Spring Rates For Coilovers

[Simple Simon]

So my current coilovers are shot, knocking like crazy and need sorting. I can't be bothered rebuilding them as I think the piston inside is actually bent, and I also don't particularly like the ride on the current spring rates.

So I've been doing some reading on spring rates and I'm proper confused! haha

Correct me if I am wrong but the "general" idea of FWD is to have a stiffer rear of the car than the front as this will promote oversteer? Thats just guessing though.

I know things like ARB's, track width, tyres sizes etc all have an effect. It seems though that the majority of Japanese coilover kits have a firmer front spring rate and a softer rear. Compared to the UK based offerings like Meister R, BC's etc which are primarily the opposite unless custom.

The conclusion I came to was that it's down to personal preference as everyones cars are slightly different in their set ups, and also the fact that every thread ended with people arguing about whats best! No one seemed to agree! haha

What would your recommendations be?

Car is an EP3 and spec is currently

• Still primarily used on the road but I'm wanting to do a lot more track days.
• Yellow Speed coilovers. Spring rates are 8KG all round.
• JDM rear ARB which is thicker than the UK spec one.
• Buddyblub roll centre adjusters
• Caster increase bushes

Was thinking something like a 14kg in the rear and 10kg up front. Sound extreme? Or should the spring rates be reversed?

Any information is appreciated as my mind is beginning to fry! lol

 

[jesse888]

It all gets very confusing when you start talking about wheel frequencies etc
Remember that stiffness of the spring is relative to the weight on the axle...
So although rear rates in Japan may be less so is the weight of the rear.

 

[Simple Simon]

It all gets very confusing when you start talking about wheel frequencies etc
Remember that stiffness of the spring is relative to the weight on the axle...
So although rear rates in Japan may be less so is the weight of the rear.

Yeh when the threads I was reading went into the physics involved with suspension and giving equations that's where I got completely lost! Lol

That's a fair point actually, didn't even think about the car being much lighter at the rear. At the moment I have full interior, and last time I had my car corner weighted it came in at 58% front and 42% rear for the distribution.

I'm also considering getting a slightly better set of coilovers compared to the Yellowspeeds which are pretty much entry level along with the like of Zeta-R's & BC BR's

Considering:

• BC RM's with inverted monotube's
• Meister R's New CRD's with custom Spring rates
• KW Variant 2's with rebound & damping adjustment (unsure on Spring rates though)
• Bilstein B16's (if I can find any adjustable top mounts to fit though as they use oem)

Any others that come to anyone's mind in that sort of price range?

 

[Miffy_K]

I'm using DC5 HSD's on my ep3 The Spring rates are 10kg and 14kg. Personally I really rate this setup.

 

[Simple Simon]

I'm using DC5 HSD's on my ep3 The Spring rates are 10kg and 14kg. Personally I really rate this setup.

Presuming you bought them second hand, hence using DC5 fitment? Is that 10kg front and 14 rear? MonoPro's or DualTech's?

Had a quick look on Driftworks and they offer them in 9kg front and 12kg rear off the shelf for the MonoPro's. Of course you can ask for specific spring rates. Going by price though, I can't imagine them being TOO different from the other manufacturers with coilovers in the same price range (my current ones included).

I'll keep them in mind though, thanks mate