So, do people think it's ok to increase the boost (assuming all other required/reccommended mods are done) with original factory turbines that have done at least 100 000k's? (My tacho says 100 000, but the condition of the vehicle suggests that it might actually be somewhere around that mark). If I was to replace them, I'd probably want to go with something bigger, especially since the engine has to come out. But then, having read other posts, it seems like there's significant modification involved in running the gt28 turbines. Do the original ones deteriorate, or is it the level of boost alone that determines the point at which the impeller will shatter, sending shards into the motor and killing it? Given that i've got the big zorst from teh turbo's back and a/m filters and about to put in the big coolers, I'd like to increase boost slightly but not if something tragic is going to happen. Also, are there any turbine upgrades that produce a reasonable result which don't require going to a 5 bolt setup or modifying the engine mounts, changing actuators etc etc (not interested in hi-flowing).
RE: Factory Turbo's.... I am unaware of this ever happening, during the past 5-6 years of my involvement with "things Zed", perhaps you're getting confused with the "Ceramic Turbine Jitters" suffered by some Skyline engines. I ran 16psi(and then 18psi) for three years, on an everyday user, without any major mods, and without any drama(until I decided to replace my turbo's with a pair of rebuilt units for Garrett in Sydney,then all Hell broke loose and resulted in the need for a total rebuild of my engine, due to turbo failure(turbo bearings)filling the engine with powdered bearing material.
Yes, the skyline turbines were precisely the ones I was thinking of... As I used to own an r33 with the ceramic. I thought the whole point was that they were lighter and spooled faster, but to be honest the 300 has smoother accelleration than (my particular) r33 ever did. I recall reading earlier that the 300zx wheels aren't ceramic, so they should be able to handle more boost, is that right? I think the concensus around the group seems to be that 12 pounds is pretty safe, and 14 if you're wanting to push it.
The 300ZX stock turbines are definitely steel 12psi is certainly no issue and 14psi will only be an issue with a stock ECU. With a modified or aftermarket ECU higher boost can be used relatively safely. It is not until 18psi you begin to reach the efficiency limit, anything over that and accelerated wear may occur.
Re: The 300ZX stock turbines are definitely steel If it is any help, I am running about 17 PSI on Stock turbos and Stock intercoolers and engine internals (injectors / pistons etc). My Tune is via the unichip, which is allowing me to run at that boost level (ie the injectors can manintain mixture at that boost level). I don't boost everywhere I go, but the turbos don't seem to mind, and if/when the fail, then I get some new ones . Everything mechanical will fail eventually, and obviously at higher boost failure will be premature, but that is the game we play. My opinion for what it is worth, is not to exceed 14-15 PSI without the ability to custom tune, but the stock turbos are goot for 16-17 PSI up to about 6000rpm. Above that, they run out of puff!!
18 pounds? Holy Jeesus, that would fly. I suppose you'd have to run bigge bigger injectors, or at least a modified fuel pressure regulator. 18 pounds. That is so crazy. Can i go to 12 with the welding tips? I want to get full engine management, but would like some added boost in the interim.
Re: 18 pounds? Holy Jeesus, that would fly. I suppose you'd have to run bigge You can easily go to 12 PSI with welding tips, just tempoarily install a boost gauge so you can check the PSI properly and see that there is no spike in boost pressure etc.
Re: 18 pounds? Holy Jeesus, that would fly. I suppose you'd have to run bigge You might just get away with 18 PSI on std injectors with a really good tune, but man that's right at the limit!! Anybody disagree?
Re: 18 pounds? Holy Jeesus, that would fly. I suppose you'd have to run b whats the cheapest way to get her to 14PSI?
Re: 18 pounds? Holy Jeesus, that would fly. I suppose you'd have to run b 2 x wire welding tips. Loan a boost gauge for the day from some kind zedder. A length of 6mm vac hose (about 2 metre). Buy a few different sizes 1.2 mm, 1.1mm 1.0mm 0.9mm. I paid about $6 for a 10 pack, and about $10 for the vac hose. So about $30, and you have some spare tips to offer to the next zedder that needs some. You might even find someone out there that has the jets, and can supply to you.
Re: 18 pounds? Holy Jeesus, that would fly. I suppose you'd have to run b i have an autometer boost guage.. (bought it one day for when i would have boost.. supercheap was getting rid of them cheap as they dont stock them anymore!!) aswell as a mech water temp and oil pressure.. i also have a monster tach.. but think they are a little wanky for a Z so tell more.. is there a tech article?
