discopotato03

Yes the "R" variant has the larger 90 trim turbine and 56 trim compressor . The std 2835 uses an 84 trim turbine and 52 trim compressor . Just on the "R" prefix , I always tack it onto the end of Garrett GT BB turbos because it usually means rolling element centre section . Cheers A .

I assume your turbo is the Ford XR6 type GT3540R which uses a TO4E .50AR compressor cover similar to this TB31 . Indexing the covers/housings can make life difficult with integral gate type turbos but usually something can be made to work . Most brackets I've seem made were 1/8 mild steel plate and if folds were needed they were made in a vise with a hammer . Cardboard templates help out and can be traced to the plate initially complete with holes marked out . Given a choise I would always mount them off the comp cover to backplate bolt holes . Cheers A .

The problem I see is the actuator not working in the same plane as the wastegate lever so the actuator rod deflects and this may not suit its spring and diaphram . I have had one modified but we used a die nut to run a thread along the shaft and screwed an adapter and lock nut onto it . The actuator on yours is way clear of the compressor cover but closer to the turbine housing and the bracket is bolted to it which is a worry heat wise . Some turbos have the actuator a long way forward and use long rods . I have a pic of a Garrett TB31 (propper factory T3/TO4E) that I'll post up so you can see how they did it . Back soon cheers A .

Yes there are some options . Brett at GCG rebuilds the GT BB range so if its just the bearing cartridge should not be to difficult . If the wheels have rubbed on the housings it may be a different story . Garrett do a turbo they call the GT3071R "WG" for wastegated and it I think uses a similar cartridge to the GT2835R depending on which turbine and compressor trims your 2835R's have . If you can give me the numbers off the turbos ID plate (should be something like 700177-00XX or -50XX) I'll check it out . Brett sells some of the HKS range of unique turbine housings so he may have or be able to get the next size up of turbine housing which from memory would be .73AR in T28 flange . The listings for GT2835R I have are . CHRA No 700177-0002 , -0003 , -0004 and -0001 I suspect is another possibly 48 comp trim variant . The unit numbers I have are 700382-2 , 3 , 4 , 6 , 7 , 18 , 19 , 20 , 21 and -24 . If that -1 CHRA is a 2835 its unit no is 700177-0001 or -5001 . Hope this helps cheers A .

Garrett are supposed to be releasing a .82AR integral gate GT30R and GT3540R housings about now so I'd enquire about those . GCG also have a .70AR TO4S comp cover that fits the GT3540R but with the same plumbing dimensions as the XR6's comp cover . Cheers A .

Chris I believe the one HKS used with that manifold was a TA45S which I'm pretty sure used a .72AR comp cover . The modern equivalent would be a GT40 or GT4088R with .72AR cover . I would not like to guess if a GT42/42R would fit in the available space , the comp covers on HKS's T51R are enormous so hard to imagine it going in but not sure . Cheers A .

Available in .78 AR ratio only .

Hmm , does the She Jay 20 make it a Subalime or a Skyloo ?

Really need to see it with the housings removed . Turbine housing is RB20/25 but core looks like water cooled T3 . Aluminium compressor backplate looks like TO4B , the compressor being 7/14 blade is probably the Buick Grand National TA34 299-4 . She's a typical bitza Hi Flow and the results are usually very average .

Yeah arguably what makes the TO4Z cartridge is its TO4R compressor , the P trim turbine is a bit long in the tooth nowdays and long overdue to be replaced by one of the GT UHP turbines in a sensible size and trim . The HKS version gets a leg up from housings that are not truck diesel types and can have custom AR's and diffusers to optomise for petrol performance apps . Their GT2510 is old and old thinking compared to more modern GT28BB combinations , they learnt to lower the boost threshold by going down in comp trim rather than turbine trim and style . A couple of the SR20 spec GT-SS cartridges would be very interesting on an RB26 as they are basically a GT2530 cartridge with 60 rather than 63 trim compressors . Garrett sells this cartridge as well from memory . Out of time cheers A .

Hi all , I'm curious to know if anyone has thought of using the later type Garrett GT4088R or Precision Turbos GT4067R which is same but with the TO4Z's TO4R 67 compressor and housing . The turbines used in these GT40BBG's are 78 compressor trim so a little less laggy than the bush bearing versions 84T turbine . A fellow I speak to from Full Race Motorsports in the US is getting 850 odd Hp from a drag Honda so must work ok . The exhaust housings come in .85 .95 1.06 and I think 1.16 . Cheers A .

ATP turbo is releasing T3 flanged split pulse or divided non gated turbine housings for the GT30R and GT3540R (GT3582R) range of turbos . No details yet on which AR ratios they intend to do but may be useful for some . They are also selling the .85AR T4 flanged divided Garrett housing for GT40R based turbos . Cheers Adrian .

Hi all , is there any information available on HKS's GT-ZZ . Have seen the odd mention but no specs . Cheers Adrian .

I don't think Garrett make a T3 flanged GT28 turbine housing so theirs don't bolt up . Your probably limited to a Hi Flow or one of the GT28BB's in a reprofiled RB20 or RB25 housing . The HKS T3 flanged GT2530 or GT-SS stand the best chance of giving good results because they're designed to suit the application . Cost aside GT-SS sounds best to me for road . SR20's are much better looked after because they were designed around T25/GT28 turbos with the common T25/28 flange . Cheers A .

Very true , they are still a production engine but far more potential than SR20's .

It would be interesting to know if the RB20 head went through any revisions in later Skylines . I think I remember seeing a picture of an R34 NA version that had some inlet manifold changes so is it possible that the chambers and porting improved in the last Skyline (R34) era ? I would think that higher tech engine management / cats / pump fuel etc in Japan would have allowed it plus market pressure to have higher numbers out of the base NA R34 . With SR20's and heads the later or low port version (with SOCT) or switch over cam timing was very much an emissions design so not really the best example . Some American groups have spent a lot of time and money on SR20's and they always go with the early high port S13 era heads . They will tell you that SR20's used for tarmac race have no end of problems mainly because the heads have serious cooling issues . At high power and heat outputs water flow is not flash because of the casting finish in the jackets so there is endurance limits with the SR20 head . The RNN14 GTiR head is different again and also an evolution of the early high port design . We could argue this topic forever and not get a satisfactory answer suitable for everyone . For an endurance race engine such as we have at Bathurst my money would be on the RB20 , I think its a low stressed engine with less piston innertia than an SR20 and so can have the piss bags flogged out of it and come back for more . In road trim its a well mannered smooth thing like all the RB series and the marque of a Skyline . To give its best the RB20 would have to have all the effort thrown at the head . Those inlet valves are going to suffer a bit of low lift shrouding so there may be other ways to skin the cat ie smaller valves and more lift , if the factory didn't change the chambers later maybe a bit of weld to improve the quench zones and a slightly higher compression ratio . Possibly bore the block and lay back the chamber walls a little - but then its not 2L any more . One area where the RB20 lucked out is the GTS-R exhaust manifold for Grp A , it may not be the best sedate road use manifold but its a step in the right direction - forget the turbo though . The most highly tuned SR's that I know of were the NA super tourer version for the Primera but these were hardly a production evolution - about the only thing Nissan was the head and block but you'd be hard pressed to see ANY similarities . Dimensionally they were more like an FJ20's bore and stroke and the heads were more weld than casting . Anyhow at the end of the day you have what you have so why not try to enjoy it for what it is and accept its limitations . Not everyone can afford the SR20 blitzing RB25/26 or RB30DET .... so there . I can't resist burial rights , have a look at Micra.com.au and Cisco's build up of a K11 Micra . Hard to believe he got 165Kw at the wheels of an 820 odd kg roller skate when he decided his S14 was not the car for him . Also note the other cars he thrashed along the way . With fuel prices going balistic how much fun would one these things be with - a little help ! Now can I fit another diff and tailshaft and and ... Cheers all , Adrian .

I reckon if an RB20DET was developed to make the same type power as a std or mild SR20DET it could do it . If it was sized to run out of air and exhaust flow at the same point that is . The thing is who's going to put 9:1 pistons along with porting /cams/ turbo etc to make SR20 type torque for their Skyline ? You don't need to anyway because an R32 looks much faster parked in the street than any Silvia .....

If it was to be twins I suppose a pair of GT3567R's (technically should be called GT3584R's) from Full Race Motorsports could generate enough airflow for 1200+ Hp with large enough GT35 turbine housings . Geoff Raicer makes good stainless manifolds that don't fail on the Honda and Supra drag specials so I would talk to him . Cheers A .

I think 10mm of lift will do me and the 260 odd duration should make up the difference (for road) with the larger cylinders . It sounds like RB26 heads need a fair bit of exhaust port work and this would be more important with 500cc pots venting through them . Has anyone go a link to HKS RB26 cams in english as I can't find one . I'd like to know if the pair are sold with differences in lift or duration (~260 degree set that is) . Would these be step 2 cams ? Cheers A .

My next aftermarket ECU will be a PFC because I want the advantages of MAF load sensing . I have used earlier Haltech's and an Autronic SMC and have to admit that the software makes a HUGE difference to the end result . I cannot see how any MAP sensed ECU has a hope of controlling any multi throttled engine accurately because once manifold pressure rises to atmospheric (throttles wide open) the MAP sensor reading is constant so all you have is an rpm and air/water temp sensor signals to tune from . If the TPS signal shows fully open its a constant too . Once you get some positive manifold pressure different story . I can't understand the resistance to PFC's , plug - tune , maybe with larger injectors and MAF metre . It sounds too easy and maybe thats the problem . Cheers A .

I don't think its so much a case of GT-RS's being too big for an RB26/30 but more to do with the compressors being a little big for the turbines in their case . You really can't separate compressor and turbine performance because they're physically joined at the turbine shaft . From a legality point of view I was told a while back its not strictly legal to use non genuine windscreen wiper blades so where does it begin and end ? The subject of high or low mount and single or twins gets bandied round often and how the user goes about it and the attitude/image they project spells how much attention their car attracts . I want an RB26/31 that looks like an RB20 though it won't fool anyone whos in the know . If I was using an RB26 or GTR it would still use a single preferably low mounted and off a cast manifold because its far easier to work with/on . Anyhow my preferences aside you get into a grey area with twins because of the gap between the GT28 and GT30 turbine families and turbine housings/AR's . Toyota were among the few in Japan to produce a 3L twin cam turbo motor and at the time I don't suppose Garrett/HKS were breaking their necks to make an in between size to cater for it . Most of the 2JZGTE Supra people end up with GT30R/GT35R/GT40R/GT42R single turbos and in that range you can have mild to very wild performance with many options for trims and housing AR's plus some very interesting hybrids and HKS options . Your call .

R32TT I'm not a big fan of the GT2871R series of which HKS's GT-RS is the 52 compressor trim version , with their housings . I know Garrett is now selling a GT2871R 52T which is supposed to be identical to HKS's SR20DET specific GT-RS . I can't help thinking the 71mm compressors are a little big for the 54mm GT turbine except maybe the 48 trim wheel . The one that is interesting is HKS's GT2535 and if you can believe the specs at HKS USA it is supposed to use a 69 ? mm compressor so probably about as far as the GT28 turbine could efficiently go . The real problem with the GT28BB turbos in twin form for the RB26 is the lack of a turbine housing in a slightly larger AR than .64 but not as big as .86 . Something around a .70 - .72 would be better but then again this is with 2960cc's not 2570 . Those turbines really come alive as their map shows with the .86 housings but probably a bit much by two for 3 litres . I still tend to think the big single have so many advantages over twins and its a pitty some GTR/RB26 owners feel that using a single is like living with only one ball - even a big one . Warm cams should make for sharper induction and exhaust pulses so spooling larger turbos should not be too much of a problem . The multi throttle inlet system is there to breathe and resist reversion . Cheers A .

I think I mentioned this last time round but the 2510 is older thinking within HKS's range , sort of along the same lines as the GT2540 and GT3040 . Using a lower flowing and smaller turbine is not the best way to tone down the 2530s compressor end (ie 2510) . A better way to do it is to use the more open bladed GT28 turbine with a slightly smaller trim compressor than the 2530 or 2510 did . This gives you better turbine response and ultimately more overall exhaust flow through the turbos hot side . Tis far better to limit a turbos capacity with the compressor side than the turbine side . HKS knows this and sells a model specific GT28BB known as the GT-SS which is intended for the SR20DET . This version gets the right combination of turbine and I think a 60mm 60 trim compressor . Needs the HKS turbine housing from the 2530 or GT-RS for their T3 flange and RB type dump pipe flange . I sure I found a Garrett GT BB cartridge with similar or same wheels so something to look into . Don't confuse the SR20 and RB26 GT-SS's because the turbines and compressors are not the same . Cheers A .

Forgot to add , where would be the trade off between big cams and larger valves ? Dread to think of the cost of cams and valves and springs and guides and shimming .

Gary do you think its fair to say that in higher gears at highway speeds small differences in throttle openings make for significant changes in manifold pressure and volumetric efficiency so the turbos want to take off ? Back to the cam situation I thought that the buckets were taking all the side loads so guide and seal wear would have been much lower than say a rocker type valve train . I can understand the more agressive lift rates and spring rates giving the seat and face a hard time though an RB30 may not have to rev as far so possibly get away with less spring rate before valve crash or bounce sets in . I was reading a while back about cam profiles and opening plus closing ramps for high lift shortish duration cams . I don't suppose anyone has had the Tomei and HKS cams on the Cam Doctor to see how well they were speced ? 260 10mm sounds nice - std base circle ? Don't want to restart the big'n vs two litlun's debate but I did see somewhere (can't find it now) that the twins favour short stroke motors and singles the longer stroke ones . Cheers A .