Bilstein 6112's with no differential drop

I never said preload changes anything, but it does oppose any force being introduced to the spring and if the amount of preload is greater than the force then nothing happens, exactly what you don't want suspension to do. All I'm saying is a cautionary tale against using preload to jack your truck all the way up. A little is fine, more is worse, and full preload is just asking to blow shocks because your shock now likely has NO uptravel left, meaning that the biggest hits are being absorbed by the structure of the shock, not the piston inside it and the balance between the oil and air pressures

 

I don't think anyone in this thread was suggesting to go out of range of whatever the manufacturers are suggesting for preload amounts - which they tell you flat you if you do, your ride quality will change and your shocks will not be working as intended.

 

Pretty much every single coilover that is ride height adjustable does so via spring preload. There is nothing bad about the system. The same exact thing is done on trophy trucks, short course trucks, etc.

Some people here go on and on about "choose the spring for the lift and set it at zero preload" , there is nothing inherently better about this than using spring preload. As long as the spring you are using has enough travel there is no danger. The limits that shock manufacturers put on spring preload are related to both available spring travel and ride quality. Do trophy trucks get custom springs for everything? No. They buy off the shelf springs from Eibach etc. They come in every rate imaginable and in 1-2" length increases.

This whole thread belongs on reddit.com/r/iamverysmart

 

If that was written as one sentence I would agree. Mostly.

But, most users around here don't have enough spring. Many use Billy's top perch and OE spring. 0 setting is what allows max articulation. And with that you aren't going to get any lift unless you have a different spring.

Preload via threaded shock bodies is great for final tuning of things like corner weighting a vehicle. Every set I've ever installed comes with a 'starting point' and a range. Quality units sometimes even have internally threaded shock bodies so you can literally adjust the shock length as well as the perch position to compliment that choice.

Being 'long enough' has physical limitations of mounting in an OE environment.

Maybe @geekhouse23 would like to join the party?

I'll mosey along and let ya'll play engineers.............

 

Do you see the difference between this post and your original one with the tone "preloading springs = cheap"? Generalizing like that is just as bad as being ignorant and blatantly ignoring facts.

Also, this is a 6112 thread which comes with its own spring.

 

buy what you can afford, then complain about the ride, then buy something else and either be happy or sad......then repeat.

sure beats reading and re-reading or writing and re-writing an opinion about what is better than what. When it comes down to it, most of us can't really appreciate the valving of a shock, let alone a spring rate or pre-load placed upon the spring. just saying. then again, this is just MY opinion

 

Okay after reading this thread a few times now over the past few days... Were basically all right in the little parts of this debate we can each take ownership for. c4lvinnn is correct in saying there is nothing 'wrong' with using preload to get desired ride height, or as others have stated using preload to get corner weighting perfect.

I am also correct in saying that the IDEAL way to achieve all of those things is to buy a spring or set of springs that are the correct length, and spring rate for the chosen application and then find a shock that suits the travel length and rebound/compression rate that is required to control those springs.

Read my posts again if you would like but I never said there was anything wrong with using threaded collars to adjust preload, only that it is not THE BEST solution to suspension tuning. Using preload is going to limit the suspensions ability to flex. PERIOD. It will not affect the amount of travel, only the initial input required to use said travel. But the less the suspension can articulate, the more disconnected, and less predictable it will be because the tires are no longer gripping the road, dirt, snow, sand, etc as well as they would be if the springs and shocks could freely articulate. Don't take my word for it though, watch the difference between a factory modded truck driving offroad and a true race truck. Factory modded trucks at high speed tend to 'crab walk' or slide back and forth as they are driving straight forwards. Watch closely and you will be able to see it. This effect is not nearly as pronounced, if it presents itself at all in a race truck. Ideally, it wouldnt. The difference is that in the factory modded truck the suspension doesn't move hardly at all until a big hit, whereas the race trucks suspension will bend and flex to try and grip a surface constantly, allowing better contact between tire and surface and reducing or eliminating undesirable handling characteristics. That was my point, I am just saying there are other ways to get to the same answer. None of what I have said was intended to offend anyone or say there ideas are wrong, Im simply pointing out that while manufacturers say its 'fine' to adjust things a certain way, does not make it 'the best' way to get those same results.

 

In technicality, what we're saying can apply to your thoughts on getting correct length springs and shocks to match. However, that's not always going to be the case where corner weight or height is going to be equal or set up some specific way for a car (professional racer or daily driver). Even with specific built springs and shocks, especially on corner weighting, your preloads may be different on every corner. It's just silly generalizing "preload=bad" in any sense. It's useful in its own ways. It's not inherently bad like the other guy was saying. If you don't go way overboard and out of recommended specs, you will be fine 99.99999999% of the time adjusting via preload. That's what it's for.

 

You're right but our point is that, generally speaking, coilover systems have an acceptable range of preload within which the suspension will behave as designed. Yes, more preload will, in theory, make the spring harder to compress but if your changes are within the manufacturer's recommended range it's not going to be enough for you to notice in the cab and it's certainly not going to rattle your frame apart.

 

So if I set 6112s on 2nd notch vs. Setting them at 5th or 6th notch, no noticeable difference in ride stiffness on road?

 

A little bit maybe, if you're a princess, but it's not going to rattle your brain into mush and make it start leaking out of your ears or whatever dramatic scenario is being imagined to draw the conclusion that a small increase in preload is too janky for a $35k truck.

 

Well my truck was $40k so...

 

smitty has a point here. Sorry to burst your bubble dsmdylan but you would definitely feel that big of a difference. One would be essentially a static lift, meaning those springs are basically never going to compress. You would probably have to use a spring compressor to get the spring to seat properly at that point no matter whether you've got a threaded mount or a tiered mount... Which means you would need hundreds of pounds of pressure to get the suspension to compress any further than it already is. You ever ride a really stiff pogo stick? Thats what your $35K truck will feel like

 

This is what is so maddening about this whole situation. There are no good, easy and economical ways to just add 1-2 inches up front. I have heavy armor and have actually lost an inch. I would like 6112s because I don't want to pull them off the truck and rebuild them every 6-12 months like Icons, etc. But I need a different spring for the extra weight so now I have to buy an OME spring since they seem to be the only company that makes a spring for guys with extra weight then throw away the 6112 springs that I paid $500 for since you can't buy them without the springs.

If anybody knows a way I can get 2 stinking inches in the front of the truck with a good ride for around $700 I would love to hear about it.

 

I'm going to do the 6112s with a couple of inches of lift. It'll suit my needs perfectly.

If we are comparing off the shelf suspension to a trophy truck I think we're getting ahead of ourselves. Ever see a trophy truck take a corner on the street? They lift tires. Super flexy but terrible road manners.

The difference in stiffness between stock and a small bilstein lift (with new coils) is minor.

 

But there are good, easy, and economical ways to add 1-2 in up front. Set the shocks at a higher groove to take care of the extra weight. Or measure the spring length and buy an off the shelf 3in ID spring in a higher rate if you want. OME springs will not work.

 

These people believe that if you preload the spring by an extra inch (2-3 grooves on 6112s) you will literally compress the spring so much that the suspension will not move at all and it will be like your're driving a wheelbarrow. See below:

A ridiculous assertion, of course. You might feel a slight difference in stiffness but it's not going to be as if your suspension doesn't move at all. Do you think everyone with their coilovers turned up a little bit or with 6112s or 5100s with the perch above the 0 notch is literally driving around with their truck bouncing around like it's one of those cheap trailers with no suspension?

Of course you have to use a spring compressor. A strut should always be preloaded.

 

It wont, it will ride fine. I bet that 90% of people on this forum who have installed 6112 at 5th or 6th position arent complaining.

There seems to be a whole lot of information missing when people talk about spring preload and spring rate in regards to ride. Lets ignore the damper for this part.
The common consensus appears to be that more spring preload = harsher ride, so to get a better ride go to a higher spring rate with less preload. Lets do some math.

So in order to get "x" ride height you need "y" amount of force to hold the truck up. SF (spring force) =k(spring rate)*d (distance spring is compressed)

Lets say we need 2000lbs of force to hold the truck at the ride height we want. We are going to try it with 2 different spring rates. 600lb/in and 700lb/in. These are popular tacoma rates.
For the 600lb spring we need 3.33in of preload. For the 700lb spring we need 2.86in of preload.
Now for the scenario. You hit a bump that makes the shock travel 1in from ride height. To get one more inch of shock travel takes 600lbs and 700lbs of force respectively. The force required to move the shock one inch from ride height is purely equal to the spring rate.
Which truck in this scenario rides harsher? The one with the higher spring rate because it takes more force to move the wheel 1in. Notice how spring preload didnt come into account at all when the truck hit a bump?

It takes a fixed amount of force to hold a truck at ride height. This force does not matter what your spring rate its.
This is a very simplified scenario and does not take damping force into consideration.

To be honest, i think the vendors here on TW have brainwashed everybody into thinking they have to buy new springs for everything, so they can increase their sales.