Hello all,

Im planning to build my DIY billies using:

Maruha Extend tophats
hard s nb bilstein (already on car)
7" BC 6kg rear springs
6" BC 9kg front springs
5" Allstar sleeves
Allstar perches
Delrin spring washers
Spring isolators 9.6103G
Integra Shock Bumpers 310 3019-50

How can I ensure I don't get any spring rubbing and coil bind? I want my car to be lowered to 4.5" pinch welds.
I also saw that no one runs a dust boot on their coilovers. What's the reason for this, and should I use a dust boot, given that I daily drive my car and sometimes drive on gravel/dirt roads.

 

.25 rake f/r is preferred for handling. Consider 4.75 rear, especially with those spring rates. Bottoming out sucks. Dirt and gravel roads exacerbate this.

Dust boots are not needed and are a personal preference item. Dust doesn't make them fail. Impacts and corrosion of chrome can. Boots can hide leaks/weeping.

Centering is a problem with some tophats. Sometimes it's helpful to use a collared shim for centering and sometimes the tophat seat design is enough. I can't recall on the Maruhas.

 

Hello thanks for the reply,

I want my car to be a street car that can be driven really hard and sometimes taken on track. I do plan to turbo this car in the next year or two -- are my spring rates reasonable?.

How common is it to bottom out? my first time installing/building coilovers.

The maruhas extended top hats aren't perfectly flat; there is a slight seat, more like a manufacturing issue, but I doubt it would center the springs. Im unfamiliar with "collared shims" never heard of them, what else can I do to avoid coilbind and/or spring rubbing. I saw some people mentioned they glued the spring isolator onto the tophat.

 

I am a fan of the dust boots. My DIY Billie setup had damage to the paint on the springs in short order in the sort of mixed use on gravel roads you describe. that leads to corrosion. It takes only seconds to open and close the covers up to inspect whenever you have the wheel off already.

I'm running a different setup now (and a lot less gravel roads) but even after 35k miles of use my coilovers look almost new.

 

why did you decide to leave the diy bilstein life? and what setup are you running now and on what car?

 

I crashed the car and one coilover would have required replacement to move it over to a new car. Another was leaking - I can't say if that's just because I used 16 year old used parts, or if it's because I used to literally catch air in that car on some roads. I also moved from the Appalachians to Michigan after the crash, so most of the time when I was turning the steering wheel it was to dodge a pothole.

I sold the parts that were still good and moved on to some MSM takeoff Bilsteins (including springs) and stiffer sways. Now I'm on Flyin' Miata Fox coilovers. I've been happy with each setup for the price I paid and the use I put them to.

 

In your case dust boots sound like a good idea. Pretty sure 949 has them.