Coilover Sleeve Options

I need to replace the shocks on my rallycross Miata. I figured this would be a good time to switch to threaded coilover sleeves and 2.5" springs on the Bilsteins before I put them back on. The current sleeves I have are from ebay and they sit directly on the circlip on the shock body. This doesn't leave enough room to install the 10" spring on the front. Are there any sleeves that will slide over the circlip and seat farther down to gain more length without machining a new slot in the shock body for the clip? 

I know the allstar sleeves sit over the clip but it seems like they just cover it, not extend further down from it. Are there any other options?

I'd call Ground Control and see what they say. I never used any setup like that on my Miata. (VMaxx then XIDA's)

Pretty sure I remember the ground control sleeves sitting with the circlip well up inside the sleeve body. But I only ever ran them on konis, not sure if they interface with other dampers differently. This was an autocross car with (way too) low ride height and the front fit 7" long super stiff springs with room to spare. So I would think with rallycross ride height and softer springs that 10" length would fit.

GC uses a couple of different mounting styles depending on the shock. I don't know about the Bilstein aspect, but they're definitely the first people I'd call.

Machining another groove in the shock is not a taxing job, though. Bonus GRM points if you do it with a drill and an angle grinder!

I used the GC sleeves in a homebrew setup about 2 years ago. From what I can recall, the GC sleeve only extended an inch or two past the circlip 

An inch or two is better than nothing. Does anyone know if GC well sell the sleeves individually?

Related question. I have hated the bilsteins ever since they were revalved, the compression damping is way too harsh. Is there any way to work around that with spring rate? Softer or stiffer? I had msm springs on them with 215 lb/in rate.

Machining a new groove might be the excuse i need to get my lathe running.

If it's too harsh (overdamped) then more spring rate would be the solution. Can't guarantee that won't cause other issues though, especially with rallycross use in the picture.

I don't know if they've changed styles but the GC sleeves I had were two peice, a donut that hugged the damper and sat on the circlip, and the generic outer sleeve with a step to the ID that the donut sat on. I'd be much more excited about machining the sleeve ID step further up than putting a second groove on the damper body.

Hard compression damping is something I associate with Bilsteins. I'd be tempted to run less spring rate in that case, but you have to control those big movements if you're doing rallyx (he says, having taken part in one whole rallycross in his life).

In reply to dps214 :

I had the ID cut up into my ebay sleeves but I could only go up about half an inch. The threads of the ebay sleeve are deep enough so that there would not be enough metal left between the circlip and the threads. In hindsight I think I should have had the shocks cut for a lower circlip. Although I am not sure how far down the springs can be lowered before suspension interference on the miata.

Allstar sleeves are asymmetrical, the land that takes the circlip groove is fairly well recessed on one end.

Whether they will fit your shock bodies, I am not sure.  And Summit changed their website to be completely un-navigable.

Pete. (l33t FS) said:

Allstar sleeves are asymmetrical, the land that takes the circlip groove is fairly well recessed on one end.

 

Whether they will fit your shock bodies, I am not sure.  And Summit changed their website to be completely un-navigable.

That's good to know. I was reading through some Miata threads for bilstein coilovers and a few people were using the allstar sleeves but had them oriented so it was just covering the circlip. But most of them were using 7" springs and didn't need any extra length. 

I have a pair of sleeves that I'm pretty sure are Ground Control pieces. They have a step at either end. The lower end is recessed so the C-clip is trapped inside the sleeve. The upper end is flush, no recess to accommodate the clip. If the current GC sleeves are this way you could machine out the upper step and invert them. That way you would have threads from about one inch above the clip to almost 5 inches below it. I'll bet that's too much. If it were me, I'd get some quality sleeves and machine a new C-clip groove where I needed it.

Edit: I also remember having a pair of sleeves on my GTI race car that had a single step about an inch from one end. Those could be inverted and give more lower adjustment. I can't remember what brand they were.

In reply to EvanB (Forum Supporter) :

Why do you need a 10" spring when the shock has about 4-4.5" of total travel? Wouldn't an 8" be long enough? I'm playing with 10" ones on Miata shocks for my Challenge car, but that's only because the springs were cheap. My Ebay sleeves are very close to the upper A-arm and I don't expect to see the kind of suspension travel a rallycross car would.

In reply to DeadSkunk (Warren) :

Mainly because I have the 10" springs and if I am buying different springs I might as well order proper sleeves at the same time. 

I may try putting some stock 1.6 Miata springs on the Bilsteins for the event this weekend to see what it does. 

DeadSkunk (Warren) said:

In reply to EvanB (Forum Supporter) :

Why do you need a 10" spring when the shock has about 4-4.5" of total travel?

That is about how much travel most 10" springs have.

I have 14" springs on the front of the RX-7 and still have to be mindful of coil bind with only 6-7" of travel.

The more expensive springs are made with more resilient wire, so they can be made with fewer coils (fewer coils means more metal twisting) which means more travel available.  I have bought cheap 12" springs that only had 5" of travel before.

I hate to be that guy and bump a two year old thread...  however I'm in the exact same predicament trying to get max travel on some off the shelf Bilsteins and coilover sleeves. 
 

Did you find any data on the GC sleeves, another solution, or just machine a new groove lower down?

I bought a cheap Allstar 5" sleeve, and this is what I found:

There's a square lip approximately 15mm in from one end, and another support ~30mm from the other, but it has a chamfered edge.

I got distracted by other things and forgot about it. I have just been running stock suspension on the front of the Miata and complaining about it every event. 

Now that my lathe is working maybe I should revisit.