discopotato03

Just another couple of model specific versions of the GT28BB . The SR 20 version looks a bit like a GT28RS with a .64ARR turbine housing and a more OEM style compressor and cover - 60mm 60 trim .60 ARR . The R34 GTR version looks like a Garrett GTBB effort aimed at quick response , the sort of thing Garrett would have used if they had been fitted std . If I was doing an SR20 it would wear a GT28RS , I've not had the GTR experience but the majority like GT2530's for twins . If I was starting from nothing with a GTR and wanted twins I would use the GT28RS CHRA with the RB26 specific GT2530 housings . The two are nearly identical CHRA wise though the compressor wheel is a slightly smaller trim (62 vs 63) but the exducer tip height is greater and blade form a slightly later design . What it means is a slight reduction in turbine energy to spin it and slightly greater flow potential . I'm not a huge fan of HKS turbos because the price they charge for basically re hashed Garrett components . RPS13 Comp 60 trim 60.1 x 46.6mm ARR .60 turbine 76 trim 53.8 x 47mm ARR .64 BNR34 Comp 62 trim 59.41 x 44.46mm ARR .42 Turbine 62 trim 53.85 x 42.4 ARR .64

The HKS USA site don't mention it and the other one is in Japanese .

What spec turbine / compressor and housings do these use , I searched HKS but could not find them Cheers A .

Can someone confirm that Z32 Alumunium Brake Calipers bolt to DR30 front struts centrally over the std disc . I heard somewhere that spacers were used behind the pads to make up for the difference in disc thickness . Will this work ? Cheers A .

With your engine management sorted I would throw the rising rate regulator a long long way away . The correct way to controll fuel pressure is to keep it in sync with manifold pressure and use an adequate fuel pump . You could always look for another cast HKS manifold as there is a few kicking around . I would use cast ones in preference to fabricated ones as they seem to be more durable . Cheers A .

Just off the tellingbone , EFI Technology will be using the Bosch LSU Version 4.2 wide band 5 wire oxygen sensor which they say should cost $140 by itself . Their next Haltuner version kit with the above probe should retail for $300-350 complete . I don't know if it will have a memory function or logging facility but may suit some for monitoring or diagnostics . I haven't used one that had a numeric display , only the LED type but I suppose its the accuracy thats important . I gather most professional level equipment is numeric from what Ive seen . Cheers A .

Thanks SK , did a search on the LM1 and found lots of information on the 6066 Bosch probe and some on the NTK version . I'll contact EFI Technology and see which one they're going to use . Was yours imported from the land of George Dubya or are they available here ? Thanks A .

My answer would be yes but they have a new version soon to be released . They are getting a 5 wire Uego probe which will read between 10 and 20:1 AFR and could sell for around $300 (current estimate) . This is good news to me because the LED display should work with it once the narrow band eproms are exchanged for the wide band ones . EFI technology say the sticker on the front of the display is changed for one with numbers ie 10 11 etc up to 20:1 . Does anyone have any details or experience with the Uego 5 wire wide band oxygen sensor ? Cheers A .

The LM1 , I'll do a search on that one . Agree with the high cost of good equipment in the early and mid 90's . My reason for parting with the Haltech and Autronic computers was I wanted something that could load sense via a mass air sensor rather than MAP . I feel there's to many air temp correction advantages to pass up and it seems logical to match air to fuel ratios by mass . I'd like my next car to have some form of AFR meter so I'll see whats around then . Cheers A .

I don't want to get involved in an argument here but I know what I saw with my own eyes . The NTC probe I have I bought with the E6 computer in about 90 - 91 . Much later I bought the Haltuner which if memory serves me correct was around $235 trade - not including the probe which I already had . The NTC probe is heated and I think four wire . As I mentioned I got it tested in tandem with EFI Technology's own Uego equipment because I suspected my probe was poisoned . If you can find him Justin is the man to ask , I believe he left EFI Technology some years back to start his own aftermarket EFI fitting and tuning business . Anyhow I tuned that FJ20ET with 550 cc injectors to give 27-28 mpg , good hot and cold starting and smooth transitions - good manners and no closed loop correction . I put a lot of that down to the Autronic SMC's fine resolution and charge temperature management , but it didn't tune itself (pre autotune) and the Haltuner was the only AFR measurement device used . Having said this I do not suggest people should tune their own cars on the street , I had a bad experience with a chassis dyno operator who cooked my no 4 piston and was using Autronic/Bosch 4 Wire equipment - cost me 5 G's . After that I did my own using MK1 eyes and ears and a Haltuner . The car was daily driven and it was in my best interest to get good fuel consumption . I also switched to a button (padle) clutch and as everyone who uses them knows engine response and part throttle torque needs to be the best it can particularly with lowish 8.5 CR . As I said before it worked well for me so was good value . My opinion only , cheers A .

RB30 Power I think you'll find the supplied NTC probe is wide band , mine read from about 10:1 to above 16:1 . Cheers A .

Yes I have one of those and it works very well . I got the Haltech people in Taren Point (Syd) to test mine along side a Uego probe of theirs some years ago (on their static 1GGEU test engine) and the readings were virtually identical . I used it for years on an Autroniced FJ20ET powered Bluebird with great results . The Haltuner is not the tool to tune engines on the bleeding edge , but it has more than enough scope to tell you if the mixtures are reasonable or getting out of hand . Its a fantastic thing to have permanently installed to give you an idea whats happening ALL the time . If I was made of money I would have the Autronic air fuel ratio meter with the Bosch 4 wire probe , people trust them and they give a numeric rather than LED read out . For the cost the Haltuner is probably hard to beat . Cheers A .

54mm NS111 turbine way too small for any RB30 and the 46 trim T04E compressor a generation behind the times . IMO a bad combination of turbine and compressor so not worth having . Your call . Cheers A .

SK what sort of service work is required for the dog boxes and are the dog rings a press/spline fit on the side of the mainshaft gears ? Cheers A .

If you wanted OEM type performance , ie 4 - 6 pounds of boost no doubt a GT30R could do it . To do this you would probably need a rather large waste gate to prevent exhaust restriction . Always remember that when looking for higher boost levels (waste gate shut) marginally sized turbines can form a restriction for exhaust flow . With your example the 63ARR turbine housing is painfully small for a three litre blowing into a GT30 turbine . I try to look at what the manufacturers do - they have many millions to spend on R and D . I see the XR6T as a good example , the GT35R is perfect for a low performance (boost) four litre but note its housings choise . Its turbine housing is the largest of the three sizes available while the compressor cover is the smallest ratio (of three) and a family size down on what GT40 compressors generally use . I believe Ford was looking for absolute minimum exhaust restriction (large 1.06 ARR turbine housing) and not very high airflow rates to enhance a large capacity engine . For most of us Nissan fans we're looking at three litres and a more sporting breed of transport ! The same principles apply though the variation's are less weight and a smaller airpump (donk) . If it were me I'd use the largest available turbine housing for that GT30R and the port shrouded .60 ARR comp cover they normally come with . Even this with a large gate and lowish boost is really only suitable for a low rev ceiling engine but thats good enough for some especially on the street . Cheers A .

The GT28RS CHRA is very similar to the HKS GT2530 , the compressor wheel is a 60mm 62 trim instead of a 60mm 63 trim . The tip height is slightly greater making it a more efficient wheel with slightly better flow . In original form the GT28RS uses a .86ARR T2/25/28 flange exhaust housing and a .60ARR TO4B compressor cover . ATP Turbo are now doing them with the optional GT28 compressor cover (internally same as TO4B) which has the two bolt inlet and three bolt outlet compressor cover . There is a .64 exhaust housing you can use but dont know if its suitable for TT RB26 .

Interesting Steve , I've never seen an RB71 (GTST) box with anything but single baulk ring syncro hubs . I think all the the 25T and 26TT boxes use twin cone syncros . Cheers A .

Rebuilding a HKS GTBB is the same as rebuilding a Garrett GTBB because that's what it is . If you want fresh bearings and seals the damage is around $600 or so GCG (SYD) tells me . I'm sure a few different turbo shops can do them so ask around . Cheers A .

I did compare an S13 box to a GTST box once , the RB bellhousing is shorter but should fit the SR20 gearbox . If so then it would bolt to any RB block , torque limitations could be an issue behind a healthy RB26 . Cheers A .

In basic terms the HKS GT2510 uses the same compressor as their GT2530 (63 trim 60mm) and the same turbine as Garretts base BB GT28R . Its not really a performance turbine as such , more of a standard high response type thing aimed at OEM apps .There are better things out there for RB25's .

GT40R's and GT42R's would probably make the power with less cost and better response , those HKS T51's I think need spanky V Band clamp mounting hardware just to be different .

Cubes I think you'll find its more a case of pumping losses through exhaust restriction that held back the .82 GT30R .

With 200B's I think there was a Jap as well as the BW . Early Bluebirds got BW gearboxes and diffs but too many died and Jap stuff got the nod . There are some options for the local R31 followers . The 260 , 280 and I think 300C's used a H190 live rear end which would be probably wide enough for an R31 . They have 5 stud hubs and LSD is available though rare . I'd say the best option is to fit the factory IRS which we did to a Bluebird or buy an import R31 that has it std . With local Bluebirds the mount locations are there but not the crush tubes and or studs . At least there's some chance of an LSD for an R200 and the ride / handling is so much better with the semi trailing arm IRS than the live axle . Cheers A .

Cubes that example of the GT30R that ran out of puff , did it use the largest 1.06 ARR hot side and .70 ARR "E" cover on the comp side ? Also what was its boost level . Cheers A .

Tell me if I'm wrong guys but does the R31 series use a Borg warner 78 diff ? A friend of mine who's also a mechanic of many years once said that the late BW 78's were a bit soft in the ring / pinion gears . The fix is to source an early set from an old Cortina as the material spec was better . Not really sure of the facts .