Differences: JDM and USDM VG30DETT

[Justin VanWinkle]

Help me out guys, I'm new to Z's...

I am getting a Z with a JDM VG-TT in it, and a spare USDM VG-TT...

1. What is the difference between JDM and USDM VG-TT's?

2. When swapping between the 2, what else will need to be changed? (ECU, MAFS, Wiring, Hoses, Radiator, etc...)

Thanks guys!

[nsrZ32]

very little

I have a list of all the minor differences somewhere (its a short list). I'll do my best to dig it up and post it up here shortly unless somebody else takes care of it

[Justin VanWinkle]

score! That would be awesome!

[Justin VanWinkle]

Anyone??

[nsrZ32]

Ok here goes....

-Most TT engine that come over from Japan have different cam profiles than US engines. US 5spd TT's have 248 intake cams and 248 exhaust cams. US Auto TT's have 240 intake cams and 248 exhaust cams. Now...the Japanese VG30DETT did not have different cams, its just a very large portion of the TT Z's sold over there were automatic so most motors that make their way over here have the 240 intake cams

-For the same reasons as in the above paragraph, most JDM motors have smaller turbos as the turbochargers on the automatic VG30DETT's are smaller than those on 5spd TT's.

-Since Japan is right hand drive and the steering column runs down the other side of the car, the oil pressure sending unit is on 'our' driver's side of the engine, connected to the line feeding 'our' driver's side turbo.

-The JDM downpipes also dont have catalytic converters (called precats here) in them and they flow much better than the factory US spec downpipes, but they are of different length from US TT precats. You would have to use non-turbo midpipes to join to JDM downpipes.

-The PCV valves are different so youll want to use the ones off your US engine

-The EGR equipment is also a bit different and lacks a conenctor which can be installed from your US engine.

I might have missed a few things as I couldn't find my list and this is just out of memory but for the most part, the rest of the engine is identical.

[Justin VanWinkle]

Perfect... so Performance wise... there really isn't a huge difference..

Just to broaden my understanding... when you were talking about the oil sending unit that feeds the turbo... Can you clarify on this alittle? I'm a bit confused..

From a swap, do you need to re-route the lines from the sending unit?

Also, do you know how much of Kyle's swap has been completed for sure? He was telling me that as far as he knows.. It's vacuum lines, MAFS, and a few other small things.... I'm just trying to gather an idea of all the work i will be facing over the next little while....

Thanks a ton!

[nsrZ32]

I worked on Kyle's old Z32, the silver one on northshoreracing.com, a decent amount but I've never touched this new one so I don't know much about the swap and what all has been done. He picked it up as a project and it was over his head and he didn't have the time/money/whatever to get it done. Really I can't imagine it would need a whole lot, its already in the car

[deknick]

yes there is a performance difference, depending on the engine, and how you view it. in japan they only rate thiers up to 280HP in most case, and that's what the VG is rated at, but in reality it puts out closer to 300 if not higher depending on condition and mods/lack-there-of.