sixshooter

iTrader: (12)

Easier? Now where is the fun in that?

Joe Perez

iTrader: (8)

I can't speak to the capabilities of the Koni Street shock, however IMO, the FM spring is still a tad on the soft side. I've had a set of them installed on my FCM Bilsteins for a few years now. I'm no suspension guru (and knew even less when I bought these) however if I had it to do over again, I'd have gone with a threaded coilover system and springs in maybe the 400/300 neighborhood.

I keep telling myself that I need to get off my **** and buy a new set, but I'm both cheap and lazy.

Braineack

iTrader: (62)

That's all Todd wants (a soft street setup).

Hell, the only setup I liked on my Koni sports were FM springs. Stock were too soft and lent nothing to anything spirited. FM were still smooth, perfect ride hide, and competent performance -- to an extent.

When I went to 550/300 it was harsh and plowed. 400/250 was still harsh and still plowed.

miatauser884

iTrader: (11)

What spring rates are you running now. Based on FCM calculator your 400/250 with a stock rear sway should be great.

What F/R spring rate bias are the track guys actually finding yields the best balance. My FM springs and FM sways made my car a little too tail happy. Not terrible, but more than I would like.

Braineack

iTrader: (62)

I run 7/6kg now and love it. i dont believe in the FCM calcs anymore.

atlnb

What settings do you have your sways on?

jacob300zx

I bought all of Treys stuff bitchz

nashvill

Hi,
I bought this set(http://www.ebay.co.uk/itm/2005714276...84.m1423.l2649) to my 2001 year 1.9 and after installing the car is very bouncy over the bumps and it does not go much better when i adjust the shock either max or min stiff. I think the spring that came with the kit are not very good but i don't know if i have to go to stiffer spring or softer. Car is mostly daily drive with Z-engineering SC but i use it for track as well in summer. Any suggestions?

2ndGearRubber

The springs rates are probably too soft. Did you reuse the stock bumpstops? How much travel does the car have?

nashvill

I put a new set of bump stops. To my belief it does not touch the bump stop on bumps.

Edit: bump stops i used http://www.ebay.co.uk/itm/Mazda-Mx5-...item2c62819a24

bbundy

Pretty much everything uses the bump stops on a miata, even my 800/500 lb setup. maybe if I ran stock ride hight and didnt corner hard or go over bumps I could stay off the bump stops with those rates.

Bob

dustinb

I honestly haven't been in a miata that isn't bumpy. I'm not familiar with that kit you bought but it says it has some sort of adjustment. How many different settings have you tried on them?

Oh, and I just wanted to highlight that Brain said Shaft Travel.

bbundy

FWIW what the body perceives as change in stiffness is not the spring stiffness but the amount the springs change the natural frequency of your suspension. The natural frequency is proportional to the square root of the spring rate not the spring rate by itself. Therefor for example In terms of the effect on suspension stiffness a 700# spring is roughly only twice as stiff as a 195# spring in the change it makes in suspension behavior.

Lowering your car by ~2” is roughly a 40% reduction in bump travel if I remember right.
With stock springs at 164/97# to make up for the reduction in ride height without blowing through suspension travel and keeping similar front to rear balance, doing the natural frequency math the springs you would want are something like 455/269# to make up for the reduction in travel on an NA. NB is assuming stock 162/118 you’re looking at 450/327#

Cut stock springs, Racing Beat, and I think Even FM springs are inadequate for the amount of lowering they provide. The only way they work is by relying heavily on the bump stops for a source of added spring rate. They may ride well for you a smooth road but handle like garbage if you really lean on them and rely heavily on progressive bump stops for springs.

Bob