Bilstien HD?
 

What are they worth used with 35K miles on them? Maximum spring rates?

Would they be compatible with GM sleeves made for KYB AGX?

Thanks.

Jay

About $200 shipped. :cool:

I run them with 700s up front, but they're on their way out after 20k miles.

Thinking about replacing my AGX with a set. If they'll be compatible with my GC sleeves I might just pick them up.

i haven't had my agx 's that long and the right rear is blown already

They are compatible w/ GC sleeves. But I would go with Illuminas over the HD's. The ability to soften the ride a bit during mud and frost heave season is worth the adjustability to me. Performance wise the Illuminas turned up feel as good as the HD's.
I was actually considering getting rid of my HD's (but I don't drive that one much and never when the roads are bad) so I've got more pressing projects.

Since I also have Illuminas (w/ RB springs) and Koni's w/ GC, the Koni's and Illuminas see more DD.

Also if you do go with Illuminas and have the NB tophats(or get some), you could order the NB Illuminas, which on the rear have the adjuster in the same place as the AGX (outside and accessible), where the NA Illuminas have the adjustment on top (Like Konis), which in my case just means leaving the trunk apart all the time..lol...

One nice feature of the HD's, they mount up great w/ the GC perches because of the C clip design Bilstein uses...

Thanks for the info Jefe!

I have HD's with 450/375 springs...bilstein says they can take 500lb springs.

They are rough as fuck in the rear on the street, but are fucking awesome on the track. I have tokico adjustables on my other miata and they are a bit more compliant, but still kind of rough. I don't know what the cold weather means because I'm from Texas, but I'd take the bilsteins for the longevity factor.

The Bilsteins with ground controls, corner weighted, and a good alignment are fucking absurd on the street.

the GC Sleeves from the KYB's will not fit the Bilsteins.

Details? Too small? Big?

Maybe, maybe not. I tried to test fit my used GC sleeves/springs in original Ground Control box labeled "90-97 Miata w/AGX" on my HDs. No go, the sleeve won't slide over the shock body. Started to look at the sleeve and noticed a machined AL insert (with ID smaller than HD OD) pressed into the bottom (insert is .5 tall). Flipped the shock, used it as a slide hammer and popped out the insert. The GC sleeve now fits over the HD, albeit a little loose compared to the nicely machined Bilstein AL perches they supply for the stock springs. I'm not wild about the current fit, called GC a week or so ago and got some dweeb who couldn't answer my questions..need to try again next week.

Jefe, have you got pics of how the GC sleeves fit on Bilstein HDs???

I removed my GC sleeves from my KYBs. They use an aluminum spacer ring that slid onto the KYB to size the shock to the sleeve. I transferred the sleeves to my bilsteins and they were a loose fit. Used em anyway like that. Had one fail (sleeve slid all the way down) after hitting a big bump in the road. Fixed it and been fine since. Probably have 50k miles on em like that. While they are working for me it's not the proper way to do it.

EDIT: Was posting this at the same time sn95 was posting. He says exactly what I am talking about. The sleeve is loose on the Bilstein. I emailed GC thinking maybe they just made a different aluminum ring for the Bilstein but they wrote me back that they didn't so I used them as is.

I believe GC uses the same sleeve for all Miata shocks, with the exception of Tokico shocks, but with brand-specific aluminum spacer rings. Replacement rings are available from GC directly to the tune of ~$16 each, last time I checked. So, for ~$64, the GC sleeves for KYB will fit the Bilsteins.

Ouch, thanks for the clarification Paul but that is NOT what I wanted to hear. I think you are being extremely generous in your description of how the GC sleeves (sans AL insert) fit the HDs. I guess it's time to fire up the 3n1 machine in the basment and start boring AGX inserts...I really don't like the fit of the HDs in the stock GC sleeve.