Lithium

bozodos - What do you mean by the appropriate sizes? Suitable turbine housing size or..? I treat the HX35 as roughly equivalent to a GT30R. Quite keen to see these videos of 7s runs?

I'm not sure it'd be worth the effort, the R34 RB25 has a variety of improvements - ie, solid lifters/more aggressive cams apparently and the real world performance difference seems negligable. I'd rather just get a decent set of aftermarket cams gives they tend to give good gains across the board.

You are clearly assuming/hoping that the Skyline isn't similarly equipped There were Skylines running around on the streets of Japan ten years ago with the same power or more than what you'd make with an EVO with an HX52.

I think he is implying that RB20s are stronger than RB25s, I tend to ignore those comments these days haha.

How are you going to address the fact that the bore sizes are seriously huge mismatches? 78mm bore into a chamber designed for something with a 86mm bore? Its not going to be nice in there at all.

Thats not with twins though, thats a dirty big GT42RS turbo I went in one of his cars running a twin scroll T04Z setup on a FullRace manifold with twin wastegates and I honestly can't see how you'd get more responsive than it. He stomped it from anywhere between 3000rpm and the rest and the thing would literally launch up the road, I honestly wouldn't believe how hard it pulled from virtually any revs if I hadn't been in the car myself. The dyno plots definitely don't tell the full story. A very staunch pro RB26 mate of mine with a 500whp R32 GTR was in the back seat (I have always been pro no-replacement-for-displacement) and while it was more than I expected despite expecting it to be really good, he was an instant convert.

Are those races 3rd gear roll ons or something?? I couldn't watch the clip so just going from the datalog. And 30psi!!!! How much power are you making on that?

Here was me initially thinking this was a topical pisstake thread relating to the RB26 vs 30 one hahaha. Seeing as there was a question asked about trying to make an RB20 breathe I may as well try an answer - doesn't one of the R34 offerings have a Neo RB20 head? Are they any better than the R32 one? Maybe that could be something worth looking at?

This should at least give an idea - exact same car, dyno etc. Went in to RIPS as a typical R34 GTR with all the normal bolt ons done to it, came out as an RB30DET with a T04Z. Sure the new engine is running a bigger turbo and more boost etc, but everyone here knows that if it were still a 2.6 the power would start climbing far far later. I'm sure there was another plot somewhere of an RB26 with twin T67s that ended up becoming a 3litre, I might be wrong though. Boltons RB26DETT (stock R34 BB turbos) vs RB30DET T04Z otherwise same car:

Pretty sure the motor in question is the TB48DE which is a twin cam injected petrol 4.8litre straight 6 complete with VTC (like RB25DETs). They don't rev particularly hard but are strong as hell and at the end of the day a huge motor so torque and power are going to come naturally. They are a 99.5mm bore, I doubt very very much anything RBish will suit them - I'd expect new mounts would need to be made up and they'd generally pack out an RB-intended engine bay easily, not sure what you'd use for transmission. There is a little aftermarket support out there too, lots of >700hp ones running around in the Arab nations so there is bound to be information on them somewhere. Have a nosy here: http://www.briancrower.com/makes/nissan/tb48.shtml

I know of them from marvelling at Arab drag/sand racing patrols over the years but not so sure they'd drop straight into an engine bay designed for an RB-series engine. An RB30 is not a completely different family of engine by any stretch.

Exactly, and my 2.5 powered R33 with a GT30R on 18psi has far less acceleration EVERYWHERE than a much heavier R33 GTR I have been in with an RB30DET and a T04Z... my car has basically felt like a bit of a joke since going in that Actually an RB30DET's 1.77 r/s ratio is closer to what seems to be a generally accepted "ideal" Rod/stroke ratio (1.75) than RB25s and RB26s which are in the 1.6s. You don't have to change engine mounts etc etc, the head bolts right up and its directly recognizeable as an RB still. All the aftermarket support is still there, there is no re-inventing the wheel - it makes a lot of sense.

Yeah it wasn't directed at you Just addressing the fact that there is a perception that RB30s have at best a similar powerband to the smaller engines, just that it comes earlier. I wish it were true, but I have an RB25 in my car and after having been in a few too many RB30s I can really tell where its lacking.

This guy you are quoting is comparing an RB30ET with an RB25DET? Quite different kettle of fish if so, I agree RB25DET > RB30ET. However an RB30DET using a decent head is more like 500rpm faster building boost and barely give anything away in terms of peak revs. I've been in a 10s RB25DET powered "GTS" and a 10s RB30DET powered "GTS", a 10s RB30DET powered GTR and a couple of RB26 GTRs making enough power to get around the 10s mark... I know those comments were made by someone else but I thought I'd just give some background to what at least I have been in/driven so I'm not just assuming how the different combinations do their thing, not sure about others but some things I have read suggest a fair bit of assumption is being made.

Haha maybe you are just discovering than twin turbos AREN'T actually better than a good single Twin GT3037s also probably flow similar to or more than a GT4508R..

Venting to atmosphere wastegates sound bloody aweful, especially when drowning out a tidy tight RB exhaust note - so thats a good reason to not go for one in the first place. 360kw @ wheels isn't an awefully huge amount of power in the grand scheme of things, there may be a little advantage in venting to atmo but really I doubt its needed. There are heaps of people running twin GT2530s and GT-RSs on their GTRs on here and they're all internally gated, hell one of my mates with an EVO is making >350kw @ wheels on BP98 with full legal exhaust on his 2litre with wastegate plumbed into his exhaust... he's relying on ~28psi of boost to do that power and if anything is going to start feeling the pinch from exhaust pressure he would.

I lean a bit more towards The Mafia's view on going full ECU instead of S-AFC. I guess the good thing about S-AFCs are you tend to be able to buy them used for a reasonable price and sell them for a similar price when you (almost inevitably) decide that it wasn't that great and you would have been better off just buying a full ECU. I personally can't help but notice that the people who are saying "Get a full ECU" are people who have been down the S-AFC path, and the people who are for the S-AFC are ones who haven't had one yet or are in the early days. Hardly anyone who has gone S-AFC seem to stay with them for any real length of time. The gains are often OK but I'm not convinced they are enough to pay for themselves. If you don't have the money to go full ECU, then you shouldn't be wasting it on an S-AFC imo.

Nice - won't argue with that Yeah absolutely Will be good to see how you go with them! The obvious point taste aside is all things being equal the bigger motor will always make more power and torque easier.

You just made a very nonsensical comment there man... "More average power, over a certain rpm means dick all if you spend your time between 4-8.5k. "... if you make more average power between 4000-8500rpm (thats a certain rpm) and spend all your time there, then you will have more acceleration/response between 4-8.5krpm, very very simple. I don't know why you guys are going on about the RB30 being shit/old/whatever, if you use the RB26 head then you have all the advantage the RB26 has an a dirty old iron block thats 3litres instead of a dirty old iron block thats only 2.6litres. They are both dirty and old, its just that one is bigger than the other. It seems there is a lot of confusion of the old days when the old 2.6litre RB26 beat the older 5litre Oz V8s due to technology... it didn't win because it was smaller, it won because the stuff it had it used better. The ultimate is applying the technology to bigger displacement, you get the best of both worlds.

Sorry I was referring to the fact that I was essentially doing a "I don't know but I have heard..." type post, a friend of a friend of a friend said blah.

Hmm I have had it for >2 years but if I remember rightly around NZ$2k at the time I purchased it. Runs an internal wastegate and is on stock manifold so all RELATIVELY straight forward/cheap to set up.

Spoken truly like someone who hasn't been in a decent RB30 setup. The Japanese have some interesting ideas, and they aren't always to do with whats best. You say all the top drag cars would be using RB30s instead of RB26s, aside from the fact that RB30s didn't come out in "JDM" cars what do you say about the fact they never really got too into their 2JZGTEs yet the 2Js have been proven to be the toughest straight 6 engines for ages? God knows how much power the Titan motorsport 6.4s cars were running but I am betting that they are a couple more than Heat Treatments GTR which to my knowledge is the undisputed RB horsepower king at this stage? The Japanese have proven to be scared of big things, their bigger Honda motors, bigger Toyota and bigger Nissan motors never got the love they deserved when elsewhere in the world people have proven them to stick to the "Size does matter" addage, even if some people convince themselves that "How you use it" makes up for it a bit. For some reason with Nissans people are a bit slow to pick up that the 2.6 isn't the be all, probably easier to do so for purities sake given that it came in the flagship. I've been in various GTRs with different engine configs etc and so far an R33 GTR with a RIPS RB30DET/T04Z combination making ~600whp made all the others seem like childs play. Response/torque/power/sheer brutal it was awesome - but maybe some people like the softer touch of a RB26, less scary

Well I had for ages favoured the idea of going GT-RS but eventually went the GT3076R, interesting difference here is I have never looked back

Congrats on the extra power, and good show manning up with the news etc - it all helps clear things up and make them more useful for future. Might be worth bumping the thread the discussion was had in and clarifying that for people using the search function in future

Not very useful, but I have been told very good things about them... I haven't had such a setup using them but I know of guys running up to near 600whp/25psi/7200rpm (RB30) with them I believe.