Ok, that sounds reasonable. I just don't think i can get a full 1" of travel from squishing 31mm bump. 1"=25mm so 31-25=6mm. That would have to be a super soft bump in order not to become a very stiff virtual spring at that point. I'm going to inspect my mounts/shocks again and see if there is anything wrong with install or parts, but I've looked at them a few times already

 

Just verified this and you are closer than I was. Stock NB tophats are 5/8" deep (0.625").

 

Quick (Stupid) question. I just got extended rear hats in the mail (Thanks ISC!) and I'd be right to assume that if I left the spring perch in the exact same spot and just changed out hats, I would lower the car right? Thus a change in top hats means I need to raise my spring perch a bit?

 

Nope, should be about the same.

 

You are absolutely right. Do you have the force/deflection curve of your bumpstops?

 

i do not. They are Flyin Miata bumps. I had them around (bought barely used locally) so used them instead of buying new speedthane.

 

If changing from stock NB hats, no. If changing from NA hats, definitely. If anything, I would guess that just swapping the hats will actually raise the car a fraction of an inch, due to the thickness of the plates used for the flange portion of the hat on all the aftermarket options. This may only be 1/16" difference at the mount (just guessing here). Multiplying this by the 1.33 NB rear ratio (according to HarryB), you would raise the rear by about 1/12" (0.083"). Pretty insignificant.

 

Ordered TSM hats, will be here next week. Hopefully this will help.

 

Does anyone have a suggestion where to buy bilstein circlips to use with OEM bilstein take offs? When I removed the spring mounts a few got bent. I know a lot of people used the rotor clips early in the thread, but since I'm using all star sleeves I need one that resembles stock, so the sleeve can fit over. Summit Racing has a one MONTH wait to get these, no auto parts stores have them, hardware stores, etc. Any suggestions?


It looks like amazon has them for 5 bucks a piece

 

http://www.speedwaymotors.com/Bilste...ng,138388.html

 

I saw that, it looks correct, but the part number doesnt match what someone posted early in the thread, "2522880" .

 

Just took front's out and put new tophats in, put shocks back but ran out of time to get everything finished up and height adjusted.




Top surface of tophats is almost 1" apart between NB OEM and TSM.

 

Those are on the fronts right? Let me know how well they work up front. I plan on ordering TSM mounts for the front as well.

 

Yes, those are the fronts.

Small update - so far so good with install of TSM hats. I haven't gone much lower (even though I have maybe about an inch left on the sleeve), but at least now I have shock travel before bumps engage. Went for a short test ride - so far so good.

Notes on TSM hats: decent quality (not high end like Xida or Feal hats). The hole in the hat does not accept the nipple from the OEM lower bushing. If you want to use it - you will need to enlarge the hole. I've just used some electric tape until hat was snug against it. Should help with centering and preventing noise and some vibrations. Lower bushing is too big for this hat in general. I've used MCU bump cut-offs inside instead of bushings and then OEM bushing on top. Hat is lighter than stock, dimensions are spot on, the spring locator is a nice addition.

 

Pretty sure the TSM hats are designed for NA shocks with the shorter shaft threads that don't use a bushing on the lower side of the top hat.

 

I've called Chris from TSM and he didn't say it was for NA - said it will work for me just fine. I don't think it's a good idea to not use a lower bushing as this will directly connect shock to tophat and provide no isolation from NVH. With a solid metal to metal connection, this will be noticeable in the car.

 

Correct, you have to use a bushing with NB style mounts, in your situation you can either drill out the mount to fit your bushing with the nub, or cut the nub off. I personally would drill the top mount to keep the nub as it prevents the shock shaft from rubbing on the top mount.

 

I've used enough electric tape to make the hat hard to slide over shaft thus replicating the rubber nub isolating effect. Then used bump cut-off for lower bushing. So far so good.

 

Finally got my bilstein setup on, sorted and tested on both daily commute and track.
NA bilsteins
Allstar sleeves
Eibach 7 inch 450 front and 7 inch 300 rear
12.5F/13R
New DC2 integra Bumpstops (trimmed to 36mm and V-cuts to make engagement progressive)

Front:
0 Toe
4.5 Caster
1.7 Camber

Rear :
0 Toe
1.7 Camber

Wheel/Tire setup
185/60/14 Nankang NS2-R 120 Treadwear
14x6.5 Panasport Prorally

Sway Bars
Stock R package sizes (S-special type I is an R package with power windows and AC)

Results
Excellent ride dd for most but not all bumps I think the springs are still soft enough to jack down on bumpstos, great turn in response, very light understeer on corner entry and perfectly balanced mid and exit with a torsen.

 

Hmmm. Need to get back to this - I have some ideas for what I want F/V curves to look like, a disassembled digressive circle track Bilstein that I took measurements from, a dyno plot on a DIY dyno I did with the shock in question, and a copy of Restackor... seems like it should be possible to fiddle the geometry in Restackor until things correlate, then try to predict valving for F/V curves. I mean no disrespect to any vendors or pioneers, but now looking at data people have published, it seems like there's a certain range of stuff that works pretty well at getting close.

Or maybe I have delusions of building my own runoffs grade shocks, whatever.