I need to replace the (oe) shocks on my $500 91 Miata, I've narrowed it down to Koni sports or Bilstein. Either of the shock would have the addition of bumpstops and mounts from a vendor that does not advertise in GRM. I am of the opinion that the monotube bilsteins are a better product, build and general design wise, and the Koni twin tube is better valved for the car. The info that leads me to these conclusions is talk on THAT miata website. Most of the talk on there says the Bilsteins ride bad and don't handle broken pavement well, for that matter the blown shocks on the car now don't do that well, there has to be improvement there. The konis do allow for some lowering which would be nice, but being 6 ft 2 getting in and out now is enough of a hassle. The factory springs will remain for the time being, with a ground control setup at some point down the road.
I'm really interested in real world experience, I don't expect the car to ride like a cadillac. I am used to a rough ride as my civic has stiff springs and koni sports on it.
The hype over monotube shocks overshadows the more important thing - how well are they valved and set up. I think the Konis are a good match to stock springs on the Miata. It's what I put on my father's Miata.
I'm not as big a fan of the idea of putting the NB mounts on an NA Miata personally. I'd rather see a complete NB suspension put under the car.
Keith wrote:
I'd rather see a complete NB suspension put under the car.
Do the subframes bolt in? What's the stpry with that?
There's not that much difference between the NA and NB when you get down to it. The Targa Miata has the big suspension pieces from a 2005 Mazdaspeed underneath, but the rear uprights are from a 1994 because they tuck the wheels in by 5mm per side for more fender clearance.
I was referring to the spring/shock/upper mount assembly, though. It's the easiest swap to do. The upper mounts Brad is considering are the NB ones, and putting them on a set of NA springs and shocks drops the car down about 1/2" and gives a bit more suspension travel. This is the hot setup in Spec Miata now from what I understand. It seems to work with stock springs or with coilover setups. If the shocks are being changed out anyhow, I prefer to use a complete NB set of springs/shocks/mounts. It doesn't lower the car as much though. You end up with more compression travel.
The NB subframes do indeed bolt in. In the front, that gets you some tweaked suspension geometry (mostly caster), a better steering rack mount and a few other detail changes. You'll want to use the upper control arm, front uprights, steering rack and subframe from the NB. In the rear, the only advantage to the subframe swap would be some better bracing options. The rear uprights give an extra 5mm of track as mentioned. Since one or two of the exhaust hangers are on the rear subframe, this needs to be sorted out as you'll end up with a mix of NA and NB hangers that don't really match anything.
