Here in Australia coilover legalities are murky if you can lower your coilovers from the perches so I'm looking to stick to non-adjustable. I've tried to look around but can't really find some solid info. I have an NB and my usage is solely street with 380tw ultra performance tires on 15x7 wheels. I want to lower the car by around 30-40mm mainly to reduce the 4x4 look of the rear wheels while maintaining at least 100mm ground clearance. I'm not crazy about chasing extreme performance. From what I can see the main options are either Bilstein B8 or B6, or Koni Yellows (bad I know) alongside springs and bumpstops. I'm not sure what is else applicable from the coilover conversion you guys like to roll. My desired budget would be around $800 USD but I'm happy to stretch that if its worth it.

 

DIY Billies with non-adjustable perches and extended top hats?

 

Know how I go about doing that? Do I need to buy an aftermarket perch or do bilsteins come with perches that can house the springs that people often recommend? Before when I was looking at using adjustable sleeves I was going to use 450/300 7" summit racing springs, integra bumpstops and maruha tophats. Should/can I use FM springs, b8's and maruhas?

 

If you go down the FM spring route, stock spring perches will do the trick. The rates of those are a bit on the soft side for most (close to 350/250 lb/in from memory). You can still fit extended top hats (I would vote for Maruha) and shorter bump stops.

The other way round would be to machine some spring seats that also hold the circlip in place and use the typical 2.5" coilover springs. Cheaper springs, wide choice of rates, but you will most probably need to do it twice to get the ride height just right.

 

Bilstein NB B6 shocks (come with perches), Flyin Miata springs, NB top hats, FCM bump stops.

 

Think I'm leaning towards this from what I've been reading. From what I understand I need to get 36/36 bump stops to get near a 1 inch drop yet FCM recommends 36/46 pretty hard so it seems I would need to fit a larger front sway bar and maybe extended top hats? I'd rather use my stock ones but I wouldn't want to blow money on suspension and have it be poor just because I want a moderate drop. I also like the idea of cheaper bump stops cut to length like the integras as I take it they're equivalent to FCM and cheaper/easier to ship to Aus.

 

Hi blaster117,
What setup did you end up with?
I'm looking to achieve something very similar with bilstein b6. Just a moderate drop like 1" – 1.25", and wondering how it's going to ride and seat. From what I understand extended top hats are a must so that b6s have a decent shock travel. As for the springs I have a very good deal on eibach pro kit (1" lowering), not sure if they fit this setup though

 

I'm in Australia and this is what I am running. It's a very good set up. Definitely go with extended top hats.

I'm not running this because of legality though. My old r 32 skyline ran adjustable coilers and had every suspension arm replaced with something adjustable and I never had a problem with rego in it. I chose the FM spring/bilstein combo because it is just a really nice set up for the street without being very expensive.