discopotato03

My apologies good people , due to a screw up in Garretts advertising blurb the turbo/cartridge is not what it said it was . I'm not 100% sure but I think its a BB version of their GT2252 or possibly a GT2552 . The specs don't match the maps so I'd disregard unless you have intentions of boosting the Micra . Sorry folks , cheers A .

I'm not a big fan of the HKS GT2510 , it sort of went along the lines of the turbo thinking of the time ie get a good a good turbo (ie GT2530) and make it a bit more responsive with a slightly more restrictive turbine/housing combination . Basically a 2510 is a 2530 with the 11 bladed 62T turbine instead of the latters 9 bladed 76T turbine . What HKS did later for the SR20s was a different spec "GTSS" to their RB26 version , they kept the 2530's 76T turbine but opted for a smaller trim 60mm compressor (60T vs 63T), better later thinking IMO . Hard to argue with an RB spec 2530 but there can be other ways to skin the cat . Really the critical part of that 2530 is the turbine housing , if you could find a cheap trashed 2530 with a good turbine housing you could fit that to say a GT2860RS cartridge and comp housing and your away . Modern day 2530 with HKSs custom turbine housing . Just in case people are confused with the GT25xxR and GT28xxR numbering system ... Garrett in their wisdom have finally tried to unify their numbering system and it works like this . The above mentioned turbines , 53.8mm OD 62T turbine is now called GT25 . The 53.8mm 76T one is now called GT28 . So in the current system a GT2510 would be called a GT2560R and the GT2530 a GT2860R , the problem goes back to the days of the earliest T25 to GT25 ball bearing center sections where all the T25 type conversions were called GT25BB . A . Just for the die hard propeller heads , I recently found the cartridge number for that SR20 only spec GTSS and its 446179-53 . Bloody Garrett have recently released it in an OEM looking turbo (off christ only knows what) - and they call it a GT2554R ? GT28 turbine and 60mm compressor wheel ? How the hell do you get GT25 and 54 out of that ?

I can tell what SK found on their R33 RB25 and that was that headwork really paid off , with the standard cams and turbo . At the time he told me that cams were an easier way to partly achieve what better porting and valve sizes do . Personally I would err on the conservative side with cams for a couple of reasons . First the thing gets wheeled out for a spin on the weekends so needs to be a nice drive on the street , torque where its needed most makes a much easier car to live with . Secondly these RB25's are a single throttle inlet system so unlike an RB26's individual throttle system won't cope as well with longer duration cams and reversion . Thirdly if you make the thing rev other expensive things need to be done to keep it reliable over time . Wear and tear lives at higher revs so if you can find ways to make torque at lower revs it should cut down on the wear/tear thing . Personally I would put the money into headwork even if it meant buying another head to mod and fit when convenient , cams I'd do second and turbo last . Thats what I'm doing with my R33 only the Poncams are in the head waiting to be fitted . I guess I'm lucky , I got to see Gary's progress with that RB25 and it was done in stages so it could be still used between steps . I only have one VG30 turbine housing and I wish I had two because if I did id use it with the std RB25 turbo when the head and cams go on , I want to keep mine for a Hi Flow if I go that way . My 2c , cheers A .

IMO the GT3076R is a better wheel match than a GT3082R and I think a GT3582R is a little hard to justify (for me anyway) on an internally std RB25 . For bolt on turbos the GT2835 and GT3037s are supposed to be very good but expensive . A .

The point I'm making in simple terms is that these are like a GT2530 with a 60 rather than 63T compressor wheel . What they would achieve is less exhaust restriction than RB26 GTSSs have and a bit better "spool up" than a GT2530 . IMO not everyone wants to "idle" a GTR around at 3500-4000 revs so that it goes when they stand on it . I'll compare the compressor maps with these and whatever 2860 is close to a 2530 . A . http://www.turbobygarrett.com/turbobygarre...amp;4comp_e.jpg http://www.turbobygarrett.com/turbobygarre...160-5comp_e.jpg

This one slipped in under the radar and there are a few vague details inc its name . http:www.gcg.com.au/turbo/ViewProduct.aspx?Product=197 The thing that's interesting is that it appears to use the same spec cartridge as the SR20 version of the HKS GTSS turbo . I never could find the cartridge number for that one and it looks like being 446179-5053 (446179-53 in general terms . I can't really work out why they want to call it a GT2554R since it has a GT28 turbine and a 60mm compressor wheel , in Garretts own terms it's a GT2860R 60T . You wouldn't have to look too close at this unit to realise that's its housings won't suit a single or twin turbo RB six but its cartridge could just be the basis of an in between RB26 type turbocharger . It's got a bit more turbine and compressor than a HKS GTSS (GT2859R 56t) and a slightly smaller trim compressor wheel than a HKS "GT2530" or a GT2860RS . In the right turbine and compressor housings it could make for a punchy turbo on a fairly std RB20 provided you didn't want to use moonshot revs . Cheers A .

If for whatever reason you had to use one of those Nissan/Garrett T3s I would have picked on the slightly smaller variants off a later intercooled FJ20ET or Z18ET . They had 0.48 AR turbine housings (vs 0.63) and smaller trim compressors , I think lower ratio compressor housings as well . Your calls but really the only thing that's right is the mounting flange on the turbine housing , the rest shouldn't have escaped into the 1990s let alone the noughties ... Wouldn't the youngest of the VLTs be more than 20 yrs old ? A .

The ID tag should have a cartridge number on it and from memory a HKS GT2530 cartridge number is 446179-21 . Cheers A .

Well I'd be using something native to an RB twin cam if possible because it means more factory bits should fit together , less customisation means cheaper conversion generally . I reckon a ceramic R32 era turbo is a better thing for an R31 era RB20DET if you speaking strictly factory parts . You may even find that an R33 25DETs turbo works ok but I dunno where the factory management can get you if its expecting to see a really small bush bearing turbo (NICS type thing) . I've never had one but it sounds like RB20DETs need all the help they can get in so far as getting the turbo pumping goes . Bush bearing turbos are always going to bit a bit lazy to get going (oil sheer drag) so are often small to keep the exhaust gas velocity up . You sort of get the worst of both worlds by fitting a larger bush turbo because the turbine housing (VLT T3) is larger meaning the exhause gas speed will be lower from a 2L six at lowish engine revs . Once the engine revs climb the gas speed comes up but you still have the extra oil sheer drag to overcome so you get two stages or excuses for lag so to speak . Also T3 era compressors and turbines are pretty dated now days so don't tend to work over as broad an engine speed range as current units . If you really like RB20s and R31s a later RB20 with its later turbo and engine electrics is a better way to go IMO , an RB25DET better again . A .

I think there is a lot to be said for keeping the heat in exhaust gas , basically its the thermally driven expansion that you want to evacuate the cylinders and drive the turbine/s . You have to pay for the fuel to make the heat/expansion/cylinder pressure to drive the pistons so letting the heat escape is throwing velocity energy and money away IMO . Also some people consider that the valve size ratio is wrong in big bore RB twin cams , the exhaust is said to be a little small and if 0.5mm oversize valves are available they don't go astray . I think they can be used with std modified seats as well . Increasing valve size does to a degree what changing to mild cams does but the valve train dynamics get to stay the same (aside from a little more valve innertia) . My theory is that if you make an engine more volumetrically efficient it should make more torque rather than less . If it were me I leave the cams till later because I see them as a bolt on , maybe relieve the lifter bores if big cams were on the to do list but that can be done in situ if careful . Lastly again IMO GTRs are such a PITA to get turbos etc off I'd concentrate on porting/valves/springs while its pulled down because its not cost effective to go there again to finish the job properly . I strongly believe that there are things you can only achieve with properly modified heads and bolts ons by themselves won't give the best results . Do it once , do it properly , all cake then . A .

The facts about what people call a VL Commode T3 . I've actually got the compressor wheel and housing right next to me ATM and they are not what you'd call healthy or along modern lines for a twin cam four valves per cylinder 2.5 L six . What everyone forgets about the RB30ET was its garden variety cylinder head and its soft soft soft state of tune . You don't have to throw much more air down the hole of a 3L six to make it torquier than the NA RB30E . Off the top of my head they made a whole ~ 153 Kw std , had a very mild cam , low static compression ratio and no inter cooler . Those turbos were a reasonable upgrade for early FJ20ET's which made ~ 147 Kw from 2L and four cylinders . Really the main differences between the early FJ "T3's" and VL "T3's" was the slightly larger AR comp cover and comp wheel trim , from memory the VL was 60mm 65T and the FJ 60mm 55T . What Nissan did back in the 80's was opt for Garrett small turbine series T3 cartridges and add turbine and compressor housings made by someone else , that's why the comp covers have "Nissan Motor" on the comp cover with a Nissan emblem as well . The favorite trick was to bore the small turbine series Nissan turbine housings out for larger turbines ie TB31 ones and use larger T04B compressor wheels - or the 299-4 wheel which was the Buick Grand National comp wheel . They don't work very well , the only ones that did were a small number Fred from Turbo Logic made up and they were based on the RS500 Sierras 0.63 AR turbine housing designed around TB31 turbines . You may be surprised to learn that the VL T3's comp wheel is smaller that the RB25's Hitachi wheel , you could look at is as the low tech grand pappy to the 60mm GT wheels in the GT2860R series turbos . I wouldn't bother with the VLs dinosaur , it would cost good money to get it fitted and I think you would be disappointed with the results . Ceramic turbines can be a liability but only usually if pushed beyond their limits . The first R33GTST I ever got in had more than reasonable performance and it still had its std turbo , the mods were a pipe kit and GTR IC , and a ported head with over sized exhaust valves and slightly higher CR . Cams were std and the computer was a PFC . A .

Turbine map for GT3582R/GT3540R . Yep the 1.06 is quite a jump over the 0.82 , if you can look down the passages from the mount flange side with a torch the difference is very obvious . http://www.turbobygarrett.com/turbobygarre...8-allturb_e.jpg Cheers A .

Those petrol spec GT UHP turbines (GT30 and GT35BB) have quite thin section blades particularly towards their outer extremities to help keep inertia down . This is a lot of the reason why they are easily damaged if anything goes through them . I don't know how you'd go trying to alter the profile of the blades , if you did it would probably have to be some kind of grinding operation and its probably more trouble than its worth . Older T series turbines were a lot more rigid in their blades so can possibly be attacked with a tool and cutter grinder . I always felt that you can get stuck between a rock and a hard place with those GT3040R's/GT3082R's (same thing) . They are really a GT30 hot side with an 82mm GT40 hot side and arguably the match is a bit squiff . They can be cheaper and more plentiful than either a GT3076R or a GT3582R and I could never work out why . I do know that HKS had a Garrett make a slightly different version of the GT3040R/GT3082R , their spec had the 82mm GT40 compressor in 50 rather than 56 trim so no doubt they had issues using the larger trim compressor . I guess all you can do with those two is to use smaller ratio turbine housings and if they surge modify the comp housings to have a ported shroud . Another option would be to swap someone with a GT3076R that wants your larger turbo . Cheers A .

Neither is a T25 , T25's are made by Garrett and those two are Hitachi turbos . If you look at the center sections they are basically the same and note the small hexagonal bolt head adjacent one of the water holes . Been a long time since I've had a housing off these style turbos but I'm reasonably sure that the wheels are same/V similar . Externally the turbines look identical . The RB20 one is actually the better of the two RB20 ones IMO because it has the slightly larger compressor wheel and if you look closely inside the comp housing snout you can see the anti reversion groove . My main interest in the VG30 one was its larger ratio turbine housing , this one has "OP6" on it but people say that they don't all have it . I'm hanging onto it because if I ever had the std turbo off my R33 I'd use it , may use it on a GCG Hi Flow if I go that way . IMO these would be a dog of a turbo on an RB20DET because they need some boost low down if not to feel like a low compression ratio two liter six too far up into the useful rev range . Compared to the std BB RB20 turbo the R33 25's one is a little larger in the turbine housing a quite a bit larger in the compressor housing . It is the logical next factory style turbo step for an RB20DET . I think RB25DETs are better able to cope with the large three liter OP6 type turbine housing because they have ~ 20% more capacity , higher compression ratio , more valve and port area . A .

Sorry forgot this one .

The dirtier one is the VG30BB .

Sadly no , the GT35's turbine diameter is ~ 68mm where the GT30 is around 60mm . I always wanted to know how a GT3076R with a 1.06 AR turbine housing on an RB30 DOHC would go but I can't talk Cubes into it ... A .

Does anyone know the actual valve timing numbers for these "272" cams ? I was just looking at Tighe rally Subaru cam specs recently and they were ~ 270 degrees , I think the valve timing numbers were about 25-65 67 23 . This gives an overlap of 48 degrees and not surprisingly the engines run like chaff cutters . I wouldn't expect an RB26 with numbers like these to pull hard in the lower mid range no matter what turbos it had . To make torque you have to have sufficient cylinder pressure in the relevant engine rev range and if you use longer duration cams with lots of overlap the trapping efficiency of the valves/cylinders is nowhere until the mass of the gasses carries them in the right directions . I reckon use milder profile cams and see what happens with the turbos you have . BTW -9's are the GTSS's not -7's . Turbo wise if you wanted to build bitzers from Garrett cartridges the one I'd look at is the one from the SR20 spec "GTSS" GT2860R . These have the NS111 turbine found in GT2860RS's/GT2530's etc but the compressor wheel is the 60.1mm 60T . They are intended to be a mild bolt on for an SR20 but with GTR style housings they would be just a little tamer than a 2860RS or 2530 . Three things pull the bottom end up with GTR spec GTss's/-9's compared to 2530's . Firstly their turbines are 10 bladed 62 trim where the better NS111 ones are 9 bladed 76 trim . Secondly their compressor wheels are 59.7mm 56 trim where the 2530's are 60.1mm 63 trim . Thirdly the compressor housings are T3 dimensionally where 2530s are supposed to be T04B . A . A .

I just happen to have a pair of Hitachi ceramic turbined BB turbos in the cave , one is an RB20DET one and the other is the correct VG30 single ball bearing turbo . Will take a few pics after dinner just so you can see the differences . Cheers A .

Finally available . http://www.turbobygarrett.com/turbobygarre...shi_Lancer.htm# A .

Thanks Dennis and Josh . Cheers A .

Hi all , I need to know what flow rate std hose tail type FJ turbo injectors have . I'd prefer to know from someone whos flow tested them rather than educated guesses please . If you know the resistance figure that'd be handy too . Also if Ghostrider is around I'd like to know what the turbo L28 ones were , possibly around 280cc/min . Cheers and thanks , Adrian .

You can solve this one easily , ask yourself if your trying to impress yourself or only everyone else . I believe there are limits to how often you can realistically use the extras Nissan put into GTR's , I believe they are a compromise with the legacy of being based on a homologation special . Not many "real ones" meaning M3's Evo's STi's GTR's etc make good all round road cars that suit everyone . In the real world a budget RWD RB30 DOHC Turbo Skyline is a far more useful thing all round than a GTR - IMO . I think GTRs are way too complex/expensive/bastard to work on so I wouldn't contemplate one . Aside from that a front heavy family of cars thats even more front heavy than usual is too much of a compromise 95% of the time . From memory the GTRs driveline was based on the Mercedes 4 Matic ? Maybe good for a racer but these specials don't always work when toned down for the street . Nah for me it'd have to be a Lancer Evolution 6 though god help me probably stroked to 2.4 and this and that ..... I think GTRs are just too big and heavy - front heavy to really throw around on the street , good for what they were designed for but questionable for close in agility . Your calls .

Pipercross panel elements IMO , they do them for R33 GTS25T so possibly R34 as well . Distributed through Fabre Australia . A .

Detonation damage no question . I have seen problems over the years with after market engine management systems trying to read Nissan optical crank angle sensors and I think a lot of stems from the fact that the aftermarket is using a minimul approach to adequate processing power . From what I remember the Nissan CAS does two things , it provides 4 or 6 references pulses (the inner 4 or 6 slots) to tell the ECU which cylinder is rising towards TDC on its compression stroke (in prep for power stroke) . In later CAS's they made these 6 slots different lengths so the ECU could tell which cylinder was next without buggerising around doing a count from a No1 cylinder reference pulse . I'm told the 180 (or is it 360) fine slots around the outside of the rotating disc it to indicate to the ECU rapid changes or transients in engine speed . Now to read all this in real time the box (ECU unit) has to have adequate processing power to do it without any "ghetto" count back strategies . Haltech , or Invent Engineering/EFI Technology , used to be close to me and in the early days I used an old E6A on an injected L Series four . To run the injectors group fire and with a single coil was easy , I think the L had a reluctor dizzy/CAS , PITA system . The next engine was an FJ20ET and I went to an Autronic SMC ECU , FJ's have an optical CAS/Dizzy and that created problems for the SMC possibly because with 16 bit CPU's aren't up to Motec standards (32 bit Motorolla CPU's ?) . The fix for that setup was to alter the std Nissan CAS disc so that the photo sensors outputted signals the SMC could interpret . This sounds dodgy/ghetto etc but it did work initially . The fella that made the loom removed the optical disc and , seriously , fitted a very thin metallic sticker over the outer most row of very fine slots . He then cut a small slot in the outside of the disc to correspond with the approach to no 1 cylinder . So this becomes the no 1 sync pulse and the other four inner ones tell the ECU TDC for each cylinder . I consider this a dumbing down of the CAS to suit basic budget engine management sytstems . Nissan designed their OEM system to be very accurate and that what it takes to have a tight handle on what goes on . There are (were ?) a number of places here in Australia that lazer cut new discs which fit straight into various Nissan CAS units alowing them to talk to "limited" ECU's . With the money you've been through I'd either invest in one of those or use a system capable of reading and functioning off all the std (or whatever) engine sensors . We may be infested with Power FC's here but they do work . I in no way wish to insult you but to get good results I feel you really need a capable EMS because so much hangs off what those injectors and coil drivers do . This is not in my opinion an area to economise in no matter what other people get away with . A couple of rattles and a bang is an easy way to spend lots more money than a capable black box bites you for . I haven't used them but I like the sound of the Vipec V88 or whichever one it is that can run 6 injectors sequentially and 6 coils without a waste spark system . Guilt Toy here runs the plug in version for a R33 GTS25T and doesnt have engine failures through knock . Gissmo gadget sounds great too . Your call , cheers A .