discopotato03

Mine is an S2 so no dropping resistor on the back of the coil cover . I would think that electrical issues are a definite possibility here . Can you check that resistor or find some mod to remove it from the equation ? Just a thought cheers A .

Looking good Mr Lith . I guess we always want more , guilty , but I'm wondering what you'd think of a 7670 in the same form . I'd like to think that it would be more responsive than a GT3076R and get the round 300 figure with less boost like say 17 -18 pounds . I'll have to look for dimensions but pics I've seen of the T4 twin scroll IW housing looks like they put the turbos centre line a bit closer to the mount flange face . Makes me wonder how it would fit up in an R33 with a flange adapter plate . If you're reading this Geoff what does your crystal ball say the response difference is like with a TS 7670 vs single scroll T3 7064 . Cheers A .

It will be through the original ECU . You may find it easier to look for the locally sold MR30 (2.4E) WSM because things like fuel pump wiring is probably the same .

Just a couple of thoughts that come to mind - just thinking out loud . I would have thought that a hydraulic bucket RB25 would be the least desirable version to take drag racing . I'm under the impression that hydro buckets are a low maint production item that don't lend themselves to high rev use . I can see value in using aftermarket plain buckets and shims - and cams to suit . Basically it isn't really a 33 series top end then . If you can find one a Neo RB25T engine is better as in shim over bucket valve train but even they aren't something I'd like to regularly rev to 8000 plus . In std form Neo turbo's have better rods and pistons than R32/33 RB25Ts . Imo the 26 valve train was the one that could take the most revs and be reliable , of course extra work to service shim under bucket valve trains . Also the 26 six throttle inlet is the way to have minimum pressure drop on the cold side . What people are trying to tell you is that to have your approx 500 Hp and a usefull rev range , valve train rev limited , is to keep the VCT . If you set a sane rev limit of say 7500 and want a 4000 useful rev span then its going to need to be taking off at 3500 revs . I guess its easy to look at it from a revs going up to sky perspective but I kind of like seeing it from the top down rather than the mid rev range up . From what I read the hydraulic 25s don't cope well with lots of cam lift so to get the upper end breathing they use extended duration . Trouble is you reduce the usable rev range because it wakes up later - closer to a sane rev ceiling . The Neos can stand more aggressive lift ramps so (in theory) get better breathing with a bit more lift and a bit less duration . Anyway theorizing aside if you wanted a high rev capable RB then IMO the RB26 , head anyway , is a better basis to start with . With 25s the Neos were the latest and more highly developed versions that made more power more reliably than the R33 version . Just my take and my 2c spent .

Keep the results coming please , I'm sure lots of people are all over this thread . Mr Lithium , I'm very interested to know where that RB25/7064 T3 hits 300Kw rev and boost wise . Obviously its going to shame a GT3076R in that it starts much earlier and should have turbo response much closer to throttle response . Thanks all , cheers A .

AFAIK all three versions of the GT/X3071R use the same GT30 turbine , which dates back to around 1991.

I think you'll find that many OE hoses on our 18+ year old cars go hard and don't want to seal . If you have the original heater hoses on your R33 squeeze them and feel them crackle . And the plastic hose joiners on the firewall won't last forever . The EGR and breather hoses go hard and brittle as does the brake booster hose .

Yes the N14 Pulsar GA16DE one I "looked at" in the you pull it wreckers will never work again , I don't experiment with my original import car parts if I can help it . I suspect some of the probs with these things is that the plunger valves spring loses tension over time and no amount of cleaning or changing electrics can fix this problem . I think they are fitted together and the spring tension is pre set with that brass bung and then its epoxied so it won't screw itself in or out . If I can find a way to successfully remove the epoxy and get that bung out without damaging it or the alloy castings threads I can possibly adjust the spring tension . I really need to see one apart to see how the valve seats and seals . I can't justify 500 dollars for this so I'm looking for a more sensibly priced fix . Also what I REALLY want to know is how hard is it to pull the main vacuum tube out and swap it into another IAC assembly . The ones that are similar enough are the S14 SR20DET ones and the late 93 N14 GA16DE ones . The main difference is the steel tubular part . A .

Yes looking good so far . A .

Just Jap keeps the one between the cam covers and the other one off the pass side I got from Kudos . Just on this , with idle issues take a close look at the IAC Valve on R33 RB25s . If you've checked everything and cleaned the bastard yet still have a slightly fast or intermittent idle issue these can be the culprit . Expensive ex Japan ie 500 ish there is a few alternatives . If interested look at the thread in the maint section . A .

Just on this I found a picture on an American site where someone stripped an IAC housing ie removed the epoxy resin over the plunger/pistons brass plug and pulled the guts out . He said once the resin is removed to screw the brass plug in first to get the resin out of its fine threads . Clear and then screw the plug out and rempve the piston and spring . There is a youtube of someone trying to stretch the spring to increase the preload on the piston . More later cheers A .

Thread resurrection . Been searching for hours about R33 RB25DET IAC valve/housing assemblies because I reckon mines shot . I went to a self serve wrecker yesterday to see if I could find anything similar in a locally available Nissan . Turns out that N14 Pulsar GA16DE cars use the same gasket and pattern as R33 RB25DET , the 1993 ones anyway . N15 GA16DEs use a totally different system . An early 93 N14 had the older IAC motor with the sleeve valve system like I think R32 RB20s had . I got the complete assembly off an 11/93 N14 and from the outside it looked the same as my 96 GTS25Ts one . Where OP found a blanking plug the N14 unit has a tube the same size as the RB25s one but without the cross tube that's plumbed back to the crossover pipe . If you could swap the pipes over the N14 one would probably work fine . I grabbed the solenoid itself to try but it does pretty much the same thing as the original one does , I think the valve or the housing bore wears and leaks and this gives an erratic idle and undershoot returns at times . For the record I've tried every which way to tune around this and nothing works . I have to use an idle "retard ramp" to hold the idle speed back and still get issues . My idle screw is almost all the way in . Clearly it has a leaky valve issue . Kudos in QLD can bring this IACV assembly in but they are exy like 500 odd dollars . Can someone tell me how to get the steel tube out of the housing without destroying it plz . Thanks in advance cheers A .

Aftermarket fuel pressure regs , which work best . Hi all , I'm using a Turbosmart FPR 800 which I went to when the Plazma rail and ID850s went in . I'm suspicious that these "entry level" 800s may do some unusual things compared to an OE RB25 reg anyway . First up they obviously don't hold pressure very long after shut down and the fuel pump sounds excited when priming up to start . Also I seem to get a lightning quick lean spike when opening the throttle at light loads and lowish revs . I use a Tech Edge WB3A2 with a Bosch LSU 4.9 02 probe . It seems impossible to tune out the lean spike and mostly it can't be felt when driving . I've never been inside one of these regs to see what they use for a regulating valve so don't know how well it works compared to an OE FPR . I've been searching to see what others have found and note some seeing marked pressure fluctuations when the injectors open initially . I did have a play with injector dead time voltages and it did improve the spike partially but its not the real fix . One FPR tester found that there can be a wide range in FPR performance and while they didn't want to mention brands they did say that the Turbosmart FPR2000 worked quite well . Also btw I'm using a new Nizmo 33GTR fuel pump . If you want a know good adjustable FPR what's the deluxe option . Thanks in advance cheers A .

Yes it should be real interesting to see the results particularly for the 7064 on the standard manifold . In some ways its a pity that the inlet side isn't standard but the 7064 may make up for the G/Fredys suggested torque loss at lowish revs . Would anyone be prepared to guess how well a 7670 T3 IW would go on the standard RB25 manifold . My guess is better than a 0.82 IW 3076R but not sure where the manifold becomes the greatest limitation . Liths 7064 T3 IW very probably could be the gun IW turbo for the standard manifold . Looking forward to the results cheers A .

Rounding up R33 GTS25T crank case breather issues . Just got from Kudos the last breather hose or "Hose -Air Inlet" Pn 11826-21U00 . In the middle is an alloy reducer with an around 5mm hole . I'm not sure if the original hose still has this because its gone too hard to tell . Its cracked at the right cam cover side and letting vapors out . I'll cut it open when I stick the new one on . A .

Found one of the main issues . I had the crossover pipe off to clean the throttllebody and when looking under the inlet manifold I noticed a blue plug hanging down . Turned out to be the air regulator plug and what a mongrel job it was to get it back on . There's no room to do it in situ so you have to remove its mounting bolts and pull it forward to plug it back in . The R34 Neo turbo engine is better in that it has a wax pellet cold start air valve built into its IAC valve housing making the plumbing a lot simpler , no regulator and air hoses like the R33 version has . Upshot is it now warms up and idles better . The whole off idle and return to idle range from around 1700 revs is a LOT smoother . It used to flat spot and have lots of mixture control issues I'd say because the IAC valve was trying to work over a wider range than it was designed for . Those air regulators work off electrical current from the fuel pump relay as well as conducted heat from its mounting point on the water log under the manifold . BTW if you ever have to R & R that air regulator get one of those small mirrors with the ball mount on the telescopic handle , mine has small LED lights on the mirror and came from Bursons . You can't see under the manifold so the smallish mirror is a godsend . The bolts have 10mm heads and having a 1/4 drive socket set is also a big help . When refitting slide a small screwdriver through the lower hole to line it up and fiddle the top bolt in . Make sure the hose spring clamps are positioned so they don't block access to the bolts and you can get at them in situ . Bank on a couple of hours for this job . A .

I've got some sort of vacuum leak drama giving mine idle issues speed and mixture . Yesterday I pulled each vacuum hose off the plenum and used the highly scientific method of sucking on each hose and tongue over hole to see if it held partial vacuum . There are two on the back for brake booster and OE boost gauge . Three on the rear right hand side , two for the charcoal canister and one for the BOV . Last two on the front for PCV and fuel pressure reg .They seem good except the signal line to the Turbo Smart FPR which leaks off very slowly . Its the reg not the hose . Had the IAC housing off the back of the plenum to clean , been done before but now extra clean . Engine breather system . As I said the the PCV valve grommet and hose are new and the U shaped hose from left to right cam cover was replaced genuine a few months back . The upper hose on the right hand cover "T"(viewed from front of engine) is old and hard but doesn't appear to leak . This is the one that runs to a straight steel joiner and another hose runs down to the smaller fitting on the turbos inlet pipe . I've got Scotty's inlet pipe so it joins in slightly below and behind the larger BOV return hose . For some reason I can hear a hissing coming from the PCV valve and if I pinch the hose it stops and the idle slows a bit and half returns , it sounds like that PCV is passing a lot of air but it can be intermittent which gives me idle issues . I would have thought its open or its not . Something I have to look into is that second old hard hose because I'm sure I've seen a pic of a genuine replacement and it had what looks like a short piece of aluminium bar inside with a hole drilled through it - restrictor . Anyway to get that hose off the turbo inlet pipe the airbox and the two main steel pipes (to/from intercooler) had to come out and I didn't find any obvious leak points . What's got me stuffed is why the PCV system is passing so much air at idle . I'm wonder if air is getting into the crank case somewhere else , dip stick is properly seated so it isn't there . Anyone got any clues , cheers Adrian .

I'm interested to know what other leaks you found , I'm sure I have a few more . Cheers Adrian .

R33 RB25 PCV grommet issues . Hi all , just a tip for those looking for vacuum/boost leaks on these old girls . For a while I've been replacing water and breather hoses on the 21 yr old boat and found an issue that had teased me for ages . Silly tuning issues mainly right down low and a bit more boost lag than I thought I should have . Amongst other bits I had Kudos send me a genuine PCV valve grommet and hose . The old valve had been loose in the grommet and when I removed the original one the bottom third of the seals lip was missing . Not surprisingly the hose was old and hard and may have been leaking under boost as well . Feels better to drive and shows lower manifold pressure at part throttle , goes into positive pressure a bit more easily and the slight lean spikes off idle are almost gone . "Valve Control" Pn 11810-21U00 , "Insulator-PCV" Pn 11812-41B00 , "Hose - Blow By" Pn 11823-AA510 . Grommet same on R34 GTt . Grommet around $8.80 , kit inc PCV $44 , all three around $70 . Something to keep an eye on cheers A .

No not ignoring at all , and thanks for your pics because they answer a few questions , like keeping the factory R33 airbox and how neat your external gate setup is . A recirc valve mount plate could be made with a barb on it and joined to the one on the back of the U pipe with a rubber hose . Only problem with that cold pipe style is that it runs right over the top of where my fuel reg is but it could probably be moved . Can't see yours . On topic , that looks like when you had the gate off your Hypergear turbos turbine housing and before the turbo was upgraded . I like the sound of Taos ATR43G SAT in BB form but I'd need an XR6 style turbine housing because that's what my 3076R has with 3 1/2" dump to suit . I'm not a big fan of Garretts GT30 turbine and Taos certainly put a mountain of turbo/turbine development into his units . Also if those 256 Poncams do SFA except add agro I can put the originals ack in . I'd rather have a little better turbo response and forsake 3 Kw up high . One last one for Tao , you revised the turbine in your ATR45SAT and gained response with no power loss . Is this something that could be considered for the ATR43GSAT turbo ? Thank you Jonny and Tao for your input its much appreciated . Cheers Adrian .

Cheers thanks for that . A .

Thanks Tao , I know people want to keep this thread on topic but I want to follow your ideas of making my GTS25T capable of getting the best from my turbo and maybe one of yours . I'd like to know what you recommend for the cold side pipe that allows me to keep the factory recirc valve or which aftermarket plumb back type to use . I know some cold side pipes link up to the standard cast crossover pipe but not sure if they clear the factory airbox . Not even sure if the standard box and snorkel is good enough for 300-320 Kw performance levels . The pictures of your yellow R34GTT show a large elbow , I'm guessing 4" , and a pod filter . Did you box this in to keep the inlet air cool and what box do you like on an R33 GTS25T . Once this is sorted and tuned I'd like to look at your ATR43G SAT in BB form but with the XR6 type integral waste gate 0.82 turbine housing . Thanks in advance cheers Adrian .

GTS25T Intercooler pipework. Hi all , I want to fit my PWR 600x300x81mm FMIC but want to keep the std GTS25T airbox and snorkel . I have Scottys inlet pipe feeding my GT3076R . JJR aren't that far away and I'll be looking at their pipe kit because I like the idea of keeping the std crossover pipe for the recirc valve . I did like the look of MickOs top pipe because it has the U bend over the cam covers and a base to keep that std recirc valve and plumbing . The "Mick Pipe" looks easiest but does he or anyone else still make them ? Cheers Adrian .

Its a Garrett GT3076R 52T in their 0.82AR integral gate T3 flanged turbine housing . I'm back on E70 now but last on the rollers 268 RWKW on 98 Pulp . I think the fuel intercooler and a better cat will allow us to max out the ole 3076R at last . I'm chasing facts on Taos ATR43SAT ATM , he said they are a bit more responsive than the 76R . Cheers A .

I finally got that PWR intercooler today and man its HEAVY . Tao I looked at the pics of yours on page 250 of this thread and yours may have slightly different tubes . Mine is flat faced on the tubes where yours looks to be rounded ? Same number 17 from memory . I think you mentioned that you used JJR pipes on the yellow R34GTT and they are around 2 1/2" and go over the fan and link up to the std crossover pipe . Will try to get this in soon and track down a decent 100 cell cat ie Venom 5" body one . Then hopefully back on Insights dyno for an E70 tune . Also I think you mentioned than Tomei Poncams don't do much except add about 250 revs of boost lag , would you give them a miss on an R33 spec RB25DET ? If they're useless may have to go back to the factory 33 25T cams . Lastly do you think the factory airbox and snorkel are good for 300 plus RWKW with a decent filter panel . Thanks in advance cheers Adrian .