veilsidefd3

tried search first, no luck.

are j-spec motors the same as ours? just the short block.

if it is different, how?

FormerPorscheGuy

There was a post about this last year, I will try to find it.

Kento

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

mr g lord focker

I actually own ABCracing.net. On it I sell J-spec motors only. There is a bit of difference with them vs usdm. First of all they have more power and torque than the american version on the motor. For instance, the H22A Preluda Honda motor is Jspec is 200HP and usdm 190HP. So fairly large stock power difference. Second, the trannies are set up for RHD so there are sometimes mods needed to set it up with a LHD american car. As for the RX-7 13b motor, the intercooler is top mount on jspec and not top mount of course as with our usdm motors. Small differences cary from motor to motor. But basically the main difference is the power output.

FormerPorscheGuy

Here is another one of interest.

http://www.rx7.net.nz/newrx7.htm

FormerPorscheGuy

Incorrect. We don't drive Honda's here and there really isn't that much of a power difference in the j-spec 13b.

Kento

Maybe the later R and RZ versions of the 13B-REW do, but when Mazda was selling the FD in the U.S., rated hp was the same.

Just because the Hondas are different doesn't mean Mazda is the same.

Not sure what you're talking about here....

racer1

i've got a 2000 Type R model. The differences i know since now are: No precat in JDM models, 99spec turbos, different cooling system In and outside of the engine, different lubrication system, powertrain was upgraded, top mount IC, 99spec Y pipe, rats nest looks different(not sure whats the difference) vacum hoses simplified.

If i missed anything please mention it.

Still searching for differences

Garrett

That is what is so unique and different about our cars. Jspec this and jspec that, when it boils down to it, those phrases aren't even an issue with rotaries. I would much rather buy american configured motors than get one imported from Japan. They are virtually the same damn thing as our Japanese counterparts. Even the newer engines over there share identical parts. The power increase in the later models such as the RZ can be attributed to the increased flow characteristics such as improved design stock twin turbos, exhaust, intake etc.

Garrett

GVR4_431

top mount intercoolers are like Subaru WRX where the intercooler is on top of the motor, or even still in front of the motor but layed up top, level with the hood. Where as the FD has a front mounted intercooler.

BicuspiD

Top Mount Factory IC in an FD? Got Pics?



Also, Doesn't the intake manifold NOT have the EGR port on non us spec?

FormerPorscheGuy

I think what racer1 is refering to as a top mount is actually your standard stock mount IC. The intercoolers in all factory third gens sit in virtually the same position.

RTS3GEN

I think he was trying to pimp his own site for honda stuff, and he was probably thinking of the 13B-T from the 2nd gens. Also the difference in the 2000 up Jspecs power (280hp) was due to more boost and more efficient dynamic seal turbos.
Art

Kento

Uh huh...and so the j-spec FD has a top-mount IC? Right. Let's see some factory pics, please...

Geez...

BNA_ELLIS

Some models are the same as your U.S spec ones some are different. There are approx 18 different models of fd's in Japan since production in 91. from 91-95 all we're 255bhp from 96-98 some were 255 autos the rest we're 265bhp from 99 - 02 some we're 255 autos, some we're 265, some we're 280. The differences we're minimal in general but there we're a few models that we're quite different. With 99 onwards car the exhaust system had 10% less back pressure a better oil metering pump that lubricated the seals better. A little more boost on the ecu 12-10-12 was the boost pattern. slight modding of turbos and a few other minor bits and pieces.

rgds

veilsidefd3

i was aware the turbos, exhaust etc. are different I was just curious about the motor its self. ie: rotors, housings, intake manifold, exhaust manifold etc.....

ptrhahn

iTrader: (9)

If they JSpec motors (13B) make more power, its the ancillary stuff like the turbos, the y-pipe, no precat, etc.

There are some slight differences with regard to the emission vac routing, and rets nest... but they aren't responsible for any horsepower

It cracks me up when people just arbitrarily worship anything "JSpec"... The actual rotors, housings, compression, etc is the same.

SPOautos

Thank God this thread isnt full of JSpec junkies. I'm glad to see the standard concensus of the board getting away from worshiping "Jspec" like it freak'n means something. There are a few updated external parts like the different rats nest, but generally speaking all the engines themselves make the same power. The reason some made more is cause they turned up the boost and didnt have as much emmissions crap.

STEPHEN

veilsidefd3

my reason for asking is i have a friend who is in Japan for the marine corps. if he can get a newer low mileage engine for cheap would this be better than a remanufactured one over here. aso, would it bolt up the same? what about tuning on the pfc would that make any difference?

RTS3GEN

If he can get a new or slightly used Jspec motor then it would definitely be worth the price. That would mean a low mileage all new internal motor(except for the mileage)a reman here you never know what you are getting. Hell the rotor housing could be within .0003 of spec and they would reuse them, even if they had 140K miles on them. As long as the parts are within spec they will rebuild with them. I've taken apart low mileage remans(blown water oring) and found fairly large scrapes and gouges out of the intermediate housings and banged up rotor faces.
Art

Kento

Egads. I'd be fuggin' pissed....

veilsidefd3

i guess ill go ahead and have him start looking for one for me.

HEns

um, 8 series jspec rx7's have uprated turbos from whatever they are in series 6 to 270kw