Coilover Spring Length
 

I have a 2003 LS and I'm about to pull the trigger on a set of Bilstein Sports. I've got Allstar sleeves, seats and house-brand springs picked out at Summit. I want to use 400lb front and 275lb rear. I would like to get the hub-to-fender lip measurement at 12.25-12.5" I believe I can get there with a 7" front and 8" rear spring. Does that sound correct?

That's going to be close. Do those sleeves screw all the way down to the perch? My perches only get to within .5" and I needed to go with 6" in the front for 550lb and 7" in the rear for 350lb.

Here is a picture of a Bilstein / Allstar combo from elsewhere on this forum.

https://www.miataturbo.net/miata-par...omplete-66803/

Thanks. What height are you at with those rates and lengths? Are the perches as lowest setting now?

for 475/275

I'd probably go 7/8".

Thank you.

I just removed my obx springs and upgraded to 504/336. The obx were 370/275 and 6"/7" but they actually use much thinner wire than most of the cheaper springs so you get more travel before coil bind. I was at 12.5/12.75 with enough travel to put the tire in the fender liner and didn't get coil bind. I would definitely go 7"/8" to be safe though. My 504 lb front springs are 6" and look dangerously close to coil binding but they are stance springs on ebay because I cheaped out. It really depends on the spring.
https://www.miataturbo.net/attachmen...ine=1369080813

I had coil bind on 400lb 7" front springs running revalved bilsteins. You might want to try stiffer or slightly taller spring at that rate. I swapped to 500lb 7" and did not have binding issues.

In the rear I ran 250lb 7" and had hella coil bind. Don't run less than 8" if you want under 300lb rear rates. I have since tried 300lb 8" and 180lb 9" with no coil bind issues and I can still adjust the ride height in a reasonable range.