discopotato03

I was at GCG today to pickup a special I had them do for my Subie dinosaur and enquired about their Hi Flow RB/VG BB turbo . It seems they have not long ago changed to a slightly more modern compressor wheel and the limited feedback is that it works slightly better than the original I think "450" Hp one . The wheel is still 7/14 bladed but I didn't check it's number out and wouldn't let the cat out if I had . I'm beginning to think that if people are reliably getting ~ 260 265 Kw out of these things then that should be enough for a road car , particularly if it bolts on . I have a used VG30 OP6 turbo here but I need a little info from those that have used these things . Firstly I had a vague notion that the VG30 BB turbo had a slightly smaller compressor housing than the R33 RB25 Hitachi's comp cover . Secondly do any of the R34 GTt turbos have a larger comp cover again than the VG30 or RB25 Hitachi turbos ? I'm just thinking that if I do end up having GCG build me a Hi Flow I'd like to have the highest capacity factory housings available to get the most potential from it . Thoughts ? Cheers Adrian .

That wheel's had a big rub and it would be good to find out why . GCG used to convert GT3582R's into GT3584R's (T04Z comp wheel) so you could try them . You really need to get someone to asses what the cartridge is like inside and see if the housing/s the wheel/s rubbed on are fixable . Sometimes it's better to replace the complete cartridge and wheels because all of the center section and wheels are brand new . Its more than just the bearing section and wheels that get "used up" . If the turbine end piston ring has cut it's way into the butt of the bearing housing it can be the sign of a used up cartridge . Get it checked out , cheers A .

You have to look at the number on the turbine housing , from memory look inside the mounting flange and one side should have 68 or 87 meaning 0.68 or 0.87 A/R ratio . Cheers A .

No I don't want a clutch like that in a road car . He's talking about an organic plate and a bit higher clamp pressure diaphragm assembly . He said that actually OEM Nissan plates have real good center sections and the linings are quite good - aside from the 250mm R33 GTR one but he does have a few good alternatives . I am interested in one idea of his which is to use the 250mm plate and a diaphragm assembly that is dimensionally the same as and fits R33 GTS25T flywheels . The std plate for these cars is 240mm so an extra 5 on the radius shouldn't be an issue . The extra clamp area always helps particularly on the OD I'd think - still learning . The diaphragm assembly he suggested is rated at 2500 pounds and the whole set is a new thing he is developing . I don't do the err um howly wheelie stuff on purpose so a semi race clutch is not what I need , I've been there with three button sprung center feramic clutches and they are a bastard to live with . Sydney's traffic driving is getting worse with more people and cars moving in every day , the computerised traffic light system screws everyone everywhere so grabby clutches just make the torture more unbearable . The feller I bought my GTS25T from said ex compliance the clutch slipped so demanded they fix it . He thinks just the plate was replaced though with god only knows what . It doesn't do anything too bad just lacks feel at times . I just want something that can stand up to a few performance mods beforehand . Jim doesn't like lightened flywheels in turbo cars and some of the reasoning makes sense . If I do end up with a slightly larger diameter friction plate I don't want any more revolving mass than these cars have std as that's the maximum I'd want . I'm waiting for him to call back with a few more details . Actually he mentioned that these RB25DET's have two slightly differently sized rear main oil seals and is not entirely sure when the changeover point was . Mine is a mid to late 96 build car with I think it's original engine , may have to see John Robinson Nissan spares at Rockdale in Sydney to see if they know by VIN numbers . Lastly is it much of a job to change the gearboxes front oil seal ? Thanks and thoughts , cheers Adrian . PS memory thinks that VLT's used a 250mm plate and I believe VG30DE/T/TT too . Are they similar same as 33 GTR ?

This has been a really interesting thread and many different ideas have been brought to the table . I am no one , except a learner , in the grand scheme of things so I have nothing to add . Maybe it's suffice to say that different people have had varying levels of success in this area so what they've learnt and applied works for them . It sounds to me like there is differing requirements for street strip/dedicated race/dedicated drag race . I think the issue is that people come here for advice and get a number of conflicting methodologies and a bit of a war erupts . When I was younger , and sillier , I asked a number of people how to go about things and got confused and growled at for questioning and comparing different peoples solutions . A wise person eventually took me aside and said look you have to pick one person and try to learn from them otherwise you won't get anywhere unless you do it all yourself . Cheers A .

Will be calling Jim tomorrow , need clutch that can cope with 260 odd Kw max and be super street friendly in a GTS25T . Cheers A .

I'm curious to know what you're using to control the fans and more importantly what temperature they switch on/off at . A lot of people don't agree but I see it like this . For the radiator to control the engines water temperature it must be able to cool the water in it (rad) to a LOWER temp than you want to run the engine water temp at , I think too many people with elec fans try to control the engines water temp with the fans switch settings and it ends up being a tail chase . Provided you can get the switch sensor in the radiator , not the engine , it can be made to work properly . In a nutshell you use the fan/s to control radiator temp and the water thermostat to control the engines water temp . It was explained to me that the engines water thermostat is there to control its minimum running temperature not it's maximum , I had to think hard about that one . Lets just say that you had the guts cut out of your thermostat and it had full flow all the time , under normal circumstances the engine water temp would be low because there is nothing to regulate its proper minimum running temperature . If the coolant temp gets high then the thermostat opens up and blindly hopes more flow will bring the temp down again . As an experiment try running the fans all the time and leave the std 76 deg © thermostat to control the actual engine water temp . It's probably not so different to running around in the winter time because its the THERMOSTAT that's trying to control the water temp not the fan switch setting . Also some people fret about the fans not switching off sometimes for reasonably long time periods (in warm running conditions) - so what - they're doing their job . I'm not suggesting you have your elec fans run 100% of the time but this is effectively what the std mechanical one does . It also pushes air through the engine bay all the time which is not a bad thing . From cases I've seen engine conversions and high engine/bay temps go like this . Fit bulkier engine than the manufacturer intended which alters airflow characteristics through the engine bay . Fit elec fans because there is not enough room for the factory viscous hub one . Fit two small fans rather than one big one in the belief that they cover more of the core . Fit behind the core . To make a radiator transfer heat the post rad air has to have somewhere to go and that's through the bay and out around the gearboxes bellhousing and off underneath the car . The very best radiator in the world won't do a real lot if there is nowhere for the air to flow behind it . A GTR radiator is probably tall enough to get two fans on but I reckon at least one needs to be the full height of the core . People try to set the fan on temps at some mythical upper cooling temp because they think Ok the fans come on and cool the engine water temp down . What they succeed in doing is ensuring that the whole cooling system temp is up there and when the fans switch on dumping all that heat into the engine bay . Had it been a std engine in a std bay there may well have been sufficient airflow through the system at speed to maintain a workable engine temperature but things have changed and air may not pass through so well unassisted . Now if you have the fans switching on at a temp below your engines normal temperature you have a reserve of cooler water in the radiator , when the engine water temp rises for whatever reason the thermostat can open up and take advantage of the reserve cooler water . If there is no reserve then the whole cooling system rises as does the temp of the air going through the core . To my way of thinking you need to get in early and ensure that the temperature of the water in the radiator is reasonably cool and then let the thermostat do its job . It's on the cards that the fan/s are going to have to work longer because it's harder to get air through a core and more specifically an engine bay with more flow restriction in it . Beyond this the only other thing you can do is consider oil cooling and cash in on the fact that generally the difference between oil and air temp is greater than cooling water and air temp so better chance to reject the heat . My 20c , cheers A .

Well the theories suggest that a 0.68 A/R turbine housing would be small for a 3 liter engine . I always reckoned that the 0.68 and 0.87 were developed with the RB20 and RB25 in mind , the only other std T3 flanged engine was the FJ20 and even those were old news by that stage . Cubes here has (I think) a Garrett 0.82 A/R integral waste gate or IW turbine housing on a GT3076R fitted to an RB25/30 . From memory he said it comes on boost reasonably early . I wouldn't mind a Pro S housing if anyone has one to sell . Cheers A .

Out of curiosity which 0.83 turbine housing do you have there ? Garrett do have a 0.83 A/R integral gate turbine housing but AFAIK they don't come on any HKS marketed GT3037's . HKS have a couple of integral gate "T3" flanged turbine housings for GT3037 Pro S turbos but they are 0.68 or 0.87 A/R sizes . Also those Pro S turbos have port shrouded compressor housings which help a bit . I agree with Nismoid , a GT3037 or the real Garrett GT3076R equivalent is a bit over the top for 260 odd Kw . HKS's GT2835 Pro S is possibly the more responsive option in that power range . Exy yes but there are options if you're good at chasing second hand and modded housings to create one . Cheers A .

I've been wondering for some time when this issue of only venting one side of a twin scroll turbine housing would arise . The problems going to be that you're attempting to "waste" or bypass the gas from only half of your cylinders so the turbine inlet pressure , back pressure if you like , will be higher in those not plumbed into a wastegate . I'd also question the ability of half the manifold and half the turbine housing having the volume capacity to control boost pressure . Imagine for a minute that you had a TT GTR engine but only one of the turbos waste gates was operating (opening at all) . It'd be a grim outlook for the engine I'd reckon . There really is only one way to have an integral gated turbine housing , a single scroll one needs no explanation but the TS one needs to be able to vent or bypass from both sides . Both Mitsy and Subaru have used twin scroll twin integral gate turbine housings that have separate vent paths from each side of the housings passages . Sometimes they have two outlet holes and sometimes they simplify it to a mirror imaged "D" shape for the flat valve or valves to close on . I don't know about Holset and Borg Warner but Garrett sometimes use twin scroll twin integral gate turbine housings on Diesel turbos , I have a T4 flanged GT3576 in the cave and it has a HUGE I think 1.19 A/R split T4 flanged GT40 based turbine housing on it . For the laugh and convenience I call these housings TWIG - twin wastegate internal gig . Garrett have done a model specific GT3076R (TWIG) for the Mitsy Evo 10 though people want to hold off on this one because it has - issues - Garrett needs to solve in this area . I hear the housing is a really good design but the - well - in time . A twin scroll system won't work properly unless the volute or internal passages are TOTALLY isolated all the way to the twin nozzles and turbine blades . It's not good enough to have the twin scrolls joined by a common waste gate path if there is communication between them when the gate is shut . This is why the OEM twin integral gate housings use either two separate vent paths and close them with two flat disc shaped valves or one over the mirror imaged D shaped outlets . The HKS single cast low mount manifolds for RB25 and RB26 do a similar kind of thing but with an external gate parked on top of the double D outlets . Sorry to say it but if this was simple and cheap everyone'd be doing it . Cheers A .

From the Factory R30 R200 LSD's only had I think one set of active plates in each side of their production LSD center . The go is to buy extra sets of plates and replace the wide spacers with more of the active plates . Jacko explained to me that most OEM plate type LSD's aren't designed to work well because Joe/Josephene average don't like the noises and effects that a "properly" functioning one makes . I carried my "plated up" long nose R200 LSD from the Bluebird to the DR30 and with ~ 65 odd lbs of static preload it work well - for me . Trust me , DRIVE an R32/33 now you know what an R30 feels like and make your decision . I went for a spin in Skid33 and not long after bought one . Never looked back .

I thought the Ser 4/5 RX7T's got the HT18S version . It's been a long long time but from memory those turbo have a reasonably large turbine with a smallish compressor wheel , probably something to do with Rotors not liking turbine inlet pressure (backpressure) . Again from memory these turbos internally were a bit like a Japanese T3 shaft wise . As they are probably not so good on a piston motor because they have different gas flow characteristics . Also it would be a shame to make all the changes to get it on an RB and discover it was cactus . Your calls but I think turbos are too much stuffing about to bother fitting one that was an unknown quantity - bush bearing ones I mean . By the time you remove and reco it you've spent the price of a more modern one so why not go that way first up . A .

Hi all , a while back I read an article from Autospeed (JE) that made me stop and think . Google EBDI or ethanol boosted direct injection and there's a bit to read , this PDF one looks interesting . http://www.ethanolboost.com/LFEE-2005-01.pdf Just as a taste I believe some of the manufacturers are trying to find ways to close the gap on fuel consumption between Unleaded Petrol and Ethanol blends of which E85 is one . The thing that was always going to be the stumbling block for ethanol blended fuel was the greater usage and how to make that cost neutral or even cheaper . Well it seems that ways are being found by upping the static CR's and I'd say playing with dynamic (effective CR's) with sophisticated variable valve lift/duration valve trains . I haven't had time to read much yet but I get the feeling that direct injection and evaporative cooling properties of Ethanol are helping with detonation supression and I'd imagine NOx emissions . I think what the manufacturers are trying to achieve is more power from smaller than usual capacity engines run in a higher state of tune . The smaller capacity engines have the ability to get better consumption but they have to be able to make acceptable torque to haul the typical SUV barge around . I think there's a shift towards lowering C02 output as well so the manufacturers are obviously concerned about political correctness , Kermit customers and the real danger of this #@^&*ng carbon credit scheme business . All I care about is interest in ethanol fuels and the available blends ratio increasing . I think the secret with fuel consumption is higher CR's but detonation and NOx have to be delt with . Thoughts , cheers A .

I reckon a well set up RB25DET would be more than enough , if you can get tyre fryer power out of them in an R33 GTST then it would be same deal in a slightly lighter car and the conversion is straightforward . I reckon one you break traction big time any more performance is a waste of time and money and probably makes it a lot harder to drive . I think a street sorted 260 Kw Rb25 - head/cams/inlet manifold/injectors/bolt on turbo/pipes/GTR IC/PFC etc - done . A .

Jaycar also do a kit called Intelligent Boost Controller and it can be referenced off an airflow meter signal from memory . I think SK built one some time back to get better boost response in a Stagea . Just on the VTN/VATN thing , don't forget this is Variable Area Turbine NOZZLE - not variable area radius ratio (A/R)turbine housing . There are a few ways to "throttle" the exhaust gas speed through the nozzle and into the turbine blades . You could also argue that they are a variable turbine inlet pressure ratio housing . I believe VATN controllers are quite involved to set up because accelerating the compressor and getting boost at the wrong times can lead to surge and detonation issues so not quite as easy as the usual bypass waste gate system . You mainly see these on dieseasels because they generally have lower EGT than petrol engines so the device used to vary the area of the turbine housings nozzle doesn't have to cope with as much heat (cheaper material spec parts) . If you don't mind using bush bearing turbos Garrett also do GT wheel spec plain bearing units for diesels so it doesn't all begin and end with museum pieces like crude old T04B/E/S/R units . I've been wondering for some time now why someone hasn't tried using a Garrett GT4082 turbocharger . These use a 77mm 73 trim GT40 turbine in a T4 flanged I think 0.94 A/R TS T4 flanged turbine housing . The compressor is an 82mm GT40 which is the same family as the compressor in a ball bearing GT3582R only in 50 rather than 56 trim . The comp housing is from memory a 0.58 A/R GT40 port shrouded thing and from pics I've seen isn't much if any bulkier than the GT3582R's T04S housing . Giz a sec and I'll look for the link . Best I can do cheers A . http://www.extremeturbosystems.com/product...roducts_id=1421

I think this link is a bit buggy but try it anyway . http://www.modified.com/projectcars/0306sc...rt_2/index.html Cheers A .

Personally I don't equate boost pressure to power because to my way of thinking its how much air you get to burn that tells the story . Really its a case of the better you can make the manifolds and head breathe the lesser the pressure you need to get the air in . With turbine housings Garrett makes two sizes for their GT28 turbine based turbos 0.64 A/R and 0.86 A/R . JC , no another one , cooked up the original DP GT2860RS and he amongst other at Garrett America will tell you that it's not a real DP if you use the smaller 0.64 A/R turbine housing . The whole idea of this turbocharger was to have good response and minimul exhaust restriction and they work well provided the mixtures and timing are tuned to suit it . The mob at Silvia net don't always agree and I get the feeling that they may be trying to use these turbos on SR20DET's with std computers tuned around a more restrictive turbine and housing ie the S whatever BB turbo . AJ from the then Road and Rally Center fabricated an exhaust manifold for my FJ20 because they have T3 flanged ones std and there is no such thing as a T3 flanged GT28 0.86 A/R turbine housing . The runners in that manifold were not real big diameter wise , may have been 1.25"/32mm bore but it worked well . I also think the Silvia mob are scared of the 0.86 A/R number because it is a reasonably big ratio but in a small/medium family of of turbines ie T2/25/28 . Honestly if you had say a VL Turbos 0.63 A/R T3 turbine housing next to a GT28 0.86 A/R one you wouldn't think the 0.86 GT28 one was huge . Its a very clever combination of a larger tip height low blade count , and open bladed turbine , in a large ratio medium sized family of turbine housing . From memory the only OEM GT28 turbo that used this kind of 0.86 A/R turbine housing was the GTiR spec SR20DETs turbo . Don't try and pinch one of those housings BTW because it used a slightly different family 10 bladed 79 trim turbine , the one in the GT2530/GT2860RS/GT2871R's is 76 trim . Also Garrett and HKS opted for the T04B compressor housing because it uses a larger diameter back plate meaning a larger diffuser diameter which effectively widens the islands on the compressor map . It's the combination of this and the larger turbine housing (for a GT28BB) that make the GT2860RS such a wide ranging turbocharger - suitable for engines I guess in the 1600 - 2400 cc range depending on the intended use . I initially used electronic boost control (Autronic SMC) but found the std actuator worked pretty good as it was . Just make sure that it has sufficient pre load to keep the gate shut until the boost comes up or it'll be a laggy dog as any turbo would be . And lastly with the GT2871R's , they can be laggy dogs if they have the largest 56 trim compressor fitted - and with the 0.86 A/R turbine housing . The 71.1mm compressor wheel is available in 48 52 and 56 trims and I reckon the most common GT2871R , had to be the 56T one didn't it , tends to be a laggy dog . I believe the problem is that the 56T 71.1mm compressor is good for maybe 460-480 Hp but the GT28 turbine is struggling much past ~360-380 Hp . Imo too much compressor for the turbine . The smaller 48 and 52T compressors seem to work better but its often difficult to get people to understand that less than the biggest is a better match for that turbine . Now for the last few who haven't fallen asleep . It is absolutely critical not to oversize a turbocharger when using production gearbox/diff ratios because the power (torque) delivery can get peaky and you end up falling off the boost curve or looking for more revs up near the red line . An engine that gets going about a third of the way up the rev range and has real punchy stump pulling torque is more than happy to pull your typical tallish and reasonably wide gearbox ratios in style . If it takes half or more of the available rev range just to begin to find some boost and torque you virtually have to go to the red line every gear just to keep the turbo on the boil . The bloke with the properly sized turbo well get you out of the tight bends every time . So now its your call , GT2860RS 0.86 A/R would be my first choice . Read that article in SCC , I think they tell you that everyone that had a ride in that S13 was highly impressed at how well it went and how well mannered it was . Cheers A .

All BS aside the GT2860RS is a really good practical turbocharger for a road and track two liter four cylinder . It's prototype was a club race turbo for an MX5 BP18 Mazda turbo engine . I ran one on an FJ20ET and it was really good for the road . It's easy to get carried away by the must have 400 Hp/300Kw train of thought but its too much IMO for a nice street car . The Disco Potato GT2860RS turbo was designed to be responsive without being restrictive on the exhaust side which is exactly what you want in a street/club race application . Technically a GT2860RS is VERY similar to the HKS spec Garret "GT2530" , the only difference being the compressor wheel which is still the same 60.1 mm OD but 62 rather than 63 trim with greater exducer tip height . The GT2860RS uses the same 0.60 A/R T04B compressor housing as many single app GT2530's but without the smaller inlet barb bolted on machined snout . The real difference is the 0.86 vs 0.64 A/R turbine housing . Neither of these turbos needs the smaller 0.64 A/R turbine housing on 2L and up 4's as they "spool" quite well with the larger one . My old FJ20ET got positive pressure at 15-1600 revs in upper gears and was easily capable of hauling my Bluebird around roundabouts at slow speeds in 3rd gear . Turbos like these are whats needed to get torque numbers in foot pounds similar to horse power numbers , if you can get up around 300+ ft/lbs of torque it feels real punchy . 300 odd Hp may not sound like a lot but from memory R32 GTRs were quoted as having ~ 290 in std form - from memory . Regardless torque is what you want and you need it usable in every day driving . What you will notice with the DP turbo is how much extra low end and light to medium load ignition advance you can use without detonation . Going from a std RB20 ceramic BB turbo to the DP I was able to screw in an extra 6-8 degrees of timing which really picked up the bottom end torque and throttle response . I really don't think you need an 044 pump as these kinds of power levels , I used a 975 at the time and even it may have been overkill . If you use larger than std injectors and a programmable computer the std FPR should be fine if it's in good condition . Do a search for an article from the June 2003 edition of Sport Compact Car Magazine , Google "Project Nissan Silvia Part II Behold the Potato" . Basically a USDM S13 with a JDM SR20DET fitted then the DP turbo upgrade . Good pics and the usual wowza story . I had the ear of JC from Garrett in the US at the time and he couldn't speak highly enough of that turbo . I went to Brett at GCG Turbos with the part numbers and he brought the first batch of them into Australia about 5 years ago . I know what I'd do , cheers A .

Wrong style of turbine and compressor housings , RB26 turbos are an engine specific T28/GT28 so not the same as a generic T28 or GT28 turbo housing wise . Something had to be done to get two parallel turbos close in to the head on an RB26 and somehow leave space for oil/water/air/exhaust in and out . A .

The Dell D610 is finally here and came with a good supply of power adapters , the travel one has two separate removable plugs for 240 AC or 12V cig DC . It all sits nicely in the 33 with the Datalogit connected and unlimited 12V DC . All that's left to do is get the Tech Edge connected and running through the Datalogit as well . Actually I'm going to have to find 12v supply for that as well but may use the better all weather bike style socket and plug for that . Really like this Dell Latitude D610 , used it heaps on the Wi Fi at home and even does an acceptable job of playing a DVD movie . Its light and compact (14" screen) and the battery is quite good too . You can rip the DVD drive out and fit an optional 2nd battery or Hard Drive if needed . Its been an ex corporate and they threw in unopened copies of XP Pro/Power DVD 7/Dell driver disc . Bargain for 380 ? Now about the Steak Knives ......LOL

This question gets asked a lot and the most basic truth is that many "T3/T04E" turbos don't work too well . The reason is that they are based around a "T3" turbine , which was designed to drive a 60 odd mm OD compressor , trying to drive a 76mm OD T04E compressor wheel . You have a fixed amount of turbine (exhaust gas) energy to work with so giving it a larger and heavier compressor to drive isn't the best way to get response from the turbo . The fact that the larger wheel can churn more air means that its drive power requirements go up so it means more turbo lag in the real world . The other drama is that when it finally gets up and happening the extra air from the larger compressor equates to more exhaust gas production and because the turbine wheel is small in relation to the compressor and it becomes an exhaust restriction . Ideally turbine and compressor size need to increase when you want extra turbocharger capacity . Now back to the "T3" turbine bit . Many turbines get called T3 when they could well be T3/TB03/TB31/TA34/T350 etc etc . Many "high flowed" turbos get TB31 turbines because they are very similar dimensionally (shaft wise) to the old dinosaur T3 turbine . The blade form is very different and it doesn't necessarily like being fitted inside bored out Nissan/Garrett T3 or Hitachi T3 flanged turbine housings . Garret did make a turbo that some may call a T3/T04E hybrid only they call theirs a TA34-1 from memory , it may have used a TA34 turbine and a small trim T04E compressor - been a long time since I looked at one . I do remember Fred from Turbo logic near Wollongong saying they worked quite well on RB20's . In my opinion RB20 and RB25 engines were factory tuned around getting boost at reasonably low revs and they feel pretty flat if you fit a turbo with a higher (engine rev wise) boost threshold unions . I also think new players to the turbo world think they can have more power and torque from a larger than std dryer and have it start at the same point . These engines have ball bearing turbos from the factory and fitting a larger plain bearing (higher drag loss bearing) turbo is a recipe for more turbo lag . Really the only thing that's terribly useful in a T3/T04E hybrid is the "T3" mount flange and the integral waste gate . Very convenient for fitting the bastardised turbo but neither guarantees that it will work very well . My call is that these turbos are build down to a price , budget if you like , rather than up to a performance standard . Its a shame people don't go looking for performance in other parts of their Skyline first , the first R33 I ever got in had the std turbo , GTR IC and pipe kit , PFC , exhaust , modified head with std cams and match ported std manifolds . Its performance was very good and more than good enough to unstick the rear and light up its 245/45/17's . If I wanted to Hi Flow an R33 turbo I'd have a Garrett GT2871R cartridge fitted into reprofiled std housings , the complete unit would be shorter than a std turbo and have smaller oil and water unions but you end up with a better center section than any T3 or small series T4 . Another alternative is the GCG BB Hi Flow though there are mixed opinions on those . I have very little faith in Hi Flowed "T3/T04e's" , a lot of their trouble is that many totally unworkable combinations can be bolted together because of the common T3/small shaft T4 turbine shaft dimensions . A .

That's what I'd herd as well , around 1mm . It doesn't sound like very much but being on the periphery of the valve means it probably makes a very real difference to how much gas can get past them with opened up or larger seats/throats . It may be a case of larger valves with shortish high lift cams (provided the valves don't touch on the overlap phase) may work well . Personal bent I suppose but I like the idea of really well modified heads and just barely enough cams to get the job done , probably because its difficult to get around cams that have gone too far duration and overlap wise . Cheers A .

Your call but to my way of thinking you need to take into consideration that a factory NA engine will have a higher compression ratio and cams speced around that and the engines breathing characteristics . OEMs almost always drop the static CR and use shorter cams in factory turbo engines . It becomes very important (IMO anyway) NOT to restrict the exhaust path from the ports any more than is absolutely necessary or chronic detonation often sets in . OE turbos are intended for OE turbo engines not OE NA ones , I'd be wanting to go a bit larger on the hot side for your sort of app . A factory NA engine should have higher cylinder pressure than a factory turbo engine off boost , if you then raise the cylinder pressure with forced induction the extra pressure and heat is what drives it into detonation - especially with factory NA ignition timing control . If its good response and a torque boost needed you could do worse than to try a GT2860RS or one of the small or medium trim GT2871R's - in the larger of the two available (0.86 A/R) turbine housing . Something else to think about is the torque capacity of your transmission , if its full time 4WD (AWD) you need to be real careful of how much torque you feed through it - particularly if it has a low range (two spd transfer case) . I find lots of late model cars , some with reasonable capacity , lack torque down low and I have to wonder if it allows factories to use lighter weight and less expensive drive lines to cut production costs . I'd hate to see you trash a late model and likely expensive gearbox doing your own "R and D" . Like a lot of things I reckon if you approach it conservatively and have realistic expectations it could work quite well . One last , you may give it more stick but don't forget that type of cars original intended use which is not really to be a sports car . Brakes and handling are very important - I'll leave it at that . Cheers A .

Hi , I haven't been to them for ages but you could have a sniff around in the American Sentra SE/R and SE/R Net sites - if they still exist ! From memory in the US Nissan smallish front wheel drive platforms were B series rather than N series like ADM Pulsars but they had sort of parallel mechanicals like engines and gearboxes etc . For example our N15 Pulsars had GA16DEs and SR20DEs and I believe their B15's were similar deal . However unlike their B16s I don't think we got the QR25DE in the N16 like they did in their B16SE/R - I think SE/R is sort of like SSS in Pulsars . Also from memory QR25DEs are reasonably long in the stroke and may have a pair of balance shafts to smooth things out . In the states they were playing with turbocharged versions and JWT (Jim Wolf Technology) was possibly doing parts for them . Cheers A . Ah also it may not be relevant to compare an inline 6 with an inline four because for the same capacity the 4 has larger capacity cylinders and a flat plane 180 degree crankshaft , its a bit like comparing an SR20 to an RB20 with their different relative characteristics .

Yes I think that's ultimately the way to go , when it absolutely has to work use the proper tool for the job . I've seen early Dell Latitude D400s and D410's going for two hundredish , actually those early critters were very good at using very little battery power which is what you want when out on the road . The problem is that they may not be so good at playing a DVD movie or hardware intensive games - but the point of all this is tuning an engine management system so a fair bit of folding stuff hangs in the balance if it goes wrong . Am sure quite a few here have had instances of the lap top lemoning out whilst tuning on the road and then your stuck with whatever settings your EMS feels like remembering . It could be a long wait for a USB cable/co-operative Lap Top to get it right . In my experience serial ports and cables either work or they don't , and another serial cable is inexpensive and reasonably easy to get . A computer head friend of mine keeps telling me that very expensive scientific test equipment nearly always interfaces through serial RS232 hardware . He also said that is the reason why expensive Business or Desk Top replacement Lap Tops tend to have serial ports where the home entertainment ones don't . He has less than zero faith in USB and I agree that it often works poorly when you need it most , depends on the application I suppose . If your car/engine/EMS is worth more to you than 200-250 buy a cheapie serial equipt lap top . Only way to be sure , cheers A .