Spring Rates

[SteveS1]

Just to get this question out to a wider audience ......

What spring rates do track orientated people recommend?

I understand the Teins come with 7kg/6kg, but have read recommendations on this forum for 5kg rear springs. On the 949racing ebay advert they say \"For a daily driver and occasional drifting, autocross or track days, the standard Flex 7/6kg springs are great. For a more competition oriented setup with wider race tires I recommend increasing the front spring rate between 9kg-12kg/504-672# and rear spring between 7-8kg/392-448# . \" Anyone agree or disagree with this for local (Aus) tracks??

My application is for track work (sprints and hopefully racing), street registered, but I don't care if its stiff on the road as it doesn't get dríven much.

Cheers
Steve

[Hellmun]

I'm running a 7/6 set of Tein springs over Monoflex shocks. I was considering going harder but was warned off it. Our roads and track are not as glass smooth as a lot of Japanese and US circuits. The 7/6 setup is still very stiff too... Still I'd love to try a set of 9/8, I don't feel I get too much body roll cornering even before I had swaybars but it still dives a little more than I like under brakes.

[manga_blue]

I have 5/4 on Teins. Suits me well as a balance between road and track. I don't feel the need to go stiffer than that for sprinting on street tyres.

[Rob E]

7/6 is good, but you will want a bigger front bar to bring handling back to neutral (7/6 is a bit oversteery on stock bars)

[SteveS1]

thanks for the feedback guys.

i think i read once that springs should be sorted to give the handling you desire, and swaybars can then be added for fine tuning. that theory would be fine for track work where comfort is not an issue, but on the road swaybars are useful for providing additional stiffness with reduced compromising of comfort.

from my reading of various threads on miata.net it seems as though ratings of about 9/6 might be a good ratio for track work, and sway bars can be adjusted for fine tuning. sway bar adjustments may just be upgrading the front swaybar and using the standard rear bar. or perhaps even removing the rear bar.

these numbers have also come about from playing with the mx5 suspension spreadsheet at fatcatmotorsports.com if anyone is interested.

cheers
steve

[Muzdaman]

Do you have a link to the FCM spreadsheet?

Thanks

[SteveS1]

Spreadsheet (best to right click, save target as... and run from there)
http://www.fatcatmotorsports.com/FCM_MSDS_v7_6.xls

Other interesting suspension stuff
http://www.fatcatmotorsports.com/chassis.htm

A guy from fatcatmotorsports seems to post regularly on the miata forum.

Cheers
Steve

[Hellmun]

With the standard swaybars on 7/6 it was still pretty neutral...slightly taily but certainly not that much. I got it neutral using just the shocks...I think full hard front(8), 8 hard on the rear was neutral..... I just tuned it on the fly with an EDFC.

With a front 24mm(from the 22mm stock one) adjustable solid sway on 7/6 in the medium setting I had to run full 16 soft on the rear, 5 hard on the rear for balance on that setup.

Next track day I should have a 16mm rear bar on full soft (Vs the 11mm stock one) and I'll try and put the front on full hard which will pre-load it a bit. Hopefully it'll be close enough to balanced I can tune it with just the shocks rather than having to swap a swaybar adjustment on the day.

This is on a 2001 NB8B btw.

[Fatty]

there was lots of discussion about this sort of stuff recently, have a look at this thread

http://www.aus-cartalk.com/viewtopic.php?t=26949

as per hellmun, i also found 7/6 felt pretty nuetral, tending a little bit towards oversteer. removing the rear bar was terrible, the car was understeering really badly. i still need to fiddle around with soft / hard settings to get it a bit more neutral, and then maybe look at a front bar, once i get a handle on everything and get my head around it. i'm still learning about all this tuff.