Does n e one here own a mazda rx-7 infini(JDM engine)? Or that is running an infini engine? I'm probly gettin one

 

Uhmm... so... isn't the only difference in the ECU?

(hope you didn't pay extra for that engine... )

 

The only difference is a better flowing exhaust. The engine and ECU are the same as any other Jspec.

Steve

P.S. Jspec != Infini

 

I was pretty sure it got a tuned ECU too...

Regardless, the engine is the same... so don't pay more!

Jspec = Jspec.... Infini = Jspec.... Jspec <> Infini...

 

So... and Infini engine is just any J-spec, but the Infini models came w/ better exhaust. Also, I heard that the Jspecs had a slightly bumped up compression ratio and maybe lighter rotors too somewhere. Is this true or just a myth?

 

Umm... if it's not a myth, it's news to me. And I've never heard anything about the ecu bit, although, I might be inclined to believe it, because a better flowing exhaust would generate more boost, and the engine might need more fuel. Guys, Jspec engines are EXACTLY the same as Aspec ones. There's nothing special about them, other than that they are much cheaper when compared to a rebuild. They don't have bigger turbos, or better intercoolers or lighter rotors or any of that nonsense!

Steve

 

If any one has the specs. Pleez inform me. Thanx!!!!!!

 

Why?&nbsp There's really nothing special about the car except for being a limited edition model.&nbsp There is nothing fancy about the engine; the suspension and exhaust is tweaked for a little more power.&nbsp The true value of the Infini models is the chassis itself - the engine would end up being a plain-vanilla turbo engine.



-Ted

 

actually there is diffrences
there is no pulsation damper(les chance of fire)
there is no stupid egr on the manifold
and they have a lil bit of extra places where you can mount after market temp gauges.

 

Jspec motors are fundamentally the same as US motors - there are a few minor differences, mainly pertaining to emissions controls and right hand versus left hand drive. But, the important parts are the same - US and Jspec rotors, turbos, manifold size, TB size, etc. are all the same.

There were numerous Infini models in Japan made over the course of the FC's production run. Ted's dead on - what made them special was the chassis - better dampeners and springs, some had strut tower bars, lower weight, etc. The power gains over a stock FC were minor, again just from Mazda playing with the exhaust, not a special ECU or anything. I think it was only up like 5 horsepower or the like on the Infini IV.

Dale

 

the JSpec engines do have a couple differences, but as far as I know, they're not in the internals of the engine. Like RudeBoy said, the EGR and PD are things that come to mind. I wouldn't exactly pay more for a JSpec engine, especially since I've seem them used and barely warrantied (www.corksport.com). But I think I might be looking for an engine swap after i graduate college in May, so I'll probably look for more detailed info at that point. I'm still debating if I want another Turbo Rotary though... I kind of like the idea of the GNX engine a little better. Don't flame me here though.

 

The Jspec motors *do* have pulsation dampeners - they're identical to the US fuel rails. And, just like US, the '89-91 engines have the better pulsation dampener.

None of the '89-91 engines (US or Japan) have EGR. The '86-88 Jspec engines don't have EGR like the US engines do, but that's a minor point - one blockoff plate and you're done.

I don't get the point of "extra places to mount temp gauges" - again, that's about the chassis and not the engine. That's really not a big deal - people in the US don't seem to have problems with mounting gauges.

Dale

 

i want a set of infini IV rims....

 

I have the write up on the LAST FC Infini model...I can write up the main points....

Let me read it first.

 

Okay....this write up was done RIGHT BEFORE Mazda shipped it back to Japan. I am just going to note down the major points

As follows:

The cockpit:
(Right-hand drive)
Bolstered, snug, light black cloth racing style seats that are not adjustable for rake (cannot recline). The stock seat belts are used. Rectagular pads on the center console and door served as braces for hard cornering. A foot rail (rest) was added on the left side for passenger comfort. A fat-rimmed Momo steering wheel (large Monte Carlo w/Infini button). No radio and NO A/C.

Weight Drop:
The engineers removed the interior insulation. A lighter, less restrictive and noiser exhaust system. At this point the weight of the car is now 2,700lb, 287lb less then the US Spec Turbo.

Power:
The exhaust increased 15hp over the US market of 200hp.

Drivetrain:
Standard 5-speed manual gear box. The rear is updated with the Torsen limited-slip differential. Sorry, no specs.

Torsen = non-clutch type, longer lasting, helps prevent push in tight corners. It is basically an open diff until about 2/3's the way through the corner then it locks the *outside* wheel to about 40-45%.

Suspension:
Spring rates are upped to 10%, shock are 25% stiffy, harder bushings (no specs), DTSS removed, OEM front strut bar (red anodized cross member, aluminum color 3bolt brackets). SMALLER 23MM FRONT ANTI-ROLL BAR. Over all height is lower by 1 inch.

Wheels:
16x7 standard BBS mesh wheels, P-Zero 205/55/16, specifically developed by Pirelli for the Infini

Brakes:
Harder compond break pads on the standard turbo brake system.

Steering:
Engine-speed dependent power steering (from the base model), ration slowed from 15.2:1 to 17.4:1 (better for autox and tacetrack events)

Exterior:
(My favorite part)
No Mazda badges anywhere, just the Infini symbol decal over the left rear tail lamp, infinity symbol on the BBS hubs, AMBER FOG LAMPS, GREEN-BLACK paint,

Test specs:
0.91g on the skid pad
7sec to 0-60
14.9sec @ 94mph in the quarter
stopping from 60mph is 141ft

The performace specs are from the testers from one of the US mags....do not know which one. Their quater-mile (street) times are not too off, could be faster probably with an upgraded airbox. It is still stock on the Infini model. I believe the stock ECU was upgraded to handle the upped boost from the upgraded exhaust system.

Enjoy!