Also, it depends on the shocks—if you can find a shock that's narrower, you can probably find a sleeve that's narrower. Not sure why you'd want to though. Is the extra 1/8" tire clearance you'd get really worth the hassle?

 

Here's mine (in progress)

Hard S
550/350 summit - 7" f&b
summit isolaters
Trick NB extended top hats f7/8" r1 3/8"
5x sleeves 5X Racing 2.5" Coilover Kits for Bilstein Shocks
Civic bumpstops

This is for a '90 with 1.8 swap and lots of lightness.

Ive got Cal Boprey doing the revalve cal@resuspension.com at RE Suspension

I need a dyno graph to give Cal as a target. Someone had a Xida line that'll work?

 

Yeah, definitely.

But also this. I've felt myself wishing that things were a bit stiffer. I think the low speed damping is a bit off because it feels way better on bumpy roads at higher speeds than lower speeds.
Obviously not expecting this to act like $2000 suspension but...

 

um, help.

Yep found a dyno chart for xida. Btw I have a car with Gen1's.

Couple more questions.

1. What do I want to tell this tech doing the revalve? What do I want with regard to high/low speed dampening? They should try to match what area of xida adjustment range (which line?)?
2. I'll be running street tires. 550/350 is more spring than I need for those tires. I'm thinking of doing 550/350 anyway just to help keep me off bumpstops. My xida's ride great with 550/350 R-S4's. But is there a point of diminishing returns on that? 195/50 Comp2's. Would 500/300 be better?
3. Using 5x spec miata sleeves (same as advance autosport). Do I need to cut another c-clip groove lower like when using ebay sleeves? Or is the Advance Autosport sleeve get you low enough at stock clip location?
4. I want to be down around 11.5f and 12ish at rear. Will 7" springs get me there without coilbind? Shoudl I use 6" spring at front?

Thanks in advance.

For your enjoyment here's another pic of my top hat fabrication.

 

I believe Advanced Auto sleeves sit just fine. I got mine as a part of the Spec Kit and i believe they used these sleeves - i didn't need to move the c-clip, did it in stock location.

 

The xida's esp gen 2's have a pretty large damping sweep from soft to hard, I guess you could pick a middle setting to copy, but it's a bit of a stab in the dark as to how that's going to work with your chosen spring rates. If you're just trying to improve the comfort level/ride quality (given the 550/350 spring rates this is what I'm assuming) you'd be running xidas near full soft. To simulate that on the bilstein you'd probably just increase the bleed amount which would reduce the amount of 'nose' on dyno curves.

Xida dynos also seem to vary quite a bit front to rear - the front's are considerably softer at low shaft speeds. Here's the Front MSM OEM bilstein vs xida gen 2 dyno (I drew in the MSM in red):

and Rear (MSM orange line):

 

I kind of think it's not really worth revolving if you're just wanting to run 550/350 spring rates, it's only when you want to up the spring rates much higher that the BBB approach + revalve will be worth it for a good budget race/competition suspension if you already have a lot of the parts.

While revalving for 550/350 could improve the ride quality, there's probably a lot that contributes to that that's not only going to be solved by re-valving- amount of compression / droop travel, gas pressure, amount of stiction/response to small movements (think piston seals, internal body surface/coating or lack there of), bump stop lengths and the transition on to them / bottoming behaviour (lol).

 

I decided to cut into one of mine that was damaged in an accident. Thankfully, I've got another one with a scored shaft to to cut into, because this one was a huge pain to get apart and I basically destroyed every single piece.



I'm going to try to revalve on my own at some point for the experience, so I picked these up for less than the price of a single new Bilstein. In the meantime, Michigan roads suck so I'll probably stick with the stock Mazdaspeed springs or find some FM ones used.

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BAHKAK, those top hats are beautiful!

Also, if/when I do this coilover conversion again, I will definitely cut additional grooves into the shock and lower the spring seat. Even if you don't need it to reach your target ride height, it will reduce the likelihood of your springs hitting the sleeves.

 

Thanks on the top hats. I can't claim the welding skills. I had the fab shop at work do it (Ford Motor Compay Design Center!). The top hats are now "OEM" ;p

Yeah I think cutting a lower groove is good insurance.

I've rethought some things. I'm going to still run 550/350 in 7" but I've found some zero weight helper/tender springs. The helpers coilbind at rest just like Xida and that adds to the stack so I need to be sure that I've got enough room. Going to cut 1" lower groove. THANKS

 

Doing another suspension swap at the moment and am taking the opportunity to measure bump/droop travel and sort out bump stop lengths and optimal extended tophat lengths. Car is a JDM NB1 - doing fronts first, will measure rear next. Pics:




Notes:
- fender liner removed
- wheel is 205/45/16 - this is about 7mm taller than a 225/45/15.
- with this tire fully compressed with a stock length NB Bilstein shock the tire is just making contact with the chassis before the shock bottoms out. With the 15" tire i'm not sure if shock or tire would bottom first, either way it's so close we're at max compression without a bumpstop that it's within what I can easily measure.

Conclusion: Optimal tophat extension for using stock length nb bilsteins on a bilstein chassis is about the block-height of your bumpstops in the front. After that you're losing droop travel with no gain of compression travel possible (as you're tire's into the tub at that point).

 

Blockheight looks to be around ~10mm for long the 46mm bumpstop. Shorter stops will have shorter block heights but probably only marginally so. There's not a lot of benefit in front extended tophats and lots of potential to lose droop travel and use your chassis as the bumpstop (bad).

 

I see you still have the OE spring perches on. We should compare the height of the spring perches between your NB Billies and my Mazdaspeed Billies since the overall length argument has been put to rest. I'll do some measuring tomorrow.

 

Cirlip location do you mean? I have both MSMs and OEM Hard-S shocks - can measure/compare if you want.

 

Interesting info point, thanks! For the rears, the limiting factor is top a-arm/chassis contact if I recall correctly. Do you plan on verifying that as well?

 

I think it's worth mentioning that we have way more droop travel then needed. Unless you're running tender springs the spring can rattle loose. The main benefit to an extended top hat is being able to run a 50 to 60mm bump stop and still use all the available bump travel. The softer engagement of a full height bump stop vs. a cut down stop is significant for how harshly the transition from spring to bump stop happens.

 

Yep will do rear next. Have NB OEM, 1" and 1.5" extended hats to try. Might not get out to the garage again till the weekend though. Edit: Will try with a 15x9 / 225/45 tire too.

 

You're gonna want to measure carefully doing that. With a (say) 60mm bump you can still only use about 10-15mm of the extended travel's length in the front, then you're using your chassis the real bumpstop- there is no more available bump travel. Also worth noting that with the plastic fender liners still in it's even less.

 

Absolutely, you have to custom tailor your bump stop length for your combo. No way you can just slap on off the shelf bump stops.

 

Getting a weird clunking that I thought was from my suspension. Finally got around to taking video, fully expecting that my springs are too short and are flopping around over rough pavement. I don't see anything obviously wrong. Video is only a minute long, clunking occurs at :04, 0:11, 0:39, 0:42, and 0:46. It doesn't sound like much, but it's quite a bit louder in cabin. I've gone through and triple checked every nut and bolt...what am I missing?



Setup:
MSM Bilsteins
Ebay sleeves
FCM bumpstops
NB tophats
7" springs all around, believe the rates are 500/400