LX 570 Custom Springs?

[OregonLC]

Does the LX have the same spring perches as the LC? Wondering the effect of installing OE LC springs to increase weight capacity without overworking the LX AHC system? Or having custom rate springs made? I wonder how the AHC damping would interact with heavier springs?

 

[Sandroad]

When I was working on ordering/installing airbags in my '17, I learned that the rear springs have the same part number for both Toyota and Lexus (LC and LX). Edit: Apparently the springs are not the same. I assume that means the same spring perch, but I don't know the answer to your other questions.

 

[Malleus]

Does the LX have the same spring perches as the LC? Wondering the effect of installing OE LC springs to increase weight capacity without overworking the LX AHC system? Or having custom rate springs made? I wonder how the AHC damping would interact with heavier springs?

You have to consider the function of the spring and shock to answer that question.

The function of the spring is to limit the travel of the chassis, relative to the axle/wheel/road. The shock serves to dampen the vibration of the spring.

Without the spring, the chassis moves exactly the distance, at the same time, as the wheels as they travel on the road. In the case of a suspended chassis, movement is "out of phase" with the axle movement, and with the spring but without the shock, can actually move toward the ground, as the axle moves upward. With the shock, the tendency for the chassis to up and down "in phase" with the axle is promoted.

Weak springs require strong shocks to dampen their oscillations, and vice versa. So installing stronger (heavier) springs should lesson the impact on the dampening system, including the shocks and AHC, at the cost of a harsher ride, as long as the spring height = OEM. If you change the spring height, you change the suspension dynamics.

 

[OregonLC]

I'm assuming you mean the airbags have the same part number for both LX and LC? AFAIK, the LX has a greatly weaker coild spring, shouldnt' be the same part number.

 

[Sandroad]

Hmm..ok, you're probably right, given the suspension differences between the two. But, if you Google the part number, I think you get reference to both the LC and LX as the correct spring. 48231-60B11 left and 48231-60A20 right?

 

[TonyP]

48231-60E21
48231-60E31

Those are the oem LC springs.

 

[TeCKis300]

I can't say for sure, but the perches are very likely the same, like they were in the 100-series. Since we know the same part number airbag can fit between the two. And the same coil spacer can be used (like I have added to my LX570). Actually, I believe the coil spacer is compatible between the 80/100/200 series which suggests the diameter of the spring is the same.

Back in the 100-series world, there were individuals that used the normal LC spring in the AHC system. With the AHC height adjusted such that at the nominal ride height, the AHC system was at its designed for neutral pressure. That is the key to setting this up - to keep the AHC system within it's nominal load range such that sufficient damping can be applied. Dialing in the right pressure can be practically done with any spring, by adjusting ride height. But at some point, the combined spring rate still has to be reasonable.

AHC is an active system with height and accelerator sensors. So it can adapt to heavier rate springs. Also, we have a manual gain control, if you will, to increase damping rates to an extent to adapt.

Note that the people that tried the normal LC spring in the 100-series, were setup very heavy. Otherwise, that spring is just too much. Others have used an 80-series spring (lower spring rate with similar dimensions). The 80-series spring likely fits in the 200. Or even a 100-series spring in a 200 that has lots of armor. Just to give you a visual, checkout the 100-series AHC spring left vs the 80-series normal spring. Dramatically different in spring rate as you can imagine.

 

[OregonLC]

If this can be figured out it might open up a lot of opportunities for the LX...

 

[DeckerT4R]

May i just say I'm glad there are other people working on this...I just got spacers for the rear i haven't had time to install yet. A solution for the front seems to be the tricky bit to me.

 

[OregonLC]

Are you thinking the front is more complex because it's a strut/spring setup? Shouldn't be that bad, just need a coil spring compressor.

There are a number of players in the custom spring business, the link below is just an example. I imagine it would take a few prototypes to get the right balance with the AHC, and even with that I'm not certain the 'gain' on the stock AHC system would be adequate to get acceptable damping rates after messing with the springs.
Coil Springs - Custom

On the subject, does anyone have data as to what the OE LX spring rates are? And are they linear or progressive?

 

[richxd87]

I've been trying to track down some similar info myself. I've located a front spring spacer from Superpro that may work for the front. I assume what DeckerT4R is referring to being more tricky is the need to bleed/disconnect the high pressure line connected to the front shock in order to remove the coilover.

SuperPro Bushing Kit for LEXUS LX LX570 (J200) - 2007-on

Tried starting some similar discussions here: LX570 AHC height modifications (lift it!)

I've only been able to determine the OE spring rates of the LC based on the OME spring specs.
Front 500 lbf/in
Rear 170 lbf/in

 

[OregonLC]

Spacers will help with restoring stock pressures to an AHC lift but won't neutralize the added weight of a fully built truck.

That LC spring rate chart is a good starting point, thanks for posting.

 

[Ali FJ80]

Its too bad we dont actually know what the 570 pressure levels are supposed to be while its functioning. The 570 AHC is quite a bit different than the 470 and when I scanned mine it does not just display the last cycle pressure like the 470 did. The numbers fluctuate up and then zero out again. I have tried searching online and asked a few folks but nobody seems to know what ideal pressure should be or how to properly test it.

 

[OregonLC]

Are you using the 32 bit eBay Tech Stream cable/app? I wonder if the more recent versions have the capabilty?

 

[Ali FJ80]

Not sure what you mean, it can access the AHC system and shows me everything but am just not sure what pressure ranges we are looking for. The pressure ranges for the 470 are all over the internet. Nothing on the 570. Its an amazon cable, not sure what version.
Here is mine between levels:

 

[grinchy]

Here’s a pic of the four lx570 springs. The tall spring with one extra coil item is the right (us passenger) rear. To determine spring rate we just need a set of springs off the car and a stack of exercise weight plates. Add weight until the spring is compressed 1” and spring rate is identified.

 

[radman]

Here’s a pic of the four lx570 springs.

love that you resurrect a 3 year old thread to post some sexy bits.

is that extra coil to compensate for the gas tank?

 

[grinchy]

love you you resurrect a 3 year old post to post some sexy bits.

is that extra coil to compensate for the gas tank?

Assume so. Maybe we can figure spring rate using that information? The weight of a 1/2 full gas tank is about 100 lb. There are some spring weight calculators, but they require stuff like spring coil diameter and steel diameter, and I haven't been out with my caliper yet. If we can get one corner the others should be able to be approximated pretty easily based on weight comparisons between the 100 and 200.

 

[grinchy]

Shamelessly stealing from another thread discussing AHC weight upgrades

Those are the fronts. I'll take a pic of the rear ones and post by next week..

Made for Toyota Nestle in Germany..

Equipment Land Cruiser V8: OFFROAD-NESTLE

View attachment 1651572

More oil, more damping..

reputed to be $4000

 

[grinchy]

More Spring Pics of the potential options

That's pretty darn awesome you got it to work! An LC100 spring eh? Much like the LX470 days, where they'd take an 80-series spring for use in the 100-series LX470. So how does the 100-series spring feel for the application? About right? Over, under sprung?

Way to forge new paths for the community!

Embedding @Mago 's pics here:


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