A Wild Take On The NA6 Mazda Roadster

When it comes to the cars we share with you from events like last Saturday’s Attack meet at Tsukuba Circuit, there should always be an element of balance.

We can all dream about building the perfect time attack machine with a reinforced chassis, top-of-the-line suspension, big power and a custom aerodynamic package to get the most out of it all, but in reality I think this form of motorsport is more about experimentation than anything else.


I’m always on the look out for time attack cars that seek ultimate speed through innovative and often unique solutions. Cars like this Roadster, listed on the Attack entry list as the “Moty’s RS Watanabe Speed Club Jupiter JET E-NA6CE”, which is one of the most ‘out there’ NAs that we’ve ever come across.


As part of the aero treatment the whole front section has been cut, sculpted and redesigned in order to accomodate an angled radiator, itself sandwiched in a carbon fiber air guide which channels air up through the front dam, through the core and then out of the hood vent. The front wheel arches have been cut and reshaped, and the front nose now houses a pair of projectors to replace the stock pop-up headlights. The one-off cowl, which incorporates the front bumper, fender and hood, then covers the entire section.


The engine has traded its stock fuel injection system for a set of Keihin Flat-CR motorcycle carburetors, helping take an already basic car and making it that little bit simpler. We’ve seen these flat-slide carbs on numerous Roadsters and AE86s in Japan, and they’re loved by many for their immediate response and performance at wide open throttle.


Hiding inside the air guide are a few more cooler cores; one for the engine oil, the other for the transmission.


We’re no strangers to crazy and wild NA-based projects here on Speedhunters; we’ve seen all sorts at Japanese soukoukai events, but this Speed Club car is certainly up there.


Braking and handling have been addressed with adjustable arms all round and compact Wilwood calipers up front.


With the cowl in place the wide-body Roadster certainly looks the part.


You can see how the carbon aero extends along the skirt profile from the front arch extractors all the way to the rear overfenders. I loved the RS Watanabe wheels mated to chunky side-walled tires; it’s the sort of stance these cars should always run in my opinion.


I managed to get a few shots with the little Mazda before the driver took it away for a few hot laps around Tsukuba.


The car ran a best of 1:02.236, a damn respectable time if you consider there can’t be much more than 150hp on tap from the little four banger.


It goes to show what you can achieve with a little bit of imagination and knowhow. Just remember, the most important thing of all is to have fun while doing it!

Dino Dalle Carbonare
Instagram: speedhunters_dino



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Jay Soh Tsu Chung

The front-end reminds me a lot of many many SA22 RX-7s with that headlight placement. Not that it's a bad thing.

And that carbon air guide for the radiator is a really clever design.


The name of the company that makes it is called Jet Stream and the name of the kit is actually NA22 ;)

Dino Dalle Carbonare

Ah fitting name indeed!

Jay Soh Tsu Chung

That's a cool detail to know. Thanks! :D


Dino, is there a list of laptimes available for stock cars around Tsukuba? You say 1:02 is impressive for this car but it’s hard for us to understand what this laptime means in the grand scheme of things.

If we knew what - for example - a stock 1.6 MX-5 can do, that’d help.

Dino Dalle Carbonare

Stock R34 GT-R used to do 1:05 with a pro driver at the wheel. Here is the Option list


stock R34 is a gutless heavy pig , surprised it even managed a 5 !


On a track that small a 10 second gap between that Super Formula Toyota and the GT500 NSX is staggering. Unreal.


In 2016 a 911 GT3 RS in factory trim ran a 1:00.7 if that's a good benchmark for you. Over double the power for a 2 second split.


Wow, that’s good to know. Cheers, Craig: much appreciated!


I see a Porsche slant nose approach in the design.
This car may be the wildest of its class and even packing only 150hp it could slay bigger opponents easily.
The site name is "Jupiter-net.net"? that's little bit weird even the 2 "net" are not related.


Now Ecotec swap it


is the engine moved further towards the firewall?


Squint and it looks like a Porsche 935 race car


Its just the way the pic is set up. Speedhunters once made a dc2 Integra look exactly like Pagani Zonda Cinque. Exactly I tells ya...Exactly.

Dino Dalle Carbonare



That's a high compression 1.9L engine with humongous cams. It's more like 200hp.


One sick piece of work! Love it!

Guys, is it Miata Month again? LOL


With 150hp I doubt that "aero" is doing anything but causing excessive weight and drag. It's interesting how in many other examples of motorsport you see low horsepower cars opt for low drag setups with unbelievably fast lap times.

If I was going to enter something like this I would focus on reducing frontal area and drag coefficient as much as possible over complicated aerodynamic packages.


All that you need to look at is the lap times. BTW, if you design it right, aero is effective at lower speeds. Look at Formula SAE or Formula Student. They rarely get over 70MPH, but have some of the biggest wings on the smallest cars you've ever seen. Keep bringing "your friend" into it too, that makes you look really intelligent.


That's not necessarily true at all. 1- 150hp was a guesstimate power figure. 2- s2000's have low power ~190 to the ground, and splitter + wing combo makes a big difference. 3- this car put down 1:02.236, to put it in perspective Keiichi Tsuchiya recorded a 1:02.05 in a r35 GTR, so I highly doubt this car is suffering from "excessive weight" caused by downforce.


I'm going off of a friend's opinion who was the chief test driver for an Indy Car chassis manufacturer with hundreds of thousands of miles in testing aero setups. You must know substantially more than him about this stuff. My mistake.


I took my friends opinion and he is an aerospace engineer at Lockheed's Skunk Works and he didn't comment on the aero package but said that your friend is an idiot. Guess who knows substantially more now!


My guys...cause ur fuckin' retarded hahaha XD


Think even how much faster it could be with just a slight amount of boost, seeing how well NA/NB mx5's take to FI even in stock form. Cast iron, lower compression etc.


There's just something "right" about NA. In with a worked F20C and you should see a reliable 250-300 with little work - and keeping with the Miata spirit.


I love how stupid the internet is:

NA F20C will make no torque compared to a turbocharged 1.6 or 1.8L BP. 250-300hp is pretty much just scratching the surface in a Miata if the platform is tuned right.

"There's something just 'right' about NA." No. That's an opinion that has no merit or basis in fact. Is that what BMW said when they built their 1.5L that everyone foams at the mouth over? No.

K series Miata? BMW transmissions? Lmao. The comment sections here are awash with bullshit!


YOU, kind Sir - are certainly not helping in making the internet less stupid. Did I say anywhere that it WASN'T my opinion?. I like NAs. There I said it. I LOVE the 911 RSR in pCars2 that just came out. I did a monumental amount of laps in pCars1 in the Caterham and I found a new favorite. And it's NA. Funny how we all have different opinions.

Who and where did anybody say a force fed 1.6 or 1.8 wouldn't make more torque or a boat load more horsies than an NA F20C?. Ohh- that's right - nowhere and nobody - that's who.

If I wasn't so polite, I'd ask you nicely to shut up if you have nothing sensible to add - but I am, and it's not my board, so I won't....


I race a 380whp Miata from time to time. It is now making over 400whp and 350ft lbs. Runs on hoosiers and Penskes.

F20Cs are shit motors if you're going to spend the money and extremely expensive. Can't beat the torque you get in a turbocharged 1.8 compared to the NA 2 liter. Plenty of dyno time and seat time to confirm that.

I often forget that most automotive enthusiasts don't really get to drive well setup and tuned cars, let alone compare them with engine swaps. People in the comments here get extremely butt hurt when someone comes in with research and data. It's pretty funny.


Skip the F series and go directly to a K series. KMiata.com has everything you need to put a K20 or K24 in a Miata while keeping the stock transmission and diff. If you want crazier, they've got kits for BMW transmission swaps for when you need to hold more power reliably.


f20c would be the perfect engine this car! Although 250-300 N/A whp out of a f20C would require something like stroker + itb's + stand alone as f20c is basically maxed out from factory.

Steffen Hansen

I think I've made a terrible mistake. For some reason, when I wrote my comment, I had it in my head that the F20C makes 200 in the S2000. Wrong- So stick with one of those and have it blueprinted and superfinished - and please please ditch the FI the FCRs for that glorious sound. Probably cost a bit of top end, but a sound that makes me feel all funny in my pants is well worth that.

Hii Chie Fung Hyde


Here's the hot lap video for this NA6


Just wondering why his shifting is so slow? Probably lost 1/10 of a second or 2 through those slow shifts, suppose it could be mechanical related but definitely room from improvement there!

Dino Dalle Carbonare

Nice find

Marcello Spineda

looks a bit like a 944

Dino Dalle Carbonare

It does a bit uh

Marcello Spineda

Also... can we see this car into a special feature in the near future? please.. :P


Have a lot of love for the MX5/Miata platform, and it's great to see it being pushed to it's limits in the Time Attack arena.

Dino Dalle Carbonare

Pushing the envelope in every shape or form is what time attack is all about


Mazda Miaty DIck.


Love this car, especially the slantnose style front cowl.
Seeing the aero on this car makes me wonder though. And it goes for the rest of the time attack cars as well...why not extend the aero down the sides to cover the rear wheels? In the case of this car, instead of stopping the carbon side skirts at the rear over-fender, keep going and smooth that air right to the rear.
I know nothing... just thinking out loud.

Brennan McKissick

Love this. More Miata content please haha. I love that people still use this car beyond the grassroots level and add in tons of aero and still compete really well.