Hello All, I'd like to learn more about the differences between the U.S. Spec (93-95) and the J-Spec (96-02) RX-7's. Donate one thing that you know about this. I'll start it off....on the U.S. spec FD's there is a alternator mount bracket and a separate engine lift hook, on the J-Spec FD's to save weight they made the engine lift hook and the alternator bracket as one part. Thanks guys/gals

 

not that it helps much, but in a j-sped FD you have to shift gears with your left hand unless you are a total baller. the spoiler was changed, the tail lights were changed, efini rather than mazda, up until i dont know when. some had back seats, diffent packages i think... hopefully i didnt screw anything up.
-stephen

 

turbos, y-pipe, front bumper,


all in newer models

 

The steering wheel is on the right hand side

 

j-spec aftermarket downpipes have a sharp bend right after the exhaust flange to account for the steering column

 

apparently the windsheild wiper and blinkers are switched in position.

 

The J-spec Version was sold in Japan and the U.S. Spec was sold in the US. Thats my donation. Enjoy!

 

J-spec cars came with a 16 bit ecu while the us cars had an 8 bit system (this may have just been an update after they stopped importing them to the us though).

 

I might be able to chip in some info here..From what
Ive seen so far, here are the differences:

for 1993
No AWS
No EGR
The overheat exh. light is in the gauges where the CEL light should be
efini badging
of course, the RHD, but, like someone else said, the DP is a BITCH to get out if you dont remove the studs first. Ive tried. All DP's here come with the notch in them to clear the steering shaft.
stock Downpipes dont have cats in them
blinkers on the fenders
the ABS pump is on the opposite side, making harness installs really fun and challenging
mine has back seats
front seats are cloth, the rears are leather..hehehehe
thats all i can think of for the 93's, of course there are the newer models, round tail lights, different spoilers, etc etc, the new FDs are 32 bit ECU (Im pretty sure) i know there is a 16 bit ecu too, because the power FC's are different for zenki (old) and kouki (new) FD's

 

dang guys that's alot, let's try to get some more technical stuff like engine differences and parts...keep em coming guys, great so far!

 

The 1999 J-Spec

improved turbos
better flowing exhaust
improved lubrication and cooling system

netting 280 hp @ 6500 rpm and 231 lb/ft @5000 rpm from the factory

 

Doesn't the J-Spec FD have a different solenoid rack or just different vaccuum tube setup in general? I heard this before and was wondering if anyone had any info on it. If this is the case, why can't you just convert our sequential to the newer system (or better system)? Also, what is the advantage of the 32-bit ECU over a 16-bit one? What more does the new car have that the old didn't that it needs double the processing?

 

question was for 95 models but that seems to have been covered
92 jdm differences, as i've found them on my car

-no fast idle at start or most of the other emissions crap, (so no pre-cat?), so they probably run cooler, (as they were designed to)
-no arm rest pad on ash-tray
-180kph speedo, (needle will continue to around 190kph but is then internally pegged)

-3 models offered

s - rear wiper, 4 seats, dual oil coolers, cloth seats, no airbag, no cruise, black only inside, listed weight 1260kg
(not sure if rear wing was stock on S model, they all seem to have the same pt.no. wing as the r now)

the S seems to be by far the most common FD in japan, don't think i've seen a standard one yet, after 10 years they are generally all sporting big mufflers, and new shocks at least, next most popular change is 17inch wheels and tower brace, 16inch stock wheels used for snow tyres

(since i've started looking for the 2nd oil cooler i've seen only 1 car without, a 1992 X model)

r - 4 seats, dual oil coolers, front tower brace, less damping on front shocks, no airbag, no cruise, listed weight 1250kg ( i would have thought the weight saved by not having the rear wiper was balanced by the addition of the front tower brace...not sure where the 10kg diet comes from)
(r2 model lost the rear seats and all sportier models from then RZ etc)

x - leather, bose, cruise, manual or auto, no 2nd oil cooler on manual version (only version offeredin australia)

the biggest suprise is in the engine bay where lots of little things are different, no quadrant gear for cruise etc and lots less emission stuff

airbags didn't become mandatory until around 1994? when a consumer group kicked up a fuss about japanese cars in the usa being safer than the home market

sure there are lots of other little things so will be watching the thread with interest

eric e

 

Was the touring X available with auto climate control? I remember seeing a pic of it in the Yama-lama book, but it may have just been a concept.

 

Don't forget about color options! I don't know much about the JDM cars, but everybody knows about IBM and the Spirit R titanium. Any other colors that I don't know about?
Also, did the JDM cars come with sunroofs? (I don't think so.)

 

https://www.rx7club.com/forum/showth...hreadid=150053

take a look a this

 

Because of the J-Spec models having less emmissions stuff, the upper and lower intake manifolds are missing alot of provisions for EGR, etc.

 

seems like no one said tail lights or did i just miss it? and others like turbo and y-pipe people have seemed to mention already.

 

Everything else has basically been said, but they also came with 17inch rims, and special edition cars. They also came with a downpipe, instead of the pre-cat that we have here in the states.

 

Anybody have an answer to my questions?

 

Found this on PUMA's link:

"There was a post about the updated "rats nest" on the Big List a few years ago. I'm sure it's archived somewhere, probably on Steve Cirian's Lightning in a World of Thuder site. I don't remember all of it, but what I do remember was that US 93-95 FD's could not use that updated rats nest due to differences in ECU control for it. Very nice pics though, it's cool to see the differences."

So if this is the case for the rat's nest, why not upgrade the ECU?...Wouldn't it be worth the trouble?

 

ccarlisi

yes i forgot about that

the 92 x model i saw had a climate control system where it looked like you could select the temp and the air con would cycle to suit, not a digital display but 1 of those complicated dial in dial setups

eric e

 

the JDM 5th gear ratio was 0.806:1 ,The U.S. spec is 0.719:1

thats my contribution

 

oil metering pump updated looks entirely different not sure yet how it works now

 

W00, got 1, Headlights aimed differently