discopotato03

No the turbine housing wouldn't have fitted because GT2859Rs use a smaller trim version of that turbine . It might be interesting getting air plumbing onto those larger inlet bosses , cheers A .

Don't have time to search the part numbers but if you are comparing a "GT2530" to a GT2860RS in RB26 housings then yes cartridge wise the only difference is minor variations in the compressor wheels . On paper the RS is a 62 trim 60.1mm OD wheel where the 2530s is a 63 trim 60.1mm wheel . Its not just all in the inducer size and exducer tip heights will make a difference . Also I think HKS does their own turbine housings but not sure if there is any significant difference internally , both are 0.64 AR . If you want the original chico roll and can find used ones to freshen all you need is the HKS supplied turbine housings compressors and compressor housings . You could also inquire about buying the HKS spec cartridges from Garrett because sometimes they can supply HKS spec cartridges . You would have to check but from memory the cartridge number is 446179-21 . A .

1400R for my part thank you for taking the effort to try something different and showing us that there are alternarives to the old standby Z32 AFM . The potential advantages appear to be price and ease of fit once a suitable tube housing is in place . I guess the thing to look into is 80 and 90mm housings that interchange with Z32 and VH44 AFMs . The difficulty will possibly be the settings needed to interface these with common computers such as PFCs Vipecs Wolfs Haltechs etc . If you can find the necessary numbers to punch into an R33 RB25 PFC and can organise a Z32 type housing I'll consider giving it a go . I tend to think that a more modern MAF sensor should be a more accurate and reliable and anything that can give potentially better drivability emissions and economy with the old PFC would be a godsend . If its as good as it sounds it has to be cheaper and easier than an expensive computer update , cheers A . Also if settings can be known for larger bore bodies and the sensor works properly at low flow rates it starts to make the whole MAF is a restriction theory look a bit pale .

It wouldn't be my first choice , its up to you if you think the price makes it attractive . Compared to a GT3037 type GT376R its going to be bulkier with that compressor housing and possibly a bit heavier . If you were going to hold out for the real 52T version do it because of transients and a possibly a slightly lower boost threshold otherwise the 56T one may bee more readily available and possibly a bit cheaper . I'd also research the GTX3071R because they use a slightly more modern compressor and a port shrouded compressor housing . To me GTX wheels appear to be high pressure ratio wheels so probably good at making power at higher boost levels . I'd like to see a 3073 HTA on an RB25 but you have to go to GT Pumps or FP to enquire about those . I don't think any of these would be super responsive on a Cosworth YBB engine . A .

Dunno about cost but given a choice I'd run a Neo 25 if I had reason to swap motors . I think there are enough updated internals to make a difference and they will be a bit younger mileage wise - in theory . A .

I think you'll find that what they wanted to measure in a MAF sensor was ambient air temperature and from their own test development they would have had a fair idea what charge temps were anyway . In a factory std car they use protection devices to stop engines detonating and road cars generally can't legally spend a lot of time on full load . Its possibly why Nissan engines were famous for rich and retard when in danger Will Robinson mode . Obviously race cars a production homologation specials had to be able to compensate for longer periods of full load use and would have air temp sensors to allow compensations . In a MAP load based system you don't have a choice because a pressure sensor is oblivious to temperature and you need to know temperature to calculate density . To have a repeatable air to fuel ratio you need to know mass units of air so you can add mass units of fuel to to get a mass units ratio . A .

Generally late model engines warm up a lot faster than older ones , my Evo 6 warms up really quickly and its an iron block alloy headed four banger . Also remember the temperature most are seeing is the water temperature not the head block or piston temps . My RB25 is a cold cow of a thing and takes longer to heat up than I reckon it should , the temp also falls quickly on long downhill runs on cold nights . New genuine thermostat going in very soon .

I don't think it takes too long for most engines to get the chill out of their pistons , pistons don't have a real lot of thermal mass and being aluminium means they absorb combustion heat pretty quickly . Obviously the most important thing at start up is getting oil circulating everywhere and good oils lubricate pretty well even when cold . I reckon somewhere between the oil flowing properly from cold and everything expanding as it heats up uniformy enough are the important factors here . Running an engine fast from cold is obviously intended to generate enough extra heat to warm an engine up faster than it would just idling at say 9-1200 revs . The only logic I can see in this is performance if you want to drive it hard from the first turn of the wheels . As was mentioned things like gearboxes and diffs don't heat their fluids standing still . The thing to remember is that most current production cars are pretty well sorted nowdays and they start and run well . Many cars that have been played with particularly engine management wise don't run so well from cold start and can have all sorts of drivability issues . I'd say because they don't run perfectly when cold is part of the reason many petrol heads like to warm them up a bit before driving away . Anyway everyone has their own ideas but I think everyone feels better when the temp gauge climbs off its peg . IMO oil circulation is no 1 priority and what you do just after your engine fires up should probably take oil formulation and viscosity into account . Heavy grade oils won't heat or become more "fluid" as quickly as lighter grade ones so if using say a 10W60 you may need to soft pedal a bit longer than if you were using something like a 0 or 10W40 . Some engines take longer to warm up than others and if yours is like this I suggest you check and renew your coolant thermostat , I also resist the temptation to run cooler than std thermostats because a cooler running engine takes longer to get its oil up to temp . To me 76C is fine . There may be some cold start tuning strategies that help an engine generate a bit extra heat to warm up quickly , if anyone knows of any I'm all ears . A .

For quite some time you've been able to buy a ball bearing cartridge for those brand new . Search T4R 60-1 . Originally they were a Garrett turbo with a T4 P trim turbine and a T4 60-1 compressor (7/7 blade 76mm 60 trim) . T4 turbine housing and T04S 0.70 AR comp housing . The closest thing these days is probably a GT3576R . A .

Yes you do have something to prove , show me how you can properly use that turbo without breaking the law on public roads . I'd say every time you really did the authorities were not there to enforce the law . If they had it may have been a case of F$$K , no licence and impounded car . Yey . GTS25Ts and GTts have little to do with GTRs . Rs were a more limited production expensive and narrow focused car . Unique orphan in the world of production cars . The RWD Skylines were more conventional cars that almost certainly made Nissan more money at dealerships . You could argue that a factory standard GTS25T is no real ball of fire but has lots of potential , you even own or owned one . Anyway to each their own , I don't have any interest in running people on public roads .

You should probably ask GCG wich housings you use on their Hi Flow for an RB20 , I have a feeling they'll say RB20 housings . The RB20 turbine housing is slightly smaller internally so that should bring things on a bit earlier . A .

This fellas had a GCG Hi Flow a GTRS a GT3082R and GT3076R on RB25s though there were some tuning issues along the way . Anyway many areas around Sydney have reasonable grades and speed limits of 80 km/h, if you can sail up them at 2300 in 5th why wouldn't you . Crusing around at 100-110 in 5th you could throw the gearstick away because you don't need to change down with any grade I know of ie Catherin Hill down the Hume or Moonie Bridge on the Pacific . This is why in other threads I said that R33s could use slightly taller diff ratios because if they are set to make good torque at low to mid range engine revs they can pull it . If you spent all you time on expressways I reckon pulling 3.9 or even 3.7 diffs would be a snap - provided you have good usable torque in the 2300-3000 rev area . AFAIK overall gearing is exactly the same with GTS25Ts and 33GTRs and I reckon a well se up RB25 can probably make better low end torque than an RB26 and the GTS is a lighter car . These engines had different purposes but note the RB26 was designed to make power at revs more so than an RB25 . Anyway as I said I don't race and I'm not after high rev or high speed power so what I have is fine at the moment . For a road car that gets driven like a road car it works well - for me . A .

Interesting , I'm finding that being up around 18 and 22 degrees made a big difference to my cars low speed drivability though I do have to stick the wide band back in and check the mixtures because timing changes can effect AFRs . I tend to think that a reasonably well designed 4 valve engine with pent roof combustion chambers can take more low speed and light load timing because they tend to burn more efficiently and have reasonably small chamber volumes . 15 degrees isn't a lot before top dead center and if the fuel is a slow burning one like ethanol I think its possible to start the fire earlier and 18-20 degrees worked ok for me . My guess is that being around stoi (lambda 1) is where the mixtures need to be to make in burn cleanly which should help drivability - and to a degree consumption . Its always a juggle setting the fueling for steady state and accel for the transients . Mine feels about right at start/slow speeds meaning gradual throttle openings but not 100% if you open the throttle quickly in 1st gear or if you move off back off and open again . I think its to do with how and where a PFC goes from closed throttle fuel cut to injecting again . Also I probably need to stick some throttlebody cleaner in it to remove any carbon round its plate and clean out the idle bypass housing again . I'm finding with advanced timing and around stoi my engine makes good part throttle torque and I can pull higher gears in many places which helps with consumption . I think you get a lot more leeway with E70/E85 meaning it can be a bit rich or lean but unlike petrol it wont carbon the engine up or eat things as easily if its leaninish . Not sure about being lean at high loads but I don't aim to go there myself . I'll show my fuel map as well but remember that I'm using Nismo 740s and 48% in the injector correction settings . A . 1.039 1.039 1.035 1.035 1.023 1.023 1.023 1.023 1.023 1.027 1.027 1.031 1.031 1.031 1.031 1.031 1.031 1.031 1.031 1.031 1.035 1.035 1.035 1.035 1.027 1.023 1.023 1.023 1.023 1.027 1.027 1.031 1.031 1.031 1.031 1.031 1.031 1.031 1.031 1.031 1.035 1.035 1.035 1.035 1.027 1.023 1.023 1.023 1.023 1.027 1.027 1.031 1.031 1.031 1.031 1.031 1.031 1.031 1.031 1.031 1.035 1.035 1.035 1.035 1.027 1.023 1.023 1.023 1.023 1.027 1.027 1.031 1.031 1.031 1.031 1.031 1.031 1.031 1.031 1.031 1.035 1.035 1.035 1.035 1.027 1.027 1.027 1.027 1.027 1.027 1.027 1.027 1.027 1.152 1.199 1.297 1.297 1.297 1.297 1.297 1.035 1.035 1.035 1.035 1.035 1.035 1.031 1.031 1.031 1.031 1.031 1.031 1.031 1.199 1.199 1.297 1.297 1.297 1.297 1.297 1.035 1.035 1.035 1.035 1.039 1.039 1.035 1.035 1.035 1.035 1.035 1.035 1.063 1.254 1.297 1.297 1.297 1.297 1.297 1.297 1.035 1.035 1.035 1.035 1.043 1.043 1.043 1.043 1.043 1.063 1.063 1.063 1.152 1.270 1.297 1.297 1.297 1.297 1.297 1.297 1.035 1.035 1.035 1.035 1.047 1.047 1.063 1.063 1.063 1.063 1.164 1.180 1.199 1.270 1.297 1.297 1.297 1.297 1.297 1.297 1.035 1.035 1.035 1.035 1.051 1.102 1.145 1.148 1.148 1.148 1.148 1.199 1.238 1.270 1.297 1.297 1.297 1.297 1.297 1.297 1.035 1.035 1.035 1.035 1.109 1.160 1.203 1.203 1.203 1.238 1.238 1.238 1.238 1.270 1.297 1.348 1.348 1.348 1.348 1.348 1.035 1.035 1.035 1.051 1.109 1.164 1.203 1.203 1.223 1.238 1.238 1.238 1.238 1.273 1.297 1.348 1.348 1.348 1.348 1.348 1.035 1.035 1.035 1.051 1.109 1.164 1.203 1.203 1.238 1.254 1.254 1.297 1.297 1.340 1.348 1.348 1.363 1.363 1.363 1.363 1.035 1.035 1.035 1.059 1.109 1.164 1.203 1.203 1.238 1.254 1.254 1.348 1.363 1.363 1.379 1.438 1.453 1.453 1.453 1.453 1.035 1.035 1.035 1.059 1.109 1.164 1.203 1.203 1.238 1.254 1.254 1.375 1.379 1.414 1.453 1.469 1.469 1.469 1.469 1.469 1.035 1.035 1.035 1.059 1.109 1.164 1.203 1.203 1.238 1.254 1.254 1.398 1.398 1.430 1.453 1.469 1.469 1.469 1.469 1.469 1.035 1.035 1.035 1.059 1.109 1.164 1.203 1.203 1.238 1.254 1.254 1.398 1.398 1.430 1.484 1.484 1.484 1.484 1.484 1.484 1.035 1.035 1.035 1.059 1.109 1.164 1.203 1.203 1.238 1.254 1.254 1.398 1.398 1.430 1.496 1.496 1.496 1.496 1.496 1.496 1.035 1.035 1.035 1.059 1.109 1.164 1.203 1.203 1.238 1.254 1.254 1.398 1.398 1.430 1.496 1.496 1.496 1.496 1.496 1.496 1.035 1.035 1.035 1.059 1.109 1.164 1.203 1.203 1.238 1.254 1.254 1.398 1.398 1.430 1.496 1.496 1.496 1.496 1.496 1.496

yep , I'd like to see what others use in the way of numbers . A .

T04E compressor housings before the GTX era were either port shrouded or not , part numbers would relate to housings machined to suit individual compressor wheels . If you have to have one profiled to suit your compressor wheel you need a housing intended for a smaller or smaller trim comp wheel . Also the tip heights are different and it has to be taken into consideration when machined . AFAIK the GT3576 is just a GT3582R cartrudge with the compressor for a GT3076R in 56 trim . I never chased them up so I'm guessing they are the ones used in the later Typhoons ? Do the current ones crank out ~ 304 Kw ? The early XR6 GT3582R used a 0.50 AR plain snout T04E compressor housing and I can't remember if the GT3576R uses these as well . A .

Well I dunno about an RB25s strengths Lith but the people who sold them used less turbo and not a whole lot of boost or intercooler exhaust etc . I will agree that a model specific GTRS is not real big but when you compare them to the factory turbo they are not tiny either . I think you need to keep things relative meaning look at an RB30ETs turbo or the one off the single turbo four cam VG30DET . Hardly big for the engines capacity . Not too long back I was speaking to SK because my engine is very similar to how theirs was , the major difference at one stage being the GReady copy inlet manifold and they used a GCG Hi Flow in OP6 form . Also they used a 32GTR intercooler . Scott from Insight tuned that car and asked Gary how high they wanted it to go rev wise because the power was not dropping off , it kept climbing . In final form their engine had better rods and forged pistons and it cranked out 266 RWKW , it was rev limited to about 8200 . Gary said it was a great wide ranging thing and very torquey everywhere . It was raced from time to time and never warped exhaust manifolds or turbine housings , it used Shell 100 E5 till that finished and then Ultimate 98PULP . It would have gone even better on E70/E85 but we'll never know what the numbers would have been , guesses 270 with more torque everywhere . He believes the secret was the larger exhaust valves porting and the Poncams , and the 9.3ish static CR . There was at one stage a few comparisons of GTRSs and OP6 GCG Hi Flows and people who had used both claimed the performance was similar with the RS being slightly more responsive in transients . Ask Woolverine . Anyway I started this thread because at that stage I wanted a GT3076R and I was more interested in better transients and a slightly lower boost threshold if possible . I was never really happy with the GT3071Rs and HKS must have had issues with that combination and used a cropped turbine in their version . HKSs sweet spot with GT3037s is the 52T version when not looking for outright top end performance . I'm repeating myself again , if I can get better light load performance out of E70 I may still use my GT30 turbo but that means taking things to a higher level to support the GT30s gas flow requirements , pointless spending more money if what I'm currently using is good enough - for me . Lith if I had the same 266 kw and it took a 0.82 IW GT3076R to get 300 , 34 more , is it worth it ? I won't agree on your theories on fuel consumption because I believe the most torque from the least revs combined with close to chemically correct mixtures is where its at . In other words make the air pump (engine) as efficient as possible at turning chemical energy into heat energy and do so at modest revs . Most late cars except tiny boxes have moonshot gearing these days and if you can run leanish mixtures at low revs making adequate torque you will get good consumption . When you add a reasonably big turbo (compared to OE) you will get less hot side restriction but at the same time the rotating group spins slower and if thats not fast enough to make torque at cruise revs/speeds you're going back gears looking for revs to make bioost and torque . ATM I'm trying to get better than 400km/tank on Eflex E70 and I don't go everywhere like grandma . I do the speed limits and its surprising how well my car sails up some reasonably steep grades in 5th at 80 Km/h or from memory 22-2300 revs . That RS is not making much boost to do this and it has the std HKS actuator and the Apexi boost control was set to 12 pounds from the std turbo days . I can't vouch for other peoples experiences but my GTRS is not all in with a thump at 2500 and flat as a tack at 5000 , probably my inexperienced tuning but it feels strongest in the 4-5000 range and its very progressive getting there . I don't want to try driving this car flat to the boards on boost because it needs a tune on the dyno at Insight . I reckon a flat bar of boost would give it a wide enough range of compressor flow and actually I should go back and look at the map to see where the outer islands are broadest - pressure ratio wise . Anyway Lith to each their own but I'll offer this . You bring your car to Sydney and drive it in such a way that your RB25 makes decent use of its GT3076R and try and keep your licence . I don't know what you're getting away with in NZ but you don't get away with too much here in Sydney and highly likely Melbourne . If you drive an Import here and get left alone its because they know your no threat to anyones longevity . A .

I think its a case of starting the fire earlier with a slower burning fuel so the pressure rise happens when it does the most good . I reckon theres more to alcohol fuels than meets the eye and it goes away from petrol tuning practices . I'm not saying that extra advance at idle is necessarily the go but a stable ide is a good thing . I'll see if I can cut and paste part of my timing map , just don't laugh because I'm a beginner . A . 20 22 27 30 38 40 40 40 40 40 40 40 40 40 40 40 40 40 30 30 20 22 27 29 38 40 40 40 40 40 40 40 40 40 40 40 40 40 30 30 20 22 27 32 38 40 40 40 40 40 40 40 39 38 37 34 34 34 30 30 20 22 27 33 38 40 40 40 40 40 40 40 38 34 33 30 30 30 30 30 20 22 28 34 38 39 40 40 39 40 39 39 38 34 33 30 30 30 30 30 20 22 26 33 36 38 39 40 38 39 36 39 34 33 33 30 30 30 30 30 20 22 25 32 34 36 37 38 37 37 36 36 33 29 29 28 28 28 28 28 20 22 25 31 33 33 33 33 33 33 33 35 33 31 31 30 30 30 30 30 20 22 25 31 32 32 32 32 32 32 32 33 33 31 31 30 30 30 30 30 20 22 25 28 31 31 31 32 31 31 31 32 32 31 31 30 30 30 30 30 20 22 25 27 30 30 30 30 30 30 30 30 30 30 29 29 29 29 29 29 20 22 25 27 29 29 30 30 31 30 29 29 30 30 29 29 29 29 29 28 20 22 25 25 26 26 28 28 29 29 28 27 27 27 26 26 27 27 27 27 20 22 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 20 22 25 25 25 25 25 25 25 25 25 25 25 23 22 22 23 23 23 23 20 22 25 25 25 25 25 25 25 25 25 25 25 22 21 22 23 23 23 23 20 22 24 24 24 24 24 24 24 24 24 23 23 21 21 22 23 23 23 23 20 22 24 24 24 24 24 24 24 24 24 23 23 21 21 21 22 22 22 22 20 22 24 24 24 24 24 24 24 24 24 23 23 21 21 21 22 22 22 22 20 22 24 24 24 24 24 24 24 24 24 23 23 21 21 21 22 22 22 22

I wouldn't blame a turbo if you try and work it too hard , if you run it too hot thats your choice not the turbos . I'd say the reason this doesn't happen with the std Hitachi turbo is because the ceramic turbine shits itself . Many years ago RC from Garrett US said that even a GT2530 can use a 0.86 AR turbine housing and HKS was silly not to have them made in T3 flange style . It would have been better if slightly less responsive on a GTRS . They should have also done the smaller GT Pro S turbine housing in 0.73 AR rather than 0.68 because 0.73s are a good trade off size for a GT30 turbine . As has been said before the limiting factor in a GTRS is its turbine housing AR size not its turbine . If you look at turbine maps the 0.86 AR housing puts its gas flow rate closer to a GT30 UHP turbine in a proper GT30 0.63 AR turbine housing . My package has not been properly tuned yet but I don't exactly find my GTRS lightswitch like on my RB25 , not to date anyway . I was planning on going to about 1 bar because I'm chasing an all round result not a number . No I don't plan to race mines just a road car , for driving within legal speed limits it should be fine . This turbo came for reasonable money for a complete second hand kit and was intended to replace the standard ceramic turbine unit whilst not giving much if anything away . At the time I was barely driving this car enough to keep the battery charged and not sure where I was going with it . Now its a daily and for what it gets used for its turbo is fine . I have a new GT3076R 52T 0.82 AR in the box it came in and if I thought it would suit my needs I'd use it . Again as mentioned elsewhere I'm more interested in Eflex E70 tuning and if it burns cooler and proves to be significantly more detonation resistant it may give better results than those tuned on 98 PULP . Lith I know you won't agree but IMO the way a GT3076R spools on anything is a factor of turbo size , its the big trim turbine that makes them come up slowly . The thing is if you don't rev constantly past 3500 revs do these turbos do much down low ? Do you get much shove at 80ks in 4th or 100 in 5th ? I don't ratbag round the streets and touch wood I never get pulled over except for the occassional RBT . Also this mention of boost at less than full throttle , I think this is a good thing in a road car and I can only wonder what fuel consumption must be like in a car that won't boost at less than WOT . Anyway different people like different things and being a target on public roads is not what I want to be . I don't need to drag others I've nothing to prove . I spend so many hours in cars and locomotives that geting there in one piece is the no 1 priority . Today started out of Parkes with a 1730 m express freighter at ~ 2:20 and worked it through to Gunning . Then jumps in the late model Bommerdoor for the run back to Sydney and then into my car for the run home . Nothing over 120 more like 110 and now too rooted to drive anything . I don't need a 500 Hp turbo to do 120 much less the mostly 60-80 round the burbs .

No it seems I keep advancing timing in areas and it continues to get better . I know this Eflex is slow burning but how much idle and very low rev timing can an RB take ? Its idling on 22 degrees atm and the whole left ignition timing column (400 revs) is 18 degrees . I'm getting a bit braver with timing and advancing in increments the 2-5000 rev sections which are 40 degrees at the top ranging down to 25 . I don't have the wide band in all the time because the cable has to go out the window to get to the oxygen sensor . It would be better if it went through the firewall and was permanently installed . The thing I don't like doing is starting up until the probe is up to temp though its probably not such an issue with high ethanol content fuels . Anyway most of my interest currently is getting smooth running and acceptable round town consumption . I'm interested to hear what others are getting around town on a really good tune . Driven sensibly is 400 km/60L achievable ? One question and I haven't looked yet . Can you select at what revs the decel fuel cut ends because I'm having a few drivability issues when it starts fueling again at ~ 1300 revs . Lower would be better . A .

Yes an interesting combination Neo GTt engine in a 33 GTST . I wished I'd known the 33/34GTt RB25 differences because I may have gone down that road myself . Out of curiosity what was different manifold/head port wise between the two ? Also was the change to the later CAS a brand thing or are they more accurate ? A .

I reckon std replacement or a std replacement one for something that uses rubber fuel hose both sides . I cant see the point throwing money at pretty aluminium screw fittings for a road car . Its not like its being ripped apart in the pits all the time . Someone does aftermarket adjustable FPRs for Nissans and I think the SR ? one uses hose barbs both sides . Brass barb from you rail to something like this would be cheaper more stealthy and work just as well . IMO bigger injectors with a bit more pump running std fuel pressure . A .

Can't believe I started this thread nearly six years ago . It was HKS that spent the developement dollars on these GT3037S/GT3076R turbos something like 18 yrs ago . They would not have gone to the trouble of specing port shrouded compressor housings if these turbos didn't need them because they increase production costs . From memory the 4 cylinder versions for SRs CAs sometimes had plain snout T04E compressor housings and that probably had something to do with fewer larger cylinders in 2L etc fours not being as likely to have compressor surge problems . Generally turbos that have small turbine housings tend to be a bit more surge prone particularly with large compressors and especially large trim large compressors . Things like GTRSs (GT2871r-52T) also have port shrouded comp housings to stop them surging at full throttle lowish revs . There will always be some debate over conventional GT3076R-52Ts with 0.63 AR turbine housings and I still tend to think is a smidge too much turbo for the 63 housing particularly in 56T compressor form . Sadly Garrett never gave us the competition spec 30 series turbine TR30R turbine which would have been lighter and more responsive in its 73 or 76 trims . No GT30 84 trim turbine based turbo will ever be what I'd call responsive regardless of what compressor or turbine housing it has . By todays standards the GT30 turbine wheels hub is too heavy and bulky and it has arguably too many blades and 84 trim IMO is too big . They will only get off their arse and do something about it when other manufacturers start to win their sales . There is a combination I thought about after speaking to Mark at GT Pumps and that is possibly using FPs HTA73 compressor wheel on a Garrett GT30 BB cartridge . I did search to see if anyone had tried this and I tink some may have in the US . It would need carefull consideration given to its compressor housing style and turbine housing AR . HTA I did read stood for hydraulic turbine assist and may have had its grass roots in diesel turbo design . Anyway the feeling is that FPs HTA compressor and housing combinations help get these lard arse Garrett GT30 UHP turbines off their butts and up to compressor pumping speeds a little earlier . If you've followed this GT30 turbo saga you will have read about David Buschur screwing some phenominal amount of horsepower out of a Mitsy Evo engine with a "HTA3076R" . I remember thinking the torque numbers were very high as well . The HTA73 wheel may pull the power numbers down a bit with less compressor flow but the big question is how far back would the boost threshold come ? If it made "only" 400 RWHP would it be enough ? I reckon it'd be a juggle to work out turbine housing size and comp housing size to keep the hot and cold side gass flow rates in balance - and spool the thing up without comp surge reasonably early . Were the number 600-650 Hp/tq ? The hassle is trying to get the best of both worlds out of a heavy big trim turbine because you are trying to work around this turbines dated technology . If you could scale the 76 trim 53.84mm GT28 NS111 turbine exactly as it is up to 60mm major diameter it would have fewer compromises IMO . It may not support the absolute top end horsepower a GT30UHP turbine will in big or 1.06 AR turbine form but if you're shredding tyres at mid rage revs who cares . As for a stag or GTR I think its an RB30 or put up with higher rev power in its RB25/26 , power to weight ratio just isn't there for sprightly performance unless you can run a supercharger/turbocharger combination a la Lancia or VW . Close gearing would be good but an 34GTR trans with 4.4 diffs would be exy . A RWD Skyline that makes big torque at lowish revs just spins them up and goes nowhere . I can't keep my GTS25Ts rears planted with a GTRS so all a GTR30R would do is add more lag and spin them even harder . My efforts are going into Caltex Eflex to get better just engine performance and those Pilot Super Sport tyres should turn up in a few more weeks . Everyone needs traction ahead of performance because lack of traction is an expensive nowhere with more performance . A .

Sorry didn't see this thread had a second page , I think the Koyo R33s radiator is part no R020442 but not sure if its multi pass like some Koyos appear to be . Found this . R and V Series Core - Koyorad (Koyo) Racing Aluminum Radiators are available in R-Series (53mm) and V-Series (36mm) cores to provide a greater coverage for various types of engine tuning. The thickness of Core is noted by a "R" (R-series) or "V" (V-series) at the beginning of the product number. Nocolok Brazing - Each Koyorad (Koyo) Racing Aluminum Radiator has Tubes, Fins, Headers, and Brackets are brazed in a state-of-the-art Nocolok Furnace, bonding all components into an indestructible radiator. OE Specification Mounting - All Koyorad (Koyo) Racing Aluminum Radiator have fan mounts situated to OE specifications allowing for both stock and performance fans to be used. Hand-crafted Heliarc Soldering - Each Koyorad (Koyo) Racing Aluminum Radiator is TIG-welded by hand with Heliarc soldering. Heliarc soldering is the highest in industry standard for welding aluminum connections. Tube and Fin Alignment - Koyorad (Koyo) Racing Aluminum Radiators are crafted under strict quality control and solid boxing result in pristine tube and fin alignment, fresh from the factory. Mirror Finish - Koyorad (Koyo) Racing Aluminum Radiators have all aluminum surfaces buffed before boxing to a confident mirror finish. N-Flo Construction (Multi-Pass) - Koyorad (Koyo) N-Flo Racing Aluminum Radiator have strategically placed partitions make for a "N" or "U" shaped flow through the radiator. This allows for improved cooling efficiency compared to normal all-aluminum racing models. (N-Flo models are denoted by a "N" at the end of the product number) So I guess with no "N" on the end of the part number the Koyo R type Racing R33 GTR/GTS25T R020442 radiator doesn't have this multi pass business , just need a good price now . A .

I actually like the look of that Koyo in post 11 , Is that a 52mm deep twin core single pass radiator and model no is ? Theory here , mine anyway . I've had issues over the years with radiators and cooling problems and a few things are worth noting . Aluminium radiators are heaps lighter than copper brass and tend to cool better if the core is properly made . I had constant issues with the old Subaru until I found a custom made twin row core for it , which mimiced the overseas twin core auto turbo model we didn't get here . Just on this more cores (rows of tubes) are not better than 1 row of deep tubes becayse where there is gaps there cant be tube or fin area . The first row pre heats the second then third etc . Obviously multiple cores are better than a single narrow core if thats all thats available ie the old Subie . I'm not criticising others but personally my preference will always be a vertical tube radiator and single pass for one very good reasons . A multi pass core won't always thermosiphon because hot water wants to rise not fall and I'm not sure how well the multi pass works after shut down . When engines get real hot they can boil the coolant and when water boils it turns to steam bubbles . I reckon in a single pass radiator and steam bubbles will collect in the top tank and hopefully be pushed under pressure out the top tube to the overflow bottle . Ideally this is what happens with the turbos water cooling after shut down . I think the theory will multi pass rads is that each pass removes some heat but it is limited to the flow capacity of each sectioned "pass" . Truthfully I think the more tubes you have available for a given water flow rate the slower the flow speed will be in each tube and therefore the greater time spent there to reject any heat . Just my thoughts . That aside I want something that looks like a radiator and it doesn't have to be shiny only functional . I really like the look of that Koyo above because it slopes down on the top tank like the OE one next to it and I guess that means its an exact replacement - ie the std airboxes inlet fits as per normal ? Some weird ones I saw pictures of have a "stepped" section on one side and it looks really agricultural to me as not happening in my car . With this Koyo does the std fan shroud fit in exactly the same place as with the std radiator , I like things as std as possible in this area . I like Japanese made parts and I think you pay a bit more for something that does more than look the part . Thanks in advance , cheers Adrian DP03 .

I did search and surprisingly didn't find anything conclusive . Want aftermarket or even OE GTR radiator for a GTS25T . I'm not interested in cheap only effectiveness . I looked into ARC HPI Evolve Koyo and there is someone else here fabricating better radiators but can't think of their name . Things I need to know are how much core dept makes a worthwhile difference and does it get difficult mounting the std shroud on deeper cores . Also prefer the minimum number of rows as in 1 is better than 2 and 2 is better than 3 . Ages ago I bought a Koyo replacement R32 GTR radiator and it was interesting in that it had 1 deep row of tubes . I mentioned OE or equiv R33 GTR radiators because I'm guessing they had deeperer cores than the RB25 powered R33s . For the record my 96 GTS25T has its original radiator and its just about to click over 100k , those composite tanks don't last forever and I've seen them fail on other cars sometimes damaging the engine . Also I'll end up on a chassis dyno in the not too distant future and I don't want cooling issues , not that I have any ATM . I bought a genuine thermostat because my engine takes its time warming up and the temp drops on long downhill stretches in cool weather . I suspect its the original one and not seating/sealing properly when closed . Also water pump was changed with genuine at 90k with the cam belt etc . Thanks in advance , cheers A .