discopotato03

I doubt your engine would know or care which hose (top or bottom) the thermostat regulated water flow through . Production engines are designed to have water circulating around the system internally , thats to say the water pump doesn't need to draw water from the radiator as its sole supply . The thermostat is only there to regulate water based on temperature to or from the radiator . It goes like this . Earlier Nissan engines Like an L series or FJ had the thermostat at the top or water outlet so while ever the coolant was cool/cold the water pump picked up water from the blocks front jacket (timing cover actually) and pumped it through the block and up through the water passages into the head casting . At low temps the thermostat is closed so they have what I call a water pump bypass hose thats an external steel pipe and is connected to the back of the head and usually the lower part of the thermostats reservoir area . This pipe/hose is probably 19mm and feeds directly back into the pump on FJ's anyway . Where the pipe is plumbed into the back of the head rubber hoses generally duck through the fire wall to sent water from the head to the cars heater core . The return feeds post heater water to the rear of this water pump bypass hose . From this you can see that the engines coolant can do the roundies oblivious to the radiator or its hoses . When the coolant reaches a set temperature the thermostat starts to open and feed hot water to the top of the radiator which until this point is full of cold water . Cold water can then start to flow from the bottom tank of the radiator to the engines water inlet generally in the vicinity of the water pump . I can hear some of you thinking why does water flow through the thermostat/hose/rad/hose if this water pump thingy is there ? Very simply the fully open thermostat/hoses/rad pumbing is larger/higher flowing than the bypass plumbing and water like most things will take the least path of resistance . Back to RB's and the like with thermostats on the block side of the lower rad hose . If water cant flow beyond the bottom of a radiator then it can't get in the top can it ? Trust me water isn't compressible so a rad can't take in more than it can let out . Warm up process , engine heats up as per normal except that because the top water outlet and hose are in permanent communication with the radiator the water in the top tank will be at the same temperature as the water in the heads water jacket . With the thermostat down low on the block at the engines inlet virtually all of the water in the block has to reach the thermostats opening temperature before it will . Also this time round its letting post rad water into the block and pump not hottest water at the top outlet back into the top of the radiator . The RB26's post turbo water fitting is a manufacturing convienence more than anything , I doubt water from an ~ 8mm hose is going to fight its way through the flow from a what 34mm duct ? and get anywhere near the head . Before I finish - if you can source turbo water from a very low point on the bolck and feed it back into the system just beyond the main engine outlet the engine never sees (feels) heat from the turbo/s . Some people feel the need to pump water through the turbos but the thing is there is no pump driven flow once the engine stops and thats the critical time for a turbo coolant system . The bottom line is if it can't thermosiphon and the turbo/s boil off their jacket water then the system has achieve zip . It MUST be able to operate totally indipendantly or it may as well not be there at all . Cheers .

Roy if you have a HKS cast iron low mount manifold for the RB26 it will be T4 flanged so a std config GT3582R won't bolt up . ATP (US) I think were doing an open (SS) T4 flanged housing for the GT35R in I think 0.82 A/R . If it was a drag engine I'd suggest a GT4088R in its normal TS form and with a HKS or equal external gate . Actually those manifolds are supposed to have a short stub pipe that angles the WG backwards and is 3 bolt at the manifold and 4 bolt at the gates base . They also use (from memory) a 50mm valve size which is not the most common in HKS bits . If the 88R is too big then possibly a BB T4R which is P/60-1 or a T04Z but thats starting to get big again . At least there's plenty of TS T4 turbine housings to play with . Your call but I don't like the GT3082R (AKA GT3040R) , too much comp for the turbine so they tend to be laggy . Cheers A .

No that is a water - actually THE engines water outlet to the top tank of the radiator . That front water line on an RB26 is designed to take post turbo (hot) water directly to the radiator . The time it gets a workout is when the engine is shut down at operating temperature and its left up to the water in the turbos jackets to keep them cool enough not to bake the lube oil onto their shafts/bearings . Before I start here please DONT have hysterics because water boiling in a turbo is how its supposed to work . When the engine shuts down oil flow stops so the bearing temperature (bearings and bearing housing) will rise - mainly heat conducted from the turbine / turbine housing and exhaust manifold/s . IF the turbo water cooling system is designed properly it will draw coolant from lower than the turbos centres and feed it out constantly rising until it can get to the engines water outlet or header tank (eg Cosworth Sierra) . Now because RB's have the thermostat in the blocks water inlet rather that its outlet you can and should feed post turbo water to this point if at all possible - the top tank of the radiator would be better but there's no provision to do that . Now back to the turbos , coolant in their jackets begins to boil and the resulting heat and steam bubbles rises up the outlet pipe/s and via the top water outlet and hose into the top tank of the radiator . Usually the cap is at or near the highest point and it will vent these steam bubbles to the overflow tank . Fact : Cool water is denser and heavier than hot/boiling water , in a reservoir cool water sinks and hot water rises - heavy and light . Heated water rises from the turbos to be replaced by cooler water - this is call thermosyphoning and its what you cooling system does when you shut the motor off . The constant thermally driven water flow generally maintains the turbos core temp at a bit over 100 C which is not going to be hot enough long enough to do any damage . The critical thing with any cooling system is not letting steam bubbles fill an area or "trap" and displace coolant water . If you do get steam pockets you getting no localized cooling and massive temp differences with adjacent areas that do and don't have contact with the coolant . Result ? massive thermal stress and warping/cracking . People used to say that SOHC RB30's used to crack underneath the cam bearings because they have the radiator top tank lower than the engines water outlet meaning the highest point in the cooling system is not the radiator . Out of time , cheers A .

Don't forget that GTR's have the 6 throttle valve inlet system so they can and do get away with greater valve overlap without the choppy reversion characteristics . So between having virtually zero inlet communication at idle and low turbine inlet pressure from the twin parallel turbos they can get away with longer duration cams and the extra overlap to help them scavange . A Neo RB25 with its single turbo (greater average turbine inlet pressure) and single throttle plenum inlet manifold may not take very kindly to GTR cams . Your call , cheers A .

That ones a regular GT3582R with the "Farmer Brown" twin scroll turbine housing . Those housings are hard to find in the US so you won't see buckets of them either . Note in the pick that the mount flange size is T4 but the inlets are more like T4 Euro which is improperly know as twin scroll T3 . Cubes , remember how you had to port your turbine housing inlet to match your manifold ... God you people would laugh if you knew the size of the piddly dinosaur turbine thats std for that housing . As I said rumors claim Garrett will have a twin scroll GT35 1.06 A/R turbine housing available next year but don't hold your breath . Cheers a .

I was refering to the std twin switch TPS - the JECS one . Cheers A .

Hi all , I really need to know if the throttle position switches standard on L series or FJ20 are 3 wire JECS ones . I need one that turns clockwise to open and preferably has the narrow centres screw holes , some are wide out on the mounting tabs . Cheers Adrian .

You can make huge differences to an engines characteristics with better profiles and more versatile VCT . Nissan obviously thought that to run the cams they wanted non hydraulic buckets and variable rather than on/off (R33 type) was the go . Because you can then have a say in the cylinders trapping efficiency you can size the turbine housing more around wide range performance than spooling the turbo for low end torque . Cheers A .

Personally I'd just get the right sized open ended spaniard and heat it up to cherry red and bend it 90 degrees . Try to keep the bend as close as possible to the head so that the shank is not too far off the flare nuts centre in tight spaces . By any chance is that a Hitachi or non std housing on a Garrett BB cartridge ? Cheers A .

Hi Skylinecouple , just another 2c to spend - just my opinions . I would hesitate to say that exhaust flow is more important than compressor flow , IMO it is at least as important and the reason I'm guilty of thrashing the exhaust side theme is because its the part thats most often short changed . I think its entirely possible to over do things on the exhaust side and while the engine won't suffer it very likely won't get torque from boost in the rev ranges that most people use day to day . The GT3071R (-23 version) was always going to be a bit fussy in single scroll form because the turbine and compressor major diametres are reasonably close (60/71mm) and the trim sizes both sides are reasonably big . All you can really hope to do with turbine housing A/R is "tune" the exhaust gas velocity to make it spool up approximately where you need the torque from boost to start . Where this changes is when you alter an engines VE by say porting the head/larger valves/better cam profiles/manifold etc . If you can get the engine to make more low to mid range torque through breathing enhancements (breathing out in this case) you can go up a little on turbine housing A/R size so that the turbo increases performance from higher in the engines rev range . Its a pity HKS and Garrett didn't make GT30 IW turbine housings in 0.73 A/R like HKS did for some of their T28 flanged GT30 housings . You may find that 0.63 could bit a smidge small and the 0.82 a smidge big and the only real option is the 3037 Pro S IW 0.68 - hint . The burning question for you is will the 0.82 housing spin a real GT3071R fast enough early enough to make an acceptable boost threshold . If not I doubt there'd be any shortage of people wanting to buy a fresh 2nd hand IW housing from you which suits real GT3071R's/GT3076R's . Possibly with a bit of swapping going on people can experiment and end up getting what they want without buying several new housings . Cheers , A .

One would image that if there loosing blades the wheel is possibly being over sped or surging . I can't say with certainty but many found over the years that compressors with lots of blades like 71mm 8 blade T04's don't like high speed high pressure ratio use . If in that pic it was a complete blade detached from the compressor then its very likely let go at its root and rubbed on the inside of the housing . I reckon that would do all sorts of nasties balance wise and if it managed to jamb between the wheel and housing that would make itself heard . Cheers .

Yep I picked it as a 3037 , if you look at the small gaps either side of the turbine outlet that gives the game away . What I wouldn't give for the 3037 Pro S turbine housing in 0.68 A/R . If possible I'd like to see a pic looking inside the mount flange if you can shine a light through the turbine outlet . Its the shape of the volute (internal passage) and nozzle that make all the difference with most HKS turbine housings - the exception is the bored out GT28 one . The GT Pro S housings are much nicer with the gates outlet or vent path and dump pipe - what Cubes said . Good luck with it , cheers A .

Michael thats actually a HKS GT2535 . If you can find a cheap dead GT2530 (RB type) or a spare exhaust housing thats all it takes to bolt a GT2860RS on an RB six . GT2860RS/GT2530 are very similar compressor wise with the RS being the more modern of the two , both use the same identical turbine . I'm with Nismoid , off the shelf a GT2530 is difficult to beat on a 2L six . Cheers A .

No there was a single turbo version (2JZ) as well with some form of CTxx turbo .

It may be worth looking at the single 2JZGTE turbocharger . A .

Sorry , wrong non genuine turbine housing and suspect its the cropped turbine version . The Id tag must say 700177-5023 or -23 . Its results I seek not offers . Cheers A .

Its not aimed at a Nissan , my R33 has a Power FC in it . I want it for a Subie EA82T engine that uses a mechanical type dizzy with vac/pressure can sensing . It has a trap door type AFM/EFI and I can bend its signal with a Jaycar interceptor to set AFR . Later versions used hotwire AFM's and a locked optical CAS/dizzy like an FJ20 has . It would be very simple to use an ignition computer with the optical dizzy and possibly a couple of double ended coils EJ20 style . I hate MAP based aftermarket management and until they can load sense off a Hotwire AFM they can throw them all off the gap . I can live with MAP corrections for ignition control but not fueling . A second hand Haltech IG5 may be the go , cheers A .

Yes thats what I thought as well . You could get somewhere near that figure at the bleeding edge on a 2530 I'd think . A while back ATP was claiming that the real GT3071R pulled up 500-1000 revs sooner than a GT3076R though the feeling overseas is that it doesn't work like that . Most people using the 3071R in the US have them on 2L fours so the results are not the same as you'd get on a 2.5L RB 6 - particularly in a 1370 odd Kg R33 . Most people for cost reasons don't want to change their exhaust manifolds and until a twin scroll twin integral gate turbine housing becomes available (no time soon) the IW GT30 housings is all we have ATM . In the other thread someone mentioned 270 Kw at 1 bar and I was hoping they would tell me what A/R turbine housing (assuming its a GT30IW one) and confirm the -23 cartridge number . I would think if it is the real one and the propper housing type it must be a 0.63 A/R turbine housing . Given Mafias results (300 Kw from a real GT3076R 0.63 A/R) obviously the hot side can pass the gas but the burning question is can the GT30 turb/0.63 housing combination spin the 71mm GT compressor fast enough to make it feel good on a fairly std RB25 powered R33 . If we can make this work it will bridge the gap between GT28BB turbos and the GT3076R IW . If not then the only answers I know of are not going to be affordable for many people . Cheers A .

Hi Nismoid , when you say 3.5" who's exhaust is it and is this on the HR31 or the GTR ? Cheers A .

Hi all , I know Haltech used to market IG4 and IG5 ignition only computers but its seems they don't do so now because the Motorola processor was no longer available . Is anyone else selling anything like them ? Cheers A .

Thanks , I'd really like to hear from people using Garretts GT30 IW turbine housings so we can all get an idea what to expect from using the 0.63 and 0.82 A/R housings . Recently I thought I'd found a HKS GT3037 Pro S type turbine housing in 0.68 A/R but it turned out to be the 0.87 version , possibly a bit large for 2.5L and the 71mm GT compressor . Cheers A .

Hi all , many here have been wondering what sort of power characteristics Garretts GT3071R (CHRA 700177-5023) turbo gives on mechanically std RB25DET's . By standard I mean the factory exhaust manifold so that the GT30 IW turbine housings can bolt up . In another thread someone mentioned they're making 270 odd Kw at around a bar of boost with Garretts GT30 IW 0.82 A/R turbine housing . I'd very much like to know where they climb into boost engine speed wise and how it all feels with part throtle driving . Thanks in advance , cheers Adrian .

Is it possible to see a damaged turbo with the compressor housing removed ? Only problem is that the manufacturer may void any warranty if it is . From the pics so far the compressors look like 8/16 blade T04B wheels and they use fairly thick section blades . I mention this because if the wheel had a big rub and lost parts of its blades they could smash around in the snout of the housing bouncing off the leading edges of the blades . If you look at some 8/16 blade T04B wheels the vanes are pretty close together and the exducer tip hight not high like later GT series compressors . What this means is that the escape route for bits of shrapnell is not an easy one so the high speed trips around the inside of the housing could last a bit longer and do more damage . Many different things can cause a compressor to hit its housing , that GT3082R that R33 Racer sent me looks like it had an oil starvation issue long enough for the turbine end bearing to sieze up and friction weld its collar to the turbine shaft . I reckon the sudden violent decelleration made the shaft whip enough out of alignment to send the compressor blades into their housing . When I pulled it down the shaft was bent like a bannana . Very high shaft speeds and end thrust loadings are not kind to bush bearings and thrust collars/plates . Super duty use is more likely to be long term reliable with annular contact ball bearings . I have no idea why those turbos failed but the answer possibly lies with either their bearing system or the shaft loadings at high revs/boost (the turbo that is) . So as not to be O/T I'm starting new thread for those with experience of Garretts real GT3071R on RB25DET's . Cheers A .

You can buy a large frame ball bearing version of that T4 P/60-1 , its known as a "T4R" and its on ATP's site . Its cartridge is the basis of Garretts T04Z one , just with that 60-1 compressor instead of the Z's one . They were cheap when released for a big frame BB turbo . Your call but anyone who runs a GT4088R with that single scroll 0.81 A/R turbine housing , which is not a Garrrett housing but aftermarket ie PTE , hates performance and likes lag . A lot of smarts went into Garretts GT4088R and they include a twin scroll turbine housing . I think Precision actually intended that 81 housing to go on an expensive hybrid turbo they created called the GT4067R , that one is basically a GT4088R cartridge but with the T04Z's compressor and a custom backplate . They didn't exactly set the world on fire so you won't see too many . Cheers A .

Hi skylinecouple , an alternative to ATP is FullRace Motorsport in the US . Its run by Geoff Raicer and he's had lots to do with the real GT3071R and GT3076R . He's put some time into RB25's and 26's though most of what they make or sell is for Evo Lancers/Subarus/Supras because they are available in LHD . He would be able to give you a much better idea of their characteristics on an RB25 than ATP which is really just a box up and sell operation . I don't know if he offers the GT30 IW turbine housings but it would be easy to ask him via E-mail . If he's been there with a std manifold he may even be able to supply the oil and water lines . Your call but I think he's the most unbiased person to talk to about turbo systems because he's genuinely interested from a mechanical engineering point of view . If you explain up front that single scroll is all you want and need the integral gate GT30 housing he'll tell you the pros and cons of this system and the choice of turbo . Search FullRace Motorsport for the E-mail or if you can't find it lets know and I'll PM you later . Cheers A .