I was in 2 minds about replacing the bushings, I’ve not even picked the car up yet so that might actually be the deciding factor here. I’m not sure how well 10 year old bushings would be doing on a 40k mile car, I know on my 45k mile MK2 they were absolutely destroyed but that’s mostly due to the material rotting away as opposed to being hammered through use.
So my plan for now is:
Check bushings, replace if needed
Look for RX8 arbs, or get new ones
Get Coilovers
With 3 being punted down the line as the bilstein dampers are apparently fine.
Yup, rubber bushings become unserviceable through age more often than through mileage.
It’s sometimes possible to get 40% uprated rubber ones. Or there are poly bushes, the hardest of which be noticeably harsher and noisier. They’re measured in Shore with the common ones for MX5s being 70, 80 and 90. Even 70s will make everything more precise. 90s are recommended by dentists as they bring them extra work.
I’m a cheapskate so I wouldn’t buy new arbs. The NC has mostly an RX8 chassis which is why I’d use cheap ones off an RX8. They don’t wear out, though they are one area of suspension where poly bushes will work well without adding NVH.
Maybe Bilstein could advise on what shorter springs would still work well with their dampers? If there are some they approve or even supply, then the car might keep a decent ride and handle better due to having a lower centre of gravity (and possibly stiffer springs if they’re shorter?)? Shorter springs will certainly make it look more like a sports car. If you can, aim to have the front on the car 1/2" lower than the rear measured from the centre of the wheel to the inner top of the wheelarch.
Flyin’ Miata have a brilliant video on YouTube about why they (well Keith Tanner) suggest arbs first if you’re only doing one suspension mod or for your first suspension mod. Indeed, Keith says if you only do one mod at all to your MX5, it should be arbs - although 'Mericans call them sway bars, which is the opposite of what you want them to do - a bit like cough medicine. https://www.youtube.com/watch?v=wvqw-f4dhlA&t=80s
Awesome information thanks. I’ve picked up the car and drove it 450 miles home. Nothing seems weird about the handling, not odd rattles or bottom outs going on. I’ll be getting it up on the stands this weekend to see up close how the bushings are doing and go from there.
Not sure who to use locally for to the cars geometry, I am in Scotland, Fife. Will do a quick Google but if anyone here has any recommendations drop them here.
I’m in a pretty similar boat to you, and not far away (Clacks)
Mine is an NC launch edition, so a 2005 car. It’s currently on original Bilstiens with the Eibach 30mm lowering springs. Ride was best described as simultaneously crashy and wallowy.
I just replaced ARBs with the yellow dot ones from ther RX8 sport while I figure out what to do with suspension. Made a good difference to the car. Feels sharper on turn in and rolls less.
The car wasn’t aligned (i believe) when the lowering springs were fitted so that’s all shot too. I was probably going to use these guys in Larbart:
They seem to have the best of kit and are very serious about alignment!
I’m also fairly local (West Lothian) and was in a similar situation a few years ago. Mine is a low mileage NC1 1.8. It had the original shocks and springs on it, had a slight issue with a rear top mount and needed the geometry done but was otherwise remarkably clean and original. I went for RX8 yellow dot ARBs (~£85 from an RX8 forum), new bushes, new drop links, very low mileage NC3 standard Bilsteins and springs, standard sport strut brace and did the geometry myself (had access to the kit and have some experience doing it). Completely transformed the car. Very little body roll, std springs so no speed bump issues and ok ride height. Total cost probably around £250 and great for fast road and occasional track stuff. Unless you want to spend a fortune, you don’t have to IMO .
Mine is running on the common eibach -30mm lowering springs at the moment and I wonder how well it would ride with just some replacement shocks like that.
Some say the billys were never good with the lowered springs and also that it will hasten their demise.
I’m pretty certain mine are shot. Ride quite wallowy and rubs in corners sometimes despite running at 335mm
I’d considered lowering springs but felt dropping it by 30mm was slightly too much for me. 20mm would have been ideal but I didn’t want to go down the fully adjustable route. Changing to the later bilsteins did drop the ride height at the front by 10mm anyway.
I also sold the original shocks and springs for £60, so total cost was actually under £200
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