acke15

iTrader: (1)

I'm looking to upgrade my springs to a stiffer rate. I'm currently running a 12k/5k oem style coilover setup. Any advice on what rates to try to get? I was thinking like 14/12? Thanks

Lightning Guy

iTrader: (8)

I'm running 12/10 but it really depends on a lot of things, Tires, driving style, etc... 14/12 is a little stiff IMO but I know many people that run that setup and like it.

acke15

iTrader: (1)

Tires will be r-s3's. I have my coils set to a stiffer setting. I like it stiffer than most.

Zazz93

iTrader: (2)

12/5 in the oem style? Maybe you meant 12/5 in the "true coilover style". Otherwise 5 in the rear is softer than stock. If you are refering to 5kg on the shock thats about the average spring rate for mosts setups on the rear and and may be a little soft in comparison to the front spring. I don't remember the exact ratio but I think its .67 and that would suggest a spring in the 7kg range on the shock would be a similar setup to the 12/10 I and Lightning Guy run.

What type of coilovers are you running?

terrasmak

iTrader: (8)

12/5 with true rear is almost identical to 12/10 OEM style. I run 12.4 front 5k rear right now. Depending on your entire setup you may be able to get away with a stiffer spring. The biggest factor will actually be your shock, followed by alignment (that running your current tires)

BTW what size are the tires?

acke15

iTrader: (1)

Stance coilovers. (ya I know). The tires are 285/35/18 f and r

acke15

iTrader: (1)

I misread, the coils I have are a oem style coilover. With 12kF/11kR.

Zazz93

iTrader: (2)

That ratio is more than double?

Zazz93

iTrader: (2)

That's pretty aggressive, but if you want more... I guess. What is the car doing that you don't like?

terrasmak

iTrader: (8)

Here is what i go off of

acke15

iTrader: (1)

The rear end hops some times when I turn hard

terrasmak

iTrader: (8)

How low is your car? Could be a lot of things causing that, first thing i would look at is ride height.

Zazz93

iTrader: (2)

Quick question- Is the surface fairly smooth, moderate or rough?

Things I would look at for that problem:

-Too low - This refers to you being on the bumpstops effectively increasing the spring rate
-Too much rebound dialed-in - This would cause the suspension to not hold the road's contours
-Bad shock
-Bad bushing
-Too much spring rate

So its likely more spring rate is only going to make this worse. Remember stiffer is not always better. Rule of thumb, run it as stiff as you can while keeping the suspension moving and working. When the wheel is hopping around generally you want softer settings to keep the tire in contact with the ground. The exception to this is when there is too little rebound and the wheel is boucing around with no dampening but this exception is more likely a broken shock.

Z1 Performance

iTrader: (564)

spring rates are generally the last thing to change unless you've got a lot of data to back up the change that you're making

the problem likely lies elsewhere

setting dampers to a stiff setting in the first place could be part of the issue, as can ride height as mentioned, as can a poorly valved (or blown) damper.

acke15

iTrader: (1)

I'm pretty low. That is prolly what is causing it.

Lightning Guy

iTrader: (8)

you may want to also soften up your sway bars.


I generally don't go any lower than setting my half axles level to the ground. just my setup.

acke15

iTrader: (1)

I have stock sways. I'll be getting hotchkis this winter

Lightning Guy

iTrader: (8)

I'm thinking about going back to the stock rear bar, the hotchkis is too stiff for my liking and my setup.

terrasmak

iTrader: (8)

Post pics of the car, as you said its probably way to low. BTW do you have a proper diff?

Zazz93

iTrader: (2)

I don't think the sways would cause rear hopping Lightning Guy. They may create more roll resistance than needed with an 11k spring, but unlikely to create wheel hop/chatter. I run a 12/10k set-up with Hotchkis bars and think its a little aggressive if I'm aggressive with my inputs otherwise its pretty docile.

+1 on the pics for ride height.