discopotato03

I've followed both strings on this mod , anyone have any idea why SK can get it to work and most others can't . What are the potential problems aside from bent cams/incorrect cam and CAS timing/cam journal cap bolts . In other words if the cams are exchanged with no dramas and the timing/s are the same its difficult to understand the idle problem . Nissan must have had the multi throttle system in mind with its anti reversion properties when they developed the RB26 profiles which would allow greater overlap period without the rough low speed / idle problems . I would have thought opening up the cams (reducing the overlap) would have got an acceptable idle ie enough trapping efficiency always assuming the valves closed . I guess a bit of reversion at the AFM could cause problems , does SK do anything different to all else here . Would larger capacity inlet ducting/MAF/IC/better filter make any difference . Cheers A .

Yes homologation papers like to be specific , there was some controversy over the DJ RS500 turbos which had some "alterations" to the compressor . The scrutineers could see the difference but the measurements fit the specs . Higher spec steel alloys are used for turbines that see prolonged use on petrol engines to cope with higher exhaust gas temperatures . Cheers A .

Can someone tell me the difference between the normal HKS GT2530 and the Kai or Kansai edition - search did not find much . Thanks A .

Hi peoples , I did some sniffing around and it seems that Garretts GT40R and 42R are similar deal to HKS's T04R's and T51R's . For the juicy pics search GT40R Pictures and look at the two image search pages . Then drop down to the 9th site (FresnoRacing etc) for some pics comparing GT40R and T78 . With a bit of searching there may be a twin entry T3 flange with suitable ARR housing to make it fit . These turbos are getting really big (huge) so maybe twins are not so bad after all . Note the 40R and 42R use threaded bore compressors rather than a nut . Cheers A .

Wash my mouth out but the HKS GT2535 may be a good alternative because of its 69mm compressor wheel . I can't find this wheel in any Garrett marketed item - yet ......... Its interesting that it uses a T3 comp cover as well . Cheers A .

Guys I was thinking about some of this stuff but what is the real world cost of GTS4 with the GTR diffs/gearbox .

I remember searching somewhere in US sites for Garrett GT42R's and finding some mob that does custom housings for GT42R cartridges to recreate the HKS T51R's (KAI/SPL?) . Now that some of these monsters (GT40R's and GT42R's) are available with ball bearing cartridges they no doubt will wind up on RB's , but with more conventional mounting flanges than the HKS T51R's with there specific V band mounts to suit their exclu er expensive manifolds . For what big turbos cost I would not be without the ball bearinga either , the oil shear resistance on big shafts is considerable so bushes ? no way . Again what Arnie said , cheers A .

AntonRX7 , do a search on 471182-0007 . The first site shows a table of Ray Halls medium frame Garrett TB03/T31/TA34 turbos . At the second site (not in english) if you scroll down a bit there's a couple of decent pics of the 471182-0007 turbo that Fred reckons works well on RB20DET's . T3 flange , integral gate , 40 trim T04E compressor in .50 E housing . Turbine housing is .58 and even has a V-band exhaust outlet on it . I know the one you saw has the large 57 trim compressor but don't forget that these are 3" or 76mm compressor wheels and its all too easy to go too big and create lag monsters which RB20's don't like . Look at FATGTS-R's pics of the compressor side , that's no huge trim wheel either . Nissan and Garrett would have had their heads together to spec the turbo for a limited production homologation special car (R31 GTS-R) so its worth a close look . Personally I prefer more modern Garrett GT Ball Bearing turbos but finding something with a properly designed integral wastegate T3 flanged exhaust housing is difficult and expensive . At least that TB31 has no hard to get bits and would be cheap to service . Let us know how it goes cheers A .

FATGTS-R it looks like a T04E compressor side with the Nissan type T3 integral exhaust housing - nice manifolds those GTS-R's . The turbo could probably be recreated without too much trouble depending on wheels and trims . cheers A .

There's nothing remarkable about any of that . 57 trim 76mm T04E compressor in .60 ARR T04E cover . Stage 5 turbine also known as a T350 in Inconel and 5 bolt .48ARR T3 turbine housing . This thing would be pretty laggy on an RB20 . Fred from Turbo Logic once showed me a Garrett factory hybrid T3/T04E (TA34 series in Garrett speak) which the RB20 followers in the Gong like . It used a T3 turbine in an integral gate T3 flanged .58ARR housing with a 40 trim T04E compressor in .50 ARR cover . Do a search on Garrett T31/TA34 turbos .

I would say that Nissan must have found a surge problem when using the larger compressors on RB25's with the relatively small ARR exhaust housings . I'd say the VG30's having a much larger ARR turbine housing with a smaller diametre compressor did not go into surge conditions at lower revs . My RB20 turbo also has the anti reversion groove in its snout , probably because of its even smaller ARR turbine housing . I'm curious to know why the GTt housing has the 5 and the VG30 the 6 . The only way to tell is to seal the sides of the housing and measure the fliud volume required to fill it up with the flange perfectly level , sort of like buretting combustion chambers . Cheers A .

Yes and the cover as well please , its larger isn't it ? Cheers A .

Also a while back someone posted pictures of the R34 GTt turbo from the compressor cover side next to the R33 version , tried searching but can't find it . Anyone ? Thanks A .

Cubes I've been down in the cave looking at an old RB25 housing and an RB20 turbo I have . I did a very rough rule measurement and both are similar at this point . What I did notice is that when I put two fingers (middle and index) down the turbine inlet flange they go slightly further into the RB25 housing . You can see a difference when looking into the inlet's just downstream of where the wastegate port comes in from the left hand side . The passage is slightly taller on the 25 housing . Just to compare my 25 housing has 726B next to the T3 flange on the cartridge side in fine figures , and 2IU in bold figures nearby . On the dump side it has a "D" and the bold 2IU again . Just inside the turbine inlet flange on the LHS there is a number "2" rotated 90 degrees . The RB20 housing has 123C on the core side and 04U in bold print , nothing inside the flange . Cubes you may be able to tell me if the VG30 housing has a number inside the flange etc . I have not had a 30 housing for ages but it was very obvious that the passage downstream of the gate outlet was much bigger than the 25's , which itself was only a little larger than the 20's . What may tell the story is measuring the outside diametre of the housing as this goes up with ARR . As has been mentioned before , factory stealth bitz ie VG30 housing on RB25 (R33/34) turbo is about as good as it gets provided you have cheap access to them and for a first try as they bolt on . Not a race std turbo but pretty passable first off .

I forgot to add if you must use the FJ style T3 I would get it rebuilt using the larger 60 trim compressor which goes with the VLT's larger ARR comp cover . I think I may still have the VL cover and wheel kicking around if you can't find them . Cheers A .

Ghostrider the VG30 BB ceramic turbo can be looked at as an RB25DET one with a fair bit larger ARR turbine housing and slightly (tiny bit) smaller compressor and ARR cover . They are drying up fast as someone (red face) let the world know how handy they are . You could use the VG30 item on an L28 easily enough , or use its all important exhaust housing on the RB25 ceramic BB if the L series can support 180-200 Kw . If you could find one another option is the R34GTt turbo as I believe its compressor and cover is slightly larger than the 25DET's cartridge . These made Rb26DETT (206Kw) power from 2500cc but with infinitely variable cam timing . From what I see I think the large ARR VG30 turbine housing with the R33 or 34 cartridge is the limit for these Hitachi ceramic BB turbos . Of these only the series 1 R33's used an aluminium compressor wheel , the later 33/34 used some form of plastic or composite material which generally lets go before the ceramic turbine if over reved . I'd be keeping it down to about 10 lbs boost for reliability - not too foul with 2760 odd cc's . Sorry to get O/T , much better design than the FJ's Garrett T3 with Nissan exhaust housing . Low friction ball bearings and much lighter turbine , just not a high speed capable turbine . Cheers A .

T3 on L20a too small , plenty have turbocharged NA FJ's - you need to use a modern turbo with emphasis on turbine flow and response . This style of turbo will make more power for less boost (remember its airflow not pressure that gets the job done) and the extra CR pulls up the bottom end/consumption/throttle response . Side draught FJ's are noisy expensive and very thirsty - cop bait too . EFI is way to go . You can always look into KA24DE's - easier to get bits for and no under bucket shims . One timing chain and the local Navara version uses 8.4 CR pistons . Bellhousing style is SR20 so gearboxes a cinch . North south inlet manifolds came on US S14 240SX . Jim wolf Technology does all the aftermarket goodies . 2.4 litres = torque .

Has anyone got the ID tag numbers for the HKS GT2535 , 69mm compressor wheel is a little unusual but would help spool characteristics without giving away much flow capacity over 71.1mm GT35 wheels . Note it uses a T3 comp cover instead of the Nissan style T04B cover found on the GT28R and HKS's GT-RS . Cheers A .

A thing to watch with lowered cars is the front control arms , if they are horizontal the camber will decrease as the wheel rises . With correct geometry they will angle down at the outer ends so that camber increases with body roll . For some strange reason people want to have the ride height low at the front of R30's , I suspect its a fill the arches look thing . All it really ends up doing is hitting the bump stops , bump steering , damaged sumps - bad geometry and lack of travel . The right spring/damper/anti roll bars work well believe it or not at standard height . If you set them up for extra positive caster they don't need much if any static negative camber , which lowering gives but with std caster results in a smaller contact patch on the inside tyre . This is why wally's always wear the insides of their front tyres out . With high spring rates the dampers MUST be valved to suit or the pogo effect merely causes the wheels to bounce off the ground causing lack of steering / drive/brake adhesion .

446179-21 is the cartridge number and 56T is the compressor wheel trim . Cheers A .

Yes what Doughboy said , 82mm 56 trim compressor same as GT3540R . Sometimes turbos don't have an assembly number because they are a generic cartridge that is not sold to an original equipment manufacturer (OEM) with specific turbine and compressor housings . The other number is probably a batch number . Note the Garrett Japan - this is where all the GT BB's are made . Cheers A .

The truth is that is difficult to compare 4 and 6 cylinder engines when it comes to turbo response . Differing cylinder sizes and 180 vs 120 degree power stroke phasing puts them in different worlds . Something worth look at is the different styles of SR20 exhaust manifolds (designed around T25/28 flanges) and HKS's GT30 exhaust housings . A look around sites such as SR20.com , Sentra Net , SE/R Net tells us that the Americans are sold on the Pulsar GTiR exhaust manifold which was the highest performance factory version of the SR20DET . From what I can tell more effort was put into equalising the 4 runners and it was a little larger in size/volume where they all merged . With a bit of extrude honing (lucky Yanks have people that know what just a little to smooth things up means) makes a good relatively cheap manifold option . The transverse SR20 and U13 Bluebird versions were designed for less pereformance and more response . HKS as we know sell GT30 exhaust housings in T25/28 flange as well as T3 which is what most of the single turbo RB brigade want/need . There is a huge number of aftermarket SR20/T28 external manifolds out there which is probably way to go for GT28/GT30 turbos in a hurry . Welding up a large bore steam pipe log and a T3 flange is the best way to loose gas speed and turbine response . I'd say it doesn't matter which style of wastegate you use from a turbo response point of view , the manifold and housing type has most of the say with gas speed into the turbine blades for a given engine speed . So in the SR20 GT2835 instance the manifold and housing style would have had more to do with response than the waste gate type .

Fantasy I am not complaining about your manifold , if it does the job for its owner then its a success . The fact that I might approach it in a different way is merely subjective . A .

Yes Diesel engines have the advantage of no air throttle so get a better shot at better cylinder filling ie higher volumetric efficiency . When diesels run lean (being compression ignition with lower flashpoint fuel) they drop heat/cylinder pressure/power rather than becoming a self consuming oxy torch like petrol engines . Back to turbines , this is from an early Hugh Macinnes book - Turbochargers . Total time required to reach maximum speed is a functionof overall turbocharger efficiency and the polar moment of innertia of the rotating group . Moment of innertia is the resistance of a rotating body to a change in speed represented by the letter I . I=K(squared)M where K is the radius of gyration and M is the mass of the body . Radius of gyration is the distance from the rotating axis to a point where all the mass of the body could be located to have the same I as the body itself . In other words a turbine 1 foot in diametre might be represented by a ring with a diametre of 7 inches . In this case K = 3.5 inches . For good rotor acceleration it is essential to have the lowest moment of innertia . Turbine wheels are designed with a minimum of material near the outside diametre to reduce K because the moment varies as the square of K . Always remember that the turbine while being light needs to be free flowing enough to pass the gas . A forced induced engine gives the torque AND exhaust flow of larger NA engines so it critical not to choke it . A big NA engine with a tiny tail pie is a similar kind of dog . Cheers A .

If anyone seriously wanted a twin plenum RB26 type inlet it could be done before the six throttles , its function I guess would be slightly better air distribution to 5 and 6 . Like Roy , not here to flame , I wonder about the plenum form of the Jap style manifolds as in where they curve in half way down the master side . From what I've seen of factory manifolds and intercooler tanks they go to a fair bit of trouble to follow an outside radius to distribute air over a large area ie intercooler core or inlet manifold runners . I guess you build what people ask for and many think if it works on Terrakumis 1500 hp planet mover its just apples . This is not intended to be an insult just one persons view of the drag fraternitys monkey see monkey do thing . Cheers A .