Okay....I've come up to this awesome offer, its 2k for a 87 TII body, but s4 JDM motor, needs a new thermostat/radiator and thermosensor(how much do those go for) might need to be replaced.

anyways the real question is what is the difference between a JDM motor and the USD motor of the s4's

 

the difference is, you cant pass smog.

 

It can if you add a ACV and cat to it.

I have a S5 Jspec in my S4 but have removed both of those plus the solenoid rack.

When Emissions time comes up for me next year I will slap a ACV on it and a cat and then wire the ACV to pump constant to the cat.

S4's do have EGR valves but unless you have a rotary pro searching for it they won't see if it's gone. Or you can tell the Emissions guys it is a replaced engine from a newer Rx7(S5) and that those didn't have EGR's.

 

somethign about not having an emmisions related nipple on the lower IM, you cant pass smog without it. i dunno i forgot the details...

 

Hmm My S5 Jspec had all nipples except the cold start assist thing. I'd say it should be fine.

Then again my S5 Jspec has proved to be an oddity with stuff not even on the manifold like ASV port.

 

So it sounds more like, "Which do you prefer: Japanese or American nipples?"

I'll take an asian anyday.

Or rather, JDM over USDM....

 

hehe, same here! maybe ill try to gather up some more detailed info, and let you know tomorrow or something.

 

You could also just use the corvette smog pump trick from www.1300cc.com when emissions time comes along.

 

Yeah but my state require a pump,cat , and acv so I have a ACV and pump already. Not hard to slaqp those on when you have a permacool fan instead of that huge *** shroud.

 

Performance-wise there's no difference.

To fully comply with emissions regs in the US, S4's are required to have EGR valves fitted. There's no way to fit one to a J-spec LIM, so if this is an issue you'll need to fit a US one.

 

how about that thermosensor cost?

i don't know anything about the smog equipment, how hardd is it to put it on and what not? gotta be a way around smog!

 

well i didnt get any more info on it, but i DO remember now, that it is in fact on the IM either lower or upper, but if its a TRUE full JDM motor you will NOT pass smog, but you could put the US parts onto it to pass.

 

Man, if your county doesn't have smog testing then don't put it on. My county doesn't (I live in Ohio too).

 

my county does.

i heard there a trick to getting it to pass by running on alcohol? is that true? it does sound dangerous

 

That will pass your through the sniffer but you have to pass visual as well.

I plan to just tell the guy I put a newer engine in it if he asks.
The law here says you can go up in engine model years but not down.

S5 engines seems to be easier to get than S4's right now too. You also get a newer engine so you get a better chance of getting a healty one.