New guy with K24 swapped Miata
 

First post, but I've been reading forums here for a few years now. I have a 2002 SE with a K24 that I've been driving/tracking for about a year and a half now. The swap completely changes the car, I'd recommend it to anybody. Just a few photos:

https://cimg4.ibsrv.net/gimg/www.mia...83afff95bd.jpg
https://cimg0.ibsrv.net/gimg/www.mia...a6b2387f3d.jpg
https://cimg8.ibsrv.net/gimg/www.mia...139f6dbaf8.jpg
https://cimg7.ibsrv.net/gimg/www.mia...de0c8988d5.jpg
https://cimg6.ibsrv.net/gimg/www.mia...af9175335b.jpg
https://cimg5.ibsrv.net/gimg/www.mia...2a28b53110.jpg

I'm always open to answering questions. I know not a whole lot of info is out on this swap so info can be hard to find. It's a blast!

I'm going to need an explanation on that dyno screen....

The ftlbs are all kinds of whacky, and what is the 4.910 ratio all about?

Yeah, divide by the ratio to get 190 lb-ft. He fat fingered the ratio, should be 3.91. Doesn't effect the rest of the numbers.

That torque number is actual "rear wheel torque" (as in torque measured at the rear wheels with a load cell, as multiplied through the driveline), but the X-axis is confusingly labelled with engine RPM rather than wheel RPM. Dynapacks also have a "flywheel torque" screen which divides the measured number by the driveline ratio in order to produce a chart that looks more like the torque you'd see on a dynojet display (Despite the name, this is not a figure that tries to back-calculate driveline losses).

--Ian

Nice job on the exhaust!

Welcome! Really nice, clean installation. Love the exhaust and the gauge setup too.

Not sure how I even noticed this, but I'd suggest moving that oil temp sender off the side of the block and mount it right to the chassis and use a stainless line to connect it. The sender will eventually crack off from engine vibration if you have it mounted that way. I'd hate to see that ruin your day.

That's some cool customer service.

I watched my friend almost get his k24 project completed then give up on the home stretch. Definitely could be the future of my sunburst.

So where are you located because i saw this on CL this morning

https://cimg7.ibsrv.net/gimg/www.mia...20a2b38c22.jpg

Now that I'm on lunch, I'll post more photos:

Here's the day I bought the car. It wasn't cheap, but it was a garaged 75k mile SE model with a hardtop. It already had a roll bar and an oil cooler so I was willing to pay a bit more. I think I paid $6500 - despite everybody saying "you can get a mint NB for like 2 grand bro!". Uh, maybe it's different around here, but that wasn't what I was looking for.
https://cimg9.ibsrv.net/gimg/www.mia...6368e05074.jpg

https://cimg1.ibsrv.net/gimg/www.mia...795f71c39a.jpg
Car was clean inside and out.

https://cimg0.ibsrv.net/gimg/www.mia...6efeadb344.jpg
First mod: Brakes, wheels & tires. I can get Dynapro for a good price through work so that's what I did. The fixed 4 piston has lots of stiffness and clamping force. BP-20 pads work great as a dual-duty compound.


https://cimg3.ibsrv.net/gimg/www.mia...3ea9d4cfe2.jpg
Break in was tough. As you can see I managed to get the rotors warm, but not real hot. The rotors are 11.6" diameter and shed lots of heat. Caliper to wheel is tight but acceptable.

https://cimg2.ibsrv.net/gimg/www.mia...db2c7b59d2.jpg
She's a bit of a pig as stock, about 2600lbs with me in it (I think I weighed 180 at the time)
https://cimg4.ibsrv.net/gimg/www.mia...4384aa998d.jpg
100HP just got old. Time to do something about it.



https://cimg0.ibsrv.net/gimg/www.mia...9b2c2b9998.jpg
Got the K24 stripped and primed with acid etch.



https://cimg2.ibsrv.net/gimg/www.mia...856c13335f.jpg
A few coats of 2K basecoat and trial fit parts. Notice the Mazda logo on the intake, this fools most people - "What Mazda motor is that??"

https://cimg5.ibsrv.net/gimg/www.mia...84dd672319.jpg
I like to mark all fasteners after torquing to keep my sanity. I always take photos of flywheel bolts to ensure myself later they are torqued to spec.


https://cimg0.ibsrv.net/gimg/www.mia...3e9aa7553c.jpg
I have nothing but good things to say about the ACT street clutch. The pedal feels almost stock if not a bit lighter.


https://cimg6.ibsrv.net/gimg/www.mia...d3f9209dc3.jpg
I pinned the adapter plate to the trans. I dialed in the adapter plate to the motor first to make sure it was concentric with the crankshaft. Then I transferred that to the trans, dialed it in, and drilled for dowel pins. This way it guarantees the trans input shaft is within a few thou concentricity to the crank. I think I got it down to .003". It took around 4-6 IIRC but it's worth the effort.



https://cimg9.ibsrv.net/gimg/www.mia...406ae291fa.jpg
Nice clean trans with adapter plate ready to go. I don't work with greasy parts, I'm a sissy that way. I like my shit clean.



https://cimg8.ibsrv.net/gimg/www.mia...c6bfaa4d6b.jpg
Steering rack must be depowered. I printed plugs to thread in for a clean look.


https://cimg1.ibsrv.net/gimg/www.mia...1a48d891b3.jpg
About time!


https://cimg4.ibsrv.net/gimg/www.mia...b5f35b239e.jpg
This was sketchy.


https://cimg9.ibsrv.net/gimg/www.mia...e14046431b.jpg
Holy shit it fits.


https://cimg7.ibsrv.net/gimg/www.mia...74db432839.jpg
Header trial fit. Looks good.


https://cimg4.ibsrv.net/gimg/www.mia...592d80338c.jpg
Tight fit. The header is of good quality.


https://cimg8.ibsrv.net/gimg/www.mia...a74e1164df.jpg
255lph fuel pump


https://cimg0.ibsrv.net/gimg/www.mia...32f5ae74d0.jpg
Removing sound deadening with a mixture of alcohol and dry ice, works like a charm. It all comes off in big chunks.


https://cimg9.ibsrv.net/gimg/www.mia...f78d11dd0e.jpg
Cascade Audio VB-1X applied. Works much better and lighter than Dynamat. I removed about 9 lbs of factory deadener and applied 10lbs of VB-1X for a net gain of 1 lb, and this stuff is way more effective.


https://cimg0.ibsrv.net/gimg/www.mia...9ef061c655.jpg
I'm not aiming for things to be super quiet, just cut down the rattles. K24's vibrate quite a bit.


https://cimg2.ibsrv.net/gimg/www.mia...c13a70de01.jpg
You can tell when it's dry when it is no longer purple.


https://cimg7.ibsrv.net/gimg/www.mia...1a22fa3456.jpg
I went through a metric shit ton of molded hoses. I probably spent $300 and returned all but a few. I like the OE look and less stress on aluminum or copper heater hose outlets from strained hoses.


https://cimg6.ibsrv.net/gimg/www.mia...df77551a27.jpg
Getting closer.


https://cimg1.ibsrv.net/gimg/www.mia...f95cbd9a88.jpg
3D scan for printing an air intake. The dots allow the scanner to know where it is relative in space.


https://cimg0.ibsrv.net/gimg/www.mia...b5c74b3a14.jpg
Huge Magnaflow muffler. I like things quiet!
https://cimg8.ibsrv.net/gimg/www.mia...48face736c.jpg
Outlet


https://cimg2.ibsrv.net/gimg/www.mia...9bfde5a74a.jpg
If this isn't centered it will irritate me forever.


https://cimg4.ibsrv.net/gimg/www.mia...4bac7871a7.jpg
Routing isn't too bad.


https://cimg8.ibsrv.net/gimg/www.mia...25aa67d219.jpg
Time to figure the dash: I didn't like the old gauges and I want something more track focused, also I didn't want to fiddle with the stock gagues to work with the K24. Might as well just start over. Here's the initial mock up. All gauges must be visible all the time.


https://cimg6.ibsrv.net/gimg/www.mia...21c72c7e0d.jpg
Mock up wth 3D printed shroud. The tach is huge but it's the main focus, as it should be IMO.
https://cimg8.ibsrv.net/gimg/www.mia...9cc2799336.jpg
All wired up. Notice the OLED display for speedo and fuel level. The 3D printed panel was textured and painted to look like OEM plastic trim. Not easy to do but looks nice.


https://cimg0.ibsrv.net/gimg/www.mia...88931d036a.jpg
Final product.


https://cimg3.ibsrv.net/gimg/www.mia...bf5bcb262e.jpg
On to coilovers: Here's 3 urethane bumpstops I cast to get the desired results. I knew what I wanted in terms of force/displacement and thought it might be fun to 3D print a mold and cast them myself. Works well.


https://cimg3.ibsrv.net/gimg/www.mia...4f0d6a5a20.jpg
Here's the adjuster knob of the Bilstein AS2 coilovers. Very easy to get to, adjust, and read at a glance.


https://cimg2.ibsrv.net/gimg/www.mia...4d0d06839a.jpg
Finished product.

Yep, that's me! I've decided it's finally time. I have 4 toy cars and it's hurting my family. I hate to see it go, this is the most enjoyable car I've ever owned.

Will do!! Thanks!!

Your kit was great, it turned a dream to reality. This car set the bar really high for future projects and I worry I'll never be able to top it.

Nerding Out
 

Let's paint a picture: I'm a car nerd. I'm a car guy, but an automotive suspension engineer as well. So I nerd out on everything. Hopefully these pics will give people some ideas now that 3D printing is becoming a reality for home users:

https://cimg9.ibsrv.net/gimg/www.mia...640d36c167.jpg
RPF-1s were scanned to make sure the Dynapro's would fit with a Mini Cooper 11.6" rotor. Big, cheap rotors combined with a stiff caliper. Win!


https://cimg6.ibsrv.net/gimg/www.mia...d2448d4e2c.jpg
I recreated the Kmiata adapter plate in 7075 aluminum. The Kmiata is steel, but for a good reason: thread stripping. I made one out of aluminum, lightened it, and used thread inserts.


https://cimg4.ibsrv.net/gimg/www.mia...5c2068d0a3.jpg
I scanned the deal in the console to turn off the passenger airbag. Using that profile, I created a new panel to mount the Wilwood remote proportioning knob. Looks factory. I'll get a photo of the finished product.


https://cimg3.ibsrv.net/gimg/www.mia...6959e59830.jpg
Front suspension to check clearances with the Bilstein AS2's and a 15x9 wheel.


https://cimg1.ibsrv.net/gimg/www.mia...6c5c3af023.jpg
Same for the rear.


https://cimg5.ibsrv.net/gimg/www.mia...5db8b090e5.jpg
I like to use a combo of poly and bronze bushings. The control arm pinches on the center steel sleeve while the poly rotates with the aid of the bronze bushing. This helps to remove bind and rely more on the shock/spring to control movement. I think I'm on McMaster's christmas card list.


https://cimg5.ibsrv.net/gimg/www.mia...1820543af6.jpg
Cluster modeling


https://cimg9.ibsrv.net/gimg/www.mia...1df79de4bf.jpg
This uses the square hole in the firewall for the cruise control and holds the remote bias adjuster cable. Looks clean when installed. I try to keep the firewall as clean and sealed as possible.


https://cimg7.ibsrv.net/gimg/www.mia...d522e38b0e.jpg
Weight of steel radiator bracket.


https://cimg1.ibsrv.net/gimg/www.mia...4b7666748d.jpg
Weight of 3D printed bracket. Every ounce counts, I did this on numerous parts, but ended up scrapping a couple due to durability.

Looks dead on how my car would look if K-swaps were road legal here, except the gauges. Great work, keep the updates coming!

Thanks Harry. Gauges are tough - everybody has their own idea of how they should look - just like wheels.

I hope to give back to people on this forum that I've been lurking on for so many years but never had anything to contribute.

I now feel like a cave man, with my MIG and hammer, etc. Me make pretty things some day....

Freaking lovely.

I am in love with this car. It's everything I want.

That exhaust looks almost exactly like my Artech system. Is that header at risk of vibrating on the oilpan/trans?

Well if you buy it you can store it at my house until you are in the area for work again.

Well, it is for sale! I can't post an ad here yet, I think I need to be approved? Not sure.

I'd have to double check on the header. I know it's damn close to the flywheel cover, but decent clearance to the oil pan. I was worried about oil temps but it hasn't proven to be an issue at all.

If anybody has any questions be sure to ask, I don't mind helping at all.

Uh huh. You seem like an intelligent person. We are to believe that you don't know why you can't post an ad, and that you don't know what you're actually trying to do with this thread?

I didn't think I was trying to convince people of anything, but to be frank I haven't been able to look at the rules as the link times out. If you review the thread, you'll see that I was not the one who first mentioned the car was for sale. If it appears that I'm being deceitful, I apologize as it was not my intention.

My intention of this thread was to help others who are considering going down this expensive road. I remember being somewhat unsure of this project as K24 swaps weren't that popular. If I can help ease that pain, I'd like to take that opportunity.

This is a community, and for a couple years I was taking without contributing. Now is my time to give back before the car is gone.

I mean, even if he just joined to list it for sale, he hasn't been shitposting or anything. He posted his beautiful car with some build information, and has answered questions after someone else brought up that it was for sale.

If you're going to join a forum in order to sell something, this is the way to do it, and this is the kind of vehicle we want for sale here anyway. I don't see a problem here.

Headpipe to trans clearance
 

I checked out the clearance last tight of that area. Oil pan is good, and I do remember making clearance between the flywheel cover and headpipe. It was touching as-is. If I were to do it again I'd have it all ceramic coated by Swain Tech.

https://cimg4.ibsrv.net/gimg/www.mia...697ab0aedd.jpg

Remote Bias Adjuster
 

Here's some photos of the remote bias adjuster. I did this for a couple reasons:
1. I added a front caliper with a slightly different piston area than stock;
2. I track the car on rain days. I've found the car behaves differently enough between full and near empty (fuel) that it helps to add forward bias, but only in the rain. Two clicks is all it takes and makes me more consistent.

IMO, the blue knob sticks out like a sore thumb and if I were to do it again I would just paint it or something. The placement is wonderful, you can drop your right hand quickly and give it a couple clicks without breaking concentration. I have the STL file if anybody wants it, but you'll need a pretty good printer to make it work.


https://cimg1.ibsrv.net/gimg/www.mia...0809b20e4d.jpg
https://cimg9.ibsrv.net/gimg/www.mia...fac781e5e6.jpg

Coilovers
 

This was a subject I debated not bringing up. There are a few good coilovers out there for Miatas that are plug and play and have the valving about as good as you can ask for - thinking of Xidas here. You just can't go wrong with these and the price is market aggressive.

Because I have the mental disability of being an engineer, I like to over-complicate things. Shocks are one of my favorite parts to design, test and build. I have a shock dyno in my office and Excel spreadsheets that spit out rough ideas of what the valving should look like, so I wanted a shock that was user-buildable and user-serviceable. Enter the Bilstein family of shocks.

The only issue with Bilstein is obtaining the parts you need. For example, for these AS2's, you buy a bare shock (body cap, body, top cap, piston, and DA shaft). No shims, no oil, no nitrogen. It's a dry shock. YOU figure out what shims you want (and be sure to order the shock with the right piston), build it, oil it, then fill to 200PSI and test. Repeat, test, make changes. It took me about 7 iterations to get what I wanted, then small adjustments to make sure all the sweep settings were equal for both front and rear axles.

Funny thing is, the compression curve I ended up with is about exactly what the Xidas have. I chose a linear rebound because that's what I prefer. Everybody has their own opinion on this.

The adjusters on AS2s have a nice solid detent and are of high quality. Sweep tests are very, very repeatable which is a must for high quality shocks. As you can see the adjusters are easy to access when using Bilstein's stem type shaft typically used on strut builds.

Anyway, in the end, you get a car that is sprung stiff but rides amazingly well - better than my E46 Performance Package I used to have. Having the freedom to choose body lengths, you can get the rear travel to be more than acceptable. These shocks, along with the K24, is what I will miss the most.

As you can see in the photos, I run a stock sway bar. I find this setup easy to drive on wet track days. Up here in Washington, limiting yourself to dry days makes the track season pretty short.

https://cimg0.ibsrv.net/gimg/www.mia...0d4285b352.jpg
Front


https://cimg9.ibsrv.net/gimg/www.mia...ea5239c64b.jpg
Rear


https://cimg7.ibsrv.net/gimg/www.mia...256a8437f4.jpg
Rear adjuster


https://cimg8.ibsrv.net/gimg/www.mia...8e1e846957.jpg
Front adjuster

You got a very nice surface finish on the knob for a printed part. Has that been vapor-bathed? What kinda printer, SLA?

Beautiful car, top notch work. For modeling the suspension, did you model all the components (control arms and knuckles mainly) from scratch?

Killer build. Love the attention to detail.

Good luck with the sale. I wish I had room for it...

Glad to hear that, it's definitely a really fun setup.

Regarding your header clearance - everything is inherently really tight under the pan. Try loosening up the lower header flange bolts (and the upper flange on the head if needed) and moving the lower section around a bit and then re-tightening. It's usually not hard to make a bit more clearance just by doing that.

Thank you. I actually downloaded the model for the suspension online, that saved me a ton of time. Everything is pretty accurate within reason, but not accurate enough to do an analysis on geometry. I probably just Googled "Miata suspension CAD download" and avoided the gay popups.

The blue knob is a Wilwood part, I printed the panel it attaches to. I scanned the airbag key switch panel and modeled the shape, then added the boss for the knob and detents.

https://cimg3.ibsrv.net/gimg/www.mia...3ec579d3e4.jpg


The printed part is skim coated with Bondo, sanded, polyester primed, sanded, more primer, more sanding, then SEM Trim Black. Works great.

It wouldn't hurt to make a little more room. It's OK the way it is now, but I'll try your suggestion. Your right, it's crazy tight but works just fine.

Ahh, I see, I misunderstood and thought the entire assembly was printed.

The other cars in your quiver must be pretty sick to be letting this one go!

Thanks! It took a good 6 months. I was wore out at the end but it was worth the effort.

Probably! They better behave now!

Seriously though, in the past, I have had no problem selling a car when I'm not happy with it any longer. Make the decision, boom, gone. This is the first time I've decided to sell one that I truly enjoy. It's sad. It's not a money thing, I'm getting older and my kids are too; I need to maximize the time I have with them while I can. The other 3 toy cars came from my family so I can't let those go. Ugh. I question sometimes if I'm doing the right thing but I need to keep my focus.

So, we all want to know what else is in the stable, if this is the one you'v decided to part with? Beautiful build!

1969 Camaro, Corvette front / IRS rear suspension, LS motor
1967 Chevelle, stock paint/interior, 383 with fuel injection
1964 Corvette, aftermarket frame, 5.3L LS

Two came from my family, and I bought the Camaro in college back when they were cheap. I have serious attachments to these cars because of the history.

Oil Cooler
 

Here's one I forgot about. Before I put in the K24, my oil temps were OK on the track but still on the high side. I ran the 1.8 for a couple years and removed & cleaned the oil cooler to make sure it was as efficient as it could be. That didn't change anything, but adding (printing) a shroud around the oil cooler helped quite a bit. Temps were noticeably cooler and more consistent.



https://cimg2.ibsrv.net/gimg/www.mia...a78911941c.jpg


https://cimg1.ibsrv.net/gimg/www.mia...e64f74d294.jpg
3D Model

What 3d printer do you have? I am in the market for one

That oil cooler shroud makes sense; it limits spill-over. We had something similar made up for a friends' stock AE86 Corolla oil cooler, worked like a charm.

Great work. Really cool stuff. Good humor too.

It's a Fusion3D F306. Very happy with this printer. Thousands of hours on it and it just simply works great. Mid priced, but probably too much for home use. Most (well, all) are printed in ABS.

I should admit this printer is at my work, I don't own it. I'm poor 'cause I have too many cars.

Thanks Ed.

Lol, yes, I am looking to spend like a tenth of that. But it does make beautiful pieces.

Any idea how much weight you lost with the swap? Or specifically how much lighter your aluminum adapter plate is than the Kmiata steel piece?

The weight was 2630 with me before the swap, and 2480 after. It lost 150lbs which is good, but F/R bias didn't change. I was hoping it would. The more I think about it, the car lost about 30lbs from mostly the rear, which explains the lack of F/R bias change. The K swap itself resulted in about a 120lb loss.

The aluminum adapter plate was 6lbs lighter. I wouldn't worry about using the steel one.

This is an awesome build!
Could you lend some more info about your shock build? It's not everyday we get the opportunity to chat with a suspension engineer.

I want to preface this with restating your note that there are numerous awesome low cost options for the miata.
However the AS2 is much more general purpose and could lend to helping both miata and non-miata projects.

Namely when I look up the AS2 with my highly functioning caveman skills, I can't find much other than non-adjustable circle track stuff.
Where would one buy the drilled/jetted/etc shaft and the bleed screw adjuster?

I believe you can specify these to Bilstein when ordering parts for the AS2

https://cart.bilsteinus.com/Portals/...-2019(WEB).pdf

I'll post some info on the shocks. It's hard to think of what to say, you could damn near write a book about it. I'll show the basics and if people have questions they can ask.

Harry is right about the shaft, you can spec that on the order.

Bilstein AS2 Info
 

Here's some notes on the coilovers:

First, as said before, this is not the best solution for most people. You need to know how to purchase from Bilstein (not easy), understand oil flow (through different piston types and shim stacks), and have a direction to go (force/velocity data), and have a method to validate (shock dyno & on-car data acquisition). If you don't have all four of these, you probably don't want to go this route unless you are a glutton for punishment which I think we all are.

1. Purchasing: Honestly I don't know how most people would even get through this part. My work is a dealer of Bilstein, so I just send an email and the part shows up 5 days later. I don't even get a confirmation email, it just shows up - what I'm getting as is Bilstein is a huge ass company and they don't have much time to chit chat with us car guys. Sure, you're speaking to the motorsports division so they're car guys too - but their customers spend thousands or ten times that. This means most of the time you have to deal with a Bilstein dealer which really slows things down if you don't have part numbers. Get the part numbers you need, double and triple check, then call a dealer. Each shock is $595 IIRC.

Ok, so you purchased the shock. But wait, there's a huge problem! There's nothing inside! It's a dry shock. Yes, you just paid $595 for an empty aluminum coilover. What you bought was the lower body cap, threaded body, upper cap, digressive or linear piston (you know which one you want, right?), adjustable shaft, and the adjuster. They way I understand it, and it does make sense, if you have the balls to get this far and purchase this thing, you know what you want for a shim stack. You already have shim assortments, tools, oil, nitrogen, etc. You don't want Bilstein to tell you what to run because it's your car and you know it best. Ugh.

2. Valves and shim stacks: Obviously I can't explain everything, but hopefully I give some tips to maybe make this possible to some people who are as retarded as I am. You have three piston choices, and these determine what valve profile you will have. Your choices are linear, digressive, and COB (check on bleed). Here's the thing: you can make a linear piston behave like a digressive by the shims and vise versa, but COB will be easiest to get high low velocity force (little low speed bleed) which is what most of us want. Problem is, they are tricky. Linear is easy, COB just adds a level of complexity that makes oil flow a bit more difficult to control. But when you got it, it's good! Now, on to shims. Shims are easy, they just flex and allow oil to flow past them. Shims vary is thickness and diameter to allow more or less flex and WHEN that flex happens (either high or low velocity). Shims closer to the piston control low speed bleed, farther away controls high speed bleed. Now, for DA shocks, keep in mind the shaft is 12mm in diameter unlike the non-adjustable which is 8mm. You need to buy shims with a 12mm ID hole for double adjustable shocks. This seems obvious, but for some reason they're shim assortment kit only comes with 8mm ID shims. You need to build your own kit, and it's going to cost a few hundred $$ (unless if you already know the shims you want, then just buy those shims).

3. Goals: You need to know what you want before you get started. I have an excel spreadsheet that kicks out force/velocity data based on inputs I give it. Garbage in, garbage out. And, you have to tailor the numbers based on "intuition". That's the trouble with engineering suspensions, there is no right or wrong answer. It's more of an art. And I hate art. I like math, 2+2 always equals 4 no matter what. But I think that's why suspension engineering is a black art, it's difficult to take all this data, then put your own personal touch on it. But over the years I've gained enough experience to be confident in getting a good result the first time. So, what I'm saying is, you'll need to do the math on roll centers, g loads, critical damping blah blah then use coefficients to modify the output slightly to reflect how you want the car to behave.

4. Validate: I couldn't do this without a shock dyno. If you have access to one, good for you and I'd give this a shot. On-car data acquisition will get you to the end result faster but isn't necessary for non pro-level guys. Count on doing probably 30 dyno sessions trying to get the valve dialed in if you know what you are doing, 3 to 4 times that if you're a noob.

I guess it's it for the basics. I'll post some pictures for illustration. If you're new to this, I would just copy somebody else's valve (look online or use one of the examples in the Bilstein rebuild catalog). You are NOT going to get a valve as good as Xida's quickly. It's going to take you lots of time and a dyno for sure. If you want to learn shocks inside and out, rebuildable Bilsteins are awesome.

Coilover photos
 

https://cimg5.ibsrv.net/gimg/www.mia...b63f2a53df.jpg
This is what you purchase for $600. This one has the bearing at the adjuster, Miata's will use a stem type mount shown in the Bilstein catalog. You need to specify you want the stem type shaft when you order the shock!



https://cimg3.ibsrv.net/gimg/www.mia...4f85a65fbe.jpg
Close up on the adjuster. Very high quality, easy to read, strong detent with a satisfying "click". Notice the red and blue adjusters are actually two piece so they can be indexed if needed.



https://cimg6.ibsrv.net/gimg/www.mia...44ef9013db.jpg
Another cool thing about Bilsteins: If you don't see the length you need, get the longest one and cut the threaded body down. You'll want to do this on a lathe to ensure you have a good o-ring sealing surface. You can remove the lower body cap by heating it as there is lots of red Locktite.



https://cimg5.ibsrv.net/gimg/www.mia...82f4ce63bf.jpg
Here's a linear (left) and digressive (right) piston. Noobs may opt for the linear as it's simple.



https://cimg7.ibsrv.net/gimg/www.mia...126fb1abf3.jpg
Here's the shim layout and DA shaft. Lower row is the compression shims, upper is rebound. The bleed shims up top (the ones with the notches) shouldn't be there, I didn't clean up after myself. Be METICULOUS with your procedure, it's so easy to get shims mixed up. Come up with an assembly procedure and do it exactly the same each time.



https://cimg2.ibsrv.net/gimg/www.mia...add9dce840.jpg
Shims for 12mm shaft



https://cimg5.ibsrv.net/gimg/www.mia...7e2ae98e4d.jpg
More shims

Pos-cats for super informative posts; especially the 1st one should be directly pasted to my ex-FSAE team suspension discussion.

Thank you. I still owe you a pm.

I just realized how many spelling errors I had, Damn. Embarrassing.