Miata Spring Rate Question

[storz]

I recently picked up a set of the cheapO ebay coilovers and I was going to run them as is. However after reading through a ton of threads on miata.net I think I am going to opt for some better springs, the QA1s seem to be getting good reviews.

I am setting the car up as a fun autox/DD toy for STS2, that being said I don't mind a fairly stiff ride and I only have a 2 mile commute to work in the morning. I am currently on the stock springs with Bilstein shocks, which I am pretty sure are the HDs not the Sports (plan to look up part numbers tomorrow night)

So this is the setup I am thinking of running, lemme know what you guys think. Thanks!

Bilstein Shocks

Ebay coilover sleeves

7" 450# QA1 - Front
7" 350# QA1 - Rear

Is 7" too long? How do the rates look?

The springs that came with the coilover kit are (I think) 450/400 and 5.5" in length, I think they would just be too short and I would be on the bumpstops all the time.....any advice?
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91 Miata
05 Subaru Impreza RS - The Wife's

[tirewarmer]

Some of the guys on Miata.net scare me. Be careful whose advice you take there.

Any name brand linear rate spring should be fine. QA1, H&R, Eibach, SSS, etc.

I think your rates are a little too close front to rear. You could end up with a bunch of oversteer. What do you have for swaybars? They'll factor into the equation also.

Here is my setup since it is no big secret:

Koni Race Valved shocks (about 1 inch shorter than yours so I can run lower than you can)
Modified NB shock mounts
2.5" Coilover Sleeves
700 lb 6" Front Springs
450 lb 6" Rear Springs
Racing Beat Tubular Front Swaybar
No Rear Swaybar
~3.0 degrees front negative camber
~2.5 degrees rear negative camber
0 front toe
1/16 rear toe in
4.5" ride height at the front of the pinch weld

You probably won't be able to run much below 5" of ride height because your shaocks aren't shortened. As you can see, my front rear bias is alot different than yours. I'd recommend running ~550 front ~350 rear with your bilsteins. 7" springs should be fine, and if you go with QA1's, I believe those are the shortest that they make.

[storz]

^^ Thanks for the info.

I am a little worried the 550/350 would be really harsh on the street since the car has to remain my daily driver for some time. At this point my sway bars are stock, I was talking with some other Miata owners local to me and they recommend running a bit softer spring (still stiffer than stock of course) and huge sway bars.

How do you think 350/250 would be with aftermarket sway bars?

[stealthgtfour]

i run the tokico strut/spring matched set they sell and i like it a lot for dual purpose auto-x and daily street use. ride height isnt adjustable but the struts have five settings.
and the whole system was less than 500 bucks.
i will admit that im thinking about upping the spring rate about 100lbs though

[tirewarmer]

May 18, 2008 7:24:46 GMT -5 storz said:

^^ Thanks for the info.

I am a little worried the 550/350 would be really harsh on the street since the car has to remain my daily driver for some time.

Ride quality is more directly linked to the quality of the shock you get than the rate of your springs. My car Miata has a more comfortable ride than my stock class prepared MINI does even with the 700/450 springs due to the valving of the shocks. I daily drive mine also, and it feels great.

[storz]

The car is riding on a set of brand new Bilstein HD shocks, I scored a set of Eibach springs off of craigslist for cheap so that is what I am going to go with for now.