discopotato03

Roy one on this boad runs the EWP but not for road , I really like the idea but I worry about the reliability of the plastic body . If it failed the engine could die quickly and there's too much money at stake for an RB30 . It would be entertaining to see if Davis Craig is prepared to wear the rebuild cost or only replace their bastard pump if it failed . I guess the only way to be almost safe would be to have the pump up near the highest point of the system so if it lunched itself there may be time to shut down and save the engine . I may sound like a wuzz but I've seen expensive engines die because of plastic rad tanks failing so anything plastic in an engines cooling system I think is a risk . If and when they make an aluminium one I'm all ears . I don't suppose anyone knows pumping rates of the RB20/25/26/30 so we could fiddle pulleys to get a good/cheap solution ? Cheers A . PS: can the impellers be changed ie one off stuffed RB26 pump on cheap new RB30 pump or as the case may be ?

The story I've always had is that its best to have a fresh working surface on the deck of the head . I've almost always had the usual 3 thou taken off particularly if things got a bit hot . I believe it works because head gasket fire rings will compress slightly the head material when bolted down . When its time to replace the gasket there is a much better chance of it sealing if its flat . Should mention I used Nismo gaskets on the L and genuine gaskets on the FJ20 - never had any problems . When the RB30 gets built I'm thinking of trying the brass rings with the fire rings removed from which ever is the apropriate gasket though this obviously would be difficult to do to an engine in situ . Don't know , depends on what sort of cylinder pressures its likely to run . I should do a search and see if Cometic or Nismo do a gasket to suit the 87.5 bore I want to run . If I get the CR/cams/turbo to my liking it probably won't need much more than mild boost to make the torque I want so maybe just a good conventional one will do . Cheers A . PS : A fello I used to know was using the brass ring system on FJ20's that were running 30+ lbs boost and cranking out around 720 Hp on Dave Handleys engine dyno without problems . Definatly super duty system ! This was a few years back though , don't know where he's up to now .

According to the turbobygarrett site the GT2560R's are SR20 packaged turbos meaning the turbine and compressor covers won't suit an RB26 . Specifically the exhaust inlet at the turbo is wider and the dump pipe flange pattern is different ie SR20 type rather than RB26 . The compressor covers are 3 bolt outlet instead of 2 and the inlet suits SR rather than RB26 as well . Its doubtful SR20 type turbos would have the mounting eyes on the bottom of the comp covers for the water/oil plumbing gadgets . I would not attempt to use non specific low mount turbos on an RB26 because all the fiddly bits blow the costs out . Space really is a premium on that side of a GTR head and even Nissan had to make compromises to get it all in . Are you sure you have searched every avenue to find bolt on Garrett GT BB's ? Cheers A .

Yep that is dangerous and dumb . I'd say the plate bolted to the top of the bearing housing is warped so not flat and won't seal oil in . That aside the use of rubber hose and wormald clamps is ridiculous given the heat in that area . I would be removing that "adapter gadget" and flattening it with a big hammer . Then I would be looking at the oil feed hole in the top of the turbos bearing housing to see if it has a thread in it . If it has your in luck and can screw an adapter fitting into it and then plumb a propper braided line or even steel pipe if you like . If its not threaded buy the two bolt plate adapter from Garrett or which ever turbo parts supplier you use . Then screw the threaded adapter or banjo and banjo bolt into the bolt on plate . Corky Bell has a chapter in his book Maximum Boost devoted to turbos and oil inc supply and drains . I suggest you read it . Cheers .

Hi Dale , the results should be interesting and there is some room to move with obtainable bits if it does not meet with expectation . Say for example the HKS exhaust housings do turn up occasionally and there is a Garrett comp cover in .60 AR ratio that has the three bolt outlet to suit some Nissan apps . If you want to follow it right through you could measure exhaust manifold pressure and compare it to inlet manifold pressure under load . Also exhaust gas temperature is good to know as well , temp laser gun aimed at dump pipe or housing usually tells the story . Cheers A .

Just a thought Roy , is it worth considering using early Mazda RX7 four piston calipers on the rear . I thought they were aluminium and designed for either 20 or 22mm thick disks . I know the mounting ears are quite wide between centres but hydraulically speaking may suit your needs . Pads should be available is all sorts of compounds for them . Cheers A .

I put a bit of time recently into searches on synthetic engine oils because there is so much conflicting information doing the rounds . The first surprise was that the 10W of for example 10W40 is not a cold viscosity rating but a cold pumping index . The author of that thread said how can you make a fluid more viscous by increasing its temperature . He said this is what the marketing types want Joe average to believe . The second was that there appears to be only four or five manufacturers of real synthetic base stock oil on this rock . The third was that many advertised synthetic oils are really modified mineral oils or as some say "Dino Oil' . The fourth was that Castrol R/Edge oil fits this category . I find it hard to separate truth from fiction because I've never damaged an engine that had enough oil in it . I think I'll be leaning towards Mobil 1 except for running in . I'm keen on the idea of lower viscosity synthetic oil and oil coolers . Just on that 80+ PSI running oil pressure , I was always told that all very high oil pressure achieved was power loss with driving the oil pump and heat build up in the oil itself . Not flaming just repeating what I was told . Cheers A .

Thanks , be interested to see how the 350Z/GTR Brembo set up goes . Cheers A .

I believe at $75 a tank fill power down where its needed most often is more practical . Cheers .

Hi all , just curious to know if piston sizes changed from R32/Z32 through to R34 GTR . Not after specs on Brembo or aftermarket calipers just the normal bits . I'm interested in what works and is cost effective on an R33 GTS25T . From a little searching the R34GTt fronts look straightforward except the bolt hole size . Provided the upright is removed and placed in a radial drill it should be simple depending on how tough the material is . Can someone tell me if the GTt calipers are aluminium because unsprung weight is important to me . Also I don't know off hand what R33GTS25T's use on the back but suspect ventilated with internal drum park brake ? What is the usual upgrade from std ie R32/33 GTR ? Thanks A .

Torque is king , luckily the largest (RB30) is the cheapest to work on . If on a budget RB30ET's can make good power . Cheers A .

This is from a couple of American books I have by Frank Honzowetz . L24 with single 2 Bbl Carburettor 38mm intake 33mm exhaust valves . L24 up to 7/73 42 and 33mm . L24 after 8/76 42 and 35mm . I'm told that the best L24 head in Australia was the one from the 1981 only build Skyline MR30 2.4E . I can't remember which casting number it has but someone in here will quote . Im opretty sure it used the larger 35mm exhaust valves and has closed heart shaped chambers like the 1600 SSS had . If you can find one in good nick its the one to use . Basically most L heads need help in the exhaust side and the best available combustion chamber shape is a huge bonus . Cheers A .

Yes its hard to imagine good boost control without any real means of turbo speed control . Sizing a turbo so that the hot side won't choke at peak engine power and revs usually means big so not a real lot of go down low . I suppose if he could control the turbos speed by varying the compressor vent valve accurately he may be able to have a handle on the pumping loads that the turbine side has . In other words if he can "unload" the compressor the turbine has very little to push against so it would tend to windmill faster . The extra rotating group speed and the lack of exhaust manifold pressure would help the trade off of restriction vs turbo excitation but the vent valve actuation and Motec programming would have to be spot on . It would be a real juggle to make sure that turbo speed did not run away with itself and damage the wheels and bearings . The want to delete the waste gate is valid , they are costly and a pain to fit and plumb but just about everyone uses them in petrol apps . Its a pity that F1 banned turbos when they did because they would have evolved at a faster rate with the development dollars F1 has . The future is probably the VATN or variable area turbine nozzle though how well it can be made to cope with petrol engine EGT's is hard to say . The electronic control will have a large say on how effective it will be . I think there is a way to go yet with the conventional BB turbo but getting Garrett to give us the wheels and trims we want with effective integral waste gates is the issue . It is not impossible to get integral gates to work well as WRC has proven but it means strict control of turbine inlet pressure (so as not to force the flat valve open) and power through greater airflow rather than vastly higher boost pressure . This is why I thought for a while about something like an integral gate GT3540R but with a smaller trim GT40 comp (50 rather than 56) or the compressor side of a GT3076R . It also means an engine with a good head and cam profiles because the turbo can't do it all by itself . Lastly look at HKS's GT Pro S exhaust housing and dump pipe design , they went to a bit of trouble to make the waste gates flow path good given the available space . They could make money out of selling GT35/TO4Z/GT40 versions as well . Cheers A .

Oil lines are quite easy , we used to buy -4AN mild steel weld on fittings drill them to size and braze them to a short section of the original steel pipe at either end . Then its straightforward to make up braided line with female -4AN fittings and join it all up . Have to support the line properly off metalic things . Cheers A .

If you could get your hands on a used 2535 it could be ok . Or since you have the T3 flanged HKS exhaust housing you could buy a Garrett GT2871R in 48 compressor trim - minus the exhaust housing and fit it in your existing HKS exhaust housing . Assuming your 2530 is a Skyline specific one it has the TO4B compressor cover like Garretts GT2871R series uses so externally it would look the same and use the same water/oil/exhaust plumbing and waste gate actuator . The only difference may be the comp cover inlet boss being 3" or 76mm where the HKS 2530 probably had this bit machined off and an adapter bolted on . You could either get this boss turned down in a lathe or use some kind of step down in the inlet plumbing depending on what you car has . Just in case you didn't know the 2530 and 2535 and all GT2871R series plus a few others use the same identical turbine and bearing housing so the HKS exhaust housing goes bolt . Done the above mentioned way you wind up with virtually a HKS GT-RS but in 48 comp trim instead of 52 trim (better when boost threshold is an issue eg Cu in starved RB20) and without HKS's custom port shrouded comp cover . The 48 trim compressor is less likely to surge than the 52 trim GT-RS but you could get the 2871R's comp cover drilled and slotted so the port shrouding worked TO4Z style if required . So if you play your cards right this could be a very cost effective upgrade with what is really a brand newin . Cheers A .

Search HKS Japan , click first site and look at the menue on the LHS of page . Click on Turbo , GT-RS and scroll down through the S13 (SR20 version) , R34 GTR version to RB20/25 version . Even shows bling pic of port shrouded comp cover . Enjoy .

Sorry to be a bitch Cubes but the GT28 exhaust housings are .64 and .86AR ratio , T3/GT30/GT35 are available in .63 and .82AR ratio . Seems to come up often the question of which GT28BB based Garrett for the RB20 . Results from 2L 4's don't reflect what a 2L six needs . My opinion only (not based on experience) is that the turbo needs to compliment the standard state of tune of the engine so its not out of step with gearing and so on . There are a couple of options for RB20's and as usual the issues are cost and fitting convenience . The two bolt up options are HKS's RB20/25 specific GT2530 and the GCG Hi Flow . I think HKS also do an RB specific GT-RS which is a Garrett GT2871R 52 comp trim but with HKS's T3 flanged integral gate .64AR exhaust housing and their own custom port shrouded comp cover . I've got a few pics from this site of an RB specific GT2535 as well . Garrett has been a bit lazy and don't make a T3 flanged GT28 exhaust housing so if you buy one of theirs it usually means a T28 flange which won't bolt to your manifold . Hi Flows aside you really need that HKS T3 flanged housing to marry the GT28BB series to a T3 flanged manifold . If you beg/borrow/buy this housing cheaper Garrett GT28 BB's will bolt up as will the std or aftermarket dump pipe . The results from the Garrett GT28RS (GT2860RS) are very similar to a GT2530 as they can both be optioned with the same TO4B .60AR comp cover . When you go above the 60mm compressors you start to compromise response for extra airflow capacity so its a judgment call where you want the useful usable power spread to be in the engines rev range . I don't have a high opinion of the 2871 series because I think its a bit more load than the turbine likes and if I couldn't get enough air from a 60mm compressor it would be the smallest or 48 trim GT2871R . Turbobygarrett's maps are convienent but notice how they pretty much use the same turbine map for the three different comp trim versions , fibs because turbine efficiency varies with comp trim which is directly related to drive loads . If you look at the comp maps for all 3 note where the surge and choke (minimum/maximum flow) areas are along the 2 pressure ratio or 1 bar boost line . Off the top of my head the 48 comp trim version starts at ~ 11 lbs of air and chokes at ~ 39 lbs air At 2PR or 1 bar . The 56 trim version I think spans 16 to 44 lbs so the range has moved up . What I'm try to point out is that the smaller comp trim version will pull from lower revs and be less likely to surge if you need the smaller .64AR exhaust housing to excite it with . With 39lbs of air you have the potential to make ~ 390 Hp which may be enough . People say RB20's need all the help they can get low down so erring on the conservative side compressor wise I feel is a better compromise than risking losing a bit too much bottom end and getting caught in the dead zone at upchange time . You may not like this idea but if you started out with a Skyline type GT2530 it gets you the correct exhaust housing , if its not enough then you could fit any of the three compressor trim GT2871R's to it meaning there is an upgrade path . Any decent turbo seller could supply you a 2871R minus the exhaust housing so it makes for a cheap upgrade . All the actuator and plumbing could be reused provided you started with as I said the Skyline specific GT2530 , these should be around 2nd hand cheaper than new . Nearly forgot to add those T04B comp covers can be port shrouded if they are the large 3" inlet boss type , this means all is not lost if you ran into surge issues . Not at my own computer ATM or I would post a pic I have of a HKS RB20/25 type comp cover that has the original boss machined off and a turned aluminium adapter bolted to it to fit the original inlet plumbing . Not difficult to get around . Cheers A .

Does Setrab or anyone make a good thermostat bypass sandwich that fits between the filter and the block for RB's ? Cheers A .

Mighty G11 3 cylinder 1L , around 47 mpg with carb and points . Naturally can't catch the Gen 3's but they are halving in resale value at 3 yrs old so owners tore up 8G+ a year for the privelage of owning a veeee hate . Dread to think what the V8 cruiser barges cost to run ...

I tend to think that the gudgeon pin tried to sieze in the small end bush . You can see how the bush has tried to screw itself out of the rod and no doubt up against the inside of the pistons gudgeon pin boss . Since both pins are sheared in the middle it seems logical that half the pin was trying to stop the piston articulating with the rod and was the weakest link . Luckily the other half must have kept the small end located in the piston otherwise the rods and pistons would now be schrapnell on the road . I would be measuring up the broken and surviving pins to see if the tolerances were adequate . I would also check to see if the propper lubrication was available to all four rods/pins/pistons . Cheers .

Any details , I know the integral gate exhaust housings are due any day now for the GT30R and GT35R series . Cheers .

HKS once made a TO4E kit for FJ20ET's , it ued a high rear mount T4 flanged manifold with a small external gate underneath it . The turbos exhaust housing was a HKS special and quite small ie .4x ish AR ratio so that you could get same day boost response . Not positive but I think the turbine was an "O" trim meaning mid trim T4 . Really stretching the memory banks but I believe the comp cover was .50 AR TO4E . For their day they had far greater potential than the std T3 but better things are available now . A GT3037 with the smaller 52 trim compressor would be more responsive and if the integral gate T3 flanged exhaust housing due any day now was used with the std DR30 manifold it goes bolt . The real GT30R which is just the big comp trim GT3037 would be Ok and no less laggy than the dinosaur bush/plate bearing TO4E . Cheers .

I reckon that turbo can support a lot more airflow (power potential) than an RB25 could reliably withstand so a bit pointless unless you beefed up the internals . To get the boost threshold down to an acceptable point for a road car would mean using a small AR ratio exhaust housing so the 750 odd Hp compressor is wasted . As Chris said you don't hear of these things surging , guesstimate only but HKS may have done the cover like that knowing that heroes like to put big turbos on small engines with small AR exhaust housings . By small I mean under 2L 4's . Not sure what you mean by "efficient boost" . Airflow makes for power and pressure just moves it along . I have been told that these wheels make their greatest efficiency at surprisingly low pressure and flow rate but the "islands" are very long meaning that they work over a wide range of flow and pressure ratio . Its a pity Garrett dont make a 76mm version of this wheel because it would be a good thing with a GT35 turbine . Cheers .

2rismo I can't follow you logic , if you mean "covered" as in out of sight then 99.99% of port shrouded compressor covers the world over are covered . This does not prevent them working as they were designed to . Many Diesel turbos have port shrouding and very rarely are they run without ducting to an air filter . If the manufacturer wanted it not to work the gas ports would exit the cover through the outside of the boss ie the parallel section behind the barb .

RBSandy they are the vent paths for the ported shroud within the inlet boss . 2rismo I'm not sure what you mean by they are covered by the filter or inlet ducting ? So long as the vent paths can vent air from the radial slot in between the main and splitter compressor blades to the atmosphere side of the boss they will work . I have a feeling that HKS do this partly for bling factor (marketing) but I also get the feeling that doing it like this or by having the trumpet mouth insert like say their GT3037's have reduces the shrieking screaming noise that the more common port shroud like say a GT30R (GT3076R) tends to have . Thanks for the link as well , always wanted to see inside the HKS TO4Z comp cover . Cheers A .