"That coilover is inferior becuase the lower mount can't be adjusted."
"That coilover is inferior becuase the lower mount can't be adjusted." And other things that are incorrect.
Coilover adjustment seems easy. Spin this, rotate that, repeat, repeat, then repeat. While it's not rocket science, there is a lesser science to doing it right. In another blog post, we went into detail on setting up the common dual height adjustable coilovers. I would like to talk about one aspect of dual height adjustable coilover (you know, the one that adjusts via the lower mount, but also the spring perch).
A lot of the coilover options you see on our site have an adjustable lower mount, and a lot of the options you search on google do too. When you go through the set up instructions, you'll see they only mention adjusting height via the lower mount and to not touch the spring preload. One even said "do not adjust the spring perch as damage may occur." Excuse me but what!? If you're looking at coilovers and they tell you not to adjust spring pre-load, 1) they don't know how to adjust coilovers, and B) if they don't know how to adjust coilovers, do they even know how to build them!?
If you haven't seen our blog post about dual height adjustable coilover set up, make sure you read that too. Moving on...let's talk about differences between single and dual height adjustable coilovers.
So what's better, single or dual height adjustable?
This isn't a better or worse design, but maybe what's better for you.
Single height adjustable:
Pros: Usually uses a longer shock body, so it usually has more travel. It's also much easier to set up and dial in ride height because you adjust the perch, that's it. Less moving parts means less can go wrong. the shock is designed for your application specifically.
Cons: As you go lower, you reduce bump travel. This style is generally found in higher end coilovers and not designed for the stance crowd.
Dual height adjustable:
Pros: Uses a shorter shock cartridge that accommodates the folks looking to scrape their front lips going over a leaf on the road. Typically can get really low. Easy to replace individual parts. Generally less expensive.
Cons: As it generally uses a shorter cartridge, there is considerably less travel. Because you primarily lower using the lower mount, you reduce suspension droop travel which greatly decreases grip on hard corners. In some cases, the shock used is the same shock across multiple applications; this is especially true on the less expensive options.
So how do you adjust ride height on a single adjustable?
As I said before, we already talked about the dual adjustable in another blog post, so I wont repeat that info here. Setting ride height on a single adjustable is easy. Really easy. Single adjustables almost always have a helper spring (the thin flat coil spring under the main spring).
When you took the coilovers out of the box the springs should be at zero preload. We set ours with maybe 5mm of preload just to ensure everything is snug during shipping. When you installed, hopefully you may have played with it (or not if you're well behaved)...in any case, go ahead and spin the lock ring out of the way and spin your perch clock wise until there's no tension on the helper spring and there's no space between the helper and perch (thats zero).
Note: There are two ways to do this step...I'll cover one way, and give a brief tutorial on the second.
Ok, the suspension is bolted in place, you've torqued all your bolts with a jack under the arm to relieve tension as you installed (right??) and you're ready to set ride height. Next you're going to put the car on the ground...but, it's going to be low. Ideally, the lowest you'll want to go because any lower and the spring will flop when the suspension drops.
Take a look. Right now your helper is completely compressed and the main spring is compressed about 1/2" or so. If you're happy with the height, you're done. If you want to be an inch higher, lift the car and grab your coilover spanner wrench. Your helper is now fully decompressed and at full length. Measure from the bottom of the perch to the end of the threads below. Lets just say its 3.5" for arguments sake. To add an inch, just rotate the spring perch counter-clockwise until your spacing is 4.5" - you raised it 1 inch from where it sat before. That's literally it. Now, you'll want to drive around, let everything settle in and come back a few days later and readjust.
You're just doing the opposite. When you initially install, rotate the perch all the way up so it completely compresses the helper. Set it on the ground, and if you want to be 2" lower than where it is right now, just rotate the spring perch clock-wise 2 inches. Done.
I personally prefer the single adjustables. I think it's easier to set up. In fact, we are slowly rolling out single adjustable coilovers across the board; at least in the ST, SX, and GR models.
Questions? Comment below!