I've been educating myself about the FD and was aware that the JDM turbos were an upgrade from stock by quite a few horsies, but have never read about the JDM engines themselves being different. Well, this one add claims the J-spec motor he just installed produces 305 hp and that's thrown me off. Is this guy misinformed or am i? thanks in advance -Clint

 

I put a JSpec 96 motor in to my FD and it dyno'd 500 rwhp with the stock turbos and PFC.

 

J/K I did have a 96 JSpec motor and you know that they are pretty much the same. A block is a block. The only good thing about JSpec motors is that you can get them pretty cheap with low miles on them...I didn't have time to rebuild so I bought and dropped a motor that was brought in for me.

It ran great especially on the T04S till the day my car was stolen.

 

In my opnion i'd rather spend my money on getting a rebuild from a good rotary shop. Jspec motor come with low mileage but man you just never know...

 

It's funny that he'd claim 305 hp since Japanese auto manufacturers are legally only allowed to claim 276 hp max in Japan.

 

Hi

I have 99 FD.
No modification on the motor.
Just stock replacing K&N air filter and KSP titanium exhaust.
And normal boost and RE-A ECU.
Then , 310 HP by RE-A dyno.

Thanks

 

yeah, the 99 turbos make a lot of power, they had to put a smaller downpipe to limit power to 280.

 

Where did you hear about the downpipe? I'm not saying you're wrong, I'm just curious. Japanese manufacturers don't have to "limit" their output to 276hp/280ps ... they just can't claim any more than that. JZA80s, GTRs, EVOs, etc. all "claim" 276hp/280ps, but they all actually put out significantly more than that from the factory.

 

Actually part of the power increase was that they were able to use a LARGER downpipe. Technically, the outer diameter is the same, but the wall thickness is thinner, so the inside diameter is a touch larger.

Even if they had to cut power back down, exhaust restriction would be the wrong way to go. Remember, it's a TURBO car. No sense in adding exhaust restriction (which hurts response and engine longevity) to limit power when you could just as easily lower the boost level a hair - lower boost means lower intake temps, longer engine and turbo life, and faster spoolup to max boost (simply because max boost is lower!).

 

I can buy that. 310...

I'm somewhare around there with the same stuff you have... for now.

 

Claims and dyno's can be different...
I was on the plane to NZ, talking with a guy who imports Aussie GTR's. He said that it's not uncommon for a healthy stock GTR to put down 300 hp. Unless he was just blowing smoke... Just what I heard, though.

 

Of course ... if you see my second post in the thread, I mention that stock GTRs, EVOs, JAZ80s, Aristos, etc actually output much higher than the listed claim of 276/280. That's just the legal bound for an output claim from the factory. No one believes that the US gets a stock JAZ80 @ 320 hp and they're only 276 in Japan, do they?? I didn't think so.

My question here was I know for a fact that the current stock FD does not put down over 300, so how could this guy be claiming 305? It sounds like a claim, without dyno backing, and he'd have to get that number from somewhere ... which brings me back to my point -- it couldn't possibly be published anywhere for the two reasons I mentioned before.

 

http://www.apexjapan.com/j_sportcar/track.html

The 99-spec FDs supposedly pull high 12s with "280" hp, so my guess is that it's actually underrated somewhat.