Is this right?

[RadioLobo]

Im been building my 280zx coilovers for my 510, but im a little confused for as to how the spring sits lower then the strut insert. The insert sits taller then the coilover spring even with i have it set to the top. Is this how its suppose to sit and the weight of the car will push it all together? Or are my springs too short? Or the struts too tall?

I have 83 280zx struts, new kyb gr2 inserts, and some coilover springs that have no markings but they slide on the struts perfect. Any help would be much appreciated thanks.

 

[JDM510]

it will work.... to get it to go low though you may have to reposition that colar lower on the strut housing

[thisismatt]

Yes, that's how it should be. The strut insert has some gas pressure pushing it into it's topped out position. When you install them and lower the car onto the wheels, the weight of the car will easily overcome this gas pressure and some of the spring force. You would not want your spring longer and with a large enough force to hold the strut insert at this fully topped out position with the weight of the car on it, otherwise you would have no suspension droop (for when you drive over a hole/dip) and your insert would be constantly topping out which will damage it.

 

The more general question of what length springs to use depends on how the car will be driven. The short spring can cause some issues, such as if you were to go over a hole large enough to completely unload your spring, then the strut will possibly drop far enough to leave your "short" spring hanging there loose. Then when the strut is recompressed as you bottom or exit the hole it will slam into the upper hat, possibly out of alignment with the hat. To deal with this issue people will put limit straps on suspension arms or zip-tie the spring at both ends to hold everything together in that situation, or use "zero rate" helper springs to take up the slack in this occurrence. Here's an example of helper springs in place:

 

[thisismatt]

You can also get tender springs in a different (or progressive) rate from your main springs and give your setup a progressive spring rate. Tender springs look very similar to helper springs but have high spring rates like normal coilover springs. They could be used to take up extra slack as well, though, if necessary. JDM510 is right in that your collar may be a lot higher than you're going to want. Depending on your spring rate, you might not get your car as low as you want and you might not put the strut insert into a favorable position (eg compressed midway so that you have both droop and compression travel, not just one or the other because you have the setup topped or bottomed out).

[JDM510]

thats a good idea with the helper spring thats what i need in my set up..

[RadioLobo]

Thanks for the info, ill look into those helper springs. Should i be worried since i dont know the spring rate on mine? How do i know how far to put the collar down without running into problems later when driving. Just trying to get my daily driver low. :P

[thisismatt]

Going to be kind of hard to say without a spring rate. Did you already weld the lower perch? If not, you could get collar clamps as a temporary lower perch (some people use them as a permanent solution but there is the chance they could slip).

[Yakuza]

it looks like the collar needs to come down some...

[RadioLobo]

It actually just the weld from the stock spring perch, its going to go down some