Meet RE Amemiya’s 4-Rotor Twin-Turbo Testarossa

When I heard that RE Amemiya was working on a 4-rotor Ferrari Testarossa as their main showpiece for the 2021 Tokyo Auto Salon, my reaction was probably the same as yours reading the headline above – pure shock quickly followed up with big dose of curiosity.

After seeing a few build shots on Option magazine’s website, my curiosity took me all the way to Ama-san’s shop in Chiba last weekend.


Ken Amemiya, RE Amemiya founder Isami Amemiya’s son, said I was one of the first to photograph the car, but also that it’s only 85% complete and still in prototype guise. This means RE Amemiya still have a few jobs to complete, including getting the engine up and running. Once it’s moving under its own power, the Ferrari-Mazda mash-up will be stripped right back down for paint and then reassembled.

But regardless of its primer gray state and incompleteness, I just had to see this wild creation with my own eyes.


In my head this was way too much of a cool project, but one thing I didn’t count on was the extent to which Ama-san had modified the bodywork. I probably should have though. This was – obviously – never going to be a Testarossa with a surprise engine, but rather a complete RE Amemiya custom build, as we’ve seen many of over the years.


The look of this thing is sure to divide opinion, but I don’t think Ama-san really worries about that sort of thing. This is a project two years in the making so far, as commissioned by a longtime RE Amemiya customer who just so happened to have a Testarossa he was bored with. That’s a car many would consider it sacrilegious to even mildly modify, but the owner of this one would simply rather have a truly one-of-a-kind RE Amemiya creation in his garage.


It took me a while to digest the car at face value. It’s a strange-looking machine to say the least, but there are tons of little details and you certainly can’t deny it has presence.


I mean, when was the last time you saw a Testarossa with a roof scoop?


This thing is so far removed from the car it started out life as, that the only visual cue it’s based upon one of Ferrari’s most iconic models is the windscreen and door glass. This shot may emphasize that, but if not, squint a little.


The legendary louvered side intakes have remained in spirit but have been given a totally different look.


The front however is all new. The entire section ahead of the front struts was removed and replaced with a custom frame to support the cowl and other ancillaries. Compared to a stock Testarossa, the front overhang has been shortened significantly.

Like all RE Amemiya builds, the car wears a set of Enkei wheels – in this case 19-inch PF05s – wrapped in Yokohama Advan Sport tires. Meanwhile, the brake system now features modern StopTech calipers and 2-piece rotors.


Most of the work has taken place at the rear end, where the chassis was cut at the firewall and a custom section created to support the new engine and gearbox combo. Because of the length of the 4-rotor engine and the transmission behind it, the wheelbase had to be extended, which makes the rear of the car extremely long. It sort has a McLaren Speedtail look about it, and almost a hypercar feel.


The need to stretch the rear becomes obvious once you pop the engine hood.

By Mazda rotary standards a four-rotor is a large engine, but in the Testarossa it’s far more compact and much lighter than the bulky flat-12 it replaces. It sits as low as it can go and is straddled by a pair of Trust TD06 externally gated turbos.


These feed into a custom top-mount intercooler, which is shrouded by and fed air through the roof scoop. The cooled and compressed charge is then distributed to each of the four rotors through a custom-made intake manifold.

In essence, this engine is the same as the unit in RE Amemiya’s D1 FD3S RX-7, but is geared to have a broader spread of torque. Once set up and dialled in through the Link engine management system, the four-rotor should develop 800 to 850hp.


Behind it, and being used as a transaxle to drive the rear wheels, is a beefed-up Subaru 5-speed transmission.


It’s a really nicely laid out driveline which should provided balanced weight distribution. The rear end has a dramatic cut-out feel about it; it kind of looks like an LMP car, proudly showing all its guts through the carbon bodywork and copious use of grilles.


It’s from here that the Power Craft exhaust and screamer pipes sprout.


What does this rotary-powered Ferrari look like inside?


Before we get there, you need to check out the Ferrari logo etched onto the door’s glass.


The interior has been modernized through numerous custom touches, starting with an AiM digital display neatly recessed into the instrument binnacle, and the Alpine navigation/multimedia 2DIN unit recessed into the center of the now leather-clad dashboard. In order to mount the screen, two louvered center vents had to be eliminated, meaning that the only in-cabin air will be supplied via the round side air vents.


Custom Alcantara-trimmed Bride reclinable seats complete the RE Amemiya conversion.


Our final stop is under the single-piece front cowl. Much like the rest of the bodywork, this panel is made from wet carbon fiber, with Kevlar added in high-impact areas.


Here’s a view of the custom-made Aragosta dampers with Swift springs, and the yet-to-be-plumbed-up flat-mounted radiator, which will keep the screaming, boosted rotary engine out back cool.


You have to hand it to Ama-san for taking on a project like this, which when completed will be added to a long list of custom vehicles built to coincide with the annual Tokyo Auto Salon. The Testarossa joins non-Mazda-based RE Amemiya builds like his Lotus Europa and the Westfield ‘Furin Kazan’, which I shot 11 years ago now.


Of all his builds though, this one will really have people talking. But despite the base car, Ama-san has approached this build in exactly the same way he’s approached his past projects, with a total aesthetic transformation and some kind of rotary engine swap. If this was his goal, he’s certainly achieved it. It’s the Ferrari Testarossa part that some people may not digest so easily.

I’ve had my say, so now let’s hear your thoughts about this build in the comments section below…

Dino Dalle Carbonare
Instagram: dino_dalle_carbonare



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Jay Soh Tsu Chung

Ah, finally! It's weird to see how much the whole body conversion changed both ends of the car. You know that the Testarossa's shape is very angular, and to see both front and rear-ends become so rounded is just strange. And I feel that the rear could do with a large wing to complete the LMP-esque look.

And it seems to be a go-to solution for Ama-san to use Subaru gearbox? I remember the Europa used the same thing.

Dino Dalle Carbonare

Well it makes sense as in its original orientation it drives the front wheels, flip it round and boom it's a transaxle for RWD cars.


You don't need to flip it


The interior of this car looks like straight out of cyberpunk :D


Looks original TR to me..


Should have used a 512M. Those thing beg to be rid of their ghastly face.


I'd forgotten what the F512M looked like. Now it's stuck in my head.

Thanks a lot.

Dino Dalle Carbonare

So agree!


It looks great from some angles, but awkward from others. What state was the Testarossa in beforehand? It does almost seem that he should've started from scratch, but that would be a much bigger job I suppose and would get less notice if I'm being cynical.


Well, the roof's intact, so whatever it was probably didn't end with someone pointing and shouting, "DID YOU SEE THAT???!!! THAT WAS AWESOME!!!!

Dino Dalle Carbonare

I don't know about the state of the car, I'll found out when I re-shoot it when it's 100% done so we can finally hear it


I think it will look better painted. The front looks like a w30 mr2. Extending the wheelbase has made it look awkward, maybe a rear spoiler would help with that.


The Ferrari emblem does not sit well there..

Dino Dalle Carbonare

Painted will definitely improve it overall


The Testarrossa indeed had a long front overhang, esp. seen from the side, while the coke bottle body flares towards the rear.
With the shortened front cowl, and rounded edges made this car smallish, and totally unrecognizable from its origin.

I am very keen to hear how the turbo-ed RE sings, compared to the original NA flat-12


Original flat 12 in USA trim was kinda tame.. Nothing like the BBLM versions

Dino Dalle Carbonare

So am I! If it sounds anything like the D1 car it will be wild. Although there are massive silencers in there


If the tail was longer and the cabin "bubble" didn't reach so far back then maybe, currently it's just awkward looking. It looks real good from the rear but otherwise it's a tough one to like. The engine will be incredible though, no doubt there.


At this point, why even bother using a Testarossa as a base? Could have started with an MX5 for all the modifications that have been done to it.


I'm thinking because the chassis is already a decently long wheel-base and already mid-engine.

But, in all you're right. I think it's for the attention grabbing nature of the build; they could've used an MR2 or MR-S, or even an NSX as the base for the build. But... that doesn't generate the same amount of hype as 'Ferrari Testarossa' does.

Dino Dalle Carbonare

Not really for attention. He was basically presented with a Testarossa from the owner and told to go nuts on it. I don't think anyone would turn a chance like that down.


Was the TR damaged?.. I wouldnt do this to a clean one.. No way


Very true. Not having a go at RE Amemiya, just wondering what's going on inside the owner's head.


Nissan R390 vibes at the rear end for sure. Cool build!

Dino Dalle Carbonare

Uhm... you do have a point


Holy hell this looks very Group C. Pretty car I must say. Kinda miffed they had to cut up a Testarossa for it (unless it was totalled), looks just as possible to build from scratch.


Insane amount of work into that. Good weight over the back to help put the power down.

There has been internet noise about Ferrari legal action on modded cars adversely affecting their brand. Might be something to watch out for although this is an old model so potential can't be applied in the same manner.

Dino Dalle Carbonare

Ferrari can try it, but Japan has such a screwed up legal system he would be untouchable

Jay Soh Tsu Chung

It may be old, but it is one of their most popular models.


Absolutely love to ear these projects are still happening the rotary engine is amazing, it is my life


it kinda looks like the arta garaiya super gt car minus the rear wing. obviously they couldnt change the glass house as much but it is an interesting shape. a lower scuttle and a higher shoulder line would make it more cohesive personally but it is a good looking car.

Dino Dalle Carbonare

Ahhh the Garaya, one of the first cars I ever drove when I started working as a jurno!


I'm sure that Rob Dahm would love this!
In case you don't know, he has a rotary Corvette, a 4 rotor RX7, and a 4 rotor C8 in the making


Mazda 767B is the last word.. IMO.. Ide buy one if i lost my mind that week

Dino Dalle Carbonare

I like what Rob has done thus far but I don't think a an old time like Amemiya that has been tuning rotaries years before Rob was even born would care much what he's doing lol


Hahaha Dino now you know what it's like to be me with racing and looking at drifters man. Same shit. No one cares about this new BS! ;)


Amemiya was doing this long before Rob Dahm.


Good point!


Youtube has replaced tuner magazines, it seems.


RE Amemiya still keeping the Golden Age alive and pushing it forward.

Dino Dalle Carbonare

Gotta give it to the old man!


I hate this car body as a whole from every view except the rear 3/4 view. At first I thought it was because I was looking at it with Testarossa tinted glasses to which I find it shares no proportions or styling cues, but even once I started looking at it as a full custom car I can't like it. Some of the close ups of the rear end or the doors look good, but once you step back and see the larger picture I cringe. The proportion and shape of the body are just not cohesive and it looks like a bad kit car. I'm normally a fan of RE's work, but this one is a miss for me. Nice quality and execution, but bad design direction in my opinion.

Dino Dalle Carbonare

It seems to have split opinion


Very odd looking. Maybe try again before spending money on the fancy paint.

Dino Dalle Carbonare



Only thing I don't like is the length addition. Different gearbox and one less rotor, maybe? Interior is excellent, front end is excellent and could and should have been the direction Ferrari took to update the BB, rather than the frankly terrible TR design. Ferrari revealed a lack of design conviction by following the boxy fad of the time.
That wheel base change, tho. ugh.


That boxy design started 2 generation's of similar by Lambo..

Dino Dalle Carbonare

Lob a rotor off? lol


I think overall the design is cool and different. But agree that a rear wing would compliment the design on a more complete way. Secondly im sure he could have used a more super car rim design than the typical drifiting look...otherwise its cool and even better a screaming 4 rotor engine....


This is awesome. I love people thinking outside the box and not being afraid of trying something different, even if it means hurting all the purists the internet has to offer.
With that said, I also have to admit that, for me -obviously-, thinking outside the box and trying something different, doesn't necessarily mean you end up with something pretty; as is this case. Once again, in my humble opinion. I love that this car was created, but at the same time, I think it's ugly as hell. Lol!

Dino Dalle Carbonare

I know what you are saying. It's far better to be doing stuff like this than taking the approach so many legacy tuners have taken these days of just doing little bits and pieces to survive and the rest of the business is there to offer maintenance to cars that were built back in the day.


Really? A 4-rotor twin-turbo and no startup video? ;-)

Jay Soh Tsu Chung

RE Amemiya still have a few jobs to complete, including getting the engine up and running

In case you missed out:

Dino Dalle Carbonare

This has to be the most popular comment, even on my IG. Text is there to be read you know hahaha


The feeling i have is strange. Whilst the look of the car is ghastly, the work gone into it especially by RE, i respect highly.


Wrong wheels, should have some bbs motorsports, deepdish, definitely need to put fin and rear wing like LeMans race car.. And make it white.. Or Black!

Jay Soh Tsu Chung

... it’s only 85% complete and still in prototype guise.

Sigh, I wish more people would read the whole article thoroughly before commenting...


I know, read all of that, i dont think that expensive enkei is a prototype wheels, and for the other parts, is just a suggestions for what I think maybe perfect for the car, its just an option, maybe in a rare cases, they'll listen to SH reader's opinion

Jay Soh Tsu Chung

Oh, I was actually referring to your paint comment. But yeah, I do agree that the wheel choice could have been better, but then again RE Amemiya has always work with Enkei for their demo cars anyway.

Dino Dalle Carbonare

There with you man ...


Looks aside, THIS is the best car speedhunters has ever covered maybe. It defines the 1980's/90's exotic hypercar, with a strange powerplant with a unique sound, hybrid of the world kings of Art Italy and Japan, and will likely never be repeated again. Likely drives like a demon single-hamdedly invading the heavens.

Dino Dalle Carbonare

Wow thanks man!


Just no, its awful


Seems pointless - if you want a mid-engine proto style with a quad rotor just start with an Ultima and add whatever bodywork you want. Not like they even used the Testarossa gearbox. Or swap the quad into a stock looking Testarossa if you really like the TR vibe. But this is jus the worst of everything - being forced to work with awkward angles of the TR for no real gain. Anyway.....

Dino Dalle Carbonare

Yeah but then it wouldn't be the same... Let the Japanese take their own approach I say, it's what's made them stand out for all these years.


Begs for a rear wing imo. Can't wait to see it painted though, I hope they go bonkers on it. However, in the first place, I'm waiting to hear this thing :3


I was more surprised when i was reading and found out it's a real Testarossa cut out and modified than the creation itself, maybe because with a name like RE-Amemiya is easily linked to wild, at the same time over the top, creations.
Am i gutted seeing a "gem destroyed"? Sure no, it's not mine and the most important point it's not destroyed it's just beautifully re-imagined.
Waiting for the finished product coverage.


Beautiful car and realy cool build. Reminds me a lot of the autozam they did

Dino Dalle Carbonare

That remains my favorite


I wonder how long until Ferrari serves a cease and desist letter on this 'creation'. At least take the Ferrari badges off! The mechanical bits i approve of but looks-wise.... well lets just say it screams mid-90's obscure British kit car, and that is not meant to be a compliment by any means.


A very interesting build indeed. I would like to see what it does around Tsukuba. I really love the interior.

Dino Dalle Carbonare

It's more of a street car


I know. But even as a street car I bet it could clear Tsukuba in under a minute. But considering how much money is probably going into this car, I wouldn't put it on the track.


This car doesn’t deserve the Ferrari badges no longer
That front looks really weird,like it’s missing something,maybe they shortened the nose to much,and a larger front splitter would have made it looked better,same as the radius from the front fender,perhaps some louvers on top of the fenders would have looked nice plus it would have benefit the downforce as well
How cool would it have looked if they had made the rear halfway from the doors to the tail a bit wider,to me that style looked always boring,even with the Testarossa’s body it missed a bit of a curve to the outside
They should have looked at the styling from the Koenig Evolution and give that style more of a modern twist


Why can't every Evo be made out of a coupe?

Dino Dalle Carbonare

I believe the main reason it looks awquard is because the front design of the car comes up too high compared to the rear. It doesn't necessarily need to have a sharper form in the front, that curve should simply not come up that high....or the rear section of the car should be that little bit higher. This aspect of its design reminds me of that anomaly Autobachs made out of the Tommy Kaira ZZII, which looked 100 times better.

Dino Dalle Carbonare

Hi Dino


The front has been shortened too much, looks cartoonish, but the rear and interior looks very cool.


why does it have a carolina squat?

Dino Dalle Carbonare

What is that?


Dude, what!? Wow!!!

This is one of those builds that reminds me why these older tuners are still some of the best in the business. Blown away. Nothing more to say.


looks like a remake of the AZ-1 Rotary of theirs

Dino Dalle Carbonare

My favorite RE-Amemiya car ever! I wonder what happened to it


20% TR left after all that.. Ide drive it..


The old man went crazy. It's amazing and disgusting at the same time

Dino Dalle Carbonare



Hmm. Personally I'd lose the front lip/splitter altogether, pull every single millimeter of height out of the middle of the bonnet I could, and rework the fenders and grill to be more reminiscient of the old Ferrari P3/4 cars.


Ok now lets forget that it was a Testarossa. Sorry purists. But all together it looks good up until the ferrari logo on the front fenders.
From there on the whole front end is just "eeeww". It would be ok on a different car but here I think it does not fit the rest of the car at all.
Should have choosen a little more angular look and a longer front end for sure. In the back I clearly get some Regera vibes.


Makes sense to me that when a Ferrari owner gets bored they get a rotary, haha.