21 4runner with KDSS need help with picking correct rear spring for fox 2.5 dsc setup

Hey! i just got a 21 4runner TRD OR with KDSS a few months ago, i have on order fox 2.5 dsc (883-06-130) for the front which is 0-3 inch of lift and i have the fox 2.5 dsc (883-26-004) which is 0-1.5 inch of lift and i really need help with the rear spring question. being KDSS i have heard to try to keep it under 1 inch of lift. how crucial is that? i have 285/70/17 tires ready for it once shocks come in and im so confused on the rear spring. I will have sliders welded on it and i eventually want to get a low pro front bumper (around 75 pounds) and probably some roof racks of some sort. nothing crazy in the rear really. what should i get? 1inch? 1.5? 2? what are the pros and cons to each one?

 

I think the closer to 3” you get, then you’ll need to hit spacers for the KDSS system. I’ve also read that panbar adjusters are recommended at that height.

 

closer to 3" for the front or rear? if its the rear, are we talking about coil lift or shock lift?

 

The rear you are limited by the KDSS ram. We just tried out the KDSS drop bracket from Black Gate which helps allow you to run a longer shock with a taller lift height, but typically a 1-2" lift is plenty to get 4Runners a good lift. If you don't use longer shocks with that lift height, the shocks wont have has much droop travel.

This article may help a little:
https://accutuneoffroad.com/kdss-suspension-tech/

 

I went with the exact set up you mention and went with a Eibach coil in the rear which gave me 1 inch lift. The front coils gave me 2.85 inches of lift with no adjustment. I installed them and made no adjustments and was at over 3 inches but once settled I ended up with 2.85 inches of from lift. 4Runner sits almost level, maybe 1/4 inch higher in the rear. Pic is with 265"s and have since went 285
.

 

I'm still confused by these statements. Wouldn't the regular sway bar limit droop eventually as well?

Agreed. I see 4runners on 3" lift and think it looks weird. I have 2.4" front and 1.5" rear lift and plenty of room for 295/70/17's which is 33.5" (H)× 12" (W). If anyone NEEDS tires much bigger than that, they're probably getting rid of their sway bars anyway.

 

non-KDSS sway bars do not limit travel nearly as bad. Without KDSS we are able to get more shock travel vs a KDSS setup. https://accutuneoffroad.com/kdss-suspension-tech/

 

What your video doesn't point out is that the passenger side will droop further when the driver's side is compressed.

I'm still curious how a sway bar with 2 fixed mounting points allows more travel than a sway bar with one fixed and one flexible mounting point. Have you guys actually measured this?


I have also seen claims that KDSS equipped 4runners are limited to 1-2" rear lift, meanwhile there are folks running 3" without issue. Personally, I think 3" is totally unnecessary. I'm just curious why there's conflicting information.

 

I have 1.5" heavy load Bilstein coils in back, and I'm very happy with them. I have full skids, and always lug around tools and recovery gear. I really need to be loaded down to notice any sag. The ride is a bit rigid, but not harsh.

I have Bilstein 5100's in the rear. With Fox 2.5's, your ride quality should be more cushy. If you're not adding weight, there are other options for coils.

I have KDSS, and no issues with 1.5" lift and a lot of off-roading this year.

 

I ended up speaking to someone and ordered the Dobinson c59-505 https://exitoffroad.com/product/dob...il-springs-for-toyota-4runner-and-fj-cruiser/ the other one i was looking at was the eibach 1inch one. anybody have any input on those 2?

 

i saw the Bilstein 1.5 also was considering them, have you heard good things about Dobinsons?

 

@Crikeymike is the Dobinson expert here.

 

I have. @Chris In Milwaukee is on a full Dobinson setup and seems to be enjoying it.

 

yup he was the one i spoke to and order the Dobinson c59-505 from hoping they work out good, the fact that you run a 1.5 in the rear with no problems makes me feel more comfortable

 

When the shocks arrive ( i have to pick them up from camburg) i will be getting them installed and BMC done and im thinking of getting some slidders made and put on from him! idk if hes on 4runners.com tho he goes by ghost ship on tacoma world. Clean work he does

 

What exactly happens if say the shock in rear only goes 0-1.5 inch of lift and the 1.5 inch coil actually gives 1.75 for example?

 

I still wouldn't worry about it. But, that's me. There is a lot of information about KDSS and lifts. I would read everything you can find and decide what you're comfortable with.

Ironman is the only lift that I can recall reading about ending up higher than advertised.

I think I got the advertised lift with mine. TBH, I didn't take before/after measurements, though.

 

True, although I only have one off-road experience with it so far. On-road manners are exceptional.

 

What happens is you'll (theoretically) be using only part of the shock travel, and worst case you will blow the shock because you're constantly "topping it out." Some rear shocks specify up to 2" lift, so if you're going for one of the bigger lifts (which, IMO, you are with those C59-505 springs), IMO you'd want a rear shock that can take up to 2" lift. From everything I've seen, you may get more than 1.5" from those 505's... I would have gone with the Dobinsons 599, or the Wheeler's T-13, or the Bilstein 1.5" if it was me. That said, if you plan on lifting the front 2.5" or more, you'll probably be happy with the 505... but yeah, maybe with a different rear shock? Your truck and money so it's your call... but I've seen plenty of shocks blown because they were run in conjunction with lift springs that lifted more than the shocks were rated for. That said, it's usually on cheaper Bilstein shocks.. so maybe those Fox's are built a little tougher, and with more tolerance with respect to lift height and "center position" variances in mind.

 

So your saying the 505 will lift more then the advertised 1.5? Your thinking I should go 1 size down to the 599 or even maybe eibach 1inch? So complicated lol I just don’t want a bad ride.

 

It is complicated.

Every truck is a little different, and Dobinsons especially seems to have a hard time figuring out how much their springs actually lift. They've adjusted their specs over the years. I tried hard to go with a Dobinsons setup so I did a ton of research on them. All I'll say for sure is that the 599 definitely lifts more than 1". The 505 is also a pretty tall rear spring, about as tall as *most* will go. I wouldn't do a 1" rear spring though, unless you don't plan on lifting the front much. How much do you want to lift? Do you want to be level or have the factory forward rake?

Regular part-time 4WD 4Runners have a "0/2" stance.. in other words, the rear sits 2" higher than the front. This is so that the rear won't sag when you load it up with gear, and is to help with MPG.

The TRD Pro gets a 1" front lift, so it gets a "1/0" lift for a "1/2" stance.

Some like to perfectly "level" their 4Runner, so they lift their non-TRD Pro front 2" more than the rear (or 1" more on TRD Pro). This is probably fine if you don't ever add much weight to the rear.

Many like to "level" it by lifting the front 1" more than the rear, so that it isn't *completely* level, but looks close while still allowing for some dynamic weight in the rear without being nose-up. This is what the TRD Pro gets from the factory. The little bit of lift up front helps with off-roading, but you still have some rake for MPG and added rear weight.

From there, add your "lift." I went with a 1" "lift" as well as a 1" "level" which means 2" in the front and 1" in the rear. This is my opinion on what looks good and functions well for the 4Runner. I use my hatch area for weight when camping and don't ever want reverse-rake.. but I also don't want stiff springs in the rear because that causes awful bouncing in the rear when it's empty.

 

I’m thinking anywhere from 2-3 in the front. The front coilover shocks go up to 3 inches in front. I have 285/70/17 tires ready to go. Your thinking I should go 599 and cancel the 505?

 

Haha, well 2" is very different than 3", so I think you need to decide how much you want to lift the front.

With 2" front lift, I think a 1" spring is great in the rear.
With 2.5" front lift, I think a 1.5" rear spring.
With 3" front lift, I'd go with a 2" rear spring.

These are just my opinion.

I believe the 599 to be a 1.3" lift spring.
I believe the 505 to be a 1.8" lift spring.

My only concern with the 505 would be the rear shocks. Hopefully, FOX's are built well, and you'll be OK.

 

The passenger side will not droop further under articulation. When the passenger side is at full droop (articulation or straight droop), its either being limited by the shock itself or the sway bar maxed out.

Yes we have measured, we own a non-KDSS 4Runner. The two sway bar systems are very different. With the Black Gates Customs drop bracket, you can fit a longer travel shock. Same shock and no bracket, the track bar will hit the sway bar and become one of your limiting factor.

This also applies to what I mentioned above with shock lengths and the KDSS bracket. You can run a 3" lift, if you accommodate those issues.

 

So, when the driver's side is compressed, the passenger rear shock limits droop? Or, is it the sway bar?

In the video, the vehicle is up on a lift with the driver's side fully extended. That does not represent the maximum droop on the passenger side, because it will droop further when the driver's side is compressed.

 

I think I’m gonna call mike and ask to switch order to the 599. I think it will be safer. Is that a good assumption?

 

Well, if you plan on sticking with a rear shock that is specified to use a max lift amount of 1.5", then yes I personally wouldn't go with the 505. The 599 will be a safer bet.

Otherwise, if you are open to going with a different shock setup, my best advice is to look at photos of 4Runners with each spring, and go from there.

Search google images for "c59-505" and "c59-599"

It really comes down to the look you're after. IMO either would be fine with a 285 tire.

 

I have a 2018 off-road with KDSS and the same Fox shocks. I put OME rear heavy duty springs on my runner. I have a Southern Style low profile front bumper with a Warn winch, Westcott rock sliders and Westcott roof rack. Sounds like you have decided to put a quality suspension set-up on your Runner. I love my set up.

 

What size front and rear shocks did you go with? Also what exact rear coil? Your setup will be similar to my end setup! Also you got the DSC ones?

 

The rear coils are ARB2898 and 2.5 Fox DSC with remote reservoir fronts were just over 2k and the rear 1.3k.