Spacer lift theory question

[CJ3Flyr]

There's currently another discussion going on that raises some questions for me. The following quote is from http://www.toyota-4runner.org/showthread.php?s=&threadid=42421 There's much discussion about top-out vs preload with spacers. I brought my question to this new thread because I didn't want to hijack what they were/are trying to figure out.

Originally posted by GoldenRage
Thanks for all you comments.
I need clarification on this: Wheeler's Off road still have a 1.25" lift front coil spacer for 39.95 - either the "on top" or under the upper coil support plate and preloads the coil". If I get the "under" one - that should level my runner with preload - I want a little preload cause at high speed 80-90 mph - I feel the truck floats a liitle, not use to this compared to me old "90 runner.

My guess is I am missing something very basic here... Within the realm of an 1

 

[J.A.]

Spring rate is not affected by the addition of a preload spacer if a straight line spring rate coil (like the factory coils and opposed to a progressive rate coil) is used. If it takes 480 lbs to move the factory spring 1" it will still take the same weight to move the spring 1" after the addition of a preload spacer.

I believe that people say ride quality gets harsher due to the spring having less room to travel in now that the spacer is there. Full compression will be realized sooner and full extension will be reached sooner with the spacer in there therefore the harsher effect by topping or bottoming out the spring/shock. That is why if ride quality preservation is the preference you should go with a smaller preload spacer and the DS old style kit has a smaller preload spacer while giving the same overall lift as the CF 3" front.

 

[CJ3Flyr]

Spring rate is not affected by the addition of a preload spacer if a straight line spring rate coil (like the factory coils and opposed to a progressive rate coil) is used. If it takes 480 lbs to move the factory spring 1" it will still take the same weight to move the spring 1" after the addition of a preload spacer.

I believe that people say ride quality gets harsher due to the spring having less room to travel in now that the spacer is there. Full compression will be realized sooner and full extension will be reached sooner with the spacer in there therefore the harsher effect by topping or bottoming out the spring/shock. That is why if ride quality preservation is the preference you should go with a smaller preload spacer and the DS old style kit has a smaller preload spacer while giving the same overall lift as the CF 3" front.

Thanks, I got it :bigok: I wasn't factoring 'bottoming' prior to hitting the stops on the LCA which is what must be happening.

:cheers:

 

[Falls]

But now the DS are only top outs ....correct ??

Chris , don't feel bad about not understanding/asking . JA has tried to pound this into my head many times , even with diagrams and I still don't really understand. BUT.... I guess from what I understand now it doesn't really matter since all the spacer kits are topout kits.

 

[CJ3Flyr]

But now the DS are only top outs ....correct ??

Chris , don't feel bad about not understanding/asking . JA has tried to pound this into my head many times , even with diagrams and I still don't really understand. BUT.... I guess from what I understand now it doesn't really matter since all the spacer kits are topout kits.

Based on the other thread it sounds like you can order the kit that uses preload and topout. It sounds like it's tricky and involves phone calls, actually getting someone on the line who has a clue and persistence :bonk:



J.A. has been very helpful. :bigok:
It is a bit confusing within the one and two inch realm!



I totally understand when you get into the two+ inch realm it becomes necessary to divide between topout and preload to prevent extending the balljoints too far on toppout or squeezing the spring so tightly there's no room to compress the spring.

Oh well, I guess the whole Daystar post is illustrative of why the CF 2/1 is so popular, it simply works. They have the split between preload and topspacer figured out to preserve the ride quality and the suspension parts. I guess the lesson is when going 'small' you have a few options, when going 'medium' go OME or when going 'big' go Coilover w/aftermarket UCAs

I recently added a 3/4" CF to mine. It came as a preload spacer. I am thrilled with it but it's so small why wouldn't I be? Who has complained about a simple front-end leveling kit? I don't recall any complaints other than an eventual desire for more.

Mike get that wrist better so you can do a little wrenching, add a level kit and finally decide on some tires before the weather turns:biggrin2:


:cheers:

 

[J.A.]

Hi Falls, the old style DS kit appears to be available at least currently, from Wheelers and for a good price too.

Do you still have that 1" CF leveling spacer waiting to be installed? Like Chris said a 1/2" spacer is not going to make a difference but is it topout or like Chris' preload?