discopotato03

Yep , I reckon the gap between those two is a bit wide too . Airflow wise the 52 and 56 trim GT3076Rs fit between and people here reckon the 56T is a little snappier than a GTX3071R . A .

Well to get a good reliable and "snappy" 300 RWKW a few things have to be a given . Exhaust from turbo back has to work . Intercooling has to be up to it . Fuel system inc computer and injectors dito . You get into a grey area of cheapest road to 300 bag wasps or a more expensive route with nice running snappy throttle response and good turbine response . On the engine probably a GT3076R and definitely EV14 injectors like Xspurt 740s . Blitz return flow IC , reasonable price and no hole sawing . Neo inlet system fine . Most people here would say 0.82 housing on the GT3076R though Mr Mafia had good times with a 0.63 on his . I think E85 should be better than 95 ULP + WMI except for consumption . If turbo response was key then you could run the 0.63 turbine housing on the 52 compressor trim version of the GT3076R , AFAIK the 52T is about a 49 pound/min turbo so easily enough for 300 Kw . Good injectors and computers make a difference to how well an engine runs and IMO that includes throttle and turbo response . I really like Vipec plug ins and the result is better than a PFC especially with an 02 controller and feedback to the computer . To me ball bearing turbos are worth having because lag generally means lack of power in the drive every day rev ranges . Sad fact of life is a nice user friendly result costs good money , a lazy laggy 300 RWKW isn't worth having in my book . A .

Kirawee Mufflers stuck a 20" long oval on the back of my 25T , I can't remember the depth and width but it is really quiet . It's an off the shelf Redback from memory available in 3 and 3.5" straight through . The Nismo rear can that was removed is larger area wise and I wonder if it can be gutted and rebuilt to keep the really big for an R33 can volume . A .

If we could get someone to make mufflers up that use all the available space , in the relevant locations , all big Skyline exhausts could be free flowing and quiet . What was the damage BTW ? A .

True but I want to see them on a single scroll GT30 turbine in a real world app . Part of the issue is if you damage one here there's no quick easy replacement like with a GT/GTX . A .

Yeah well in the past results for FPs 3073 and 3071 HTAs have been almost impossible to find . Ironically if the GTX3067R gets more exposure they may get some too . Yes Mr Lith from digging through pre TS Mitsubishi and Subaru FP turbos the alternate comp housings is mentioned as being a TD06 type thing from memory . They obviously wanted a port shrouded housing and this is the result . I'd want to see some results of this housing with these 71 and 73 HTA compressors before I'd commit to importing a reasonably exy turbo from OS . It wasn't such an issue for the 76mm version and possibly David Buschurs beat the stuffing out of them testing proved their worth to some , BTW he HATES std config GT3076Rs . A .

Well my take is that if you're going to twin scroll a system it has to have suitably sized components like housings . Something I'm guess get lost in TS translation is that sometimes larger AR housings are needed because convincing the exhaust "putts" to funnel down a passage easily needs a larger passage because the thermally (expansion) driven gasses may not not have a lot of velocity and any slower moving gas hates restriction to flow . Generally make flow happen easily - and it will . I also think some optimists would like you to believe you can bolt a BIG TS turbo on a modest engine and have it spool like a production car - optimistic . Example may be a GT40 or 42 on an SR20 . I don't believe TS is black magic but sized properly it does work . Mitsubishi and Subaru has it as OE . It is a challenge in the aftermarket particularly with integral wastegates I reckon because its more difficult to package than the original turbo system . Probably the one thing that's muddied the water in recent times is E85 fuel , it's enabled people to get away with heat and detonation issues and run stuff that would be impossible on pump fuel - minus WI/WMI . My logic is that if forced to make a good spread of power without exotic fuel and anti detonants TS done properly is a step in the right direction . Geoff I think the GDI and twin exhaust ports per cylinder takes engines to another level but ones that takes advantage of TS turbo systems . Obviously we don't know the future directions of BWs aftermarket competitors ie Garrett , they could gain substantially just from using lighter turbine wheel materials and still have good market share . My opinion is that BW has done marvellous things with the EFR range but the desire to be uncompromising can be a double edged sword , great from a design point of view - and I'll leave it at that . Last point is that the market really does want a plain compressor housing option . Cheers Adrian .

I don't know that the Neo has any greater flow potential , don't think their inlet ports are any larger or the inlet manifold as big or bigger internally . Possibly a tad more efficient combustion esp with lean cruise mixtures . If I had to guess I reckon its that combined with the fast opening/closing slightly higher lift solid cam profiles and the larger standard turbine housing that made the difference . Throw in a higher capacity SMIC and the power wouldn't have been hard to find . A .

I'm not up on turbocharger turbine production and I though friction welding was passed over to spectron beam welding ? On a Nissan RB I'd rather use the original equipment throttle recirc and by the looks of things the EFRs one is in the way on a typical bolt on Skyline app . Yes with a V Band housing the overall length is vastly shorter so adapted to an RB manifold or T3 with V out and a Scotty mount external gate it's looking easier . A .

Quantify light moderate - meaning effort and expense too . Reasonably straightforward with sub systems not overkilled to the 500 Kw degree . For example don't need the antics of 20a current draw fuel pumps and 2000cc injectors swirl pots etc . Don't need 3.5 to 4" booming exhausts or an intercooler that's looks like the car was bolted to it not the other way around . Or a hole saw . To me light moderate means something that's very easy to live with on a daily basis , that anyone can get in and drive round town feeling fine . Not to say it can't have great squirt and scare people it they boot it but you can have both worlds IMO . Hard arse means choppy cams and solid face clutches , turbos that do f**k all under 4000 revs . Everyone seems to peg Mick Os Skyline as a benchmark , it could have run any of the GT30 turbos . Would have been smooth and flexible to drive around town and all that'd differ is the boost threshold and the numbers . I think the dryer he chose took most standard and light/moderate tune bits fairly close to their perceived limits and I congratulate him for a great result too . However , for someone who wanted performance they could use all day every day and occasionally cruise down the expressways at 110 a 3067 could do it for them too . This is not to put down a GTX3071Rs abilities it's just saying in round town use the 3067 is possibly a better all rounder . A .

Most people reckon the blocks and cranks are the same but the rods are RB26 , so the pistons have to have larger diameter gudgeon pins and a lower crown to get the same CR with the smaller Neo chamber . IMO minimum changes to the R33 short are rods and pistons to run the Neo head .

Will get back to the post above my last soon . A .

Well the difference is that my road tuning is getting closer to what the engine wants and that's really finding work arounds for injectors that are hardly current tech . I don't care what anyone thinks , these engines like what they like and if you can't give them that then it doesn't matter what hangs off the manifold because drivability is not a turbo thing it's a combustion efficiency thing . I will say that slight CR increases will increase burning efficiency . 256 Tomeis cost it buggerall and I reckon the increased CR makes up for anything it did . There are accepted valve size ratios for performance and RBs are a bit lacking on the exhaust side . I did this because the SK 25 had it along with the same porting cams and CR bump . Their dryer was an OP6 equipt GCG Hi Flow and they used a Freddy inlet and GTR cooler . On BP98 and with GTR squirters it cranked out 266 at the bags and would have done better on ethanol had it been available . I remember Scott (Insight) asking him how high they wanted to rev it because it refused to fall over up top . Actually their bottom end had upgraded rods and pistons and a silght overbore , and the crank collar and 34 GTR pump - non V spec . Z32 and PFC . If you accept the usual plus 30 Kw for ethanol that car may have cranked out bloody nearly 300 wheel Kw which doesn't sound right for an IW GCG OP6 Hi Flow . We'll never know because that's as far as that car went . With ethanol and my dryer well who knows , could have snapped at Micks heels . One last , the exhaust . The ole 3" big ceramic cat was clean as a whistle and actually still white at one end . The old 3" bell mouth dump was actually better than it looked on the car . Can't see through the middle Nismo muffler and from looking at the huge rear one the twin internal tubes would most likely have been the issue . So yes every part of it is better except the smell , more acrid so the 200 cell Xforce isn't catalysing as well . A .

That pic raises another question Tao , is the compressor housing on your turbo a 0.70 AR T04B one ? The larger ratio B housing is one we don't see too often though I don't know why . It would have a bit more flow capacity than the 0.60AR B housing while being more compact than the T04E or T04S ones . 0.70AR B housings have larger 2.5" (63mm) outlets like 0.70 AR S ones . A .

More reasonably recent threads are popping up involving the GTX3067R . There's an ongoing one at NASIOC where STi people are testing them and comparing them to GT3076Rs and GTX3071Rs . Some claim the 10 blade X67 wheel has better aero than the 11 blade vesrions , first I've heard of that . Some are considering trying them with 0.82AR housings though most suspect more lag for small gain up high . Tial V Band housings are popular in the States and some opt for the 0.63AR ones with external gates . Some numbers mentioned are 375 wheel Hp on their pump 93 PULP and again a bit over 400 on E85 . They get excited at full boost ~ 3000 revs and with limited tuning not so much at what goes on much over 6000 revs . Not saying they hit a wall just that they probably fall off in the 6-7 area . The one that current uses love is the rapid boost transients and one feller who wanted an EFR 6758 reckoned basically why bother . Good to see more interest in this turbo because for a truly light to moderate tune car it's looking like the tits so far . Damn I wish these were out back in my FJ20 days . A .

Quite possibly , Andy gave me a full report so I got an independent review . Actually I'd like to get him to try my car once the injectors are changed and it's been back to Insight for a tune . The 76R 52T wouldn't have the same pumping capacity as an X71R but it's proving to have very smooth progressive power delivery . Who knows , maybe the cams porting valves and that 3 1/2 dump may do better than I'm guessing . In time , cheers A .

IMO these X3067Rs are more like a GT3071R or GT2835 Pro S replacement . If you download and go through the turbobygarrett catalog it shows the compressor maps . I don't think it's relevant to compare GT28 to GT30 based turbos because the hot side flow and shaft power can never be comparable . Obviously this is why a GTX2867R and GTX3067R don't perform the same . GTRS wise assuming you had the HKS turbine housing to start with a better comparison would be whichever GTX2860/63/67R had the same airflow potential . Without looking I reckon it would be the GTX2863R cause the X67 wheel flows a tad more than a 71mm 52T GT compressor . My GTRS topped out at 271 wheel wasps and 17 pounds of boost falling to 14 , and on Eflex E70 . It clearly ran out of exhaust flow and a bigger or bigger trim compressor would have done zip for it IMO . I've read too many accounts of people not liking the larger 0.86 GT28 turbine housing and they only ever had a T28 mount flange anyway . Anyhow my prediction is something like 370-400 wheel horsepower if the support systems are up to it and the tuning is right - on E70 or E85 . Pulp could pull that back maybe 50 horsepower at a guess . May take 17-20 pounds of boost but the potential is definitely there on a fighting fit engine . A .

Fitting one of those should be easier than all the other Garrett GT30 offerings because they use a smaller diameter compressor housing and a smaller inlet boss . You maybe doing this at the right time because GCG tells me that Garrett are keen to ditch their GT30/35 IW turbine housings , and the plain type four bolt outlet types may all be going V band outlet . I would go the 0.63 AR housing too on a GTX3067R because that's what Garrett generally offers standard . I would however ask for the big flap valve version if they aren't all like that now . I'm also keen to hear the results of your conversion , going GT30 takes a bit of effort but once done any future turbo upgrades are much easier . Hoping you''ll be impressed , cheers Adrian .

There are some examples of people using GTX3067Rs but not on Nissan RB engines - yet . The story is that on modern 2 + Litre fours they are cranking out a little over 400 whp and a similar number of wheel foot pounds of torque . One feller actually went from A GTX2867R to a GTX3067R and found the lag difference trivial , something like 1-200 revs he thought . Another fella with a 3SGTE went from a GT3071R to a GTX3067R and found it had a lower boost threshold , think 300 odd revs , and it made same or a little more power without the compressor surge issues GT3071Rs sometimes have . ATM it's supposition to guess what power a GTX3067R can make on an RB25 , preferably a GTt one . Garrett rate them at 500 engine horsepower so if you think your set up is fairly efficient and driveline ect losses won't exceed 100 horsepower then yes you could have 400 potential wheel horsepower (300Kw) . If you erred on the conservative side then 280+ RWKW is probably very doable on high ethanol fuels . On your numbers a GTX3067R pisses in 37 pounds min airflow at 2 pressure ratio (15 pounds) of boost and not at the bleeding edge of the compressor map either . The burning question should be how far up the rev range will this turbo boost usefully . Under that point I can't see any GT30R based turbo being better . A .

Don't forget that bigger alternators have heavier rotating parts which is why the big ones have wider pulleys . Some even have one way clutch pulleys so they don't give the engine the heavy flywheel effect when you back off change gears etc . High output alternators are big and heavy and take more engine power to drive . Yes you can overkill here . A .

Guys the idea was to keep the original RB25 block because you don't get the legal dramas and not everyone wants to go through emissions testing . AFAIK no one has run a significantly higher static compression ratio on an RB25 using E70/E85 and the extra compression pressure is what gives an engine better part throttle torque . Standard Neo turbo RB25s are 9.0 : 1 static CR from Nissans specs and same as R33s but , smaller capacity chambers with a lower plateau on their piston crowns . What they would have gotten is shorter flame paths and better quench so they could run slightly leaner mixtures , emissions , without detonation . Pretty sure they were made in the ULEV or Ultra Low Emissions era where R33s were not . I remember SK telling me that in the 93-97 (R33 era) there were changes with computers and coils and the later ones were cleaner than the earlier ones . The factory Neo revisions wouldn't have been cheap and you'd think they were forced to by tightening emissions regs . Obviously the hydraulic buckets didn't like fast lifting short duration cams and a slight shrinking of the inlet manifold and or plenum chamber gave slightly higher gas speeds for better part throttle torque . BTW my calcs show the RB26 stroke plus 1mm overbore to 87 works out to 2628cc which is 323cc short of a std RB30 . That's is about 11% . If you went 87.5 bore that's 2659cc or 293cc short , within 10% . What this says is that you can halve the capacity difference between an RB25 and an RB 30 and the only aftermarket parts needed are the pistons , aftermarket 26 pistons that is . Maybe not the cheapest option but it looks factory and if you scored the right crank takes the good oil pumps . You get to keep the piston oil squirters as well . A .

Thanks guys , the idea of mostly factory RB25 parts was to show what can be done with usually readily available and affordable parts . The welded bits are really just to do with plumbing a bolt on style turbo . Sorry my bad about Micks engine , don't know why I though it was a Neo though it gives me a bit more faith in my 33 engine . And yes fuel consumption is part of the fun since it's an ongoing cost that's always going to increase . I'm trying to get ~ 10/100 with mine atm but I really need those EV14 injectors , very next mod hopefully with doctored Neo rail . Will report when its done . Gut feeling is that fast accurate injector control will make a noticeable difference to drivability and consumption . A .

Ok this is a spin off from the low mount manifold thread and loosely based around what Mick O did with his GTt . People continue to get off on R33 and R34 GTS25Ts/GTts and more fun can be had with a few not too expensive mods along the way . I'll set the bar at a std block and rods because that weeds out RB30s and RB28s - not necessarily 26 cranks because they use the same rods as GTts . Also a 25 head because that's what you get standard . Also not limited to a factory spec 25 as in can mix any 32 33 34 long engine bits . That said most people reckon the R34 Neo spec engine is the best out of the box and made the highest factory power level of ~ 206 crank wasps . Mick got impressive power from his Neo and from memory the engine was never opened up as in factory fitted head and sump . I think it still had std cams as well . In fact engine mods may have only been injectors and the turbocharger itself . Since That engine got 330 plus wheel wasps I'd like this thread to base specs around a factory RB25 exhaust manifold , a factory inlet manifold , and IW turbochargers to make bolt ons straightforward . To make it easy for those with no fabrication skills I'd like to limit welding to a suction/inlet pipe , naturally the dump pipe and a compressor outlet elbow . Cams pistons injectors turbos fuel take your pick and lets see what you can come up with for a good all round street engine that's still nice to use for daily duties like carting mum in law around ... I'll put my ideas up for an unopened 33 spec engine and a rebuilt one if it wore out . Unopened : If you're going for 260-300 wheel wasps I reckon a GTS25T engine can use mild cam such as Tomeis a keep a quite reasonable idle . I think one of the modest bolt un GT30IW turbos are good upgrades so something like GTX3067R GT/X3071R GT3076R should work well . Injectors you are going to need and there is a choice direct fit or top feeds with collars and a different rail , aftermarket or modded GTt . Budget opened . A basic freshen up to get good bearings and ring and valve sealing . Maybe direct fit pistons though O/S OE ones should be ok . Would deck the head and or block to raise the static CR to 9.3 . Wire rings to better seal OE headgasket . Delux opened . Obviously more money here with a view to having a Neo built in an R33 block . If the parts could be found cheaply a 26 crank is going to get a few more ccs and use 26/Neo rods - optional . Regardless if intended for E70/85 I'd aim for higher compression pistons because the part throttle lower rev power would be be better . Neo inlet gets you drop in EV14 injectors and the head gets you solid buckets to take better cam profiles such as Tomei type As . Would anyone like to predict how Mick Os car would have gone with a little more capacity , say 9.6 CR and Type A Poncams ? If the budget stretched you could swap the GTX3071R for a GT3076HTA and have a pretty impressive RB25DET that looked pretty standard and kept the original block number . Floors open .

Yes it did sound good from what I was told . Dirty 30 would have made the bottom end pretty effortless overall but then again Neos aren't shabby either . When keeping the std RB25 block - nah this needs a stock block thread . A .

If you do you'll be the first with an RB25T engine AFAIK . From all I've been able to find with a 0.63 AR turbine housing it should be very similar to a HKS2835 Pro S and I'm guessing more responsive . If your intercooling exhaust and inlet tract is good I don't think 260 to 270 wheel wasps is unrealistic . A .