What could possibly happen when say a coilover kit with 12 kg F/R spring rate is modified with a 8 kg Front and 7 kg rear springs given both factory and replacement springs are of same length?

I'm looking to see if this scenario would make this seemingly stiff track oriented coilovers be more street friendly for guys like me who never does autox but still wants to achieve somewhat of the stance You know the "don't threaten me stance.

 

What shocks do you have?

 

At this point I'm on OEM. I'm looking at several affordable coilovers that have high spring rates. I know they can be replaced with springs (of same length) that have lower rates and definitely of better quality so to soften the ride. I'm aware this has been done but I can't find any posting of it.

Wanting to know the effect of over damping of a less high end coilover say Megan and the likes. Just as I mentioned, placing a same length spring with lesser rate on a coilover kit with high spring rate. Say replacing the springs of a Megan with 12 kg spring rate for both front and rear with a Swift springs of 8/7 kg rate.

 

in theory this shouldn't be a good fit.
but it also depends on your expectations.
i mean some cars have a crap ride but owners are happy and vice versa.
in a bottom line unless you find somebody who already tried this and can comment on it you will have to try yourself and see.

why not to go with softer springs coilovers in the first place?
H&Rs or Bilsteins for example.

 

Well I'm hoping that someone who have done this will chime in so we will know if the theory stands.

My expectation is there's always room for improvement. My goal is realistic but my satisfaction isn't .

By vice versa you mean, some cars have awesome ride but crappy owners ? j/k


Some cost can be minimize while playing. H&R coilover uses Bilstein and vice versa. Bilstein height adjustment is limited to 35 mm for both PSS and PSS9. People think they can lower the PSS more but technically you shouldn't base on factory recommendation. If you blow it because of improper install warranty goes out of the window. On the other hand H&R can be lowered up to 2.5 inches below OEM spec but their spring rate are higher and Front/Rear rates are the same. Here's what I think could be possible. Swift make damn good springs and are affordable probably around $100 per corner. Megan EZ Street shocks are good enough for the price they ask around say $700. Well with the cost about 1100 you get height adjustability and spring rate that you desire plus you can always increase the damping if the spring rate is too soft. For a somewhat or partially customized coilover I guess that's a good cost.

 

Except most tuner coilovers don't produce enough low speed force or too much high speed force to be effective with softer springs. Yes, you can do this, but I would not do it with a cheap shock. As spring rate decreases, shock force needed increases.

 

Pardon my inquiry but what is shock force?

 

Shock force is the force created by the internals of the shock as the fluid flows through the shock bits. Shock forces control the car's movements.

 

So how do we know that a tuner/manufacturer makes a proper internal to withstand the "shock force" by the price they sell their coilover or by the spring rate by which they use? Because Bilstein PSS is only $885 and Megan Racing is $900.

 

Neither. A shock dyno is the only definitive way to know what force the shock can generate.

The shock internals create the force, not withstands it.

This is my Koni shock dyno after a re valve (a change in shock forces).


If you don't get a dyno when you buy shocks then you have no idea what you are getting. I think this is a bad way to spend money.