discopotato03

All "GT25BB" equates to is GT25 turbine and ball bearing centre section . If it gets full boost at 4-4500 rpm its not very good IMO . I suspect its a GT2540R/GT2876R with either an archaic TO4S compressor or the 76mm GT compressor . Both are a woeful combination . Same deal , pics and numbers off its ID tag and we can at least tell you what you have . Until its identified its impossible to know which way to go . Cheers A .

Whilst looking at other things I came across an MQ Patrol (LD28 Eng) which had the style of BMC and booster like DR30's and JDM IRS Bluebirds have . The master was a 15/16 bore Nabco I think but did not measure the booster diametre . Looks just like the early R30 style . I also found out that D21 Navaras (this one 5/87) use a 1" master thats a slightly different style but similar to the later style R30 but without the proportioning valve . Food for thought .

I had a dig through Pick and Pay Less today and mainly found out what doesn't have what I need . Just about all the larger heavier cars like 280ZX's , Z31 300Z , 300C's use some form of BM44 15/16 bore master cylinders . The only useful thing I did find was a D21 Navara (5/87) with a Nabco BM50 1" cylinder , perfect except it had no proportioning valve . It also only had 1 front and 1 rear hydraulic line outlet so would need a "T" for the front and some kind of external rear line pressure limiting valve ie like JDM R30's and Bluebirds had . They had no Y60 (GQ) Patrols or later D50 Pathfinders to look at . Cheers A .

Well unless he's getting his own housings cast and machined he'd have to be using std exhaust housings or the newer .70 A/R offering from GCG . No offense but I believe that only Garrett and HKS do propper housings for the GT30 turbine . All the others I've seen are based on the std Hitachi housing or a flange modified GT28 based housing . Plenty of "custom kits" out there but what yardstick is there to measure them by ? Cheers A . BTW , I hear that the Garrett Syd kit will not eventuate now . I think it was based on a GT3037S/GT3076R 52T and a custom dump pipe . It needed a spacer plate to clear the std exhaust manifold (comp cover) and unique oil/water plumbing as you'd expect . Plumb air in/out and thats about it . Owner tells me the result was very good . I think he said the turbine housing was a Garrett IW .82 A/R .

Hmm , so looks like R32GTST's get the 15/16 bore master cylinder . Some more possibilities , these Nissans have 25.4mm (1") master cylinders . Maxima 5/90 on 3L , Pathfinder D21 VG30E 4x4 10/92 - 11/95 , Pathfinder R50 V6 4x4 11/95-00 . Patrol Y60 (GQ series) had both the 1" and 1 1/16 BMC . Going to have to look through wreckers or pester some poor parts person . Cheers A .

Some pics of the Nabco Z32 300ZX 1 1/16 BMC . You can tell its Nabco because of the flat phillips head screw in the opposite side to the hydraulic line fittings . This screw is between the two front line outlets on Tokico BMC's . Note the Nabco cylinder on top of the Tokico box and its allen key type socket head plug which is removed on non ABS apps . The Tokico plug is a weird five sided socket . Also note the "BM57" cast into it . These 7 pics are of a US spec LHD Z32 300ZX Nabco BMC so RHD type BMCs have the screw and fittings on the opposite sides to this one . Can GTR Geoff or anyone with an R33 GTR confirm the BM57 figures on their BMC and the Nabco brand . Also does anyone know if the manual and auto R33 GTS25T boosters are the same , some US spec Nissans use stronger boosters on auto cars . Cheers A .

I used to get mixed reactions from the people at EFI Technology when they were at Tarren Point . They were not at all keen on propper sequential injector control because it needs good injectors (if they're big)and I think their computers (at the time) were running out of drivers to run six coils and six injectors individually . The prototype E10 and production E11 series got around this but I think they still don't support mass air load sensing . One day the aftermarket ECU producers will and when this happens EFI Tech may even discover atmospheric pressure at sea level is not zero and below this a "negative pressure" . Anyhow back to your cold start problem , I'd have a look at your injection timing (if its sequential) and also cold start ignition timing . I found with my FJ20 that you can back off the cold steady state enrichmend fairly soon and virtually lose it by 40-45 deg coolant temp . A bit of extra acceleration injection compensation helps here to . If I get a chance later I'll arc up the lap top and see what I did with ignition timing in the cold start/run phase . What ever it was I got it to crank/start/run by just turning the key , that engine had no idle air motor just the cold start heated air bypass valve . Cheers .

From the pics those E Bay turbos are come in spinner junk . That last one did not have a 60-1 compressor (TO4S 60T pn 409535-1) and some unusual turbine housing . Can buy from Garrett T3/TO4E small comp trim turbos , I think their propper name is TB31 . Back in Syd I have pics of this one with a T3 flanged IW .58 A/R V Band outlet exhaust housing . Will post it up again tomorrow evening . I have my own ideas on compressor trims and exhaust housing A/R's . What I am aiming at is the 52 trim GT3037S/GT3076R because I don't need the 56 trim versions maximum airflow or lag penalty . BTW in ball bearing form these turbos should have .60 A/R TO4E compressor housings , you won't easily find the map of the 52 trim 76.2mm (GT37 comp series or BCI-18 family wheel) in this housing because it was a HKS spec turbo and they don't publish them . The .54 A/R compressor housing is a bush bearing OEM GT3776 truck turbo part . There is a .65 A/R compressor housing from a later bush bearing GT3576 but I'm still researching that one . A very important point to remember is compressor covers with ported shrouds or air inlet boss . I think the slightly smaller trim comp (52T) will give me enough airflow for strong mid range torqe , the .68 A/R HKS Pro S exhaust housing (if I can get one) good response and a good integral gate vent path , the port shrouded compressor cover better response and control compressor surge . Having driven an R33 GTST for a while now I'm not so sure 32 3400 rpm + boost threshold is a good thing . I'd really like that windmill effect the GT2860RS gave on my FJ20 and this is why having good turbine response in a turbo thats well balanced (comp to turbine flow) is important . My goal is strong torque in a reasonably free reving (and not exhaust choked) engine , I couldn't give a rats jats about kw numbers . IMO a good strreet engine (RB25 in an R33) needs to be starting to pull from 2500 and if your lucky start to fall off in the 6-7000 rpm area . Provided you get some meaningful torque in the 3000 + range it should not fall flat on the upchanges . You'd expect to upgrade other things like porting cams IC ECU etc to achieve this with a production engine of this era . Before I finish here using the smallest exhaust housing and the largest compressor trim version of any turbo is at complete opposites - most airflow for least exhaust flow . Not sure if this would be a desirable option with a GT3076R because the extra airflow won't be much advantage if the engine is restricted by the small turbine housing . Cheers A .

Don't quote me but some of HP's books on rebuilding popular engines show these thin walled sleves , they are a slight press fit and seem to work ok . The insitu seal removeal can be tricky but you can grind a flat piece of steel into a slight hook shape to get them out . It gets gently punched into the seals flat section and expands the steel inner part enough to get it out easily . A gem of an idea for crank seals . Cheers A .

Need to know the numbers/letters on the shock towewr side of the brake master cylinder ie Nabco and BM50 .

Yes brake master cylinder , pics needed of outer (tower) side . Cheers A .

I think the Piper Cross panel filter is supposed to be better . You don't mention details about the intercooler and pipe work . Also what fuel do you use ? Long shot but make sure the turbos exhaust housing is not from an R32GTST . Cheers .

Can the R32 GTR drivers here tell me if the master cylinder has Nabco and BM55 cast in on the tower side of the cylinder . Brembo cars probably have the BM57 sized master cylinder . Thanks Adrian .

Possibly . I did read somewhere that S15 Silvias may be 1" as well . Does anyone know if all Australian delivered S15's had ABS ? Also one of the Z32 300 ZX's may have a non ABS 1" BMC . US spec Z32's park the BMC and wheel on the wrong side of the car so the hydraulic lines come out of the opposite side of the BMC to RHD cars . Cheers A .

So possibly R32 or R33 GTR . Cheers A .

That one is from a four cam single turbo 300ZX , and it has a ball bearing cartridge and no internal similarities with the VLT's Garrett T3 bush/plate bearing cartridge .

Thanks Geoff . From globe trotting I found an interesting post at one of the I think S13/Silvia sites . They claim BMC's on later Nissans have a BM number that tells the bore size , mine has BM44 cast into it on the tower side . BM33/38/44/50/57 equates to 13/16 , 7/8 , 15/16 , 1" and 1 1/16 - some have 17/16 meaning same thing . They mention that only ABS cars like Z32 300ZX TT get the largest though I believe Brembo GTR do as well . Americans like to fiddle with things like BMC's , etc , and they've done all sorts of conversions on Japanese Mechano kits (Nissans) . You basically get four variations ie ABS/non ABS and Tokico or Nabco supplied BMC's . The ABS cylinders have two outlets (1 front 1 rear) and the non ABS three (2 front 1 rear) . The Americans found that ABS cylinders have a plug where the 2nd front outlet would be on a non ABS car . Its here that variations exist between Nabco and Tokico cylinders as to the type of plug and how it seats in the cylinder body . Nabco they say makes it easy with a hex head plug seating on the normal reverse flare steel fitting pressed into the cylinder body . This would be an easy upgrade to a non ABS car that needed a larger bore BMC . Tokico make it a bit harder because their blanking plug is five sided (pentagonal socket) and they left out the reverse flare insert . Their answer was to hammer (shudders) a TORX bit into it and remove it that way , they then use a different non std flare to make it seal . So unless anyone knows otherwise if I want a 1" brake master for an R33 GTST it will preferably be Nabco and from an R32 GTST/non V Spec GTR or R33 GTR non V Spec . I would then have to reform the steel lines because the R33 GTST uses a different style of BMC body and outlet position . Is it possible for people with access to the above mentioned cars to have a look at the master cylinders and confirm if they are Nabco and have BM50 cast on their off side . Cheers and thanks Adrian .

Ok no offense . From limited searches (not here-yet) it seems the difference between ABS and non ABS brake master cylinders is the number of hydraulic lines going out . The masters all seem to have three outlets , one rear and two front though the ABS ones have one front outlet plugged and no inverted flare under the plug . The Z32 may have different locations on the cylinder body to the Skylines - trying to sort out which suits what . If the R32 GTST is 25.4mm (1") and non ABS it may be a bolt on mod . In the US they say some of their 240SX's (not sure if S13 or S14) used different assist level boosters (more for Auto) so need to find out what R32/3/4's have across the range . Yes Cubes pics welcome . I would always buy Nabco or Tokiko masters new because my previous experience is that they are good things and fresh ones last for ages . Cheers A .

Silence , surprised people have not done to much in this area of an R33GTST . How about some pics of the master cylinders on R32 and R33 GTR's , maybe even a Z32 . Cheers A .

I think you'll find an "RB24" is a stretched RB20 and an "RB28" a stretched RB26 . I think there was an RD28 but it was a Diesel . Cheers A .

I think I'll go new but are any of the 1" or 25.4mm bore masters a direct fit on a non ABS R33 GTST ? Cheers A .

Don't be shy , show us the compressor wheel and exhaust housing ends ... LOL Cheers A .

Fuel rail if you'll separate , don't want injectors . Cheers A .

I've never seen anything mentioning an L24ET in any production car . I think some were screwed together for American race classes , not certain but wasn't IMSA GTU an under 2.5L capacity class ? From what I've read only the L20A and L28 had a production turbo option . Also I'm not aware of the L24E being std to anything but an MR30 . Will look into this , cheers A .

I'm interested in this topic as well , my R33 is a little spongey and I'd like to know if the larger R33 GTR master goes on a non ABS R33 GTS25T . I'm not sure what bore master R33GTST's get but I reckon I could live with a sixteenth larger and new as well . Are the lines different ABS and non ABS ? Cheers A .