N/a to turbo conversion; am I on the right trail?

S

stefan

New Forum User
Hey guys, I'm looking for a turbo Z31, but they are scarce (over here), and if you find one, it's carrying a hefty price tag.
So I guess I'll have to start looking into a vg30e to vg30et conversion, and was thinking of these items (leaving exterior and interior looks/trims out of the picture) being different on a turbo vs n/a model;
- everything in and on the engine (rotating assembly, in/ex manifolds, injectors, etc)
- in-tank fuel pump ?
- transmission internals (manual) and clutch
- rear diff ?
- drive and half shafts ?
- brakes fr/rr
- swaybars fr/rr
- exhaust/intake
- radiator ?
- gauge cluster and some other dash mounted gauges
- and thus wiring too ?

I was wondering, did I leave something out here, or am I spot on?

Just to be clear; I have the opportunity to buy a 1985 2+2 (n/a, m/t), I don't own one now... I started this topic to help me decide :cheers:
 
Sounds like nice project mate,, some of the stuff you list isnt actually needed but the one most important thing is either a turbo ecu or a mappable ecu in order to change the fueling etc,,,along with compressed mixture comes detonation if not sorted :eek: The exhaust manifold and of course a turbo ,,the stock injectors should be fine for a mild to medium setup however for anything more you would need to change em out for more flow. I'm still looking into this same swap myself as I have an early z31 na. From what ive found so far it need not be hugely expensive as long as it's thought through completely :D
On a different tack Ive been told the stock n/a ecu will compensate for a mild turbo setup but so far have not been able to confirm this ?? Anyone help :confused:
 
Oh snap, doh!
I know about the ecu, but didn't even think of it... stupid, lol

As a Z-noob I don't know for sure off course, but I guess I can compare bits and pieces of the 300ZX to my R33 Skyline GTST that was mine in better days; that had a hot-wire type air flow meter, and the ecu reads a certain value (ie. 0.5v to 1.5v, I forgot what the real values were) and knows how much air is being sucked in.
It'll compensate the mixture (helped by the narrowband O2-sensor in the downpipe) but the values differ from what's programmed into it's base maps... it'll overcompensate by injecting too much fuel and retarding the ignition too far, killing performance, fuel efficiency and in the long run, causes bore wash (13.8 afr at idle up to 10.4 afr at cruising speed, with just 10psi in stead of 6).
Also, the n/a afm will probably be a smaller bore than the f/i afm, and I don't know about voltage reading being on the same scale or not.
 
This what I'm at this point still looking into cus ive been told by a few local mechanics that the stock ecu on the na wont overcompensate re fuel and ignition retard,, but no luck finding out for certain ,,,and i dont wanna go ahead until im sure lol.
 
All Z31 use the same AFM. Fuel pump different (uprated) for turbo. Alternative is the Z32 Motorsport version which can be adapted. Personally wouldn't risk the ECU - get the right one for the job and/or consider the NisTune upgrade to give programability. Early turbo gearbox for the UK was a version of the Borg Warner T5. Late NA and Turbo shared the same Nissan gearbox.
 
Good to know about the afm, the fuel pump... well hey, a Walbro 255 will do the trick for a stock engine with some upgrades; a remap is always a good idea imo, even when the car is left stock.
I haven't read too many good things about BW transmissions, so I guess it's best to find a later, Nissan one?
 
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