs are quite soft. They compress quite a bit when you sit on the bike. Yet when you catch a bunch of air and come crashing down on the ground, you don’t break your back. It’s the shock doing that. It’s more complicated than that, but that’s the general idea.

While springs exert a force proportional to displacement, dampers (ie shocks) exert a force proportional to velocity. That means that they push back harder the faster you push.

F = -lv

 

This article is a great read as well.

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

 

Beat you to it.

 

You should probably space out the link and the YT video because it's easy to miss. I didn't see it until this comment.

 

650s will ride softer, 700s will be ride stiffer.

I run no swaybar in the front and have full armor plus a winch bumper. The 700s are a bit harsh with my Fox coils, but I still get body roll. I'd rather keep my stiffer springs with a bit of a rough ride than have more body roll from 650s.

 

It sounds like you would benefit from a lighter coil and a custom tune.

On my truck, I hade 660lb coils and OME stiff shocks. I went to (used) Kings with 700 coils and had MORE body roll because they were valved softer. But they also rode like garbage because it was too stiff a spring and it would top out over bumps. I've since swapped to a lighter coil.

 

Good idea.

 

Everyone would benefit from a custom tune - suspension is all about compromise to get the best average performance. They definitely don't cater by default directly from the factory to heavily modded rigs like ours.

If I could do it again, I would have started with a custom setup from Accutune. I would also do airbags instead of Sumosprings since I have onboard air anyways. Good thing suspension eventually wears out - it'll give me an excuse to have it rebuilt custom in a few years. I already have ~40k miles on this setup (53k on the truck).

 

I’m saving my old suspension in part because I was thinking I will temporarily reinstall it if and when I send my shocks for a rebuild/retune. I don’t think I’ll have trouble on the front, but on the rear I think my leafs (OME) have too much travel, so I’m not sure if it is workable. Can I drive carefully and get away with it?