LR shock and spring setup

[billetbirdcage]

Billet can you offer more on the digressive and progressive concepts, I dont want any secrets . Just a general conversation to better enlighten

I can't say I got all the answers here as everyone seems to like different things. There are tons of ways to do a LR stack, personally I tend to not really look at them as progressive or digressive in a normal sense on their rate. I sort of have my own way at looking at them, which is sort of hard to explain but in my mind it makes it easier to make sense of it all and figure out what the car wants.

People get so caught up in certain things, but miss the big picture. This goes back to what I said in my first reply to you: That a single linear spring on the LR behind generally don't act linear at the wheel. With that being said, here are some things that can happen (I'm not going to overly explain or get into this very far)

Example:

Car A has a 87.5# rate spring (say a 175/175) and has 300# of extended load at full droop
Car B gas a 87.5# rate spring (say a 175/175) and has 200# of extended load at full droop
Car C gas a 87.5# rate spring (say a 175/175) and has 100# of extended load at full droop

I'm keeping the rate the same for simplicity, Typically if you change nothing on the car but just change the adjuster on the car to vary the open load from car A to car C and anything in between, you'd expect the car to stay up better with more open load. This is basically because there is more tension on the spring to over come for the car to fall. While this is generally correct, without taking into the progression/digression of the LR suspension on the spring rate the wheel sees it's possible for this to happen:

Car C even with the least amount of extended load could easily be the hardest to make the car set down.

So without taking all this into account you may not be accomplishing what your trying or making it harder on yourself.

[Kromulous]

I posted those videos just for reference purposes, so people can see the technology is out there at least. Application for a SLM would need to be worked on.

Interesting thou, i kind of like the idea of one of those on the RF. You could really use some of the added compression and the rebound of that style of shock when all the weight is over on the RF in corner entry. So essentially you could have a zero point of rebound way up and then ease off after that 1st 1 or 2 inches of travel.

[Kromulous]

Along the with the springs discussion.

A stack of a 275lb spring and a 125 lb spring yield a 86lb rate, close as i could get to Billets post.

Still thinking about King1's post, but I would think you could pre-load this to 100 lbs load at full extension that would require 1.45" of pre-load on the combo as a whole.

Now at ride hgt you have 675 lbs (18"), you could set the adjuster nut / lock out to engage and carry that weight, and that would require 2.45" of compression. So from full hike 24.5" to ride HGT is 18" (Just made up numbers) thats 6.5 inches of travel. You would engage the lock out about the last 1/3 of travel.

What i don't know, but will figure out is, will i lose the initial 100 lbs of load when the lock out engages?

Anyway, i would assume this set up would handle drastically different than a 200 / 150 stack, that correct?

King1 am i on the right track? LOL

[hucktyson]

I doubt you would feel the difference between a 275/125 and a 200/150 ..... if it’s a track where you stay in the fuel the entire time and the car stays fully hiked I really can see how anything but the open load comes into play. But even if not the rate difference between those 2 can’t be much

[sidewinder69]

Okay so your example implies the extension load doesnt matter because apparently the motion ratios or rotation effects more. Tell more

[Kromulous]

One thing i would say about the 2 different spring combos is that springs at various wire diameters behave differently.

Whether you could tell a difference behind the wheel i have no idea, King1 implied there would be, but i honestly don't know.

I was late to the game with the whole light spring pre-load deal, but we love it so far.

[fastford]

thats what i cant understand about locking the heavy spring out , the reason we run a stacked left rear is to have a light spring rate with a lot of travel to keep load on tire at full droop , to me they have to work together from static ride height to full droop , i must be missing something here.......

[hucktyson]

I think a very important point that needs to be made is that NO ONE who is winning Crown Jewels is posting anything on here. I truly believe a lot of what is posted here is to baffle people with BS more than anything. I don’t even think anyone winning 10k Lucas or outlaw shows in the current era is posting anything here let alone crown jewel winning guys. We have tire loads the timing of those loads and we have rear steer ..... a bunch of different ways to generate tire loads and I’m sure different combinations of rear steer that cAn be used at different times to create different outcomes. You can try to complicate it however much you want but it still comes down to that

[hucktyson]

I hear guys talk about magic this and trick that and heard a guy during an interview say “ these shocks make more dig than anything I’ve ever felt lol. There’s a reason some guys are consistently top 5 at major events and some guys either win or DNQ ... there’s guys the fully understand what they are doing and guys who say stuff like “ these shocks make great dig “ lol

[RaceEngineer]

I have never seen a Nobel prize in physics awarded to a world 100 winner. Not even Rumley.

[fastford]

Oh , I agree with you huck , but there is knowledge to be gained on here , but the only way to gain that knowledge is to wade through all the BS , which is why i question what i dont understand......

[sidewinder69]

Exactly , nobody is looking for a setup to win the world 100. We just look for assistance to develop our own theories and knowledge .

[TeamRocket42]

Not every winning car is using a lock out nut on the left rear. The stack combo most top teams are using is nothing like I have read on this board as well. Not even close.

[hucktyson]

Many of them don’t even have a spring on the left rear. A big factor is a the huge difference an elite wheelman makes ... engineers will never fully own this sport due to the enormous variable the driver adds to the equation ... and the changing track conditions and patches of traction and patches of ice in the same corner

[Kromulous]

You can look at springs now days and pretty much guess the rates or close, and i have noticed some really thick wire diameters on the lower springs. All i can say is i tried dual 150's and a lock out and was not nearly as good as the single spring were running now. Although with the 75lb rate i did not have it pre-loaded to the degree i do now so maybe thats the difference.

Anyway great discussion, thanks to all those that share their knowledge its appreciated by me.

[TeamRocket42]

You can look at springs now days and pretty much guess the rates or close, and i have noticed some really thick wire diameters on the lower springs. All i can say is i tried dual 150's and a lock out and was not nearly as good as the single spring were running now. Although with the 75lb rate i did not have it pre-loaded to the degree i do now so maybe thats the difference. Anyway great discussion, thanks to all those that share their knowledge its appreciated by me.

That's going in the right direction....500 600 700 800 lowers. I'm not going to give it all away but if you think about it some you will figure it out.