# Unique Z31 "Turbo"



## BeyondBiscuits2 (Jan 18, 2006)

My friend just purchased a 1986 300ZX "Turbo" Z31 from a relative who owns a shop and dabbles with building drag cars. We want to get the car running, but we have some problems to sort out first, and I thought I would ask around if anyone might have a clue on how to help us. First of all, the car is in great shape. No body damage (a rarity) and no rust spots. It basically spent its whole life in and out of a garage and storage facility. Unfortunately, one owner along the way did not know how to properly store the car. The car itself is a factory badged 300ZX Turbo Z31. In the process of storing the car (had been in storage from 1989 to 2002), the turbo ceased up and the crankcase's coolant passages rusted solid. Needless to say, the previous owner was a fool.

My friend's relative bought the car in this state for around $500 to initially use as a parts car for his project 1984 ZX Turbo. He ended up deciding to restore it however, but with a "race" application in mind. Somewhere, he bought at VG33E engine from a Pathfinder or something, and dropped it in. He told us he had the engine professionally built, with a lower compression ratio (I believe the same as the supercharged VG33ER) and even had custom camshafts made for it. He, however, never got the engine to fire while in the car. As far as we know, the wiring is completely useless. He said he used the cylinder heads, sensors, injectors, and plug connectors from the original VG30E engine, but has the VG33E ECU hooked to it. We have the VG33E setup as a turbo application, using the original VG30ET manifolds, but with a new turbocharger (not sure what type, previous owner bought and installed).

Now that you know the back story, here is my question. Does anyone know how similar the wiring harnesses and ECUs for the VG30E and VG33E are? From what I have read, the VG33E is basically a VG30E with more displacement. Is this true, or do we need to gut the complete engine harness from a Pathfinder to make this thing run?


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## Zen31ZR (Mar 24, 2004)

I've read at least one magazine article where the VG33 was dropped right in and used the original Z31 equipment to run without any issues. I'd have to question the "custom" camshafts and whether they are even in the right position. The original cams make plenty of power and don't really need to be changed except as one of the last resorts. I'd also have to question the useage of the VG33 ECU, and the use of the original Z31 equipment with it, as I beleive the 2 are nowhere close to being compatible. The original ECU or a JWT Z31 ECU would work best in this application. If you want this car to run, go back to stock equipment or proven Z31 mods and then go from there.


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## BeyondBiscuits2 (Jan 18, 2006)

That's pretty much what we've been thinking. The car itself is in amazing shape other than the engine and wiring, so I suggested he just buy a running VG30ET off someone and we drop that in. He wants to see if this VG33 will run, though. I thought the cams were a bit sketchy myself, since I don't even know of any company that makes them for a VG33, nonetheless custom ones. At the moment, unfortunately, the car is sitting in his garage and until he decides what he wants to do, we just tinker with it off and on. You put the key in, all the lights and such work, and you turn the key to get nothing. We have the VG30 ECU, we'll slap it in and see what happens. As far as we know, the previous owner used the VG30ET cylinder heads; my question is if he is completely "bsing" us or if they actually will fit? As far as I can tell by comparing pictures of the VG30E and VG33E, they look pretty similar, but I am no expert on the Nissan V-6s.


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