This thread was saved without dates. "Around May 2005" is estimated from neighbouring threads.
i was under the impression that all Z31's came with a T3 turbo..
well i was looking on this one website and it stated that only the 84-87 Z's got T3's (TB0306) and that the 88 & 89 got a T25 (TB25)
here are the specs: TB25
Turbine A/R .49
Compressor A/R .48
Internaly Gated w/ actuator (7psi)
after looking a little bit more i also found a couple of sites that said the 87-88 Z31 came with a TB0205
so which is right and which is wrong??
i believe the early ones got the t25's and the late ones got the t3's or vice vera.. but the z31 did get both the t25 and t3 turbo thru the course of there production run
84-86 got t3's and 87+ got T25's
Yep, HagenZ is correct. Also, the 84 Turbo is the only one that came with a turbo that was only oil cooled. All other years got oil and water cooled turbos.
The Z31 T3 is a 50 trim compressor with a .63AR exhaust.
ok.. so the best one to grab would be from either a 85 or 86?
also.. why would they switch to a smaller turbo? didnt the 87-89 vg30et's come with the same power rating as the 84-86's ? so did they change the engine for the later years enough to keep the same power with a smaller turbo (for example putting in better cams, and adjusting the ecu)
Actually, the 87-89 300ZX Turbo had 10 more hp than the earlier T3 powered 300ZX's. However, in 87, they also switched to full floating wristpins for the pistons, different crank, and slightly different heads. Same changes are present in the 88 SE S12. The 87 SE S12 has the older VG30. Anyway, I don't know what exactly accounted for the 10hp gain, but there was supposedly a 5hp difference between the 87 and 88 SE S12's.
They changed the turbos because they wanted less apparent lag. The t3 turbo would make max boost by about 1800 rpms on my roommates 85 model, so I don't really see the point, but Nissan has this thing for undersized turbos. Magazine writers complained of lag on the earlier models, but it was just the car coming on to cam around 3,000 rpms. With no real boost gauge on the digital dash, how were they to know?
The N/A models also were supposed to have a bump in power over the 84-87 years as well by 5 hp I believe, so I don't think it was anything with the turbo swap that caused the increase.