GT-RZ

To my understanding they have all the engine numbers listen on a database along with the vehicle. So once they have the engine number they also know where it came from (stolen or not stolen) seems other states have it easy. SA is very strict. which suks on one hand but not if you do some thinking of ways around things. All i had to say was RB30 with twin cam head and i got an instant NO! Never a production engine so it can never live in a car on the road. Same as the RB30na getting turboed. Because the compression is higher when you use the NA block it's also a no no. like i said before though they only recently clacked on to this because to my understanding there was more VL 'blocks' comining through mainly in 31's i think than seemed reasonable and they made a link. I don't know about police interstate too but they don't need to prove anything here, only suspect to send you for an inspection. i know a guy who was defected (GTR) because the officer said he saw oil drip from his car while stopped at the traffic lights!!!! could not show where it came from but it was enough for an inspection which consequently put him in the dumps because it was modified. I rekon keep things looking stock and forget about it. if you were to crash and they somhow blamed it on engine modification you would be in the same amount of trouble for a different turbo. handy when you have a stock engine as a spare.

Really it's up to you whatever you decide. considering you can buy a LS6 in the box for under 4k now. turbocharged 8's are hard to beat in respect to torque and power. but really if your gonna run an 8 you wouldn't need to charge it either way unless your after some serious grunt. would need some fabrication and alike to fit but if thats what you want.... personally i think the RB can provide ample enough for anything. if you want bigger torque and power i don't think much better value comes than buying a complete 25DET head and buying a good nick RB30 and switching the heads over. that's done in under a grand and leaves you with the same limits as a stock 25 + a bunch of extra torque. If you want to change turbo's etc it's preference. but i don't see the point in putting a holden v6 in there, sorry.

prevent failure. don't wait for it.

I know in SA you must have your block stamped by the ****** at regency. but then if you happen to have access to the correct style stamps then it is up to you. but really i wouldn't care anyway. my car on the papers has RB20 and it has an RB30. Not like the cops will or even know where to check for engine numbers. if you were to restamp id be worried about the cast 'RB30' on the side of the block too. so just leave it i think and forget about it. currently my only option if i got defected is to swap the engines back over. which id rather do than return things to stock.

i think your question really refers too how does a VG30 compare to an RB25 turbo. which there is many discussions previously. VG30 is laggier than the 25. for a 20 id go the highflowed 25 imo.

26 has three runners per turbo @ much shorter lengths and less bends. 20/25 has six runnders per turbo @ much longer lengths and harder bends. I don't think it takes a genious to see why more ceramic can get in the 26 cylinders... either engine will get a taste of dust be it 25 or 26 TT or single

you were lucky, not so here. engine number is quite obviously Rb30 and they don't allow it. They even cracked down on RB30-et conversions. before they never new the difference in number coding, now they do and now it must be a RB30et genuine block. not that i care. same outcome for me, just lest costing for legalities

sounds like your engineer didn't realise what was infront of him. you can pull the wool over peoples eyes and have them believe its a RB30et because they don't always realise the difference. i was told by the authorities here when i asked about the hybrid engine RB30DET and they said it's not possible to register as it was never made from the factory and there is zero information on it "torque, emissions etc etc" but if you can get it registered with an RB30et then they will most likely never make the connection. INFACT the first thing he said when i said hybrid engine was "what ? an rb30 that runs of hydrogen and petrol or?"

If this is the case which as suggested is not. then the supra turbos may have being built with a higher Factor of safety (a larger safety margin) for example nissan may have used 30% and toyota may have used 40% who knows. going b the way toyota tends to build things it is probably true. thing to note though, generally the bigger the FOS, the more money is involved and the more weight. you could inturn reinforce a ceramic turbine with steel and get a lighter turbine with a much higher tensile stress but $$$ and not necessary in comparision to a steel wheels performance. (difference would not be much) if you think about the force that is ripping apart the ceramic wheel and then think about the kind of material that ceramic is. you realise that when it lets go and bashes in to the housing it too then will not just bend like steel would but it will break up and at the speed it was travelling the pieces are likely to be very small (dust) with easily enough force to travel back through the manifold i think you will be right with the manifold design. GTR manifolds are very small with tiny bends in comparision to the GTST manifold. i still wouldn't bank on no ceramic dust getting in to the engine though.

First up, i' using a very generalisation to steel and ceramic here. obvously different grades have different properties. Ceramic is not more flexible than steel. Ceramic is however lighter than steel and can take greater compressive stress than steel and also has a harder more durable surface than steel. That's why these new 'ceramic silicone nitride' bearings work very well in a turbo. they are much harder which leads increased wear resistance followed by there lack of reaction to heat so smaller tolerances can be used. The problem with ceramic is when it's faced with tensile stress (pulling apart). the elastic range of ceramic and the plastic range of ceramic is very close to the UTS (ultimate tensile stress) where right after it will fail. steel has much higher ranges across the chart in comparision to ceramic. What that means is basically it does not stretch if a force is trying to pull it apart (centrifugal force will increase with the RPM of the wheel) it will resist untill it reaches it's UTS and then tear apart. wheras steel will stretch and eventually plastically deform under much greater stress than a ceramic variant will. it has little to do with head as ceramic copes with heat much better than steel. so obviously when a manufacturer designes a turbo they want it to be as responsive as possible for the cheapest possible price which means the lightest and most durable material for the cause given a budget. All manufactures work in a large Factor of Safety for every part used, but. if you think about the boost people somtimes run these at (14lb)? that's almost double the standard and most definently well above there given FOS. add to that they recommond you change them every 60,000k's with nissan and you can understand why they fail. Not sure if i explained it well. i gues you could crudely comapre ceramic to concrete. take massive compressive strees easily, takes massive heat but cannot take tensile stress easily and will not stretch but will simply crack. import to note too like GTR geoff mentioned. ceramic wheels cannot be bonded as well as the steel variants can so maybe the bond lets go first followed by the ceramic hitting the housing. anyones guess, probably a blend of both. it's generally more likely for it to fail at the shaft even if only the ceramic was to blame as thats where the greatest force is placed on each propellor.

Do you have a CAS?

could be a few things. how many kms has it done?

I got quoted $500 ages ago. and $700 for the VVT head. ring up some wreckers and haggle

well the stockies with some steel wheels can give you more than that. safely. the stockies as they are can provide that power but your on a timb bomb like always.

You can only do that with the rb20 and rb25de brackets anyway. 25det,26 even RB30(exhaust side) have cast fancy looking mounts that don't really provide the room to do that, safely. really if your a smudge out using rb20 brackets id just fit the rb30de brackets as they will move the motor back a tiny bit more(5-10mm) and cost literally $5 from U-pull it or alike. if it's a bigger drama (silvias) there is more options with x members and bracket combos. best being 33 rb25det x-member with matching brackets and rb25de,rb20,rb30,rb26 engine mounts (or any custom about 40mm high that lines up) the stock 33 mounts are about double the height as the rest.

well you have two turbos too worry about. but if it's stock then that seems reasonable. what give you the incline that they were damaged or were you just asking for future reference? when it happens you will know about it. if you have the cash get some steel wheels put in there or upgrade. my 2c.

try a big clunk when the majority of it flys through your dumps. be pretty obvious as you will have no power. plus if it sucked NO ceramic dust inside the engine you would be a minority of lucky people. takes allot of stress to rip a wheel apart.

25DE are larger than the 20's ports... not sure about that 'special edition L2 20' though? . If you have ever looked in the ports of a 26 you can see there is not all that much gains to be had in terms of porting+polishing. unless you go all the way and get some serious material removed in there. i'v got specs of a 1000hp GTR that pulled 8.7s down the gtr somehwere with a 100% factory head, including stock plenum. i think the two massive leaf blowers on the side might have give it a kick? The 26 has slightly larger ports than the 25 also, mainly due to a better shape. if anything id just get the exhaust side polished and leave it be. Just to remove the 'very small' cast marks in there. Wouldn't want to polish the intake side for obvious reasons.

The problem of running lean with a fuel cut limiter is real but most likely not with 99% of the quality systems available, more theoretical/old crappy systems once upon a time? If you think about the speed at which an injector must operate and spray it's fuel in to the chamber then you can understand that a fuel cut system must be very efficient to be able to stop 100% of the fuel being injected in to the chamber to prevent combustion... It can't. but most will cut >50% of the fuel which is enough to create a fuel/air mixture that is too lean to ignite. the only scare you could have with this is that something stuffs up but then thats with every part? spark cut systems can cause more problems really. you have unburned fuel travelling out the chamber through your turbo and down your exhaust which can cause overheating problems. if you have a cat you could potentially melt your cat sitting on the rev limiter... (probably not an issue for most drift cars ) All in all a good quality fuel cut in good working condition is the way to go IMO. End of the day you shouldn't intentially be sitting on the limiter anyway. and a few cuts here and there wouldn't be much of a problem either way... hopefully.

stock pump being used as a lift pump is a good idea imo. won't run out of flow. not like you will be driving around flat foot continously to empty out your surge tank (even if you had double your target hp). if you want a lifter to the surge tank it's either use the stock one or buy a lift pump. really is a waste using a 044 or walbro as a lifter. personally i think the surge tank option is the best way. And really if your going to do something, do it once and do it right. Rather than buy a cheaper setup now to save $$ because your setup will be fine with it. may as well invest and be ready for the next upgrade.

i cant imadgine the ports to be different sizes imo. more like a batch number. but would be cool to have some comparisons.

sounds like a rev limiter at 5k lol. coils wouldn't be constant enough to literally hold it at 5k. neither would fuel delivery or boost problems. think you need a better description. if it intermittently cuts out then it could be any of the above but if it drives perfect up to 5 then holds it there....

yea i dont think 30deg is possible... unless you got some dry ice hidden in there think about it. that's room temperature. or am i missing something ? i know my oil gets up to 80-90deg pretty fast but i dont have any extra cooling.

bush bearing? does the shaft spin freely. is there a problem with the oil feed?

i'v got an rb20det silver top sitting in a tyre. says 73L 5 above the exhaust. i can measure them if you like. Edit 43mm wide 32mm high rounded to nearest mm. what does the 73 stand for? 43+32 =75 which is very close to my width/height measurments.