User Tag List

Reply
 
Thread Tools Rate Thread Display Modes
Old 05-19-2021, 09:40 AM #1
awerking awerking is offline
Junior Member
 
Join Date: Oct 2019
Location: Apex, NC
Posts: 24
awerking is on a distinguished road
awerking awerking is offline
Junior Member
 
Join Date: Oct 2019
Location: Apex, NC
Posts: 24
awerking is on a distinguished road
Bilstein 6112 spring preload question

2019 TRD Off Road Non-KDSS

Getting ready to lift - heavily leaning toward Bilstein 6112/5160. Adding a front hybrid bumper and winch so going with the 650lb springs up front. Going to keep stock rear springs for a bit until I get my rear bumper at which time I'll upgrade to heavy load springs out back.

Question - to correct driver's side lean, some recommend offsetting the spring preload (i.e. drivers side circlip on the top setting and passenger side circlip two notches down to get an even 2.5" lift on both sides). I'd prefer to have the same spring preload on both sides, so how big of a spacer will I need? I've seen recommendations that range from 10mm and up, so I'm not sure which to get.

Thanks in advance for the help.
__________________
2019 TRD Offroad XP Predator
awerking is offline   Reply With QuoteReply With Quote
Old 05-19-2021, 11:19 AM #2
4Person 4Person is offline
Member
 
Join Date: Jul 2020
Posts: 40
4Person is on a distinguished road
4Person 4Person is offline
Member
 
Join Date: Jul 2020
Posts: 40
4Person is on a distinguished road
I just did the 6112s on my 15LE last weekend. I decided to go with both at the #5 perch and add a 3/8” (~10mm) spacer on the drivers side. My reasoning was that it was easier and less expensive to add or subtract spacers rather than disassemble and reassemble the struts and springs to adjust.

The good news is that I’m sitting level side-to-side.

The bad news is that I only ended up getting about 1.75” of lift on the #5 setting. I only had the 600# springs though.
__________________
Mine - 2015 Black 4Runner LE
Hers - 2017 Black Highlander XLE

Last edited by 4Person; 05-19-2021 at 11:21 AM.
4Person is offline   Reply With QuoteReply With Quote
Old 05-19-2021, 11:50 AM #3
Muff Muff's Avatar
Muff Muff Muff Muff is offline
Member
 
Join Date: Mar 2020
Location: Corpus Christi, TX
Posts: 75
Muff Muff will become famous soon enough
Muff Muff Muff Muff is offline
Member
Muff Muff's Avatar
 
Join Date: Mar 2020
Location: Corpus Christi, TX
Posts: 75
Muff Muff will become famous soon enough
From a physics standpoint, having your struts set with a different preload is effectively going to make the more compressed side stiffer than the longer, less compressed side. It's not something I've ever done it practice, but I also wouldn't think that it'd be advisable if having a level ride is your only goal. When it comes to vehicle dynamics, having everything equal and balanced is key.
Muff Muff is offline   Reply With QuoteReply With Quote
Old 05-19-2021, 12:53 PM #4
dezertbomber dezertbomber is offline
Member
 
Join Date: Nov 2019
Location: San Diego
Posts: 120
dezertbomber will become famous soon enough
dezertbomber dezertbomber is offline
Member
 
Join Date: Nov 2019
Location: San Diego
Posts: 120
dezertbomber will become famous soon enough
Quote:
Originally Posted by Muff Muff View Post
From a physics standpoint, having your struts set with a different preload is effectively going to make the more compressed side stiffer than the longer, less compressed side. It's not something I've ever done it practice, but I also wouldn't think that it'd be advisable if having a level ride is your only goal. When it comes to vehicle dynamics, having everything equal and balanced is key.
It's the same spring rate so since these have single/linear rate springs it does not change the stiffness regardless of spring positioning (would be a different story if progressive/dual rate springs). If the suspension were to let the coils bind during compression then that's where an imbalance could occur, but that does not happen that I've experienced.

I have the 6112 7/5 650lb springs up front (stock bumper) and did a 2,000+ mile San Diego to Moab and back trip recently; feels the same on both sides. (I'm not running either sway bar so the effect would be even more exaggerated if the stiffness were different between sides.)

I have HD 2" springs in the back and the 5160's do not have enough rebound dampening valved, and leads to a sloppy feel when loaded. Unloaded, it's stiff, but smooth.

Last edited by dezertbomber; 05-19-2021 at 12:56 PM.
dezertbomber is offline   Reply With QuoteReply With Quote
Old 05-19-2021, 12:59 PM #5
TEujunga's Avatar
TEujunga TEujunga is offline
Member
 
Join Date: Apr 2017
Location: Eugene, OR
Posts: 277
TEujunga will become famous soon enough TEujunga will become famous soon enough
TEujunga TEujunga is offline
Member
TEujunga's Avatar
 
Join Date: Apr 2017
Location: Eugene, OR
Posts: 277
TEujunga will become famous soon enough TEujunga will become famous soon enough
Quote:
Originally Posted by Muff Muff View Post
From a physics standpoint, having your struts set with a different preload is effectively going to make the more compressed side stiffer than the longer, less compressed side. It's not something I've ever done it practice, but I also wouldn't think that it'd be advisable if having a level ride is your only goal. When it comes to vehicle dynamics, having everything equal and balanced is key.
Ah, the "pre-load myth" lives on - and justified as "physics," no less! Back to class with you, sir!

The amount you compress the spring to fit it into the coilover assembly prior to installation is irrelevant. It does not change the spring rate. With the weight of the truck resting on the spring, it will be compressed the same amount no matter how much "pre-load" was placed on it at installation.

Increasing the "pre-load" in effect simply moves the position of the lower spring perch upward. Being that the compressed spring will be the same height under the same load, the overall height of the truck is raised as a result. Has nothing to do with any increased "stiffness" of the spring.

Leveling by adding spacers or by increasing the "pre-load" accomplishes exactly the same thing -- it just moves the effective position of the lower spring perch on one side of the vehicle in relation to the other.

Edit: Dezertbomber beat me to the punch!
__________________
2016 Trail Edition w/KDSS - Super White - Toytec - Eibach/Bilstein - Kumho 275/70-17

Last edited by TEujunga; 05-19-2021 at 01:04 PM.
TEujunga is offline   Reply With QuoteReply With Quote
Old 05-19-2021, 01:15 PM #6
Muff Muff's Avatar
Muff Muff Muff Muff is offline
Member
 
Join Date: Mar 2020
Location: Corpus Christi, TX
Posts: 75
Muff Muff will become famous soon enough
Muff Muff Muff Muff is offline
Member
Muff Muff's Avatar
 
Join Date: Mar 2020
Location: Corpus Christi, TX
Posts: 75
Muff Muff will become famous soon enough
Quote:
Originally Posted by TEujunga View Post
Ah, the "pre-load myth" lives on - and justified as "physics," no less! Back to class with you, sir!

The amount you compress the spring to fit it into the coilover assembly prior to installation is irrelevant. It does not change the spring rate. With the weight of the truck resting on the spring, it will be compressed the same amount no matter how much "pre-load" was placed on it at installation.

Increasing the "pre-load" in effect simply moves the position of the lower spring perch upward. Being that the compressed spring will be the same height under the same load, the overall height of the truck is raised as a result. Has nothing to do with any increased "stiffness" of the spring.

Leveling by adding spacers or by increasing the "pre-load" accomplishes exactly the same thing -- it just moves the effective position of the lower spring perch on one side of the vehicle in relation to the other.

Edit: Dezertbomber beat me to the punch!
I started going over Hooke's Law in my head trying to figure out what I wasn't getting, and then I remembered about the vehicle weight...

Spend all these years doing the upper level stuff, sometimes you forget the basics. XD

Last edited by Muff Muff; 05-19-2021 at 01:18 PM.
Muff Muff is offline   Reply With QuoteReply With Quote
Old 05-19-2021, 04:42 PM #7
awerking awerking is offline
Junior Member
 
Join Date: Oct 2019
Location: Apex, NC
Posts: 24
awerking is on a distinguished road
awerking awerking is offline
Junior Member
 
Join Date: Oct 2019
Location: Apex, NC
Posts: 24
awerking is on a distinguished road
Thanks, everyone, for the responses. This board is great!

So the short of it, as I understand it, is "Just set the spring perches so that the truck is level, and don't worry about it, because it doesn't change the spring rate and will feel the same".

Appreciate the clarity!
__________________
2019 TRD Offroad XP Predator
awerking is offline   Reply With QuoteReply With Quote
Reply

Tags
bumper , preload , side , spring , springs

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
BILSTEIN 6112 / 8112 Heavy Rate Spring Upgrade Now Available! PN 53-291387 Battle Born Offroad 5th gen T4Rs 39 06-22-2021 04:40 PM
Bilstien 6112 heavy load spring question Forum148 4th Gen T4Rs 0 02-06-2020 10:14 PM
BILSTEIN 6112 / 8112 Heavy Rate Spring Upgrade Now Available! PN 53-291387 Battle Born Offroad Battle Born Offroad 1 05-10-2019 06:22 PM
Bilstein 6112 Strut Spring Assemb + 5160 Reservoirs Set 03-09 4Runner 4WD 1.9" meltdowner 4th Gen T4Rs 2 10-07-2018 10:28 PM

Powered by vBadvanced CMPS v3.2.2

All times are GMT -4. The time now is 08:13 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Feedback Buttons provided by Advanced Post Thanks / Like (Lite) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Lite) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
***This site is an unofficial Toyota site, and is not officially endorsed, supported, authorized by or affiliated with Toyota. All company, product, or service names references in this web site are used for identification purposes only and may be trademarks of their respective owners. The Toyota name, marks, designs and logos, as well as Toyota model names, are registered trademarks of Toyota Motor Corporation***Ad Management plugin by RedTyger
 
Copyright © 2020