Hello MT.netters! I've owned my Miata for about 3 years now, and have thoroughly enjoyed it in it's current form. I bought it with just over 100k on the clock, mostly stock, and had some pretty ricey things done to it. It was pretty cheap at the time, and with a little suspension and some new shoes, it was exactly what i was looking for- something to drop the top on, that was cheap to maintain, and comfortable at an autocross. Here' s what she looked like in 2017, after the suspension, wheels and tires.



Earlier this year, i was having dinner with a friend who mentioned the K24 swap. I'm not sure why it took so long for me to hear about this, but i was hooked! A month later, and i have this in my garage:


JDM K24a from some JDM spec honda we don't get. First thing i wanted to do, was to tear it open and see what mistakes i've made....

Looked pretty good! Of course i won't really know until it's in the car.

This was the point where i needed to decide how far i wanted to get into this. I knew that the open diff was already annoying when pushing the car, so i found a torsen unit and swapped that in. (sorry, no pics of that). I did drive it for a week on the new diff to shake it down, and it's glorious .

Goals for the project:
- Streetable, usable power
- autocross and some HPDE days, while being reliable
- educate my kids, get their hands dirty
- don't want to separate the head from the block, i believe honda probably does a better job of that than i can
- maximize power, with an emphasis on reliability.

So i won't be interested in running alternate fuels, and i don't want to get serious in the head at this time. That being said, I am willing to put some cams and valvetrain in it to give it a little more of an edge.
This began in April. I will update in more posts as time allows. Looking forward to getting this on the road again!

Thanks for the read.
Dan

 

While i was tearing down the k24, and finishing up the Diff install, i did a couple of cosmetic things to the car. Found a subtle front lip that took away some of the 'hairdresser' from the car.


After that, i wanted to work on instrumentation. Found my way to revlimiter.net and poked around on there for a week or two, got some opinions from my kids, and placed an order! A huge shout out to Adam @revlimiter, the gauge faces came in very quickly, packaging rivals any new apple product, along with a handwritten 'Thank You' note! You just don't get that type of detail anymore. That, and the product is amazing!

Cluster teardown:


The install went just like he says on the site. I ended up with the Dragstrip version with LED lighting, with a couple of modifications. I raised the redline to match the new engine, and changed the fuel quantity indicators to %. Here is the finished product:


But the coup de grâce is after dark:


I think they look incredible!

Back to the K24. Continuing with the cosmetic theme, I wanted the valve cover to pop, and I was waiting on parts anyway....so i bought a few cans of VHT Wrinkle blue and got to spraying.



This paint is different to work with, and i have to say the color is not what i was hoping for. Some of you might ask why i didn't do the classic wrinkle red, that's because intend to respray the car red at some point, and thought it might clash.

More to follow
Dan

 

Cam choice and installation

I did a lot of research before committing to a set of cams. Since my goals for the project can be met without separating the head from the bottom end, I wanted a set of cams that drove well across the rev range, with noticeable improvement over stock. From the information i could find of the readily available off-the-shelf cams, i liked the price point of the skunk2 tuner series. I emailed the vendor, and then called David over at Kmiata to get his opinion. What i found was that the ramp rate on these cams seem to wreak havoc on the timing tensioner, which is already a weak point of the k series engine. To top it all off, the cams i wanted 'strongly recommended' valve springs, seats, keepers, and retainers. I never got a reply from the vendor about their recommendations.

After i totalled it all up, i was within reach of a nice set of Drag Cartel cams (that i had my eye on from day 1).

After speaking to some owners of various DC cams, i decided this was the way i wanted to go. Their customer service was excellent, incredibly knowledgeable and responsive, and we decided on a set of 2.2s to put in the car.

Here is a crappy profile pic of the intake (i think) cam, stock vs DC 2.2. Should be a healthy bump!
And some pics of the installation:




Keeping the rocker assemblies together was a bit of a challenge. I used a 20" wrench hanger magnet covered with masking tape to keep it all together while i did the springs. Some people rig up zip ties to keep it all together.

As you can see, the complete valvetrain is in, torqued to spec, and lubed up. Buying from DC was great, the valvetrain kit came with everything you need to install them- there was no sourcing parts from anywhere else. Valve seals, keepers (which have a different angle from the stock TSX), retainers, dual springs, and seats were all included. Lash was set before i quit that evening.

Dan

 

Time to tear down the car, with the swap kit ordered! I put out a facebook marketplace ad for my engine, with the option to come and drive it before i pull it.
Surprisingly, that wasn't a very attractive offer! I wanted to show transparency, which i thought this would do very well. Most inquiries wanted to just come and get it ASAP.

Either way, it didn't take long to sell. I took the evening with my demolition team and got it out, didn't even take that long. 2:10 between jacking up the car and the engine/trans assembly sitting on a pallet. Man this thing is much easier to work on than a BMW!
My 'demolition team'


Afterwards, i really got deep in the project. The wiring requires the dash to come out of the car. I will be taking the opportunity to install a fresher carpet and steering wheel. Need to source some floor mats at a later date, suggestions would be welcomed! I'm also unsure if i will replace the heater core. It seems they are hard to come by, especially with the tubes going to the engine bay. Cores from local parts stores seem to just sell the heater core, and not the supply lines. I doubt it's really necessary, but one of those 'while you're in there' kind of things.

Yep. no idea if this will ever run again. Seriously questioning my decisions at this point. All of my free space in the garage is being taken up with parts. it's such a mess...

This is pretty much where it sits right now. next steps, paint engine bay, show off the Kmiata stuff that's here, and hope for more boxes soon.

Dan

 

Moss Miata "better than stock" floor mats are nice and well worth the dollars.

I would gladly pay extra for some that DON'T say "Roadster" on them, but i can live with it.

Re: Heater core. If the one you have in the car now is good, just leave it. They aren't especially failure prone and replacing one is a pretty easy afternoon job later, especially now that you know how the dash comes out.

Looks fun so far, keep it up!

 

Thanks for the tip, i'll check those out!

As for the heater core, the heater hoses were really stuck on there, and my dad smooshed one of the aluminum tubes with some pliers. I may try to straighten it out, or find one with good tubes. it's not awful, but it's there....

I really do enjoy these projects. I always wanted to build or swap something, about 7 or 8 years ago i nearly pulled the trigger on a Factory Five 818. I am glad i didn't, because i don't have the fab skills that some on this forum do!

Dan

 

I see a Kswap, I hit like!

good progress and keep the posts coming!

 

Thanks a bunch! I have read your entire thread, that's some quality stuff there. When i got to the part when you acquired the K, i was excited to see where you'd take it.

Then a few posts later, the date got current....i thought "NOOOOO!!"
I need some more of that

After the wallet recovers i may contact you about fixing my night vision.

For the other enthusiasts reading this, I will be needing some recommendations on rollbars for HPDE use. I'm 5'10", and taller in the torso than some. I was hoping to catch a deal on a used Hard Dog or something, and i know many mention the blackbird bars are great as well. I tried briefly to find their site or pricing info, but didn't see it.

Dan

 

You just stumbled upon an insider meme! Have a cat.

 

This thread pleases me and I'm also jealous.


Hard-dog "hardcore" is good for HPDE, "hardcore" denotes the rear braces are straight and not bent like the sport models. Some organizations require no bends in the rear braces of a roll-bar. The other piece of the "is my noggin guna fit" puzzle is the seat and seat-mount, have you looked into that yet?

Also you're in VA and close..... You should absolutely come to miata track day Aug 1 @ AMP - https://www.facebook.com/miatasbeforethegap/ #shamelessplug .
Then come to Miatas at the Gap - Miatas At The Gap #neverstoppedpromoting

 

I appreciate the invite, but i'm 100% sure the car won't be ready for AMP or MATG. hopefully next year!

In regards to the rollbar/seat thing: My plan is to Foamectomy the factory seat and go from there. Do any of the off-the-shelf rollbars have more clearance than another?
If i have to do seats, that will delay things a bit. The car really needs brakes before a good track day as well. These tiny stockers are a hard stop away from fading on a fast auto-x as is haha!

 

Great project, looking forward to your progress reports!

On the heater core, that car is what, 20 years old? I'd replace it, preferably with an NA one (copper vs aluminium) while you can do so easily. NB cores do fail, and if there has been some brutality upon it that does not bode well for a long and happy life. On the other hand, if the aluminium one has lasted 20 years, I would not be dying in a ditch to get the copper NA one. Either way just do it.

 

Yeah, you're right. Do you have a good source for a quality core?

 

The Parts Group (The Parts Group - Used Miata Parts). Tom is a joy to work with.

 

Well, if you find the time, come down to MATG in any car and check it out!

I honestly don't know for sure if one bar has more clearance than the other. You'll be hard pressed to actually pass broom-stick test with OEM seat, though you might get lucky.

For brakes, if you HPDE in mind you'll want good pads. PFC, Gloc, Carbotech - these are the brands I would recommend, compounds would depend on the rest of your setup. You will be at power levels where a BBK(big brake kit) is recommended. I don't have any DPE(direct personal experience) with BBKs because I have pleab power and I've always ran stock 1.8. But I haven't heard anything bad about Stoptech's ST42 setup or event STR42 if you're a big baller. I've seen and heard of both good and bad things on Wilwoods, maybe that's because there's more of them out there on NA/NBs?

Another component to consider with this upgrade, master cylinder......hopefully someone more well-versed with that will chime in?

 

Thanks for the kind words. I agree 100% on the "NOOOOO!!" statement. Life has been insane the last year between saving then later buying a house and working my way up the corporate ladder and traveling around the world. Current plan is to have the Miata at MATG for a final hoo-rrrahh on stock powertrain, then tear it down in late August for what will be many financial mistakes being made in series. The build thread will have a flurry of activity during this time.

Feel free to hit me up with any lighting questions and I can forward you links on the "go-to" parts to buy, or if you want me to do the work for you that works as well.

As far as the rollbar is concerned, I have the blackbird single diagonal bar. I like it as it has the welded in harness bar, where the hard dogs bars require you to buy an additional bolt-on harness bar. By time you pay for the additional harness bar on the hard dog setup, you aren't far off the blackbird price. Both give similar helmet clearance from what I've seen. I'm 5'9" and fit under the broomstick test with sparco sprints, PCI brackets, and BFW bar without issue. It really depends on your torso length though, as I have a 6'3" friend who fits great and another who still doesn't.

 

I have experience in the HPDE environment, and am familiar with the value good pads offer. I was looking at a BBK for the car, specifically the good-win or TSE kits. TSE doesn't list them on their site anymore, did they go out of production? Good-win has a lower end wilwood kit that would probably do fine for my goals. If some extra parts sell i'll look into that more aggressively.

Interested in master cylinder opinions!

Re: Seats- is there anyone out there passing hpde tech with stock seats? Really hope to make them work, since i don't want a track-only car.

Dan

 

I do just fine with stock brakes, stop tech sport pads, and good brake fluid.
Almost no brake fade at 20+ minute hpde sessions. And great braking power.

As for roll bars, hard dog hardcore hardtop, is a great bar. They also have a slightly taller version that wont clear a hardtop.

Also I have never ever been broom stick tested at an hpde. It seems all they care about is if you actually have a roll bar, not so much how you fit under it.

 

Remove the rear seat mounting humps and bend the rear seat rail tabs to match the new angle. You can gain 3/4 inch by doing this and bolting straight through the floor and putting a small backing plate beneath the floor to ensure it doesn't pull through.

Rockauto has good carpet kits cheap.

 

My car has this done to the seat rail and now the seat wont slide all the way back.
I guess this can work for long torso, short legged ppl.