discopotato03

If in Sydney and change your mind I'm after a set of those R33 GTR rims , the propper forged ones not the cast copy . Cheers A .

I think a few things need to be remembered about std VL Turbo Commode Doors . Firstly they were deliberatly designed to be in cheap to produce low state of tune , even for a mid 80's production engine . Can you imagine the uproar if the then new VLT with the shudders Jap hair dryer motor was equal to or better than the cast iron V8 boat anchor "batmobile" ? I have visions of the boo sham like after Bathurst 92 from the " if you haven't got a V8 you haven't got a life" brigade . RB30ET's had very low static CR , no intercooler , a dinosaur dinky bush/plate bearing T3 turbo , had to live on a farts worth of boost (4-5 lbs from memory) and had to run on the then low octane ULP which wasen't much better than power kerosene ! So picture low boost so low speed turbo rotating group and prehistoric bush and plate core which has lots of oil shear drag and loves to slow down when the exhaust gas energy falls away . I know what this flutter noise sounds like because standard DR30 turbo engines do the same thing . The one I used to have was a little louder with this because some mug cut most of the upper half off the airbox away and ditched the snorkel probably to enhance the flutter noise . It used a very similar T3 to VLT's as well . Jump forward from 1986 to the first half of the 90's and turbos amongst other things changed . More modern BB cartridges tend to spin up at lower engine speeds and load so on off throttle will make them flutter more easily . They run higher boost pressure so the turbine/comp speed is higher as well . One thing I noticed with the old DR30 was sudden feathering of the throttle (but not completly closed) caused weird engine characteristics . One was this flutter noise and the other was a slight power surge sort of back off onto over run and a slight power surge before it was all engine braking - well as far as the idle solenoid allowed . The std RB and SR powered cars I've driven don't do any of this and are pretty smooth and refined . I figure that I don't need to advertise to the world that I've backed off or changed gears so the after market "BOV's" have no useful function for me . I can see value in the std compressor bypass valves because they DO reduce the silly sound/power characteristics and the way the MAF sensor senses air coming into the engine . From Nissans point of view the benefits would have been that Mr/Mrs/Miss don't want the silly sound in their brand new Skyline and the engineers problems with over run enrichment with tightening emissions laws . I hear people say that these valves leak when they "boost" their engines so I have to assume Nissan designed it to be this way to attempt to save an expensive engine and turbo if the waste gate failed to open . I also hear people say that they have great success with the dual GTR/RB26 bypass valves and its no surprise that they work because they are native to the highest performance variant available and originally a Grp A homologation special as well . I understand none of the std GTR's make silly sound effects and their performance is recognised everywhere . At the end of the day I guess it comes down to how many of the positive benefits of factory engineering the individual wants to take advantage of . Performance cars are more obvious to the cops/RTA than ever so being incognito is way to go in my book . The less attention I attract on the road the better . Cheers A .

Ignore the heathens Roy , us Dura Cells keep on keepimg on .

Sounds about right Merlin , IRS 9" based diffs were used in Grp A Cosworth Sierras but doubt very much there was anything Ford about them . Cheers A .

Yes been thrashed to death this one , off the top of my head I think ~ 400 Hp was the limit of the thing (GT2835) depending on manifold/gate/tuning and 101 other things . GT2835 expensive especially in T3 flanged integral gate form but easy to fit . Garretts GT3071R "WG" or waste gated is a waste of space because it uses an inappropriate GT28 exhaust housing so wrong flange and Rat Sht turbine performance . IMO the best is the "real" GT3071R (CHRA no 700177-5023) with the full sized GT30 turbine in a REAL GT30 exhaust housing . ATM the REAL exhaust housings are only available without integral (internal) wastegate , though Garrett have been promising an integral .82 housing for some time . Cast Iron Rule - research turbos because they are expensive . Don't just believe its good because the bloke with the cash register says so . YOUR the one that has to live with it if you don't like it . Cheers .

My 2c worth only . Exhaust manifolds are a pain to muck around with because the turbo location and all its plumbing are altered , and making everything fit and work properly and not burn the thing to the ground takes more work than you think if you've not been there before . This is why mobs like HKS sell complete kits where everything fits nicely and works . Personally I like their cast low mount manifold but it probably really needs their exhaust housing (or turbo) and dump pipe to go together properly . To each their own but I've seen a manual R33 GTST with a few bolt ons (std turbo and manifolds) that had more power than traction with good road rubber . I think this tells the story of what can be achieved with essentially factory bits .

Congrats Dale , it sounds like your getting pretty much what you wanted . The fact that the GT cartridges wheels are just slightly larger than the originals means the machine work is reasonably easy . My first encounter with a GT BB turbo was the DP Turbo and it was interesting that my engine had more torque everywhere (literally from idle) than the RB20 BB turbo it replaced (this was on a later series slightly higher comp FJ20ET) . That DP turbo had the ability to windmill fast enough to feed the engine more air than atmospheric could without inlet manifold pressure going positive at very low revs . Going round roundabouts in 3rd gear was a great novelty ! The turbine it uses (same as yours) is very high flowing for its size mainly because of its open blade nature and wide paddle shaped exducer tips . Its significant that this NS111 series of turbines uses less blades (9 from memory) that the UHP series in GT30/35/37 etc (they use 10 I think) . The Hitachis ceramic turbine was all about being very light and responsive even at the cost of restriction because of its small diametre and the housings small volute . EGT/emissions/catalyst light up was probably involved and may have been a factor Nissan couldn't solve any other way with available technology . At the time they were going into production Garrett was doing heaps of R/D into ball bearing centre sections and wheels mainly high speed open blade designs . As I mentioned somewhere the competition TR30R turbo used recently in WRC/Cart/Audi R8 Le Mans cars is supposed to use a 60mm or approx GT30 sized version of the NS111 turbine (drools) and I have a pic of a (supposedly) HKS/Garrett VATN turbo with what looks like the same turbine . Off the track again , your power delivery being OEM like is a good sign so driving the thing should be a pleasure . Having realistic goals helps . Cheers A .

Well the theory is that greater area for the thrust collar to bear on is the advantage when it comes to wear and tear . If you look at those pics which are probably by Turbonetics you would see that the "270" thrust plate is brass or bronze while the "360" is steel or iron . The original OEM Garrett / Nissan T3 cartridges used the steel 270 type and were reliable when run at std boost . Once Roger Rev Head gets one and cranks 17lbs boost into it they fall to bits real quick . Or plan B if it was "Hi Flowed" by Sick Mate Racing ie TO4B or E compressor and cropped turbine exducer and 17lbs boost the 360 deg plate is of limited advantage . As I said the full circle thrust plate dictates that you must use the collar (two piece because it has to fit through the plate and contact both sides) oil slinger assembly that suits the mechanical or if you like carbon seal in the compressor end . The best choice for blow through applications is the piston ring type comp end seal because its offers less drag than the alternate type . Last time I asked (10 yrs ago) Garrett didn't make the two piece affair for the piston ring type collar . The problem with all these T3/T4 bush/plate cartridges is that too many unworkable combinations fit together in a core and bearing system not designed for high performance read constant high speed service . As Gary said the typical Diesel environment has lower EGT's and their usable rev range is not generally very wide . Diesels make good torque at low revs and being work horse engines break neck acceleration is not the main aim , pulling power or torque is . Now the current crop of higher speed commercial and car Diesels aside , truck Diesels use large turbines and adequate compressors because they are designed to run at peak power/boost/revs for long periods of time . The turbo doesn't have to run at stupid revs or unhealthy temperatures because its not necessary and warranty work is expensive for the manufacturers . They put together certain combinations of components , destruction test them and market them . Ford had a really bad experience with the RS500 Sierras in group A mainly because that TA34 turbo was being made to run way beyond its capabilities . Had the GT3037/GT30R (real one) been available it would have been a different story . DJR did make them competitive in the end but mainly because of a technology tie up with the engineering brains of a certain F1 team . It went into more than just its turbo - which had a few sneaky mods to get them there . Cheers A .

Yeah I won't debate in which direction the compressor wants to push under load though I suspect it could be back toward the cartridge given the vane area towards the exducer tips and how the air stream feeds the diffuser section on the backplate and comp cover . Its a given that annular contact ball bearings will have a lot less drag (meaning that they spin up with less exhaust gas velocity - provided they don't have a great galoot of a compressor on the shaft in relation to turbine size) so can afford to be slightly larger with less or no turbine lag penalty . It would not be impossible to design a bush/plate cartridge that is better than those about ATM from a shaft support and float perspective but it starts to get expensive and bulky again . For example higher wear and temperature resistant materials can be used on the shaft journals/bushes/collar/thrust plate bearing housing , the journal bearings could be further apart to better handle the axial forces and reduce the "orbit affect" that high speed and frequency shaft bearings and journals tend to have . Multiple small diametre thrust bearings could have less drag but where does it begin and end ? Would such a device demand dedicated oil pumps to prime the core and run after the engine is shut down ? With modern cars and engine bays being such a pain in the ass to work in I would not fit a device with a short life even if it was half the price of a more durable equal . I don't relish having skinned nuckles and fixing broken studs or oil/water/exhaust/air leaks so I don't want a long drawn out development programme in the quest for the ultimate turbo . In the end trying to solve the problems of older technology often takes more effort and money than just buying the right equipment . If drum brakes cross ply tyres and carburettors cost half of what the modern bits do would everyone be still using them ? I wouldn't . Cheers A .

Roy a lot comes into that subject of axial and end thrust loadings with turbo rotating groups . It was suggested to me once that the uneven balance of of pressure in the turbine and compressor housings has a large say . The person said he thought the greater turbine housing pressure tends to make the turbine and shaft thrust toward the compressr end and make the thrust collar try and force itself through the thrust plate . I have also heard it said that 360 deg or full circle thrust plates create a few problems of their own . The extra surface area makes for more oil shear drag so the rotating group acceleration will be a bit lazier . The assembly process is not quite as easy because the thrust collar has to be two piece to bear on each side of the thrust plate . This set up usually requires the use of a dynamic or mechanical face seal in the compressor backplate which adds more unnecessary drag in a blow through EFI application . We should not believe that its impossible to make a reasonable bush bearing turbo but its very probably impossible to make a wide ranging high performance (read true high speed high boost pressure capable) turbo and expect it to live . No turbocharger application is going to be seamless in its power delivery but a well thought out BB cartridge with the appropriate wheels gets noticably closer . The fact that the rotating assembly has less resistance to revolving in the critical low speed window makes a huge difference . The real enemy is the suppliers who thought they had us trapped by only supplying BB turbos or cartridges and no spares . One day someone in a newly developing industrialising nation will copy or provide non genuine bits for BB turbos and then the price will drop . Some of you should probably look around in the US for turbo prices and how the difference in currency value affects our prices . Anyway the home brew is kicking in so nite all ....

Design or fit together combinations of your own choosing ? there is a difference . Personally given a choise I would go to an annular contact water cooled ball bearing centre section every time . There are too many advantages with a low friction bearing system that allows the design engineers to use propper high speed compressors and turbines . Bush bearings are a dark age system that was never intended to carry high speed journals , they are cheap to mass produce and easy to strip / assemble . Their low speed wheels are an exercise in greater size/mass (innertia) so not really a step in the prefered direction . Housings designed for low speed wheels are also bulkier and heavier and again not a positive . If the cost was neutral bush bearing turbos would be a distant memory amongst newer vehices of any kind . If water cooling works properly there is no need for idling an engine for 3-5 minutes . Unless you've been thrashing it 30 sec to 1 minute is enough with small point contact bearing systems . Remember all the water cooling has to do is waste a bit of heat from the bearing housing and turbine housing which is not exactly a lot of thermal mass . I personally think the cost of ball bearing turbos is stupid when you consider how simple the cartridge is when pulled down . To use his term urban myth I'm sure Gary is well aware of the difference between manufacturers cost price compared to the retail price . Bearing pack aside the bb turbo is cheaper to manufacture though the material spec of the turbine and its housing can blow it out a little for higher temperature capable materials . Economies of scale can easily push down the cost of the bearing pack . Sadly ya gets what ya pays for , if you compromise the end result for cost who's fault is that ? Hands up those who use 87Oct fuel retreads and masonite for brake pads ....

I think the way it works is that there is less atmospheric pressure with which to feed the compressor wheel . Just the same as an NA engine doesn't "suck" in its charge air neither does the turbocharger . Technically there is no such thing as suck , just movement of air from an area of higher pressure to an area of lower pressure . So in other words there comes a time when there is not enough weight or mass of air (oxygen actually) available to feed the engine all it wants so power drops . Its interesting to note that piston engined aircraft often seek to only provide sea level manifold pressure up to about 40,000 Ft . In the last world war RR used multi staged two speed radial compressors (technically superchargers because they were mechanically driven) to get high altitude performance from their Merlins and Griffons . The Americans used large low pressure turbochargers for Allison V type and Pratt and Whitney radials though they were not very high tech devices . Sea level atmospheric pressure doesn't vary a whole lot arount the 1000 millibars/100Kpa/14.7 Psia so charge density would move around a little but not by a huge amount . Since we have no say about atmospheric pressure and temperature (air density) the only things we can bias our way are compressor efficiency and effective charge air cooling (intercooling) . Cheers .

Hi all , a person where I work has bought a Ford XR5T and it wears these Continentals in a 225 I think 35 18 . Interesting looking tread pattern , anyone driven on them ? I still like the idea of Michellin tyres but the level I could afford dont have the size I like . Cheers A .

If it worries you Id be looking at the cooling system itself ie radiator/std thermostat/viscous fan hub . If there is a cooling system capacity problem the lower temp thermostat probably won't change that , it'll just take a little longer to get there . Understand that once the thermostat is fully open its up to the cooling system to waste the heat so it doesn't matter if the thing opened at 62 or 75 . There must be sufficient reserve cooling capacity if the thermostat is to regulate water temperature . Cheers A .

Hi all , can't find the site I was looking at trust PE2 exhaust systems . Links ? Cheers A .

Yep have to agree , 235/45/17 Precedia probably be the go . Best compromise of side wall height width and common size . Cheers all , A .

Yes I looked into that Trust PE2 yesterday . I think more can area such as a large oval would fit at the back so maybe some gain here . If the rear steer rack is replaced by the lock bar does it fee up any more space in this area ? Also would "ovalizing" the pipe under the drive shaft mean it could fit a bit higher from terra firma ? That middle muffler looks like a double offset through one side of the oval can , what things under the floor pan get in the way towards the nearside ? Cheers A .

Yes I was looking at a few sets of various Skyline rims or Saturday and the weirdest combination I found was I think 215/50/17 on R33 GTR rims ? The sidewall angles looked ridiculous . I'm not overly concerned about 245 or 235 tyres looking skinny as long as they perform and ride well . It'll be interesting to see how prices vary according to aspect ratios but other things have to happen before I get to this stage . Cheers A .

Pics would be nice if possible , does the +/- mean centre and offset ? My previous experiences lead me to believe that mufflers with the greatest "can" volume stand the best chance of doing their job . Ones with direct perforated tubes should have the least resistance to flow . In the cave I have a rather long stainless Hitech muffler that is deep as well , left over from FJT days - ears still ringing . I'm not yet very familiar with the underside of an R33 but at a glance there's a bit of room . I sort of visualise a large can muffler in front of the axle and a cat (metalic core Catco sounds the ticket) in the std spot . There will be one at the rear though with not much pipe beyond the back of it one wonders if it does a lot in 3 or 3.5" tube size . As for the engine pipe I have no idea , the CAI one looks good but not sure which turbo so I guess the std one with the std turbo for starters . Have seen impressive performance through the std engine pipes with basically bolt ons and std turbo . Just out of curiosity how good are std R33 or 34 GTR systems after the cat ? Cheers A .

Thanks fellas , it seems most systems are around the 3" to 3.5" and the metal core cats seem to have the least restriction of all . I'm mainly interested in mild steel (titanium nice but expensive) and dont need the water main sized pretend bit out the back . Need function rather than bling . I remember reading ages ago that Fujitsubo made good quiet exhausts , anyone running one of theirs ? Cheers A . Edit : An R33 I looked at recently had a muffler just in front of the axle and split into two smaller pipes between here and the last muffler (single outlet) . I was told this shuts the noise up a bit but what about flow ? Any idea what type it could have been , was a cat back .

Hi all , I noticed a string asking all the Stagea punters what exhaust system they use and their thoughts of its performance enhancements and noise output . I'd like to hear what the R33GTS25T mob are using and their views on noise and reduced exhaust restriction . Full systems , cat backs , cats lets hear it . Cheers A .

Thanks SK , but for the record are the R33 GTST and GTR speedo drive/sensors the same . In the cheaper spec Pilot tyres they don't list a 245/45/17 but in the mid spec they do . I was thinking the 45 series rubber may be a little more compliant than 40 with the Kid spec suspension . Its the "dog house factor" you understand ... Cheers A .

Hi all , trying to find out the difference in diametre between 33GTS25T and 33GTR . By my calculations the diametre of 205/55/16 and 245/45/17 are different so I guess the speedo drive gears are different . Can anyone quote the difference in speedo drive gear or colour . Thanks , cheers A .

Probably a new or 2nd hand one from the same year MR30 . Cheers .

Sorry should have been more specific , when I mean fail I mean fracture and dump the green blood where its needed least . Cheers A .