discopotato03

The 10 or 10W is not a viscosity its a cold pouring index . So 20w50 is not 20 weight oil when its cold . Synthetic oil is supposed to be quite "thin" when it's cold like very cold and this would be a huge advantage at start up . Plenty of people like the Edge 10w60 but if the 60 number scares you Mobil do a synthetic 15w50 from memory . If I was pushing a turbo engine hard and for any length of time I'd use the 10w60 too . A .

Dale we will have to agree to differ on the turbine housing A/R with GT2835 Pro S's on RB25DET's . I also once thought that the smaller 0.68 housing was what was needed to get a reasonable boost threshold on an RB25 but from talking to people who started out with the 68 and exchanged it for an 87 I think the 87 is the go . I think its all about decreasing the restriction on the exhaust side and screwing more ignition advance into it so that the engine can use its heat energy more effectively . My thinking is more along the lines of making the engine stand on it's own two feet as in not be totally useless off boost , to do this it needs to be able to run advanced timing and clean mixtures . The challenge is to be able to do it with the least exhaust system restriction while having the turbine windmilling fast enough to accelerate quickly when boost is required . Now Nissan already gives you a decent static CR in RB25DET's so if you can uncork the hot side and screw up the ign advance you should find the light throttle light load torque increase most useful . I think there's a good chance that you could use the water methanol injection (like Mafia does) to keep the timing fairly advanced as the engine climbs into boost (initially) and the torque from advance could blend in with the torque from boost as the revs climb . As per which turbo , that's going to depend on how much effort and money you wish to put into your car and how much power potential you want it to have . There's a lot to be said for the GT-RS kits simplicity and ease of fitting , against that the GT Pro turbine housing and dump pipe I think has the most potential of any GT30 integral waste gate system out there . If I could have anything it would be very likely the 3037 Pro S 68 or 87 turbine housing on a real GT3071R - with the 2835 PS's port shrouded comp cover . Anyone want to sell me a 3037 Pro S turbine housing/dump/2835 PS comp cover ? My opinions only and I'm not looking for an argument . Your calls cheers A .

Had the turbine housing A/R ratios both been 0.87 I reckon it would have been a more even test . A .

Dale my thoughts in that first quote of mine was do we set the WI up purely to supress detonation or do we go like I think Mafia has and set it up for charge cooling and the performance benefits of lower charge temperatures as well as detonation prevention . I think option 2 would be simpler and more consistant . Option 1 would involve sophisticated means of detecting the onset of detonation and then triggering the WI system - sounds more complex than its worth . My thoughts on diesels and fuel consumption came from looking at Snow Performances web site and some of their kits aimed at production NA diesel utes - American SUV's on steroids for the vertically challenged ... The idear of the higher static CR is about making the engine develop more torque off boost , the possibility of the larger A/R turbine housing is about less turbine inlet pressure/reversion/pumping losses basically less heat so more advanced ignition timing if it makes a difference . If memory serves me correctly someone mentioned once that Grp A RB26's used something like 9.4:1 CR though god only knows what rocket ship fuel they were burning . I'm sure Mafia once said that it was possible to advance his engine to the point where power went backwards so beating the rattles in a high comp turbo engine should be doable - provided water distribution was even enough and you didn't want to run 40 pounds of boost . For your average R33 punter something upwards of 260-270 engine Kw is as much as can be used (or got to the ground) so getting that output with 9.5:1 CR should be achievable . WI or any similar means of supressing detonation always involves some risk , it would be up to the user to make sure it didn't run out . Cheers A .

Yeah WI definitely food for thought . I can't decide if using say MAF or knock sensor input to suppress detonation is the go or just work along the lines of spray it in stay cool and avoid the detonation . The site mentions diesel versions used to improve overall fuel consumption and in this day and age that's not insignificant . Who knows , maybe a small nozzle for low load use and a larger one for extra volume when needed . Mafia does your car just use the one in the cross over pipe ? Cheers A . Actually something just occurred to me , I wonder how this would go in an engine built with a higher static compression ratio that you'd normally use for a turbo engine - say 9.5 to 1 . This would in theory give more low down torque possibly allowing you to use the next size larger turbine housing and have a bit less restriction in the system - more top end potential too I suppose . Thoughts ?

Hi Mafia and all , this water/alcohol thing is getting too hard to ignore isn't it . Plainly all the benefits are there in charge cooling and the ability to run sane AFR's at high loads . The thing I'd like to know is how sophisticated the control box is in injecting the water methanol mist . I can see instances where it would be an advantage to have it misting and not necessarily on boost . What would work well is having the thing regulated off the AFM's signal so that its use would be air flow based rather than manifold pressure based . Anyhow it seems to do the trick as is so I suppose the main gains would be fluid consumption , though its possible that we could run more light load (cruise) ignition advance and save some fuel as well . In the green stakes lower combustion temps possibly means lower NOx emissions with lean AFR's like 16:1 etc . Will look into this one , cheers A . Late edit They DO do a 0-5 volt MAF signal version of their stage 2 kit .

Depends where you want to go . Increasing the power in an already heavy , and front heavy at that Skyline , is going to be expensive to feed as fuel climbs towards the inevitable $2 per liter . If you want something in the lighter/nippier/more agile - and frugal class I think Evo Lancers ie E6 are a better bet . Evo's have twin scroll exhaust manifolds and turbos std from I think E4 or 5 up . Forced performance is cleaning up in the US developing better turbos based on the E9 housings and the soon to be released FP HTA Green promises to be pretty good . It will bolt onto E5-8 with E9 factory plumbing as well . To easy , A .

Garrett only make single scroll turbine housings for the GT2554R - GT3582R range . In the larger frame BB series ie T4R and GT4088R you can get twin scroll turbine housings . Your typical Skyline owner won't spend the brass on good manifolds TS turbos and external gates . The factory solution was twin parallel turbos which achieves much the same thing . A .

Hi all , I have very few old car magazines but I have a too well hidden copy of a Wheels or Motor mag with an articled called something like Hot Laps in Next Years Bathurst or Grp A winner . It has a bit of blurb about the early R32's and a short section by Jim Richards and what he thought about the road going version . Just can't find it ATM ... Cheers A .

Thanks Geoff . Cheers A .

Yep Jeff has lots of hands on experience with RB's for someone in the US . He put lots of work into that GTR engine and full driveline conversion in his S14 240 SX . He did have an R33 GTS25T at his shop for a while too . The twin scroll theme changes things markedly on the exhaust side and in the wallet area , most people here can't justify alternative exhaust manifolds and external wastegates and are more likely to use a larger engine I'd say . If you go to the turbobygarrett site you can see the compressor maps for the real GT3071R/GT3076R and they are good in their own respects . If you wanted high Hp/Kw numbers from a 71R you have to spin it faster than a 76R but in the middle pressure ratio (boost pressure) range the 71R is wider from an air flow (mass flow) perspective . I think to run the 76R to its air flow limits would require a larger diameter compressor cover set . The port shroud is an each way bet meaning it can bypass excessive air flow if the engine can't swallow it all . My understanding is that when the engine can't accept extra air that extra amount that the higher or full height blades are trying to pump goes out through the radial slot and back to the snout . So because the wheel is running in a partially unloaded state its not demanding excessive drive power from the turbine , so the turbine can spin more freely and be less of a restriction to the exhaust gasses flowing through its blades - reduced turbine inlet or backpressure . Brett Lloyd mentioned once that when the engine and compressor get beyond their surge window the radial slot can actually feed slightly more air into the wheel than would be the case if the slot wasn't there . Anyhow the GT3076R's comp map is quite reasonable , the burning question is does the GT3071R do a similar job and be more responsive by being a little less taxing on the turbines limited shaft power supply . The only way to find out is to test them back to back and tune the engines to the nth degree . Cheers A .

Well then skylinecouple would be the one with the answers as far as the larger 0.82 housing is concerned . I knw I'm comparing apples to oranges but I found the GT2860RS really nice on the FJ20ET I used to have . It really brought home to me how much you get when you crank up the ignition timing in the low areas , even at wide open throttle and low revs it makes an incredible difference . More torque to the point when you don't have to get into boost all the time just to have a little bit of squirt around town . That was always friendly as far as fuel consumption was concerned . I know what skylinecouple means when comparing a real GT3071R to a real GT3076R , a few years ago people in the US tried these 3071R's out after using GT3076R's and unless they ran the 76R to its absolute limit with large A/R turbine housings they sometimes didn't see a lot of difference between the two . Its not impossible that they didn't advance the timing up and get the lower end advantages . I would have to look at the maps/lists but I remember thinking that the maximum flow capacity of the 56 trim 71mm GT compressor was quite similar to the 76mm 52 trim GT wheel . Something else to think about when comparing the GT3071R to the GT3076R is their compressor housings . They are both T04E series but the 71R's is 0.50 A/R non port shrouded where the 76R's is 0.60 A/R and is port shrouded . Since they both use a comp end back plate (adapter ring actually) the same size the 76R effectively has less diffuser area because its OD is larger at 76.2mm rather than 71.1mm . Now technically speaking the T3 comp housing/back-plate/diffuser set was designed for a 60mm compressor wheel , T04B set designed for a 71mm OD compressor , the T04E set was designed for a 76mm OD wheel and the T04S designed for an 82mm OD wheel . When Garrett started using 60/71/76/82mm GT series compressor wheels they often went up a housing size for the same/similarly sized (OD or exducer sized) T series wheels . Examples of this are the GT2860RS (60mm wheel in housing set designed for a 71mm T series wheel) , GT3071R's (71.1mm wheel in housing set designed for a 76mm T series wheel . The GT3076R is different in that it has a 76.2mm wheel in a housing set designed for a 76mm T series wheel . You could probably put this down to it being a HKS spec cartridge and they need to be a bit space conscious for road car apps . Possibly to give its best upper end airflow the GT3076R needed a T04S comp cover and adapter ring set . In truck form these wheels are run in 0.58 A/R GT40 comp covers and they really dwarf the wheel . If anyones been following what Forced Performance has been doing in the US they'd know about the "HTA30R" with its (I think) Borg warner 7/14 blade comp wheel in a T04S comp housing set . Rambling again , long and short is that the 3071R probably has a more optimum sized compressor housing set for the size of its wheel than the 3076R does and it possibly may even out the two flow capacitys more than the size difference of the wheels suggests . Cheers A .

Dale I am interested to hear any details about a real GT3071R with a 0.82 A/R turbine housing as long as its the proper Garrett GT30 IW one . A little OT but in a vague sort of way Garrett's GT2860RS is sort of along parallel lines to the real GT3071R - turbine size/flow a little higher than usual in relation to compressor size/flow capacity . The Garrett production engineer who spec-ed the 2860RS wanted something with low and mid range punch for a Mazda Miata (MX5 here) BP1800cc DOHC 4 cylinder . BTW the engine was also free revving and not "choked" . He used the best available GT28 turbine (~54mm NS111) with a large trim (62) 60mm GT compressor . The interesting thing is that he also used housings on both sides that are reasonably large in relation to the wheels . The exhaust side housing is a 0.86 A/R GT28 where the majority of GT28's with 60mm diameter compressors use the 0.64 A/R GT28 turbine housing . The compressor end housing is a T04B family one which on the surface is big for a 60mm compressor but it certainly would make for a free flowing path inside the volute and to its outlet . Also the current trend is to use a larger diameter back-plate on the compressor end which gives a larger diameter diffuser (air path between the exducer tips of the comp wheel and the volute section of the comp housing) . This tends to show up on the comp maps as wider islands along the horizontal axis so basically the surge line and choke flow lines move further apart . A recent example of this is Mitsubishi with their Evolution 9 Lancer , the comp housing/back-plate/diffuser section is larger in diameter than the Evo 6-8 . It makes me wonder if these real GT3071R's "idle" or windmill a bit faster than some other spec turbos so do the boost and torque building thing fairly rapidly . I always reckoned that turbos like that GT2860RS thrived on the larger A/R turbine housing because its low restriction lets you run lots of light load ignition advance which really pulls up the low end torque and throttle response on many 2L fours . Its impossible for me to say what the results of a 0.82 A/R real GT3071R would be on an RB25DET which is why if anyones done it I'd really like to know . It would be easy to presume that it would react like a GT2860RS on a 2L four but there are lots of little variations that could easily shoot down that theory in the real world . Power wise you think it would be good given the compressor and housing these GT3071R's use but the make or break is always the turbine response and boost threshold . I go with the theory that removing restrictions in a production turbo engines gas paths is the way to make power - and to do so without high boost pressure . The way I see it a turbo engine on boost is making larger capacity engine exhaust flow so you have to deal with this if you want serious broad ranging torque and a reliable healthy engine . Its also why I like the idea of big enough turbines and their housings with modest compressor wheel capacity . Free flowing exhaust paths to keep the engine happy and turbine responsive + no excessive comp wheel to rob turbine response and low down engine power . Anyway looking good so far , cheers A .

Hi all , has there been any progress with these turbos and their custom dump pipes to suit the Garrett IW GT30 exhaust housing ? Cheers A .

To the moderators , is it worth having a small number example builds and graphs - sort of along the lines of what a typical Skyline owners opts for and post them up in a separeate section ? I know this overlaps with the turbo results section but just a suggestion . Might give the new punters an idea of what to expect ? A .

Judging by size/shape/colour yes . A .

Well up to you but aside from the usual freshen up like bearings and rings there is a few things you can do with it in bits . GREAT opportunity to port the cylinder head and if oversize exhaust valves are available (that can still use original modified valve seats) do that too . Forged rods and pistons do SFA for you most of the time and if you can keep the tune and temps right surprising power can be had with many OEM Nissan pistons . Thinks like cams/turbos/injectors you can throw at it any time but you can only make internal mods when the engine is stripped down . You might also look at things like the oil restrictors in the block , lighten the flywheel , maybe do a bit of die grinding either side of the bucket bores in the head if you intent to run high lift camshafts later . I guess you could also look into better rod bolts and nuts ie from ARP or whoever . Cheers A .

Yes my thoughts exactly . Its hard to imagine a turbo in the exact same location as a std R33 RB25DET using the same hardware not struggling possibly at 270-280 Kw outputs . By this I obviously mean a GCG Hi flow type set up . To go much beyond this means physically larger turbine and compressor housings and to keep them off the exhaust manifold means the turbo has to move sideways via a spacer or a turbine housing with a longer "kneck" so to speak . I don't want to pour cold water on anyones projects but I think the most practical outcome is adapting to a dimensionally same/similar range of turbos to suit a popular car/engine that covers a wide gas flow - potential horse power - range . Thats why I mentioned the two GT30R based turbos and the GT3582R . Admittedly the GT30 based ones use T04E series comp covers and the GT3582R a T04S type (larger) one . If you wanted to future proof the thing you'd space it to suit a GT3582R knowing that it would bolt up if the means arose to slip an RB30 under your current (or alt) cylinder head . This way all the plumbing and dump pipe is fitted and you know you have everything covered except minor air pipe alterations for the T04S comp cover if you upgraded to the bigger turbo at a later stage . I think do it once and do it leaving future options open , I doubt it would cost much if any more this time but down the track very probably if you go further . Cheers A .

Trooper I think that if Garrett Sydney want to generate some interest they are going to have to show what they're offering or it all remains a mystery , and many perceive mystery to be risk . I know there is also risk involved with copying and undercutting but once there are a few sets in circulation the cats out anyway . I'm mildly curious to see what they've come up with but it would have to be something pretty effective and convienent to separate me from my money . Over to you , cheers A .

Trooper ages ago when I asked your contact he said it had a sleeve pressed into its turbine housing which was re-profiled to suit the cropped GT30 UHP turbine . At that stage the proper Garrett petrol spec GT30 IW T3 flanged turbine housings had been not been released so at times less than perfect alternatives were being used . He did quote its Garrett BB CHRA number and I don't recall which one it was other than it had the cropped turbine . The real GT3071R can be bought or I should say ordered with the designed by Garrett GT30 turbine housing and you'll know its a complete factory matching assembly . Not machined or altered in any way other than its original design parameters . To make a real IW GT3071R kit for an RB20/25 is straightforward . The water and oil fittings are the same for any GT BB Garrett turbo from GT2554R up to GT3582R because they all use the same bearing housing . One you have the spacer and fasteners to get the compressor housing off the exhaust manifold all that's left is the air in/out plumbing and the exhaust outlet pipe . I'm surprised that at this stage no ones made jigs and produced dump pipes to mate a GT30 IW turbine housing to an R33's engine pipe . The genuine GT3582R IW turbine housing uses the same outlet flange dimensions so such a dump pipe could easily cover the whole GT30R/GT35R range meaning the real GT3071R , the real GT3076R and the GT3582R . You could buy it once and know it suits turbos from ~ 420 - 650 horsepower plus and bolts straight onto an R33 RB25DET with any of these turbos . Anyhow Trooper I don't know if the turbo you are talking about is the same as the one you had when we last spoke but if it is there are issues with non factory turbo components if they need to be replaced at short notice . One down side is that it chains you to the mob who produced it and if you fall out with them or can't reach them its a bad outlook . To each their own , I'm waiting for the results of the real GT3071R with the genuine Garrett GT30 IW 0.63 A/R turbine housing on an R33 RB25DET . As an all rounder for your typical R33 driver I think it should be pretty good . Time will tell , my opinions only cheers A .

Yes , the turbine trim should be 76 rather than 62 and yes they are just like a GT2871R till you get to the compressor end . How much practical power were you after ?

Your call but your not going to fix that thing with housing alterations , the only genuine option is a larger .86 A/R turbine housing and that will only give it more turbine lag . The problem is it has a modern low blade count light weight 54mm diameter turbine trying to drive a dinosaur 76mm T04S compressor wheel . Changing housings won't alter the fact that its compressor is a really bad match for its turbine . Why Garrett continue to sell those POS things I'll never know . IMO it has to go if you want you car to be lots better . Sorry , A .

Hi Lithium , yep been keeping distant tabs on what FP have been turning out . I haven't open that link yep but from what I've read . Forced Performance have been experimenting with alternative compressors to see what they can do with GT30R and GT35R turbochargers . I'd say they are well aware of the twin scroll system and its advantages but you don't have to be Einstein to realise the money involved with non std manifolds and external waste gates . Its usually easier to make comp/housing alterations to a turbocharger but some certain characteristics will always be tied to the turbine/housing end because this is what powers the compressor wheel . My personal opinion is that healthy sized wheels and modest trims do the trick and that the turbine and its housing are the most difficult and expensive to get right . I believe the man at FP doing the work is Robert Young and he's also been cooking up hybrids for Mitsy and Subaru IHI hi flow turbos . It has been suggested to me (not by Robert) that FP could be using Borg Warner 7/14 blade compressors and port shrouded compressor housings to get similar or better boost threshold out of GT35R/GT30R Garrett turbos with a little more top end flow and power . Actually stateside they have been playing with BW turbos a few different hybrid things . Its interesting that BW turbos are mostly twin scroll and bush/plate bearing which makes sense as often the exhaust end end float is greatest and hardest on the thrust bearing . Also don't for one minute think that I have a venomous hate of all 7/14 blade compressor wheels . I don't think much of the T04S or any T series wheel really because they have old dinosaur blade forms compared to GT and other similar era designs . Garrett also use more modern 7/14 blade compressors on some of their more recent types such as the GT4088R and GT3782R 50T , these are their C117 family wheels and look very much like a 6/12 blade GT or BCI/BCCW series GT wheel with an extra pair of blades . In both cases the trim size is not big at 52 and 50 and the maps look pretty good compared to some out there . Note their turbine trims are both 78 instead of the typical largish 84T used in many GT turbos . Anyway back to the FP , they are selling a HTA version of the GT35R (HTA35R) and more recently a HTA30R as well . Rumor has it that they will be doing a HTA version of their FP Evo Green IHI turbo which is basically a reverse rotation Evo ( turbo with the Trust spec TD05H SL2 turbine and FP's exclusive 5 blade 20G compressor . I think the Subaru std rotation version may already be in circulation . Those interested should look at the NASIOC and Evolutionm.net sites . The grape vine shakes with news of a HTA T04Z and also a HTA42R . I doubt they'l bother with a HTA40R .... Lastly it looks like FP are probably making what looks like the most successful TO4S 0.70 A/R port shrouded comp housing based on Garrett's non shrouded housing (std on GT3582R) . Both the HTA30R and HTA35R look like they use these modified comp housings . David Burshur in the US reckons that the HTA35R spools noticeably earlier than a std Garrett GT3582R , note that they often use non GT turbine housings on them possibly because the real ones are more expensive and sometimes in short supply . Also the GT non gated housings have a larger conical outlet and would be a bit more trouble to package on a transverse engined Evo 4G63 app . Where people neeed to to be careful is looking for any excuse to run a turbo thats larger than necessary , it may be nice to spool a big turbo a little earlier but if its top end capacity is way above whats required its pretty pointless . A GT3582R is getting quite serious on a 2L twin cam 4 like a 4G63T but there are people who want to run them on the street for reasons best known to themselves . Matter of opinion but Evos have close and short gearing but it still wouldn't suit everyone . Cheers , A .

By the cartridge number (700177-5003) its the right one for a "GT2835" Pro S . If you look inside the turbine housings inlet flange (mounting flange) it may have a number cast into it just inside . If it does it'll say something like 0.68 or 0.87 which is the A/R size . Cheers A .

If that's an RB20 I'd say its going to be real laggy mainly because of the big heavy T04 turbine it looks like it has . For RB20's I think you can do better with the std exhaust manifold and a more modern turbocharger . A .