discopotato03

Guys the 2530 is a tarted up Garrett GT28RS and the GTRS is a tarted up Garrett GT2871R . Search ATP Turbo.com for details , Brett at GCG should be able to import and emulate the things for nothing like $4000 . ATP will also sell either cartrige seperatly for under $1000 US . For the record the GT28RS comes with a .86 AR turbine housing which is essential for 2 liters and up . The only problem is I'm not sure if Garrett or HKS make a T3 flanged .86 housing . Brett is having adapters made up and the combination will work heaps better than the .64AR . Std dump wont fit though SR20DET ones will . Cheers A .

I think the only differences are the compresor wheel , early aluminium , late some form of plastic or composite . Don't go looking for AR numbers because they don't have them . The reason they have the Hitachi emblem cast into the exhaust housing is ....... I think the early ones are better because they dont destroy the compressor wheel like later ones do . They are fine in a standard application but a liability when pushed . Ball Bearings don't give turbochargers steroids .

You dont mention for what engine/car . I was not aware HKS did a TO4E , except for a 20yr old FJ20 high mount kit . HKS charge a lot for that pretty blue tag , I would put the money into a Garrett GTBB .

Hello Mesmer , no the 6 blade wheel is less likely to surge than the 8 blade . Mind you if theres a GT30R in the wings (again only use the 6 blade compressor version) I would not waste any money on the current hybrid . You would not open it up without overhauling it so save up the bucks for a real turbo , trust me you will not regret it .

I would not be in any great hurry to put a 4.375 ratio diff in a DR30 (actually yours is the RB20 HR30) . I tried that with my FJT Bluebird (4.375 H190 LSD) and found minimal gain and lots of revs for no good reason on the highway . I always found myself trying to change from 5th to the non existant 6th . The lowest I would go is 4.1 and often wish my RSX had a 3.7 . The RB26/31 will prefer it . Cheers A .

That comp wheel looks like a TO4B in -24 or -25 , the major or base diameter is 2.75" or 71.1mm . In order to get the cover on it they must have used a T3 back plate . I cannot stress this enough , we must use matching sets of compressor wheel/back plate/compressor cover or housing . TO4B compressor wheels are a flat back design where T3 and TO4E have a sort of flare shape with completly different offsets . The base diameters are T3 2.367" (60.1mm) , TO4B 2.75" (71.1mm) , TO4E 3" (76.2mm) . By going down a size in cover and backplate all you achieve is screwed up compressor efficiency . To have any hope of working properly is needs the correct TO4B comp cover and back plate , do yourself a favour and flick the 8 bladed wheel (bad) for a six bladed TO4B wheel to get better response and flow . This sorts out the compressor side , if the turbo has the non standard turbine in the original exhaust housing this also won't work . If it has the usual TA34 turbine it needs the matching housing with its unique waste gate flap/plate . Your dump pipe won't fit it either . It can be made to work but only if you know someone with lots of second hand bits and an idea of what works and what dosen't . Certainly using the 6 blade compressor with the B type cover and backplate is a HUGE step in the right direction . If I had my way I'd line up all the 8 blade comp wheels on the rails and turn them into bottle caps under the wheels of our locomotives . Cheers A .

RSX84 are you doing this with the HR30's std tacho ? I will need to know this too . Cheers A .

I asked Brett at GCG the same Q a while back , $2500 . The only pics I was able to track down showed a .50AR compressor cover which Brett reckons is a TO4E . I don't know for sure but doubt Garrett would try to squeeze a 56 trim GT40 compressor into a 50 TO4E cover , could be 50AR TO4S cover with small snout ? I would be interested to know if Garrett do an integral gate .82 exhaust housing to suit its GT35 turbine , Ford used the 1.06AR version I think . Cheers A .

Steve the turbo you used was a normal HKS GT3037 with a .87AR exhaust housing ? Does this mean the manifold and exhaust housing have the T28 flange ? I was wondering about trying one of these (Garrett version same wheels) with a 1.06 housing on my RB26/31 . Most people are saying the GT37 compressor won't keep up with three litres so go a GT35R . Whats your opinion ? Cheers A .

SK for your 26/30 using GTST PFC , can it use the GTR's air temp sensor ?

There is nothing very exciting about these switches . I had one in bits years ago and all they have is a dual contacts for open and closed throttle . The vane type air flow meter does the rest . The genuine MR30 manual shows you how to set it .

Pretty certain the second cable quadrant is for criuse control not TPS . I have never seen an FJ20 std with a flex plate on it yet .

Forgot to add if your fitting B series or any non native compressor wheels into those RB25 Hitachi covers throw your compressor maps away . Garrett maps are plotted using their native TO4B compressor covers (this is documented in the legend) and changing to non std ones alters the flow characteristics , efficiency islands , and most importantly the surge line . To be continued , Cheers A .

So is this what GCG call the RB25 High Flow ? If any of you have seen these Nissan Hitachi Ceramic BB turbos pulled down the turbine shaft is unique . Maybe GCG is getting plain bearing turbines and having them ground to the same dimensions which is expensive to do . From memory I think there is a radius towards the turbine end of the shaft which forms the rear inner ball race . Assuming Im right this may also need to be hard chromed which is also expensive . To those that have the ability to change compressor wheels there is a six bladed TO4B compressor wheel with similar blade profile and inducer size to the V trim or dash 25 . Most of the surge problems are caused by these eight blade wheels trying to move lots of air at low revs (both compressor and crank) the six blade wheels dont do this as much but still deliver enough air when the engine can take it . I'm surprised Bill at ATS has not tried this , if he did surge would be a thing of the past for a lot less cost and effort . I'll have a look at the parts list for B series wheels and post some dimension and part no figures . Chow A .

I guess the first thing to check is the mounting on the manifold for the waste gate . I think SK has a formula to work it out , though big engine and turbo probably need high bypass capacity to keep boost at sane levels . Cheers A .

Most engines I've seen respond better to increased lift than duration , so is there a roughly standard duration cam available with increased lift for the RB26 . I've seen this type of cam give good all round improvment rather than just extended rev range gains .

If you want something really unique why not use an SR20DET loom and Apexi PFC . That way you can get direct fire ignition and a choise of MAF's ie Q45 from Infinity .

Does anyone know which GTBB CHRA goes into these GCG Hi Flows ? I suspect its one of the GT30 turbine based TO4S versions but have never seen one . If the compressor is seven bladed thats all I need to know . Back to the RB30 , a GT30R I feel would have been a better choise than the 2835 giving more turbine and compressor flow and lots cheaper . Out of interest I went back to the Garrett PDF and looked up this turbo with the 1.06 exhaust housing and its flow rating (exhaust) is very similar to the GT35R/ .82AR combination . In big housing/s form this could be the go . Cheers A .

Cheap nasty Black Silastic is the best exhaust sealer known to man . Not sure if its O2 probe and cat safe though . The qualities of silicon will blow you away .

I built up a turbo years ago along the same lines as this (minus the cropped turbine) and used a Dash 24 TO4B comp wheel in the .60AR housing . The first impression was no or very little boost on a two liter FJ20ET . I then tried the middle sized RB25 exhaust housing (reprofiled) to excite it . This time round the dreaded surge set in . If I had these dramas with two liters you will have major mayhem with three . I would check the compressor wheel to see if it is eight bladed and if so ditch it for one of the six bladed versions . The VG30 exhaust housing is designed to work with a small diameter ceramic turbine so carving heaps out of these housings destroys most of the nozzle area , resulting in higher turbine inlet pressure and low turbine efficiency . Too late now but I'd have used the VG30 turbo standard , it was designed for three liters , and saved up for something better down the track . If you still have the std RB25 turbo and can get another std VG30 exhaust housing this combination is a reasonable stepping stone . Cheers A .

Mick just my two paseos worth not from experience . I think Nissan intended the RB26DETT to run like two 1300cc' engines on a common crank . I look at them as three 430 odd cc cylinders feeding each turbo on seperate manifolds . It looks to me like the GTRS (Garrett GT2871R) was intended for 2 to 2.5L engines in road tune . These turbos use compressor wheels a significant amount larger than the turbine ie 71 and 54mm . The GT2530's use 60mm diameter compressor wheels better suited to turbine (same) . While the GTRS's work better than the 2540's I see them as a compromise just less than the 2540's . I'm not sure what your power and drivability expectations are but its questionable if the GTRS's can deliver . If not you may be able to sell them and fit something that suits you better . cheers A .

I forgot to add that the "V" trim is a TO4B wheel ie 2.75" by 2.180" (63 trim) and 8 bladed . Turbonetics list a Super V trim but never seen one . The 6 bladed compressors are the pick of the TO4B's ie the H trim at 2.75" by 2.298" (70 trim) . From memory there was one of similar dimensions to the V trim as well . Cheers A .

This could work ok if the turbine housing is the Ford style Garrett one . These were designed for turbines with 65mm O/D unlike the Nissan/Garrett type which suited 59mm OD turbines . Everyone likes to reprofile the latter for the TA34 turbines (like yours) and screws up the nossle section of the housing . Turbine efficiency goes out the door and we wind up with a laggy dog . Garrett do their own TBO3/TO4E hybrids (T31 and TA34's) which do work , the aftermarket sucks everyone in with their bastard creations which rarely do . Note Garrett uses small trim TO4E wheels to keep the workload down on the turbine to maintain some efficiency . Remember the golden rule , get the turbine side right FIRST . Its the thing that DRIVES the compressor so if its bodged nothing you can do with the compressor side will fix it . Cheers A .

I've used the sintered iron buttons because they don't eat fly wheels and pressure plates like the sintered bronze ones do . Mine have been three button sprung center plates from Penrith Brake and Clutch . Just on this topic I'd like to know where this term "puck" comes from ? cheers A .

Soon I will be looking into pistons for my RB26/30DET . If I can still get OEM Nissan pistons for me these will suit my priorities of cost quality and quiet running . However apparently there is no easy way to get the desired 9:1 compression ratio without custom pistons . IF ACL is going to get Mahle to do their pistons I'll look into these too . SK's recomendation of coated crowns will get the nod and I'm interested to hear if the Castrol R 10W60 Synthetic goes in the road engine as well . I've not used Synthetic oil in the past and did not realise it could influence piston choise . Is there any info available about low expansion ie 2.5 thou custom pistons for the RB30DET and 8:5 to 9:1 compression ratios . Cheers A .