discopotato03

Johnny thanks for that , searched for info on the HDi GT2 and RS intercoolers . There appears to be GT2 R33 kits but couldn't find an RS R33 kit . Will now look into the PWR 600x300x89mm one . Thanks all cheers A .

Tao what is your intercooler preference for a GTS25T please . I've search a little way back in this thread and you mentioned PWR . I want to lose the Blitz return flow and I agree that inlet flow restrictions are an issue and seem to peg these cars at around 280ish RWKW even if most things are sort of right . To recap I run the Blitz RF IC and 3076R 0.82 IW on std manifold , with Scotty fabbed intake tube . The exhaust is 3 1/2" from housing to behind cat which is an I can't remember 200 cell stainless one . 3" pipe with straight through mufflers x2 . Will look into Venom 100 cell if they are as good as it gets in a cat . Going to ID750s and fixing forked exhaust guides made a hell of a difference to the low down and idle mixture control , no obnoxious fumes at idle . Can just about get away with 100 cell I reckon . I do like the idea of the OE cast crossover pipe because I can keep the standard recirc valve . I think ultimately I can get away with non standard IC piping in the engine bay because after more than 10 years with this R33 I've never been asked roadside to "pop the lid" - ever . I guess I'm too old and and don't hoon so cops ignore me . Please can you tell me the gun intercooler and pipework to run to not make flow or cooling an issue ever for 300 plus wheel wasps . Also I'm running 98 PULP rather than ethanol these days so need every cooling advantage I can get to run acceptable ignition timing . Every Skyline out there is seemingly an IC with a car bolted to it and it doesn't seem to make them cop bait around here . So , money aside , what do you think rocks - PWR Plazmaman ? Looking for a result not a bargain .

I like to hear what intercoolers people are going to after the Blitz return flow . I have one and I think from memory the earlier ones had a larger bore return tube than the later ones . Also if someone's had the Blitz and changed the core to something else and then plumbed it return style I'd like to see pics of that PLZ . Cheers A .

Johnny I'm not ignoring your post , I just want to keep the standard manifold and so pointless going beyond its realistic flow capacity .

Mothot I thought of the T3 single scroll IW version too and it will be very interesting to see your results . As for the 7163 the only hands on feedback I have is that the 7064 is a bit more responsive and tends to work better on engines that don't have brilliant volumetric efficiency levels . Gut feeling is that the wheels are getting big for B1 frame sized housings but I'd say that's part of the compromise for having the flow capacity and packaging a bit more easily . I'm wondering how the 7064 and 7670 compare in single scroll IW form to the GT3076R 0.82 IW T3 turbos . Geoff has said that the 7670 is getting bigish for an RB25 but if its any more responsive than the GT3076R 0.82 AR then its still not too bad . The big question is will the standard exhaust manifold keep up flow wise with a 7670 ? A .

Just looked at mine , that fitting on the front of the plenum goes to the fuel pressure regulator hose . The rear plenum one goes to the standard boost gauge solenoid box gadget . Non standard boost solenoid here but one side goes to the waste gate actuator and the other the barb on the steel IC return pipe that feeds into the cast aluminium crossover pipe . A .

I think you'll find the static compression ratio is the same . Lower volume combustion chamber and the middle of the piston crown is lower . On the R33 spec RB25DET pistons the "plateau" is taller effectively giving deeper valve head reliefs . From memory the Neo turbo pistons may have the oil cooling channels behind the ring pack area like RB26 pistons do . Pretty sure the Nissan WSM shows the static CR as 9.0:1 . And they used a slightly larger side mount intercooler . A

I think the most practical way to look at these OP6 Turbos is that the factory used them as part of a system to make better overall performance than the R33 RB25DET spec engine did . They made a completely new cylinder head and valve train , altered cam specs and changed the inlet manifold as well . Bore stroke and static compression ratio are the same . The bigger turbine housing they already had from the four cam single BB turbo VG30DET . You should look up the standard power outputs for R33 and R34 spec RB25DETs and note the torque peaks but more importantly where they occur in the rev ranges . Don't quote me but I think with the R33 version the torque peak was up near 5000 revs where the R34 version was more like in the low 3000s . To me it looks like Nissan wanted more lowish and part throttle torque in the R34 engine and achieved that without a low turbo boost threshold or onset if you like . Things like higher air speeds through a slightly smaller runner diameter inlet manifold possibly with a smaller volume plenum chamber . Cams with a bit more lift and a bit less duration which would increase the cylinders trapping efficiencies . When you can make more low end torque you can afford to raise the boost threshold with things like larger turbine housings - which have advantages higher up . You wouldn't achieve the same thing on an otherwise standard R33 spec RB25DET by only substituting the OP6 turbine housing or complete turbo . I imagine you would start to open a dip in the torque curve by having boost start later . Nissan would have been looking for cleaner exhaust emissions for a late 90s car and I also think the R34 GTt may have been slightly heavier than the R33GTS25T . Given a choice you would always start with an R34 engine but rebuilding an R33 with the R34 spec rods pistons and head should give the best of both . Staying with the R33 inlet means all the plumbing and most electricals can stay the same . From memory just need to rejig the CAS wiring and change cam solenoid plugs . This is really only economically viable if your engine needs a rebuild or you can't quite justify an RB30 conversion . A .

My take with external waste gates is that the only sure fire way to get 100% sealing is to use 2 gates . I think relying on a divider that varies in temperature is a bit optimistic . With two gates , everything else right , the sealing point is the popet vave on its seat so if it works properly the only exit is via the twin nozzles . No offence but I don't agree with acoustics and turbo exhaust manifolds . Different story with NA engines but they aren't trying to accelerate exhaust gas pulses into a spinning turbine wheel . Like was discussed here years ago the idea is to have each cylinder blow down into the split scroll with the least pressure ahead of it ie high to low . The manifold runners are grouped to have two or three runners (I4/I6) set to have the other one or two cylinders not blowing down so the exiting gasses have the least resistance on their way to the blades . An I6 is a good example because the firing order is 153624 so front/back front/back front/back grouping makes it easy . Obviously Nissan used this to good effect with the RB26s separate 123/456 manifolds and two turbine housings/waste gates . No chance of one group leaking to the other north of their dumps .

Sorry didn't mean to repeat that post .

I have talked myself out of non standard RB25 manifolds and plenum chambers so many times it isn't funny . Just yesterday I was looking at a pretty blue Freddy going onto a GTS25T and asked again the shop owner does this cost torque and drivability right where cars are driven most of the time . Quick answer , yep more top end but costs down low . It is also very obvious that things like the thermostats housing and oil filter are considerably harder to get at . No crossover pipe but that's not real hard to remove once you've done it once or twice . I think the reality is that the J pipe or whatever is the way to go or if being real stealthy you're stuck with return flow type intercoolers . The factory alternatives are the RB26 setup or the Y pipe and plenum like some R34 RB20/25 DEs use .

I have talked myself out of non standard RB25 manifolds and plenum chambers so many times it isn't funny . Just yesterday I was looking at a pretty blue Freddy going onto a GTS25T and asked again the shop owner does this cost torque and drivability right where cars are driven most of the time . Quick answer , yep more top end but costs down low . It is also very obvious that things like the thermostats housing and oil filter are considerably harder to get at . No crossover pipe but that's not real hard to remove once you've done it once or twice . I think the reality is that the J pipe or whatever is the way to go or if being real stealthy you're stuck with return flow type intercoolers . The factory alternatives are the RB26 setup or the Y pipe and plenum like some R34 RB20/25 DEs use .

Did the R34 injector sub loom plug into the R33 main harness . I know the coil one does . Cheers A .

Just for the record does anyone know if the VCT switch/valve is the same R33/R34 - aside from the electrical connection ? Just may save some work if its a simple swap . From the above I gather the coil and injector loom plugs are the same R33 to R34 . Cheers A .

Geoff at this stage I think the 0.92 TS 7064 is the best bet for me . I noted what you said about your Ecoboost 2.3L 7670 and where it comes into power . I also like the idea of an around 3000 rev boost threshold and the slightly larger 0.92 AR turbine housing , surely this combination has to have it all over a single scroll 0.82 AR IW GT3076R . I'm trying not to have the big or small turbo feel and top end revs and power numbers aren't so important to me . 400-450 wheel Hp is fine but a broad spread of power and good part throttle running is essential . Lastly that turbine housing coating you do , how much of a real world difference does it make keeping the radiated heat in check . Be in touch cheers A .

I always thought along the lines of 300-330 rear wheel Kw on an RB25 with standard rods and pistons , it's why I wonder if a TS IW 7670 is a bit too much turbo . I don't have any volumetric efficiency figures for RB25s , they do seem to rev ok but factory manifolds were obviously intended for lower outputs with a turbo that was super restrictive on the hot side . Been a long time since I drove a standard turbo 25 but it was mediocre boost from around 2500 revs and all hisses whooshes etc . This is why the HKS GTRS (GT2871R 0.64 AR T3) felt better or less restrictive anyway . The 30R was better again but introduced a "classic" bigger turbo feel and needed tuning (timing) strategies in the low rev part throttle ranges to make it feel good on the street again . I'm long past the stage where boost at part throttle and soft pedal revs is worth it because conventional turbos that do that compromise everything else . Doesn't mean modern twin scroll systems cant help here but the whole turbine speed exhaust gas pressure/velocity thing is the hardest part to get right - and everyones "right" differs . Geoff thanks heaps for the pics of the 7163 and 7064 on the RBs , gives us some packaging ideas . I'll talk to Scott at Insight again because he's tuned most of the EFR range and reckons 7064s are good . You say these have EMAP advantages over TS 7163s , important to me because in theory I could run more advanced timing in most places . Thanks all cheers A .

Hi Lith , crystal ball question . I was reading your 2011 post at GTROUK and I'd like to hear what your gut feeling is on how the 7670 would have gone compared to your GT3076R . My 52T doesn't feel terrible but a little more slightly lower would be nice . Geoff guesstimated at the time that it should have churned out about 450 whp or around 337 WKw . At the time I think you were considering an FR manifold and the non gated 1.05 TS housing . Do you think a flange adapted std RB25 manifold would hold back the TS IW 0.92 version ? I think I've pretty much narrowed it down to this or the TS 7163 . I think the 7064 was a gap filler in the range because the development phase of the 7163 stretched out so long . One or the other will come from Full Race once the details are sorted . A .

Be real interesting to see some back to back testing of the TS 7163 and TS 7064 , final outputs may not differ a lot real world but the all round drive characteristics could . Since you've had the GTS25T and GT3076R experience what's your gut feeling with these two units if you were doing it with the standard manifold ? Also small update , been tuned on 98 recently and making my own adjustments for the part throttle low rev stuff , makes a noticeable difference advancing up the timing in these areas . In the GTRS E70 days I was doing this but eventually the limited exhaust flow took its toll , the 30s much improved exhaust flow really showed up how clean mixtures and suitable timing pulls up the low end torque and drivability . A TS 7163 is a far cry from a GTRS but just prefer to avoid the what you call smallish turbo feel . Having said that some people in the States commented that applied properly 7163s can make the next two up EFRs seem almost redundant - big call that one . Everyone will be different in regard to their ideal power delivery and engine characteristics . A . Edit . About manifolds , I want to keep mine standard and not bolt things to it that it can't usefully support flow wise . There would be a point turbine size wise where the B2 housing needs something better .

$64 question that one . For a roadie that has to vaguely pretend to look registerable I think adapting to the standard manifold is at least convenient . I've been ploughing through another thread , Evom this time , and getting different perspectives on these EFR 7163s . http://forums.nasioc.com/forums/showthread.php?t=2640508&page=3 The figures are pretty had to ignore and the most impressive data I've seen to date on 7163s esp in TS form . I gather the T4 TS IW turbine housing is what was used to make the monumental torque in one case . I reckon its sold me on the TS 7163 and B1s being compact for a BW EFR will package better than a B2 ie TS 7064 or 7670 . If a TS T3/T4 adapter gets it on the standard manifold then I'd say that's going to make a very torquey RB25 if tuned properly . My gut feeling now is a lot of thought and development went into these turbos to enable them to make good airflow early and avoiding compressor surge . Very difficult to have fast response with low hot side restriction with lots of airflow/power potential - and not surge in a plain style compressor housing . I have read where in their early days people thought these units gave sort of lackluster performance which lead me to think they had compromises built in for whatever reasons . Obviously 7163s are not a flat out drag turbo and wouldn't suit everyone , I wouldn't expect to see them as singles on many 2.5L and larger engines other than EJ25s - unless people wanted a mini V8 . My only reservation is will it allow you to soft pedal an RB25 around without flying into boost and positive pressure AFRs all the time . I guess you can't have everything but somewhere in the 7163 - 7670 range lies the answer I'm sure . A .

So Geoff do you still think TS IW 7163 over 7064 for a street RB25DET . A .

R34GTT or "Neo" head . Shim over bucket clearance adjustment and better cam profiles . Smaller cc chambers need Neo spec pistons to keep the std CR , same 9.0 to 1 static as R33 RB25DET engines . Neo spec pistons have larger diameter gudgeon pins and use RB26 rods as original equipment . No brainer IMO . A .

Thanks fellas for the feedback . The 6758 7163 7064 and 7670 are the range that interest me most . With the right IW turbine housing or a T3/T4 flange adapter plate any of these can in theory bolt up to a standard manifold RB25DET . I don't seek a squillion Hp but I like the idea of reasonably linear power delivery . Part of the aim of these EFR units is good response without high turbine inlet pressures . I've had the GT3076R experience and while these are alright for "classic type" turbo power delivery I think its possible to have the same output with a lower boost threshold and better transients . I spent hours in the last two days going through threads about 7163s mainly the long one at NASIOC and many of them are in two minds over this turbocharger . Admittedly an EJ25 is hardly an RB25 but at least the capacity is similar . Interesting that the 6758 now has the 0.80 AR TS IW turbine housing available but would possibly overspeed on an RB25 . Somewhere in the 7163 7064 area is where I think a real good street tire/power range would be and sort of line up with what the ole GT3076Rs did power wise . You'd think either would be better overall its just little seeds of doubt exist over the 7163 , like Lith the Cranium dyno scratches the casing over that big trim 71mm compressor . I mentioned elsewhere that I was surprised to read that the 7064 uses a 70mm 56 odd lb compressor with something like a 52.2mm inducer . B2 EFRs also have available a T3 flanged single scroll 0.83 IW turbine housing and this should make it a bolt on to an RB25 if you can live without twin scrolls . A TS 7163 should go on with a T3/T4 adapter plate but the result is hard to guess . I think I remember Geoff saying that the 7670 is getting to be a big turbo for an RB25 and is probably heading into "classic" power delivery . Possibly a different story on an RB26 with a decent manifold and waste gating . Anyway I'll do some more reading on the 7064 and see what results people are getting with them on 2500cc engines preferably 6s . Geoff would probably lean me towards the TS 7163 but I'd like to hear his theories on the 7064 RB25 combination . Thanks all cheers A .

Mr Lithium , I'd like to hear of your experience with the 7163 . Some users in the US think they are a bit laggy for their size and output . I don't know if anyones had one as a singleon an RB but its an interesting thought on an RB25 . A .

Hi Geoff , a few years back I spoke of using a TS T3 to T4 adapter plate to fit a TS 7163IW turbo to a stock RB25DET cast exhaust manifold . Can you supply such an adapter plate in stainless to adapt the TS IW EFR B1 turbine housing onto these Nissan exhaust manifolds ? Cheers Adrian .

I can't remember if Scott said they had or have a plug in version in the pipe to suit an R33 . I just think these KV8s sound like they use more OEM type strategies than the usual offerings . Things like volumetric efficiency tables and short/long term trim settings , more like a true self learning system than simply having closed loop oxygen sensing trying to trim conventional load/speed map systems . He said these are aimed at motorsport applications and I guess like the current eco raped emissions engines competition engines need tighter control over what's happening running close to knock and temp limits . Race engines often have to have fuel consumption limits because of limited fuel stops/weight etc . I suppose emissions will be the next thing on the race engine hit list . Anyway that aside I think tuning close to the limits safely gets the most out of whatever engine you have particularly when not driven at WOT and high revs . The things you can still call a car today feel reasonably crisp and have a broad spread of torque starting pretty early . I don't think its all purely the physical engine itself , modern engine management and tuning would have a big say in how these hot lean burn engines perform . By comparison an RB is a true dinosaur but getting a bit more out of them with smart electronics and tuning can't hurt . A .