My 1983 Mazda Cosmo (rotary injected turbo)

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sry_not4sale
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My 1983 Mazda Cosmo (rotary injected turbo)

Post by sry_not4sale »

Image

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Image (not my engine bay)

Exported as a 929 without the rotary, turbo and other goodies (LSD, etc) to NZ, Australia, South Africe and Europe.

They were offered in 3 body shapes - coupe hardtop, 4door hardtop and sedan. Came with 1.8 and 2.0l 4cyl SOHC petrol engines, 2.2l 4cyl diesels, 13b injected rotaries, 12a carbys and 12a inj turbos. Some of the low spec models were equipeed with solid rear axles.

The sedan is almost a completely different body to the hardtops, with a very sedate and roomy interior. It was the sensible car, the hardtops where the crazy ones with all the gadgets.

Very advanced for a 1983 car, with:

- power windows
- central locking
- l.e.d dash (rather than the digital displays of some other 80's jappas)
- independant rear suspension, semi-trailing arms (suspension design is almost identical to fc3s Rx-7)
- 4 wheel discs (250mm vented fronts)
- digital fm radio/cassette player and boot mounted amplifier
- air con
- power steering
- osciallating air vents in dash
- electronic climate control system
- 8 way adjustable seats, very comfy!
- cd of 0.32!
- 15" alloys!

My example is powered by the original 12a (1200cc) 2 rotor wankel engine. With a single barrel nikki style throttle body and a non intercooled turbo setup rated at 165hp standard. It was the fastest car in japan briefly until overtaken by the r30 fj20det skyline.

"Using an Hitachi ( HT-18 ) turbo, the analog controlled EFI computer devilered it's mix via 2 "high flow" injectors mounted in the engines centreplate. The air mix would arrive via a staged throttle body & progressive metering measured via a TPS to the ECU. Combining the relatively small turbo with it's short intake manifolding ( intercoolers wern't common in the early 80's ) endowed the 12A with instant throttle response devoid of any lag. The trade off however was to be found in the engines top end power." Source

"It has a 3-throat throttle , as do all the Turbo engines , and it looks a lot like a carburetor. What this does is allow a single throttle to work as the primary throttle , which means that it opens first , then the two secondary throttles open at around 15% throttle. The benefit to doing this is that Mazda could get away with running only two injectors , located in the centre engine housing in the primary ports. At closed and up to 15% throttle, the primary ports are the only ones getting air-flow through them , which means a higher gas velocity , which in turn means better atomisation of the fuel" Source

The ecu is not quite quick enough to react to big changes in throttle position, so a mechanical vacuum/boost actuated switch of some description is used to open the injectors up if you give it a sudden hit on the throttle.

They run an electronic dizzy which retards under boost.


My car:
- Rare blue interior
- Lots of new parts from Mazda
- Tein FC3S fully adjustable coilovers
- Megasquirt & water injection (setting it up atm)
- FC3S brake upgrade (setting up atm)
- Full rewire
- 17" wheels, 255 Potenzas
etc
Owner / Builder: 1983 Mazda Cosmo 12at (1200cc 2-rotor turbo) coupe [SPASTK]
165hp @ 6psi standard - fastest production car in japan Oct 82
Tony
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Re: My 1983 Mazda Cosmo (rotary injected turbo)

Post by Tony »

Very cool car i have never seen a Mazda Cosmo before the only thing we have over here with a rotary is the RX7.

I like it alot. :twisted:
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sry_not4sale
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Re: My 1983 Mazda Cosmo (rotary injected turbo)

Post by sry_not4sale »

Its very quirkly which is just what I want :D

Will post some more pics for ya ;)
Owner / Builder: 1983 Mazda Cosmo 12at (1200cc 2-rotor turbo) coupe [SPASTK]
165hp @ 6psi standard - fastest production car in japan Oct 82
Tony
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Re: My 1983 Mazda Cosmo (rotary injected turbo)

Post by Tony »

I know what you mean i have always like oddball stuff over here everybody has a Ford Mustang i always like something you dont see that often.

Yes post up more pics. :D
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Fred
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Re: My 1983 Mazda Cosmo (rotary injected turbo)

Post by Fred »

Thanks Aaron, I don't think I've seen good pics of that one before, very nice :-)

Tony, if you like obscure Jap cars, head over to http://www.oldschool.co.nz and have a read through the project section, the language used on that site is fairly coarse at times, but there are some amazing old cars there. NZ is somewhat of a dumping ground for jap cars, which suits us just fine :-) they are cheap and pretty good. It's pretty easy to make them go fast with some boost too.

Fred.
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sry_not4sale
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Re: My 1983 Mazda Cosmo (rotary injected turbo)

Post by sry_not4sale »

Tony wrote:I like it alot. :twisted:
Thanks mate. They are quite rare in rotary form also, under 10,000 were made, and the coupe shape was by far the least most popular of the 3 bodyshapes... as if you wanted a rotary coupe at the time you brought an rx-7!

Image

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the blue interior (the grey above is from my 929)

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I drive everywhere in a suit :D ;)


Image

The reason I was in the suit ;)
Owner / Builder: 1983 Mazda Cosmo 12at (1200cc 2-rotor turbo) coupe [SPASTK]
165hp @ 6psi standard - fastest production car in japan Oct 82
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sry_not4sale
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Re: My 1983 Mazda Cosmo (rotary injected turbo)

Post by sry_not4sale »

I am gonna keep with the original idea of the car, so no i/c and keep it with a small quick spooling turbo. So water injection and some tasteful but stock-looking modifications under the bonnet :)
Owner / Builder: 1983 Mazda Cosmo 12at (1200cc 2-rotor turbo) coupe [SPASTK]
165hp @ 6psi standard - fastest production car in japan Oct 82
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Fred
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Re: My 1983 Mazda Cosmo (rotary injected turbo)

Post by Fred »

Cute red-head you are holding onto there, BUT, she's blocking the view of the red car!! tut tut ;-)

Good to see your car being used as a toolbox too, I have a shot of my skyline looking that way :

http://i50.photobucket.com/albums/f323/ ... kyline.jpg
DIYEFI.org - where Open Source means Open Source, and Free means Freedom
FreeEMS.org - the open source engine management system
FreeEMS dev diary and its comments thread and my turbo truck!
n00bs, do NOT PM or email tech questions! Use the forum!
The ever growing list of FreeEMS success stories!
Tony
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Re: My 1983 Mazda Cosmo (rotary injected turbo)

Post by Tony »

Nice indeed !!! Yes simple and clean is the way to go i like the cars when you walk up to them its hard to see what is done to them.

Over here all the young kids the first thing they do is put some god awl full wing and obnoxious exhaust that sounds like a tuna can on it and they think its something to see.


Shame on you Fred i know guys over here that would kill for a right hand drive skyline.LOL
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sry_not4sale
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Re: My 1983 Mazda Cosmo (rotary injected turbo)

Post by sry_not4sale »

Lots of changes recently... engine now sports an FD Rx-7 power steering system, and on the look out for the brake master/booster from the bigger braked RZ model.

Next is to find the correct places to mount the required sensors for the megasquirt...

Where is the correct place to mount a map sensor on a vehicle with individual throttle bodies? On one of the inlet runners?
Owner / Builder: 1983 Mazda Cosmo 12at (1200cc 2-rotor turbo) coupe [SPASTK]
165hp @ 6psi standard - fastest production car in japan Oct 82
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