Hi,

I own the feed coilover for the FD (Suspension).
It is a bit too rough with 18k springs. Now I would like to change the springs.
Does anyone here have the coilover and can say the unloaded spring lenght?

greeting
Eric

 

Hello, welcome to the forum!

FEED suspension is super rare, if you post pictures that may help.

I have FEED suspension but would need photos to confirm if they are the same as yours.

Tom

 

Hi,

thank you for your answer. Here are some pictures.

Eric

 

Thanks for the pics, my dampers are slightly different to yours but it looks like we are running the same springs.

I actually just removed the rears and can measure those for you. Might be a week or two before I pull off the fronts to measure those (depends how much free time I get in the garage!)

While you are waiting; introduce yourself in the New Member section, I am interested to see what car you have if you are running those coilovers............

Tom

 

Hi,
thanks, that would be great
I'll introduce myself in the next few days. Anyway, I own a RX8 and recently a 95 FD.

 

Sorry for the delay - it's been a slow winter.....

As per the photos my FEED coilovers are based on a slightly different set of HKS Hipermax, but the springs look to be the same.

150mm is your number front and rear:

 

When you change spring rate you need to change the length of the spring or suspension won't work correctly.

Otherwise, suspension will hit the bump stop prematurely (when decreasing spring rate) or tire will hit the unibody before bump stop is engaged (when increasing spring rate).

If you put a spring with new spring rate on the coilover and adjust the vehicle ride height to be the same as before with the shock to lower mount position you are changing the ratio of extension travel (droop) to compression travel (bump).

-edit-
Good news is your suspension does not have adjustable lower mount, so you cannot mess-up the ratio of droop to bump travel to the bumpstop. You will just need a longer softer spring or your vehicle ride height will be lower than with the stiffer springs.

You can figure out the length of springs you need with vehicle corner weights, spring rates and suspension motion ratios.

 

Hi,

thanks for the pics! However, I have decided to change the coilover. I now have a tein mono sport coilover.

 

Blue TII,
Came across your post in search of info regarding the relationship between adjusting spring rates and their corresponding lengths. I just wanted to make sure I have everything straight: If I am maintaining the same ride height but wish to increase the spring rate, it must be shorter, correct?
Thanks.

 

That is correct.

If you go to a stiffer spring of the same length as original you will have to lower the increased ride height by moving the lower spring perch down.

This will work, but your spring will be loose when car is jacked up.

The loose spring can be resolved with a tender or zero rate spring and tender spring collar/seat.

If you shorten the increased rate spring the correct amount the ride height will be the same as before with the lower spring perch snugged against the spring at zero preload.

Many coilovers have a threaded lower mount where you can make the whole coilover assembly longer or shorter.

Adjusting this changes where your bump stop engages relative to tire movement.

By lowering the car via shortening the overall coilover assembly (common when using a stiffer spring of same length) its possible to set it so bump stop does not engage before the tire hits the top of the fender arch.