1984 300ZX Turbo Upgrades Questions

[twiceasfastasyou]

Hey, Ive been looking at this 1984 300ZX Turbo car in my area, for about $4,000, and was wondering, what has the best turbo been for replacing the stock one, and added with the best-fitted exhaust system for this specific model. For some reason, I am not finding a specific exhaust system or turbo upgrade for this Z model, maybe I am not looking hard enough. What is the stock turbo set at, is it 8psi or less? I'll probably be needing to get a new turbo controller, intake, exhaust, intercooler, hoses/clamps/piping, oil cooler, a new fuel management chip, possibly a new ECU, (unless the ECU also controls the fuel management), etc. With this, if you find any awesome packages, please post the pics, and I will be eternally greatfull. I'm dead for 4 days straight here with house-calls, so I wont have time to do some major researching 'till I get back, so I just wanted to check in with some of the veteran Z owners first! One last question, is the weight difference for the 1980s 300ZXs much different to the 1990s+ 300ZXs? I heard that even though the 1990s+ get around 300HP at twin turbo models, the car's infrastructure is so heavy that the 300HP is definately needed just to keep the car at a reasonable accelerated rate. Thanks in advance to all who read and post to this ridiculously long and almost irritating post...

twiceasfastasyou
Geek Squad CIA
Precinct 0016

[xXxRocker5150]

well it sounds like you're gonna' do some heavy modding... in that case, here's all you need to know http://www.redz31.com/turbofaq/turbo.faq.htm

^That's a great website on the whole, but if you're looking for the short answer, get either a custom exhaust or you can get the HKS exhaust or dynomax exhaust *both of which are only a 2.5" exhaust and you'll probly want 3"* or the certified muffler exhaust located at certifiedmuffler.com

As far as a new turbo, well the popular thing to do is to have the stock one bored out in order to fit a t/4 wheel in there *you can buy t4 wheels at garret's website... turbonectics might also sell them*, so basically you'll have a t4 turbo in a t3 housing. You can also get a Jim Wolf technology turbo unit that they sell on their website, but it's kind of pricey. As for the ECU, Jim Wolf Technology reburn's the stock ECU (actually I think they sell you an 88 or 89' ECU and than reburn that).

Stock boost is set at 6.8 PSI for 84-pre 4/87 models, and post 4/87-89 models have a different (smaller) turbo set at 4-5 PSI

[-The Stig-]

Geek Squad! nice...

[twiceasfastasyou]

Originally Posted by xXxRocker5150

well it sounds like you're gonna' do some heavy modding... in that case, here's all you need to know http://www.redz31.com/turbofaq/turbo.faq.htm

^That's a great website on the whole, but if you're looking for the short answer, get either a custom exhaust or you can get the HKS exhaust or dynomax exhaust *both of which are only a 2.5" exhaust and you'll probly want 3"* or the certified muffler exhaust located at certifiedmuffler.com

As far as a new turbo, well the popular thing to do is to have the stock one bored out in order to fit a t/4 wheel in there *you can buy t4 wheels at garret's website... turbonectics might also sell them*, so basically you'll have a t4 turbo in a t3 housing. You can also get a Jim Wolf technology turbo unit that they sell on their website, but it's kind of pricey. As for the ECU, Jim Wolf Technology reburn's the stock ECU (actually I think they sell you an 88 or 89' ECU and than reburn that).

Stock boost is set at 6.8 PSI for 84-pre 4/87 models, and post 4/87-89 models have a different (smaller) turbo set at 4-5 PSI

hey man, thanks for the info! ill definately look into boring out the stock housing... this should be a fun project, about a year ago, i was going to get another cheap four cylinder, but i decided, its time i moved on, its time i grew up! lol, anyway thanks again for all the info, ill look into it when i get back from my housecalls today

[twiceasfastasyou]

Originally Posted by -The Stig-

Geek Squad! nice...

Yes sir! You need some computer help, P.M. me up! lol

[DeleriousZ]

the t25's on the later z31's are set at 4.7 psi, yet still make more hp and tq than the larger t3 units at a higher boost...

the differences between the z31's (84-89) and z32's (90-96) are too many to try and list... the main differences being the dohc vvt heads in the z32 compared to the sohc in the z31, bunch of suspension upgrades.. twin turbo's, etc etc

if you're looking to do any sort of track or auto-x racing with the car, do yourself a favor and wait to find an 88/89 turbo... they were the most updated in terms of suspension and so on (10mm wider track, different style tension rods)

as for turbo upgrades, you can do as rocker said and get someone to rebuild/upgrade the stock t3 turbo (you'll want the t3 model not the t25 for this) or go with a new unit, usually people go with a moderatly sized t3/to4e turbo with an internal wastegate... running an external wastegate will require modification to the exhaust manifolds and could prove to be a pain... a few have done it, but most make completely new manifolds... that too is on jason's site. it seems that some people use the stock EGR port to mount a wastegate, but that only feeds off of 3 of the cylinders so it's not quite as efficient.

the supporting mods for a new turbo are plenty... starting from the ground up you'll want to go:
CM or custom 3" full exhaust including downpipe

some form of cone filter and 3" pipe to eliminate the resonator.

most people axe the stock mechanical fan for an electric unit, some go with a vertical radiator to make more room for an intercooler/piping/oil cooler (me)

the supporting mods needed for more fuel (stock injectors MAX out at 15psi on the stock turbo) such as injectors, new fuel pressure regulator set at a higher base pressure (usually around 40psi), fuel pump (255lph walbro for the 240sx is popular), some upgrade to new fuel rails at the same time (higher flow, bling factor)

with a modified motor you'll see a BIG gain by going with a 'gutted plenum' upper intake manifold, can be found at L&P performance or a few other places, but L&P have the best flowing stockish design out there...

something to control the new fuel stuff, some people get reburns done by JWT, but they're expensive and a one time thing that can't be continuously tuned... some better options are:
romulator (using the live edit software)
nistune
SDS (the best out there, usually costs around 1k but WELL worth it)
megasquirt
a few other random ones, you could use an afc, but that's somewhat of a kludge method and is just as expensive as some of the ones mentioned above.

bov or recirculation valve (can't forget that one, it's important)

suspension upgrades: springs/struts is the big one, polyurethane bushings is big too, the gains seen from going poly everything is insane. strut tower bars, thicker anti-sway bars...

wheels/tires: not often mentioned, but sticky rubber makes a HUGE difference everywhere... ligher wheels couldn't hurt either!

this is all off of the top of my head so i probably forgot something... feel free to ask away tho

[longlivetheZ]

4 grand for an 84? It better be immaculent...