RB30-POWER

they are way better (all things being equal of course) there is less pressure drop, better flow and so higher efficiency. go read corky bells turbo charging book and it shows in the intercooler section how that is the optimum design.

will run lean and too advanced timing with z32 and standard ecu... you would be able to cruise however to limp the car home if you stay off boost as closed loop will compensate some what, but as soon as you go into open loop mapping, will lean out and detonate the motor.

http://www.microtechefi.com/forum/viewtopic.php?t=29 ask over there mate.

Both type of Rb25DET engines have same static compression ratio. 9.0:1 Rb25DET Neo has same turbo as series 2 R33 RB25DET, but has the larger (OP6) exhaust turbine housing. Same housing as used on the VG30DET. (Single turbo engine)

either you didn't test 2, 4 &5 properly, or they are farked... if you tested properly, you now need to do a leak down test to determine if its headgasket, rings, valves etc

http://www.skylinesaustralia.com/forums/in...+gtt+oil+filter

check valve stem seals for those valves

did you use a brake tool (g-clamp will suffice) to push the pistons back in all the way before re-assembly?

start with the basics, check its mechanically ok first. compression test, leak down, check timing belt is not out a tooth somewhere, check CAS ignition timing is set correctly etc

maybe thats when vtek y0! is kicking in? if not then i agree with the below

its not really possible what he says, re: over pressurising the radiator. the pressure is limited to radiator cap pressure, if you get combustion gas leakage at the headgasket, it will usually push the coolant out of the engine/radiator into the expansion/overflow tank and then the combustion gas will just continue to leak out of radiator cap and into expansion tank and out to atmosphere. this sort of problem is usually evident, because the expansion tank will fill up after a drive, but when it cools, it doesn't contract and suck the coolant back into the radiator from expansion, and you always think your radiator is low on coolant, but its only because its not recovering as it cools due to the combustion gas pressure (up to radiator cap max) in the engine/cooling system.

yep, stock.

is your guage accurate? you would get maybe 18" on idle with electrical loads and a/c turned on. (more air entering through idle bypass solenoid to maintain idle rpm with loads on engine = less vac)

with standard cams and no vac leaks with engine warm it should be around 20" vac. bigger cams and you will have less vac.

What engine is this going on, RB30 or twin cam RB20/25 engine? If its an RB30 R31 as your avatar depics, then the t3/t4 is the logical choice as its straight bolton. If its got a RB20/25 conversion then get a RB20/25 turbo high flowed as it will go straight on and have the advantage of ball bearing response if you build it back to that spec. Bluey1 the cop VL, ran 10's on a t3/t4 highflow, was power ported but retained stock turbine and compressor housings, it was done by ATS. (Was stripped and ran race fuel of course) At the end of the day, highflows are kind of old school and the Garrett GT series turbos really do offer good value and performance for their money. So you need to think what the long term goal is, to save spending twice.

why would it run rich, thats the entire idea of a recirc bov, the air even if it was leaking goes back into the plumbing before turbo but after the air flow meter, so its not likes its measured twice or anything. because the pressure is equalised on each side of the bov diaphragm thanks to the rubber hose that connects to the plenum I can't see why it would be open in normal use anyway, regardless of spring tension. maybe this guy meant the wastegate actuator, not the bov?

as far as i know because its balanced as a complete rotating assembly and indexed before dismantling and re-assembling it will not be balanced even if you index it as per other turbo. im going off the fact when i have watched the guys balance wheels/tyres at work, having extra weight on one side/wheel in turbos case can offset either more or less weight on other side. if that makes sense. my answer is no, the different mass of the different sized wheels will cause out of balance. if turbo wheels were balanced seperately then it would be possible but they aren't...

to flush it properly you need to either remove the block drain plug under exhuast manifold, or its usually easier to remove the thermostat, or else the thermostat traps old water in block still. you will need to bleed it when you refill it, at the bleeder nipples. also be careful about using the drain tap, usually if the radiator is old, they just snap off and you need an entire radiator, its far easier and safer IMHO to remove the radiator lower hose. that way there is no suprises.

unless you get an oil analysis done, i doubt any one here really knows how good there oil or engine is...

The ignitors/transistors are not in the ecu at all, they are in the series II coils. Series 1/2 ecu does not matter. Hence a single model PowerFC fitting both model engines series I and II.

nice result mate. i don't know why people bother with the standard ecu either, its useless with anything above standard boost pressure.

there was a test of all zeds on top gear. the 300zx tt ate the 350z. whos to know if the 300zx was actually running stock boost though... im fairly certain a 300zx would eat a gtst (stock one anyway) so how that relates at the end of the day i dunno...

nope, temp guages are ntc type thermistor, nothing to wear out. could be guage, playing up from the geforce of acceleration, or could be the increased rpm, pumping cold water into the engine quickly, if you had a dud thermostat or something. what you would need to do is, actually measure the resistance of the sender during said conditions and see if its actually the sender output changing or not. because the guages are usally thermal, they move slow, even if the senders change quickly, so i would take a punt that you might have guage/cluster issue. but you would need to check to know for sure.

the sender is usually made from a carbon track that wears out, or atleast gets dead spots (open circuit) and whilst its at that level, it will drop to zero, then as it moves back onto a good part of the track and gets a circuit again, it will read correct. people that always keep a certain amount of fuel in their car, wear that part of the sender track out first, thats why its easy to tell when you buy a car with plenty of km second hand, tell how much fuel the previous owners used in it, because that is where the guage will read dodgy, if you get my drift. they can just fail however rather then wear and tear from the needle rubbing against the carbon track.

ditto the above