Cubes

Depends on the dyno and the car. I haven't known one to make 300rwkw on 1bar BUT I was told I will get close with a set of reasonable cams (265's). IF you run a nice exhaust manifold, nice inlet, free exhaust with big cams u can make 300rwkw on around that boost. But its not as simple as just dropping a .82 on and it will make that power on 1bar. A good example is sky30. Std inlet, std exhaust manifold gt35 managed 312rwkw on 18psi roughly. tried cams didn't help with peak power due to what I suspect is the end of the run for the std exhaust manifold. Did big cams in an rb26 head with its std short runner plenum and a nice exhaust manifold. Power jumped to 382rwkw on ~17-18psi. Making the motor breathe better via nice cams, inlet and exhaust manifold modifications is a must if you want to run big numbers on low boost.

I like lots of brutal quick spool and mid range that makes the driver work so I'm not the one to comment. On pump fuel with std cams the .6 appears to make around 270rwkwish. Do cams you can pick up 30rwkw ish push more boost in to it and you should be able to crack 300rwkw. Sure some are able to keep raming boost in on pump fuel which does make more power but its not good for longevity especially if you want it to hang together at the local track. So in saying run out of puff up top.. Really no such thing it just doesn't make as much power as easy. The .82 no doubts help with getting it to hook up and allows power to be made easier but to really make use of it a set of cams and extended rev limit would be nice. But realistically as long as it makes all its boost at 4k 3-3.5 thousand rpm band is ok. The rb20t blokes work with less.

1.7bar = 25psi. So whats the secret infected flow? How did you get it making 25psi at 3200rpm when every one else isn't able to get even a GT30 making that boost at 3200rpm. So given 25psi at 3200rpm.. That would have to be 18psi by 2900rpm??? Sounds technically impossible from the 2.5ltr unless its ramp rate was mega slow ... as I said on the brake. Not having a dig. Just trying to work out how you managed to beat the laws of physics. So tell us how you managed it.

Full boost by 3.2k with a gt35r .6 on an Rb25 when sitting it on the brake for 30seconds.

writeoff, What was the diagnosis on failure cause. :S Talking about Willala... Would any one have vids of Keirs old silver GTR down at AIR? I've missplaced the copies I saved.

I had a problem similiar for a good couple of years. When I pulled the old rb20det out I replaced all the hoses with new nissan stuff. Cost me a fortune. :S New motor went in and the little hose that connects to the turbo water feed that runs around the back of the head and the little hose that connects to the thermostat housing; both leaked over night when the motor was cold. During the day when the car was warm etc it never leaked. I spoke to my old man about it who's had a little experience in the truck and bus industry. He said they had the same problem that resulted from the manufacturer changing the rubber makeup. He said hose clamps are available that are sort of spring tensioned so when the hose gets cold it prevents leaks OR the other fix is to dap a tinny little bit of silicon on the metal and then slide the hose on and clamp it. So silicon it was and not a leak since. FYI I did try multiple hose clamps, new hose clamps etc.

Yeah RB30 requires emissions testing. Depends if they can tell there's a 3ltr block under there with all the crap hanging everywhere and bottom engine bay cover. Its quite difficult to pick.

397rwkw and soon fingers crossed 410-420rwkw It must be an absolute monster. Chops.... Andrew(sky30) had it making 380rwkw for some time on the stock 300,000km+ Rb30 bottom end. 7k rev limiter due to stock rods at the time. I don't believe it ever blew just upgraded.

Yeah I think so also.. But Its due a plug change so I'll drop them in anyway. + My coils are shagged. They were missfiring on std boost when I had the std coils so I silicone the suckers up and they have been good since. If push comes to shove I'll replace them but if I don't have to I wont. I'm hoping the problems aren't related to valve float as the numb nuts down at Milton engine Dev said "32pounds seat pressure for a dohc turbo is really good" :S It should be up around 75pounds.

A few things could be cause the poor fuel consumption.. O2 sensor, ecu coolant temp sensor, blocked cat, dirty injectors, seized viscous clutch fan (I've had one not lock at all and I've had one lock up completely) and as the car is new most likely has something to do with your right foot.

There's a couple of little hoses around the back of the head/under the plenum. I had one let go replaced it with great difficulty then had the other. So while your there replace few little hoses that are there at once.

Shotpeening the rods is a complete waste of time. Factor in the cost of shotpeening + a set of rod bolts and you may as well buy the spool rods. ---- The rb30det in my own car as a daily driver has made toodling around so so much more enjoyable. Its not just all about the increased mid range but more so the low end when just cruising. The accelerator pedal feels hard and responds to throttle input much more than the rb25det. I've even pulled tree stumps out with the R32 rb30. Did it easy as without having to rev and ride the clutch, also towed a a VN commodore for 50km's up big arsed hills etc. The motor loved it and towed it really really easy. I've since driven rb26's etc and the torque comparison and enjoyability of cruising around keeping up with trafic just isn't there. I know the GT35's on the rb30's don't feel as such but the GT30 makes the motor feel like a big arsed n/a that pulls strong from idle to 7000rpm.

I had a look at mine and can't really see a wave. I can see a slight back off in torque as the wastegate cracks open hard at 11psi and slows spool dramatically. If the slight dips up top are the ones you are talking about then yeah that got HEAPS worse with more boost; lots of unburnt fuel was floating around also which I believe indicates ignition problems or god forbid a little valve float which I doubt. I pulled the BCPR6E 0.7mm gapped plugs and they appear to be running too hot so I have a set of 7's to go in of the part number of NGK R5671A-7 recommended by a few different people/tuners. Apparently the R5671A-7's position the spark in a slightly different position which helps prevent it from blowing out. Apart from that my clutch was slipping and on the very last dyno run even on the lower boost levels power was a little over the place; the drive home had the clutch slipping in fourth when making 1bar. Was a strange sensation as initially it wasn't a clean slip but rather a shudder which felt like axle tramp in the second+ gear, later it developed in to a shudder that quickly moved to a flare. Now I have a new clutch in it she feels noticably quicker so I do suspect that was part of my problem + ignition. Time will tell.

Yeah my post count was reading minus something the other day. :S

Yeah there's a few different variants of the GT30 with the 60mm turbine wheel. GT3071 GT3076 (old school .7 comp 7blade compressor) GT3076 (HKS3037S style .6 comp cover 6 blade compressor) GT3040 (gt35r 82mm compwheel .7 comp cover)

More importantly of where 'full boost' is made, is where it makes all its boost when rolling on the throttle in second gear and or how it develops boost in first gear. A good example of this is the difference between the GT30 .8, GT35 .8 and GT35 1.06 on the dohc 3ltr. The 'full boost' difference between them on the dyno is marginal but on the road there is a HUGE difference as to how they drive. The GT30 feels like a supercharger with strong linear power from idle where as the GT35 (in the lower gears I'm talking) feels a little laggy laggy then bang your off. Interestingly they both made the same power on basically the same boost. For comparisons sake the GT35r .6 turbine map flows very close but slightly better to that of the GT30r .8 combination. The GT35 1.06 that I've seen makes all its boost around 3900rpm so marginally higher than the GT35 .82 yet on the road the difference in spool is unbelievable. Its as if the smaller housing starts making some boost and providing the windmill affect at a considerably lower rpm where as the 1.06 comes on in a rush within a few hundred rpm. I'd really like to see the comparison in spool and drive ability between the GT3040r .82 and the GT35r .6. My guess is they would be 'fairly' close. So in short; a dyno sheet making x psi at 4500rpm doesn't tell the whole story of how it performs on the road when taking off from a stand still then rolling on the throttle or accelerating out of that low speed second gear corner.

Go forged and as Adriano said don't forget that crank collar. You will soon be dropping a GT35 on it in chase of that 400rwkw. Especially as you already have a WMI setup it would be almost too easy. Rods are cheap as these days; when I built mine up a ~3yrs and 70,000km's ago forged rods were up around $1800. The Spool rods didn't exist and aftermarket pistons weren't really available for the combo. FYI I comp tested mine recently and its still got the same compression as it did after it was run in. Still the same cyl 3 is 1psi down; the rest all exactly the same. Bores still looked like new with no scuffing. I was expecting to see a little scuff up top as its running forged pistons and does slap ever so slightly when cold. I had the head off to block off the rear oil restrictor and drop a 1.5mm restrictor up front. So make sure you do this also. For 2k rods/bolts and pistons you really can't go wrong. You'll most likely be looking at in total 4.5-5k for the motor build with forged rods/pistons. There's really no reason why it should be anymore; when pricing around for my build some were charging stupid amounts and were unable to tell me what they were doing 'extra' to justify the cost of the build. Also why the N1 pump? They are not that crash hot, apparently brittle due to the hardened metal and cause an increased amount of oil floating around in the head which we really don't need. Std GTR pump is fine. I and a mate who had our motors built at the same time; we got lucky we stumbled upon a true enthusiast that got it right the first time.

Because he will be adjusting his headlight level at the same time.. hehehe All in good jest Luke.

$60 per hose is pretty damn good. I assume that doesn't include the block and turbo fittings? I had pirtek make some up out of bundy tube. $40 each. $120 all up which I was happy with.

lol.... Thanks for the update. Now everyone knows who does a search.

Disco, lol at the twin scroll. I've had a play with twinscoll turbines in the engine analyser simulator; it definitely looks promising. The only issue is the internal wastegate. I would be very curious to see how the 1.06 twin scroll drives as I wasn't impressed with the light load/part throttle boost response from the 1.06 GT35 on the RB30 in comparison to how the .82 drives. The boost response and low gear acceleration from the .82 was so so much more enjoyable. The 1.06 feels super lazy until a little before 4k. But its all a trade off; peak power or average. Hopefully the twinscroll can blurr the fine line. Mafia, I would hope mine tops out a little over 300rwkw with the .82 on pump. I have a set of cams as you may know. 265duration 8.9mm lift. Cheap regrinds so nothing is really lost of they kill low end; i'll grab another and have them reground to the 254duration spec that I know is a good thing picking up around 25-30rwkw on the same boost with no loss to low end. If I ever drop a nice exhaust manifold on mine I will most definitely sell the GT30 and drop a GT35 on it. Behind a manual and with some nice cams it shouldn't have too many problems pushing high 300's. Providing I keep rev's sensible the trusty old rb30 bottom end will hold the power fine. Zilch, Are you running the .6 or .8 turbine housing? The .8 obviously allows the motor to breathe a little better as a result you don't require as much boost to make the same/similiar power.

I was originally really interested in the HKS3037ProS as an old Adelaidian SAU'r Steve had an HKS3037S on his RB25DET with first the .69 then the .87 HKS turbine housing back a good 4years odd. With a little over 20psi a set of cams and exh manifold it made from memory spot on 323rwkw. Then I discovered the 6blade Garrett .6 port shroud is the same thing just had to wait for the int gate housings to be sold. Why do you have to modify the .8 rear Mafia? I run the small std wastegate hole on mine and it sways between just under 16psi and 15psi due to the crappy actuator and long boost reference point from the plenum. I should disconnect the actuator and see what boost it peaks too.

Darren; yeah. He's running the same 1bar Garrett can that I am. Matt; The GT3040 with the .6 rear is a waste as you require better than pump fuel to make the most of it. Essentially you sacrifice response and spool for nothing. A good example of this was R33racers old setup; GT3040 made around 320rwkw on pump; water injection (similiar to running nice fuel) had it up around 370rwkw. Dropped the GT35r on and it made the same power as the GT3040 but on pump fuel; no water injection required. The Gt3076r is 525hp rated and can push 320rwkw with a set of cams and exh manifold on low 20psi behind a manual. I've been told they max out around 350rwkw with water injection/good fuel. Regardless how big the compressor wheel is or how much it is capable of, if you can't flow the required exhaust gas past the turbine wheel its simply not going to make the power of which the compressor wheel is capable of. This is especially true on pump fuel as you quickly run in to detonation problems when the scroll backpressure skyrockets. This is why good fuel or water injection is useful. Remember a motor is nothing more than an air pump. I wouldn't consider the GT3040; it was a turbo of choice when the GT3076r (aka HKS3037S) wasn't available and the crappy GT3076 with its 7blade comp wheel and .7 comp cover was. Jump straight to the GT35r or stick with the GT3076 & 71.

lol.. identical to how my 1bar garrett actuator builds boost without any form of boost control. Mine on the dyno made 11psi at 3k then 1bar by 4500rpm. With a cheap ball/spring bleeder on it it shifted 19-20psi to a little over 3000rpm. I have been told its typical of garretts 1bar actuators. Helps with traction through the mid range with mysetup though. I'm very glad your not disappointed with the additional lag from the .82 it was a worry I had being on the 2.5ltr.