Hello folks,

My name is Tadeu, and this my 1990 Miata that I brought with me from California:



Currently the car has:
- 1.8 VVT engine from a 2005 Miata @ 135whp with bolt-ons (racing beat header and exhaust, intake, MegaSquirt MS3X ECU)
- Xida race coilovers, racing beat front sway bar and supermiata rear bar
- Miata torsen differential
- Bro-fab wheel hubs front and read
- 1.8 brakes with GLoc R10/R8 pads
- 9Lives medium downforce kit
- TCDesign custom roll cage
- PERacing pedal box, Kirkey halo racing seat, composite doors and nets all around (the car - has no side or rear windows)
- Custom wiring harness with AiM PDM, AiM Smartycam, MegaSquirt ECU, MSEL Master Switch, Antigravity battery and full suite of sensors
- Alsense infrared pyrometers on all 4 corners and Trailbrake TPMS sensor
- And a lot more stuff, there's very little left untouched in this car

It's not very fast, but at just under 890kgs (without driver or fuel), it's the most fun I've had on track.

I've been living in Sweden for almost 2 years now, but it took me a while to get setup (driver license, towing vehicle, trailer, etc), so I just made it to my first track day with the Miata in August. I joined timeattacknu at Gelleråsen for my first ever wet track day 😅. 2 years driving in California, never caught a single drop of rain, first time out here and it was pouring... not ideal when you don't have windows. But it was a lot of fun regardless.

While chatting to the very nice folks from the organization, I unfortunately found out the miata doesn't quite fit into the classes here: power-wise it should be in the lowest class, Glub Go!, mods-wise it should be in Pro class 🙃

As there is no chance in hell I'm undoing years of hard work, there's only one sensible solution: adding a K24, a turbo, 8HP70 transmission, new differential, new brakes, new ECU, new wiring harness, new fuel system, new...everything... and move up to Pro class.

Yes, it doesn't make any sense, the Miata isn't the best platform to add big power. It has a very short wheelbase which makes it quite twitchy, but let's be honest, we're not reasonable people in this sport, so I'll do it anyway and just have some fun along the way. I'll add some brief history of what I've done to the car in the next post, and I will update as I work through these changes, but be warned: I work very slowly 😅

Here's a video of the car at Laguna Seca at my last even there in 2021: https://youtu.be/HI11ZoRWjzE
And here's me struggling at Gelleråsen a couple months ago 🙈: https://youtu.be/GIZZQJcjdUQ

(And sorry for writing in English, I started studying Swedish before I even set foot here, but it's taking me a minute.)

Not only a small wheelbase, it also have quite small wheelwells, and work best with tires smaller than 600mm (23.5").
Hoosier slicks 245 wide is as good as it gets.
A NA K24 and join in Modsport 3 is one place where a Miata with som power mods fit quite nicely. You can join immediately and do mods as you go, only safety parts are required.

Welcome to the forums! Wow, looks like a really seriously built car! K24 in that thing will be extremely fast!

I am most likely also going to buy a Miata now in the upcoming weeks, want a more reliable track car that will hold up for 30mim sessions without overheating (like most of my previous cars). I will probably go for a Miata ND.

Niklas Falk skrev:

Not only a small wheelbase, it also have quite small wheelwells, and work best with tires smaller than 600mm (23.5"). Hoosier slicks 245 wide is as good as it gets. A NA K24 and join in Modsport 3 is one place where a Miata with som power mods fit quite nicely. You can join immediately and do mods as you go, only safety parts are required.

Interesting, I've never really seen that as a problem. In the US it's not unusual to see autocross folks running 295 hoosiers on 12" wide wheel even on NA miatas. In time attack it's more common to see 275 tires on a 11" wheel, which is what I plan to begin with using the Nankang AR-1s. There's also the occasional car running 18" wheels for more tire options, which obviously requires a lot more work, but I guess it's only a matter on how far are you willing to go. My understanding is that one of the biggest challenges is that it requires switching to a pedal box, since the tires interfere with the clutch and brake master cylinders, but I've already crossed that bridge since I knew that was coming sooner or later.

Modsport 3 looks interesting, I've been keeping an eye on a few organizations since before I moved here, but hadn't seen SPVM yet. The language can make finding things a little challenging at times. It looks like it's only wheel to wheel racing though, right? I don't think I'm quite ready to race my car wheel to wheel, the risk is just too high for my liking, but maybe I will consider at some point. In any case, I'll have a look through the classes and rulebook, thanks for the tip.

iqbad skrev:

Welcome to the forums! Wow, looks like a really seriously built car! K24 in that thing will be extremely fast! I am most likely also going to buy a Miata now in the upcoming weeks, want a more reliable track car that will hold up for 30mim sessions without overheating (like most of my previous cars). I will probably go for a Miata ND.

Thank you! I hope it will be fast, and probably a little scary... The plan is to start around 450whp, which will take some getting used to, so it'll probably be a while before my driving catches up to it.

I have not driven an ND yet, just NAs and NBs, but I've only heard great things about it. I think understandably, but also a little sad, fewer people are starting with NA/NBs these days... NCs seen to be rising in popularity though, and a couple weeks ago KPower had a couple cars running their K24 swap at the Miata Reunion, it looked very nice. But I guess it depends on what are you looking for, I can't leave things alone, so I'm always looking for something I can fiddle with.

Welcome

Nice car! Hope to se you on a trackday!

Below is a club that have realy good trackdays (maebe it whas on their trackday)
http://www.mx5racingclub.se/

Sweet ride! And an awesome plan, will be following

Saw the struggle on Gelleråsen.

But love the build, is the wheel hubs that's "Pro" i guess?

Other wise it should fit Challenge?

tadeuzagallo skrev:

Niklas Falk skrev: Not only a small wheelbase, it also have quite small wheelwells, and work best with tires smaller than 600mm (23.5"). Hoosier slicks 245 wide is as good as it gets. A NA K24 and join in Modsport 3 is one place where a Miata with som power mods fit quite nicely. You can join immediately and do mods as you go, only safety parts are required. Interesting, I've never really seen that as a problem. In the US it's not unusual to see autocross folks running 295 hoosiers on 12" wide wheel even on NA miatas. In time attack it's more common to see 275 tires on a 11" wheel, which is what I plan to begin with using the Nankang AR-1s. There's also the occasional car running 18" wheels for more tire options, which obviously requires a lot more work, but I guess it's only a matter on how far are you willing to go. My understanding is that one of the biggest challenges is that it requires switching to a pedal box, since the tires interfere with the clutch and brake master cylinders, but I've already crossed that bridge since I knew that was coming sooner or later.

The availability of tires plays a big role. Smaller tires with grip are rare here, and if you you want more grip you almost have to go for 18" and tires of 640 or 660 diameter. For that to work you hove some work to do, and then you can as well start to look for another platform (the NC comes to mind).

tadeuzagallo skrev:

Modsport 3 looks interesting, I've been keeping an eye on a few organizations since before I moved here, but hadn't seen SPVM yet. The language can make finding things a little challenging at times. It looks like it's only wheel to wheel racing though, right? I don't think I'm quite ready to race my car wheel to wheel, the risk is just too high for my liking, but maybe I will consider at some point. In any case, I'll have a look through the classes and rulebook, thanks for the tip.

You also have the MSCC to look at (if you are close to Skåne), there the qualification is the competition so it is in face the oldest TimeAttack series in Sweden. There you will fit in the RS class (unless you can get all of your stuff throgh the road legal inspection), but at leats you have a class/series to run in.

Wheel to wheel is not that intimidating, the off-track hard stuff is where the dangers are. Of course there can be the odd tire-marks but seldom more, especially in less crowded heats.

Mumba skrev:

Saw the struggle on Gelleråsen. But love the build, is the wheel hubs that's "Pro" i guess? Other wise it should fit Challenge?

Thanks, I saw your car there too, looking quick! I've been following your build over on Instagram, awesome stuff. I was sad I missed the dry day on Sunday, but oh well, next time.

I think it was the wiring harness, PDM and lack of dashboard that pushed me to the Pro class.

Niklas Falk skrev:

The availability of tires plays a big role. Smaller tires with grip are rare here, and if you you want more grip you almost have to go for 18" and tires of 640 or 660 diameter. For that to work you hove some work to do, and then you can as well start to look for another platform (the NC comes to mind).

Yeah, I'm aware it's an uphill battle, and if I was starting over I'd probably choose something more sensible, but I'm too invested at this point, and if I'm being honest I kinda like the challenge. But even on 15" wheels, Miatas have done ok in the US, obviously not the outright fastest cars, but there a few good examples. A good one was Supermiata's car which won Global Time Attack in 2018, running 1:44 at Buttonwillow. Still, 4s slower than the RWD record, but at "only" 400whp on a 1.8 BP engine and 275 tires, without crazy professionally-developed aero. I'll be happy if I make to that level one day, and it's proven to be within the limits of the platform, so we'll see how far I can get.

Niklas Falk skrev:

You also have the MSCC to look at (if you are close to Skåne), there the qualification is the competition so it is in face the oldest TimeAttack series in Sweden. There you will fit in the RS class (unless you can get all of your stuff throgh the road legal inspection), but at leats you have a class/series to run in. Wheel to wheel is not that intimidating, the off-track hard stuff is where the dangers are. Of course there can be the odd tire-marks but seldom more, especially in less crowded heats.

I'm near Stockholm, so MSCC sounds out of reach. I'll keep wheel to wheel in mind, maybe I'll give it a try in the near future. I still have to look it up how it works here, I assume I'd need some sort of wheel to wheel license. I'll do some reading before next season. Thanks again, really appreciate the tips, so many organizations I didn't know!

Wouldnt it be possible to get some exemptions to be able to run at a class or two lower than PRO? there have been a couple of those over the years. And then maybe be able to run a bit more "sensible" power like turboing the 1.8 like BeavisMotorsport time attack miata. Or maybe you are searching for a reason to go nuts

Cédric skrev:

Wouldnt it be possible to get some exemptions to be able to run at a class or two lower than PRO? there have been a couple of those over the years. And then maybe be able to run a bit more "sensible" power like turboing the 1.8 like BeavisMotorsport time attack miata. Or maybe you are searching for a reason to go nuts

Lol, that was a good laugh, and you're not 100% wrong. I did have a chat with them about an exception, and there were two opinions between the folks I talked to. Some folks thought that the car was a bit too far from the spirit of the lower classes, and PRO was the only option. Others thought that maybe I could run a couple classes lower, but my car would be so low on power that I would never be able to be competitive... even for Club Go I could be making more power lol. But you're right that I didn't really fight to stay in the lower classes, but rather accepted the idea of moving up rather quickly. I like having fun working on the car, and the very restrictive classes can make that difficult.

In fairness, that was always my ultimate goal, so it just pushed me to get it done (a lot) earlier than I planned. I'm still debating if I'll try to make it in 2024, or just keep the BP engine and run track days next year while I gather the parts. The k24 is the garage, the massive brakes are in the car, and the transmission and Kpower parts are on the way... I'll see how much I can get done in the next few months, but as mentioned, I'm slow. It'd be nice to find some sort of team/group to work together, during the winter it was rough to keep the motivation.

A quick size comparison of the new brake rotor vs the old:

Nice to see your car! Was nice meeting you at Gelleråsen this summer as well!

Wellcome to Rejsa and the Swedish Miata tribe/swamp......

Nice to se a crazy full out race build of a Miata

/C

Welcome to Sweden. Ofcourse you should go ahead with k24 450whp. After 3 pulls you're gonna want 600, 😁

erikjakan skrev:

Welcome to Sweden. Ofcourse you should go ahead with k24 450whp. After 3 pulls you're gonna want 600, 😁

You joke, but that's kinda the idea lol. 450whp is the initial target, as it seems safe enough with the stock K24, but from my quick math I should be allowed up 700~800bhp depending on where the weight ends up. The transmission should be able to handle that just fine, and my plan is to get a differential and axles that can also handle the same amount of power. That way, later on it's just a mater of building the engine, getting a bigger turbo and seeing how much power is actually usable. But all that is for a later stage of the build, just future proofing it a little.

double post

tadeuzagallo skrev:

erikjakan skrev: Welcome to Sweden. Ofcourse you should go ahead with k24 450whp. After 3 pulls you're gonna want 600, 😁 You joke, but that's kinda the idea lol. 450whp is the initial target, as it seems safe enough with the stock K24, but from my quick math I should be allowed up 700~800bhp depending on where the weight ends up. The transmission should be able to handle that just fine, and my plan is to get a differential and axles that can also handle the same amount of power. That way, later on it's just a mater of building the engine, getting a bigger turbo and seeing how much power is actually usable. But all that is for a later stage of the build, just future proofing it a little.

Actually I don't. 😁

Welcome to Sweden.
I would spend next season driving as many tracks as possible to see what you are building your car for, especially if you are looking at a specific series to test those tracks out. It might not be the big power you need on technical tracks compared to aero or seat time.
There is a good rejsa calender here to find trackdays, and the mx5racingclub are great to drive with and have good trackdays.
And what is needed to register you car as there can be some nice loop holes you can use as you are importing the car.

cirs skrev:

Welcome to Sweden. I would spend next season driving as many tracks as possible to see what you are building your car for, especially if you are looking at a specific series to test those tracks out. It might not be the big power you need on technical tracks compared to aero or seat time. There is a good rejsa calender here to find trackdays, and the mx5racingclub are great to drive with and have good trackdays. And what is needed to register you car as there can be some nice loop holes you can use as you are importing the car.

Thanks! That was my original plan, and it might still happen. In either case I plan to drive all the tracks where I'd be competing, but worst case scenario I'll drive the other car.

The small complication, and I know how this is gonna sound, was that my brakes were done. They were overheating and overheated my wheel bearings as well. There were other possible solutions, but considering I didn't like the pads I was using, my calipers needed rebuilding and I would have to upgrade the brakes soon anyway, I just went for it and got the biggest brakes that could possibly fit with the 15" wheels. These are 300x32mm discs and the kit uses 20mm brake pads. As expected though, none of my wheels fit anymore, and going to larger wheels would mean moving up to 245 tires, which is way too much tire for 135whp. That is gonna be slower than the 225s I was running, but it's just the first season to learn the tracks, so whatever.

The other question is whether I'll resist getting started once the parts start overflowing in the garage... but my hope is that there's enough to do that I can get started without completely taking the car out of commission for next season.