discopotato03

Um , I'm not going to agree on your dynamic CR ideas but thats going to go a little OT and really deserves another thread . Cheers A .

Still looking for a Trust Turn Flow intercooler to suit an R33 GTS25T . Cheers Adrian .

Just to complete the story are the R34 Neo turbo and NA head castings basically the same . Cheers A .

The issue is that they are not a good wheel match and personally I don't think its possible to work around it , not enough latitude to correct a poorly thought out unit . The concern for me would be that RB20's are not a mountain of torque at round town revs and not getting much help from the turbo till (guesses 4000 + revs) would be disapointing . You may be able to find another turbo and get more suitable bits from a combination of the two but than can be an expensive way to go about it . Really all thats suitable in a GT2876R is the turbine wheel/shaft because the turbine housing won't fit and the compressor and its housing are too big . Thye bearing housings front face will have been machined to take a 76mm wheel so even if you had a 60 or 71mm compressor fitted you get a step outwards from the wheel . As a minimum it would need a smaller compressor and housing and a balance all assuming the bearings and seals are good . Hard to have a win with those GT2876Rs , cheers A .

GT2876R , imagine an obsolete HKS spec GT2540 (GT2876R really) with an older tech compressor wheel in a larger trim ie 48T vs 46T and thats what 2876Rs are . "2540s" were never known to be responsive things and were just a step in the wrong direction in the early days of Garretts BB turbos . Both 2510s and 2540s are no longer available and were replaced by SR20 spec GTSSs and SR or RB spec GTRSs . A .

I think the thing to realise is that opening and closing , valve timing , is related to how the cams are timed when fitted . You can have a pair of std cams set to have a lot of overlap or long cams with SFA overlap . Its how the cams are set in relation to each other and where the pistons are in the cycle . If someone with the same cams as you have can tell you where to set their timing and you can degree the crank with the cams their should not be any dramas , always assuming your engine is in good nick . A .

From what I read more current engines cope better with lean cruise mixtures and a number of things have changed to cater for it . EGR was always an effective way of running lean mixtures without excessive combustion temps but not used on RBs I believe . Cylinder heads have changed in the cooling jackets to pull a bit more heat out from around the hot side of the chambers and exhaust ports and in some cases the spark plug bosses . This is not so much to just cool the engine its more to do with localised hot spots that can at times promote detonation . With the GTt version of the RB25DET I suspect Nissan sought ways to run a little leaner at idle and light loads for emissions and consumption . The above mentioned cooling difference sometimes allow a designer to have more advanced ignition timing with lean mixtures and its possible the chamber and piston crown differences in the GTts all help in this area . Maybe except for the std mapping the last version of the RB25DET is probably the best spec one to have given a choice . A .

GT3582Rs don't like being pushed too hard because they have big frame/shaft sized wheels in a small frame/shaft sized cartridge . Garrett do make large frame ball bearing GT3576R and GT3582Rs as OE diesel spec turbos for Hino Isuzu etc but I'm not sure if the 6 year exclusive rights thing is up yet and they use larger GT40 family housings both sides - and the larger T4 International sized mounting flange . As has been mentioned the large framed GT37BBs are probably good things for high outputs and you can look at them as a slightly smaller brother to the GT4088R . With the BB37s you have three compressor options and from memory the mid sized one uses the same 82mm 56T wheel as the GT3582R , only this time the cartridge is larger longer with a bigger shaft and bearing section . Also from memory these larger frame units use a threaded bore compressor wheel rather than a plain bore and jamb nut . The big frame units are beefier all round and pretty much push you towards that larger T4I flange and preferably twin scroll turbine housings . Some even have twin integral wastegates , cheers A .

Thats what I thought too , I just put the numbers up to cover the GT30 family of turbines . A .

Busy training with air for other purposes today . A std BB type GT30 turbine measures around 59.9 by 54.9mm inducer and exducer . The cropped ones from memory are 56.4 by 51.6mm (84 TRIM) OR 56.4 by 53.6mm (90 trim) . Your calls , my preference is for Garrett or HKS GT30 "T3" flanged GT30 turbine housings . The HKS GT Pro S ones need a bit more work to make the dump pipe and if you particularly wanted one of their different A/R ratios its probably worth it . I'm not sure what size because there isn't a lot of feedback with these GTX compressor wheels . A .

Mr Mafia did you ending up finding out the details of that alternator ? Cheers A .

Well Lithium the person to ask would be the one who walked the talk and how he felt his car performed based on his expectations and other cars . By the sounds of things he would have been in other cars quite possibly using these turbos with the 0.82 turbine housings and I think he even mentioned evaluating them at some stage . When I say my GT3076R I mean the brand new one I bought a few years back thats still in its box . I ended up buying a good second hand GTRS kit from Woolverine because my goals changed after I started owning AWD cars . It became very obvious that theres limited power you can get to the ground through two wheels and particularly when they are at the back end of a front heavy car . You have to buy something a bit better thought out than a 90s era Skyline to get 50/50 weight distribution and even then only half the weights sitting on its driving wheels . That aside I'm sure with a reasonable intercooler and good tuning my GTS25T will spin its drivers even more so than it originally did but its part throttle performance should be a lot better than the ceramic turbo had , I hope so anyway . Now I don't have any roads I can legally do more than 80 on within 20-25 minutes of where I live and most of those don't take me anywhere I generally go . So for me I don't have the need for a 300 Kw turbo and particularly one thats a bit useless under 3000-3200 revs , and probably more so in 1st and 2nd gears . I'm not aiming very high and if I end up with 240-250 RWKW that will be plenty and still more than a grands worth of Michelin rubber can hold anyway . I like good turbo response because its available 80% of your driving time rather than 30% but again that comes back to how and where you drive your car . The thing I see too often Lithium is people here and elsewhere using more turbo than they should because they fell in love with a power number . They think they can have std turbo/engine performance ie no loss anywhere but extend the power range and numbers upwards . With a larger single scroll dryer thats very often not the case and while its fun booting it around it can be weak when just soft pedaling about . I'm different and my ideas have changed over the years , I don't accept the compromises I would have 20 years ago . I'm conservative with turbochargers because at times they need to be a minimulist device rather that an unknown maximum one . My goal is a usefull torque band rather than extended rev ranges trying to reach or beat a power number . I'll keep that GT3076R just in case the dirty 30 ever eventuates and it would probably work quite well with its 0.82 turbine housing . Anyway this is only my opinion so take it as you will . A .

I don't think it was so much a band aid as making a given engine pull lower down without detonating on less than high octane pump fuel . From memory Mr Mafia couldn't get 98 or the then available elswhere 100 octane Shell pump fuel so he went with the WMI to supress detonation on possibly 96 octane fuel . A .

Look , everyone has their own ideas about turbine lag and boost threshold but there are a few factors that come into play . Firstly the compressor wheels and housings on these GT3037 family turbochargers . There were originally three compress trim options (48T/52T/56T) and two comp housing styles . The 48T compressor trim version was discontinued and the 52 and 56T ones are still available . The one you see mostly is the 56T version which became the defacto std through Garrett . This is not to say it's necessarily the best but it is the largest compressor capacity version made with a GT37 series wheel . I think to get the best/most out of it also means using the largest available 1.06 A/R GT30 turbine housing though no one seems to be brave enough to do that . Most have the idea that if they're going to use that 1.06 housing they want a GT3582R in it which is strange considering that 3582Rs use bored out GT30 turbine housings . All that research I put into GT3076Rs a few years ago pointed to a 52 compressor trim version and yes mine has an 82 turbine housing on it as well but I think it would work better for me with the 63 turbine housing . From memory HKS called the port shrouded version of the GT3037 "S" and had these comp housings available for the 52 and 56 comp trim versions . I'm just looking at my old HKS lists and it shows the std versions having 0.61/0.73/0.87 A/R turbine housings for the 48/52/56 comp trim units , in other words small/med/large housings on small/ medium/large comp trim units . For the GT3037S versions they show 1.01 and 1.12 AR turbine housings on the 52 and 56 comp trim S versions . Personally I think the 52T version is a better all rounder on a road car and to me what happens under 3000 revs is not insignificant . Its not so much that I'd want huge WOT pull under 3000 but I like road cars to have a bit of part throttle squirt as well as WOT stuff . I also don't like going up the rev range for no other reasaon than theres little or no boost when I'd like a bit of part throttle torque . Again I stress in a road car because once you track them and bias performance towards track use its getting away from whats nice on public roads and particularly in built up areas . Std road cars have , generally , tallish gearing which works well with lowish boost thresholds that OE turbo systems generally have . When the boost threshold goes up significantly I find the engine struggles to make enough torque to pull the tall gearing well and it all feels wishy washy buzzing the revs in a lower gear just in case you want some easy grunt . I'm old enough to realise that most won't get away with going too hard too often on the street so for me its pointless building high rev performance into a road car that can legally only be driven at 110 km/h max . To me some part throttle performance is essential if your going to get any shove in the back even accelerating to 80 km/h . Any way if I were buying a GT3078R now it would be the 52T version (700382-10/cartridge 700177-6) and take you pick of the 0.82 or 0.63 A/R turbine housings . Provided it makes controllable torque and spins freely enough it should go like a cut snake . If its pulling like buggery at 170+ what use is that to you on the steet ? If it boosts and pulls from 2700 that's real usefull on the street because you spend a lot of time down in that area . If your lucky E70 or E85 is available and would save you the trouble of water methanol injection so detonation shouldn't be a biggy . Anyway people have to make their own call . A .

Yes as Mr Mafia said get the real one which was and still is a HKS spec turbo , only sold through Garrett as well . The real ones Garrett part number is 700382-10 using cartridge number 700177-7 . Do it once do it right and think seriously about what he said about the 0.63 A/R turbine housing if lag troubles you at all . A .

It's your call but IMO for the expense/effort involved in removing and replacing RB26 twins , and rebuilding bush bearing cartridges , I'd prefer new ball bearing units . Perhaps you could enquire about buying cartridges used in the 707160-9/GTSS turbos but when I did a few years back they were not available as cartridges only . Off the top of my head R34 BB turbos are a GT2556R and while they may be rebuildable with steel turbines I think the best direct replacement is the -9/GTSS because they are an RB26 specific turbo rather than some generic variant . Yes they cost a bit of cash but imagine what it would cost to remove and replace rebuilt plain bearing turbos again if you damaged one . The bottom line is that well designed ball bearing cartridges are a lot more reliable long term if they are not abused and the engine serviced properly . RB26 twins are a major PITA to work on/around so you want to minimise the need to R/R them unless you are rich/someone else is doing the spannering/it's not a daily driven car . Do it once do it right . A .

Thinking back I should have ordered the 0.63 A/R turbine housing on my 76R ad if I can I'll probably exchange it . As Mr Mafia showed they make pretty good torque on an RB25 and seem to have really good response for a GT30 based IW turbocharger . A .

Foreced Performance is starting to release ball bearing versions of their "stock frame" turbochargers for the Evo 4-9 engines . This may not be real interesting here at SAu but its possible that they may do clockwise rotation versions for other applications . To me this is interesting because some Mitsubishi turbines in the TD06 range are better things than the one GT30 that Garrett have kept serving up since the early 1990s . Just something to keep an eye out for , cheers A .

You are actually very close on airflow with the GTX3076R and a 56T GT3040R like you have . It's also interesting to compare the compressor maps of the GTX3071R and the original GT3076R 56T , the 71X has very slightly higher ie 1% adiabatic efficiency but the original 76Rs center island is fractionaly wider and a tad to the left of the Xs . I compared these along the 2 bar line , remember this means absolute pressure so 2 bar here is 1 bar above sea level air pressure , because 15 pounds is not an unrealistic number for starters . Sorry to be a grinch but these GTX compressors don't look that good on paper to me especially in the T04E and T04S compressor housings . I think the 52 or 56 trim GT37 (76.2mm) compressor is comparable to the GTX71 and as Andrew said its debatable if the GT30 compressor is adequate to drive the GTX76 compressor wheel given it looks to flow similar numbers to the 82mm 56T GT40 compressor wheel . I wouldn't even bother to look at a GTX3582R because the T04S compressor housing is a bit limiting even for the 82mm GT40 compressor wheels air flow capability . The high points of the Xs seem to be high pressure ratio (boost) efficiency but over a relatively narrow range , and also they're supposed to be quieter in port shrouded compressor housings . I suspect that they would work better in larger comp housings and with larger turbines in diesel applications . A .

Yes always the same debate over the gap in Garretts turbine range - meaning GT28 to GT30 and theres little feedback on the GTXs so far . Theres also been uncertainty from those using the original GT3071Rs with some thinking in 0.63 A/R turbine housing form doesn't deliver while the 0.82 T housings seems a little laggy . As Mr Woolaf mentioned the Mafia had some good times from his GT3076R/0.63 A/R turbine housing though he did use water injection to keep temps in check . If I was going to use a GT30 based turbo on a street RB25DET I'd look for the mid or 52 compressor trim version of the GT3037S/GT3076R (same thing) and put the 0.63 A/R Garrett GT30 integral (internal) wastegate turbine housing on it . The 52T GT compressor is good for I think 90% of the 56T versions airflow and has a better comp map IMO . These like the 56T version have port shrouded compressor housings on them which removes ALL the surge issues people can have with responsive while powerfull turbochargers . My take is that if turbo (turbine actually) lag bothers you , at all , use the 0.63 A/R turbine housing because thats whats going to bring the thing on reasonably early so you get to enjoy you car/engine without having to rev the tits off it all the time . At the end of the day if you can turn and burn the tyres almost at will it doesn't matter how many killerwasps the dyno counts because you have more power/torque than traction anyway . I have a 52T GT3076R in 0.82 IW form I bought a few years ago and I think GCG and possibly Garrett here in Sydney keep them in stock these days . I'm not so sure you'd get any great discounting from either of them but sometimes when you want things a little less mainstream you cop a premium . You would have to call and ask for pricing . I'm only keeping mine in case I built a dirty 30 though I have no immediate plans for that . Personally I would not limit myself to the std dump pipe configuration with a GT30 based turbocharger , they work well for GT28 based turbos or those using the VG30 OP6 turbine housing but they lack flow potential for a 500 Hp capable turbine like the GT30 one . Its not the end of the world to buy or make a dump pipe for the IW GT30 turbine housings and the easiest ones are the open or bell mouthed ones . Being a bit bigger in the turbo flange means its probably a lot less fiddly that doing the RB or even the T28 style ones . I'm not that keen on the store bought divorced ones for these housings because some mobs cheap out by trying to hole saw two holes through the turbo flange and the gates outlet is the wrong shape and the pipe small . I think to make a divorced one properly means making what some call a "shell back" something like the HKS GT Pro S ones or the Megan Racing ones for Evos . Its a lot more work for something that may work if NASA frigged around with it for a week with lots of flow bench testing , $300,000 dollars later ... Bellmouth is simple easy and works well enough IMO . Anyway this is what I'd do for a road RB25 where power and response is the requirement . You read here all the time about people who went with big turbine housings or bigger turbos looking for the big top end power numbers but they hate how their car now drives . Sure it makes the numbers but buzzing the engine everywhere in low gears so the thing gets going when they prod it gets REALLY boring REALLY quickly . What I think the vast majority want is more poke starting not much if any higher than what the car had originally and it can be done if they think a bit conservatively . If you can live with 260 Kw maybe a GCG Hi Flow or a HKS GTRS is enough and it sounds like both would be more responsive that just about any GT30 based turbo . If anyone you know has these can you go for a spin with them ? Also I know others do good Hi Flows but its hard to impossible to beat the reliability of ball bearing centre sections , if you're going to work a turbo hard a properly designed ball bearing centre section stands up to radial and end thrust loads better and with less friction . I'm in now way insulting plain bearing Hi Flows but people have to understand that plain bearings are less costly than small high temp and speed capable ball bearings so its a costing issue . If the price was the same no one would sell plain bearing turbos , its the extra for BB ones that some cannot afford and we all have to live within our means . My 2 cents , cheers A .

Yes I wonder too , I'm still looking for one of these by the way . Anyone open to handsome bribes ? Cheers A .

Yes thats what I'd do , and if I wanted it to rev I'd use the 1.06 A/R Garrett GT30 turbine housing as well . A .

Yes they have a 76mm 46 trim T04E compressor wheel which is a bit much for the GT28 turbine , it will work but not "spool" as well as some of the other compressor wheel options . HKS replaced it with the GT2871R 52 trim and with their housings call it GTRS . AFAIK they both use the same HKS turbine housing which can take any Garrett cartridge using the GT28 NS111 turbine . So , GT2860RS/"GT2530"/GT2871R 48 62 56T and the HKS "GT2535" . A .

Yes but no to 500 . Personally I would opt for the GT3076R on an RB25DET , it would stand a better chance of making controllable power IMO in a 2/RWD car . GT3582Rs are a factory hybrid using a GT30 turbine housing and a T04S comp housing over a GT35 turbine and a GT40 compressor wheel . If I was going to have an exhaust manifold made it would be flanged to match the Evo 10 upgrade GT3076R , that way you get a Garrett made twin scroll twin integral gate GT30 turbine housing in 0.73 or 0.96 AR ratios . A .

Your call but but I hate the idea of V6 engines with one turbocharger , such a PITA to route the exhaust of two banks into one hairdryer . Done properly they should have one per bank though this has packaging issues as well . I'd opt for the RB26DETT version because there is so much aftermarket stuff for them and they are a known quantity . From a parts and labour perspective an inline engine has one head and one pair of cams to drive meaning its fairly straightforward . On a V bank engine theres two of everything meaning two heads four cams two lots of exhausts yadda yadda . Just my thoughts , cheers A .