The Miata You Wish You Built

When I first started my freelance career in the automotive scene there was nothing more fascinating than an engine swap.

Now, I’m not talking your semi-standard ‘upgrade’ swap, like replacing your Nissan KA with an SR, or ditching your Honda D-series for a new K-series, but full-blown, crossbred transplants. Like the 5.7L V8 VW Caddy I featured last year. Or this Honda K-swapped NB Mazda Miata, which I just so happened to stumble upon at the recent Import Alliance Atlanta meet.


Maybe it’s the ingenuity that gets me going, or the fact that in most cases the applied components truly have absolutely no business functioning together. Yet as always, when there’s a will, there’s a way. And that was exactly the case for David Calzada when searching for a reliable method of bringing a little more power to his daily tracker, without sacrificing the OE pleasures of his factory Miata.


So with a little help from all the right people, what started as a complete fantasy soon turned into reality as David began repetitively fabricating and testing one-off adapter plates, flywheels, sub frames, mounts and oil pans all in an effort to construct the perfect, no-compromise design, mated to the factory 6-speed Mazda transmission.


The result: a 232whp, 183wtq Miata monster with an 8,200rpm redline weighing in at only 2300lbs – and a full interior with working A/C.


But where David’s story really gets impressive is that not only did he turn his dream into a reality, but while doing so he recognized that he was far from alone in the search of bringing a seamless, reliable power source to the Miata chassis. So he decided to package and sell the design as a complete conversion kit, now readily available at


Just think. A welterweight, track-ready shredder that’s more than capable of holding its own on and off the course, all under the reliability of a Honda’s heart. What’s not to love?


Yet as much as I want to jump further into detail about the technicalities of this bad boy – as well as show off what it’s capable of with some actual, quality imagery – you’re just going to have to wait until we make it over to Illinois for the full feature. Until then, check out this video, captured around the time David was first testing his new creation.

Matthew Jones
Instagram: matthewjonesphoto



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not knocking the build, because it is amazing, but why go through all this effort for under 250 hp. the stock block with turbo and other supporting mods can make just as much but 10 times easier


The thing probably weighs less than a ton. You don't need much more than 250.


Originality is a rare commodity in our age of internet bolt on menus (can't cast too many stones, my Evo X is that very type of build). Plus, if he ever needs to take the car to the next level, the K flows more air than damn near any other production engine, so forced induction or high compression (with again, readily mapped out and proven part pathways) this makes perfect sense. Awesome car! Much prefered to the LS ALL THE THINGS that seems to have taken over the RWD import tuning scene.


K-series swap, good call and to RWD too?! Nice!


BlueStangII For a Miata? That's plenty and the K-series flow better than the original engine anyday.


Really hope your article addresses the headers and intake because those setups look bizarre!


I remember seeing on the revlimiter website (they make custom gauge faces for Miatas) that there were some gauges made for K series swapped Miatas. I wonder if this was one of them.


This may be the perfect sporty roadster. Decent power, high revs and lightweight.


Awesome car! Can't wait for a full feature.


Jalopnik would love to know about this.


tunerguy21 no those ones are for 949racing


@Paul Rudd its 1043Kg.. or 2300lbs.. Stick to movies and leaves math to the rest of us..


BlueStangII Did you miss the part about "reliable method of bringing a little more power to his daily"? One of the best parts of this swap is RELIABILITY. If you've ever tracked a car, you'd know that a turbo Miata is not a reliable choice.


Oh no another K-series swap! I am already thinking way too much about this. :)


You're playing with my emotions lol I thought I was getting a full feature.


Please SH, do a full feature on this car!


@Bruno He made an estimate and you should leave English to the rest of us...


Awesome stuff, like my car's bigger, younger brother...


Hell Yeah, Finally


Gotcha. Thanks for clarifying.


UWerqxTeam_MJ Jalopnik would love to steal any feature that will get them views....oh wait, they already do that.


hmmm cool and original swap for that it is a ten out of ten but why not go all out when you swap and get a Three rotor? There are swap kits after all and they are raced proven. On top of that is revs higher and makes more hp and I'm guessing it would wiegh about the same if not lighter because of the rotors and it being N/A + theres a better sound with a three rotor... Just saying but my opinion though.


Matt Scarbro Love that video Matt.


jacobherman14 Rotary swaps are über cool, but this is the cheapest and most reliable way of getting a Miata into that power range with an n/a engine. That is why this swap is becoming more and more popular.


He also uses it as a daily driver, so maybe he didnt want a rotary because you have to drive a rotary hard otherwise it' ll break faster than a regular engine due to deposits on the sides of the compression chamber that only burn away when you hit The redline.
If he would only useit for the track he should definitely go for a rotary imo cuz its mazda and rotarys are badass, but as a daily driver i think this is a good choice.


BlueStangII "with turbo" as you say... that is your answer right there.


There was one of these at Gridlife. So sick! Sounds good and is still very balanced. You guys need to come out this year! 3600+ people and comapnies like Stance, Touge Factory, Strictly Performance Motorsports, and even Ryan Tuerck coming out to participate in the drifing.


rv_zenki we sponsored Gridlife actually, this is the original KMiata.  Notice the Gridlife sticker on the windshield :)


While I agree that a n/a PP 3-rotor is one of the best sounding engines anywhere, they are extremely expensive.  And a "swap kit" isn't really available anyways.  You can spend over $20k doing a n/a 20b into a FD chassis and that's a much easier swap to complete.


The header primaries come up and towards the front of the car before going back under the car and switching to the driver side of the car.
I think the intake manifold is a Magnus k-series setup that has the plenum opening direction/throttle body flange revered for RWD applications.  Often the filter is placed up near the cowl on Miatas.  There was a company that made a product called the "Randall Cowl" that drew fresh air from the cowl area below the windshield.

Pete the perfect pilot

The headline says .... The Miata you'd wished you'd built. Well NO, actually. It'd have a Mazda rotary in it for me. Nothing against Hondas, I drive one, but for me, it'd be a whole heap better with a rotary. And I don't buy the reliability thing: all my Rxs have been ultra reliable and cheaper to maintain.


Easier is almost never cooler.


I have no idea how i missed that lol. The k series is such a perfect motor for this car. We need some speedhunters out there this year!


BlueStangII On track reliability and simplicity. Turbo cars have a lot more to break and go wrong when abused within an inch of their life.


is it just me or... the features are much much shorter...?


BlueStangII And not to mention the after market support for the engine.


DoyouevenM3bro? There is a picture of the header on the kmiata website.


No, no, I dont wish I built any Miata to tell the truth.


Never would have thought of a K! I own a  v8 na and this looks soooo much easier to work on. No hood clearance issues, plenty of space for exhaust, etc etc. Also he probably didn't have to swap the rearend. Nice. 
One advantage of the k vs original motor is that the intake is not right beside the exhaust manifold.


mnchk1987 From the article: "Yet as much as I want to jump further into detail about the technicalities of this bad boy – as well as show off what it’s capable of with some actual, quality imagery – you’re just going to have to wait until we make it over to Illinois for the full feature."

Maybe read it all next time?


So many K-swaps, you wonder where someone could find that many engines... To my defense, I agree it is a beautiful engine for an N/A setup, and the result sounds really good. Have any dyno numbers or graphs been published? It looks decently torquey too...


Sorry, just saw you've already published the numbers... My bad.


BlueStangII Its not difficult to achieve 300whp for a K24, with compression of atleast 11:1, and cams, with supporting mods on both ends of the pump it can do it reliably without pushing it past its OEM redline


Anyone know the front lip/splitter setup? Looks great.


Pete the perfect pilot I have a rotary swapped Miata and whilst it can be a pain sometimes(I made it harder by going carbed) I can't really think of a better suited engine power-wise than a rotary. I have driven turboed miatas and even an LS miata and it takes away a lot of fun. Surely, more horsepower is nice and all but there is nothing like driving an "underpowered" car over the limit :)


MX5_Senpai Looks like an OEM 'sport' front lip with (probably) a track dog racing splitter underneath it. Pretty popular setup stateside. Looks nice, thinking about doing a similar set up myself, looks like he's got the stays attached to the baby teeth front tow hooks.


G5555 mnchk1987 complains that the feature is too short, but doesn't read to the end. The irony is almost too much to handle hahaha!


hmm, why use the mazda tranny tho? Honda trannys are better geared and stronger all around no?


DanKhole The MR2 tranny's are pretty stout... Ive seen them used in 700hp + applications. That said I'm not sure if this is an MR2 trans


DanKhole Also, only RWD Honda tranny would be from an S2000 which is probably pretty spendy to source when the Mazda works fine with a relatively low hp/tq load.


DanKhole Because this is actually a cost effective solution not a "because I can" swap. btw several gearing options available for the Miata transmission.


DanKhole The 6-speed Mazda transmission is built by Aisin just like the Honda S2000 and Mazda Rx8 transmission. As gwhisky said, there are a few different gearing options transmission wise and there are also quite a few rear ends that can be used. The transmission is plenty strong enough for this swap, but more importantly, if you have a Miata, you don't have to buy or fabricate anything to use it.  Mazda uses a "power plant frame" that connects the transmission to the rear differential.  If you swap transmissions, a trans mount and a front differential mount are required.


MX5_Senpai I agree with MX5_Senpai, that's definitely the OEM sport lip that was standard on all 20AE models.  Track Dog Racing does make a hugely popular splitter and I thought 949 Racing was selling a similar product built by APR, but it doesn't appear to be on their page currently.


I AM DOING THIS BUILD!!!! I have been researching engine swaps for first half of the year for my NA.... I finally have a budget planned out. I of course wanted to do an LS1 in my old s13 before my built SR blew its guts on me, but opted to get a Miata instead. I thought, 'Of course I am sticking with the LSx swap...'. Then after the research, I found it puzzling to discover that an LS1 swap can be had for around 8-9k in a 240sx.... A Miata costs around 15k+ due to the fab work... 15k+?! No way, Jose. So I looked into an aluminum L33 block... still about 12k. Darn. I then found this beautiful KMiata website via Reddit and have always had a thing for the K-series engines as they are phenomenal engines. I narrowed my options to a Ford modular 5.0 (actually 4.9) with the Monster Miata swap which would be cheap to do and possibly cheaper then the KMiata option, and of course, the KMiata. Thing is, I race and value power to weight ratio also, reliability. I may end up shelling out a little more then 9k by October for the swap, but the thought of losing some weight in the front tickles my racing fancy to intense limits. 

VTEC has always been kind of a joke  (even though it is great) around my neck of the woods here in Austin, TX. There is a secret longing to have it and to have it in a lightweight, rear wheel drive roadster. SpeedHunters has been sending me all the right signs lately! First, I am taking the HPAcademy course, then SH did an article with Andre not but 1 month after I signed up on HPAcademy! Then, I found this today! Eventually, I will be tuning my own car as my 'resume'. KPro FTW.

'Follow them dreams' -indirectly says SpeedHunters!

I cannot wait to start gathering parts after I purchase my daily driver (Mercedes 190e) and starting my build thread on Instagram. 

The only question is: Save up for the K24a2 or go with a K20a2 as KMiata says this is the cheaper and easier option?


Excellent read once more, SH!


No thanks... If I were to build an MX-5, it'd stay true to the cars original characteristics.. it'd be a beautiful cross between early JDM styling and 60s british sports motoring, from which it takes inspiration.. and I wouldn't damage its resale value by installing a honda engine... wait is that from an s2k? whatever, I disapprove of this headline fam


John Key NZ The engine (K24A2) is from an Acura TSX.
No comment on "damaging resale value" haha


John Key NZ Can I have some of what you're on?


@MasterMatty DanKhole the MR2 tranny is transverse mounted, the miata is longitudinal mounted. no way would it work.


CoreyHenderson1 DanKhole gwhisky Also to mention if the transmission was replaced then shifter may not line up exactly in the factory opening location and you may have to cut the sheet metal.....also, keeping the transmission garauntee's you that the engine will be bolted down as far back in the engine compartment; hence, helping with weight distribution (all pending on how thick the adaptor plate is)


Got to see this car at an event in Joliet, IL yesterday. It was definitely one of the quicker Miata's out there. That and the 13B-powered drift guy whipping it around the track.


F20C > Any lame ass K series.


@NotAKseriesFanboy Having owned an S2000 with an F20C, the K-series is far more moddable, cheaper, and easier to get more power whether NA or turbo.


@NotAKseriesFanboy Having owned an S2000 with an F20C, the K-series is far more moddable, cheaper, and easier to get more power whether NA or turbo.


John Key NZ "it'd be a beautiful cross between early JDM styling and 60s british sports motoring"
So it'd look like a 1st-gen Miata and be as slow as an MG?


CoreyHenderson1 jacobherman14 Not to mention rotarys AREN'T light once they're all put together with accessories and such! Especially the 3-rotor. It's about equivalent to a turbo iron-block straight-6... i.e. *heavier* than an aluminum-block LSx, which is also heavier than the stock Miata engine. The K-series is actually lighter than the OEM Mazda 4-banger, so it's probably one of the only swaps, along with an SR into a 240SX that would *improve* the weight distribution! (although we're talking about 50 lbs or less in both cases).


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