pnblight

While we are talking about twin well i still think the GT2560R takes alot of beating the last gtr i did made 510rwhp at 15.8psi (~524rwhp at 16.8psi) with rasor sharp responce.And interesting how opinions change in time (was told there was nothing significant in cam timing but i found it very different). Mine runns GT2560R aswell and makes 530rwhp at 20psi and both these cars had poncams and std fuel system (nothing special like high lift cams etc). As for the boost at a set rpm, in my opinion it is important or a true indication of performance as it is only a measure of back pressure WHAT is important is the toque and hp you get through the rev range and how earily it comes in and how linera the power delivery is, as this is what makes a great streetable car and fun drive. pete

Normally even a motor that has been dusted by the ceramic fagments of a turbine wheel it will still run, it sounds more like something else has happened to stop the car(ignition problem etc) i would start by seeing if your got and spark etc and work from there.

Ok well your lucky they have hung in this long as i have seen std turbos blow that had exceed .9 of a bar. And i think you will like the GT2560R's when they go on as they hall arse when setup right.

Sounds a bit like the igniter unit might be faulty, got anyone with a rb26 you can swop parts with to find the fault?

no that is not right you need to open your eyes a little and think If yours is doing this, dont just say the pfc is crap and the knock detection does work may you should be asking why is mine not working (because i can safety tell you that they dont all do what your does) and the knocks and haromics dont have to come from inside the motor as i have seen a exhaust touching the chasis effect knock reading before,(your could be as simple as this). The knock detection system of the std gtr with apexi pfc is one of the single most helpfull tools in tuning the car a tuner can have(trust me i have know tuned a few). pete

the 700cc sards go straight in and are a good injector for the street driven gtr the nismo fuel pump should be fine for these injectors if you run close to std pressure as my std pump services them up about 80% duty at ~530rwhp so a nismo pump should be fine at the same pressure but if you turn up the pressure the flow capiability of the pumps reduce accordingly. pete

I dont think understand how the knock system works ,it's looking for more like harmonics then just bump your a knock to the car. And yes they do work very well or why would a cars like Keir wilsons retain the power fc and hand controller when his running a full metec system (knock detection). As for knock levels well i think to many people get carried away with the levels as every car is different especially car run fordge pistons and lump cams etc BUT just concide this that APEXI and i believe nissan don't think there a real issue to you get around 60 knocks as that is when they fire the warning light (not before all they would have set the level lower) all that said most responible tuner will normally stay below 40 or so to give a bit of head room for a bad datch of fuel and or different weather condition to the day of it,s tuning. pete

Sydneykids is spot on and i would just be carefull as you adjust regulator, chances are you need a new pump as they offen drop off dramatically as pressure increases (not designed to run much higher pressure but they will go a bit) I have managed good results out of my std r33 gtr fuel system but only because i retain std fuel pressure and when the other way by putting big injectors (namely 530rwhp out of std fuel system and have done so on a r34 aswell)but for safety sake they will be upgraded in time. So if your only looking for a few exact psi fuel pressure it shouldn't be a problem if your fuel pump still has a bit more in it. But if your looking for quiet a bit i would bit looking at bigger injectors and ecu to control them correctly.

By the looks of your budget left you should just buy some std afms off r32/33 gtr they will plug straight in and work with the standard computer. I believe when you quote 70mm and 80mm afm you were quoting ID not OD as the vg30(z32) is a 80mm(not 70mm)afm and a pair are good for around 650rwhp plus (a little to big i think for what you want but would work still ) and the q45(infinity) is a 90mm (not 80mm) and there good for god knows (the 1100hp 8sec apexi car runs them) way to big for what you want. By trying to use a safc or similar device to compensate you will have very poor resolution as you will only be using a fraction of the FSD of the afms and result in very ordinary control. Plus to buy the plugs alone for these units you could have bought one of the std afms anyway plus you then have to solder them in to the harness. Idealy for the hp i think you'll be chasing for drifting ie 400 to 500rwhp a APEXI pfc and a set of rb20/25 afms would be the ducks nuts and at around ($150au each and plug straight in toi straight plugs but cant be use with std computer) very cheap but your vg30 afm could work well enough with the pfc also (after fitting the new plugs to the harness). pete

3. front mount intercooler (wtf) they come std with a unit good for 450rwhp mines running 530rwhp on std cooler 4.boost controller nice to have but a bleed valve works quiet well 6.dont bother steel wheeling them rev03 lasted a month or so and had to fix them again (steel wheels could cost from 1500 to 2000) why both when brand new garrets are 2400 to 2500

i would loss the std turbos as they can come back and bite you later (by dropping and exhaust wheel and dusting the cylinders ie full rebuild) the best bolts turbos in value for money 1/gt2560r 707160-5 $2500 new 2/HKS 2530 second hand or new 3/HKS gtss there the most common 3 but you can get trust units aswell stage 1 Apexi pfc and hand controller Turbo upgrade Exhaust minium 3" pod filters (mid 300's rwhp) stage 2 Apexi pfc and hand controller Turbo upgrade Exhaust minium 3" with dump pipes pod filters afms (rb20/25 or z32)offen best to replace intake piping aswell injectors 700cc (low 400's rwhp) stage 3 same as 2 with tomei poncams tomei adjustable cam wheels (high 400's rwhp maybe 500 depending health of the motor) I have done three gtr now to stage three of different configurations all were great cars to drive every day and still drive very much like a start gtr until you put your foot down. As for boost i wouldn't exceed 18psi on std motor as a rule of thumb. pete

Matt, The best way to try and explain what happens is if you think of the turbine wheel spinning at god know what rpm starts to brake apart the ceramic piece would be traveling at hugh velocity in all directions and it's not hard to see how the pieces could over power the exhaust flow back to the exhaust valve (normally the cylinder in the centre and in line with the turbo cops the worst of it 2 on frt and 5 on the back)on the r34 i sore this happen to it even damaged the inlet valve with small dents ans scratches from the ceramic pieces getting caught. I best way to see if it has damage the engine would be a compression test on the gtr i did the three damaged cylinder were all down on compression compared to the rest.Can i ask what boost you had been running the turbos at? pete ps i hope it is all ok

i think your best option would be buy to std afms r32/r33 (there cheap here in oz $75-100au ea)plus a little postage DO NOT try and run with the other afms unless you buy a APEXI pfc on which you can select the desired afms from the hand controller (a great ecu and maybe the best for a gtr on the market)$950au

Maxx are you comparing apples with apples because I cant see how on earth you can build a rb25 with gtr and tomei forged piston for half the price of a rb20 and if your not then the rb20 with strengthen rods and forged pistons could take twice the beating the std second hand rb25(you are never sure how good a second rb25 is going to be) and the 100cc exact capacity wont out balance you'll gain you will get with the long stoke configuration. pete ps was just giving the guy alternatives to the norm

would love to see a dyno sheet as that is very healthy torque and most be fun to drive .I did some number crunching and i normally get around the 570 to580nm of torque but it is gain about 5000rpm and held through to about 7300rpm where it just starts to fade slightly does yours hold the torque through the rev range pete

Well depends a lot on your finances and your plans for the car i personally think just buying another 2 hand engine isn't the best idea you have no idea on its condition and you could be back to square one 6 months down the road. I would if the budget could cope buy gtr crank and rods(~$550 to $500) and a set of tomei 2.4litre pistons(~$1600 not sure on $) for the rb20(rb24) which then can produce more torque than a rb25 in std form because of the longer stoke. It's a bit more money but it would be strong, torquee, and new .Plus the added capacity with spool the turbo quicker and add more botoom end punch. And it would be something different to the norm. I would think a combo like this could produce 400rwhp(300rwkw) with out over extending it self (with the right surporting bolt ons). pete

Hi Nick, Normally if you buy a full n1 gasket kit ,it will have valve stem seal in it, are you doing a full engine rebuild or just the head? So your fitting some tomei valve springs does this mean your putting sum nice lumpy cams in? If you are, and if they are over the poncam sort of lift 9.15mm i would invest in some new tomei cap retaining studs ,not very $$ and good insurance (as has seen studs fail on a high lift cam setup). best of luck with the mods. pete

gtr r34 turbos still fail as they are ceramic still i just finished rebuilding one from that very problem Save a few more dollar ~$2500 and buy a set of gt2560r 707160-5 off racespec you will not regret it. An exact $1000 now is cheaper than a $6000 rebuild down the road. pete

yes i do somewhere at home but unfortunately i'm on an oil rig in the mid of nowhere for the next two weeks, might be able to dig it up when i get back. williamsf1 the nm of torque you quote how exactly do you get this figure as nearly all the dyno i have seen work in tractable effort ,or was this done on a engine dyno, i reason i ask is all new car etc are quoted in nm ,not the tractable effort you get off the normal dyno. Typically a few of the gtr i have worked on run around 1850 pounds of tractable effort pete

ok just to give people an indication when i first installed the gt 2560r(i going to continue calling them that as it is what is stamped on the cartiridge) 707160-5 is was a STD gtr with air box the works (nothing changed bar exhaust) and it was tuned to 316awhp (at all 4 wheels) the company which did the job fitted a SAFC2 to add fuel to low rpm range (nothing about 4500rpm) The GTR at 316awhp managed a 12.08 at 113mph 1.7 60 footer first run, so i think that shops that the gt2560r can still be a nice turbo combo for a std gtr Beer Baron is nice to have favorite brands but i have yet to see the small hks turbos out perform the garret units in any meanfull way(reliability or performance) so you should give them a look before dismissing them.

i wont waste your time on this turbos personally the turbos you want BRAND NEW are the garret replacements 707160-5 racepec are selling them for around $2400 new the reason i say dont waste your time are the r34 vspec turbos are still ceramic turbine wheels and still fail and if they fail under the wrong conditions will take the motor with them (like the last r34 i built) and the group "a" are laggy but strong the gt2560r 707160-5 i use in a light modify combo ,generate well over 500rwhp with basically no lag what so ever (have done a number of these combos now) so for a little more money now you will never regret it later. pete

Good question, I have been concidering trying some more aggressive cams in mine when i do a full rebuild next month( going full internals) BUT the result i achieved with the r34 vspec i mention aboved were quiet awesome. The tomei poncams stage 2 are simple an awesome on road package (as they bolt straight in and give great results) I have yet to find the limits of the gt2560r's yet but i believe i must be getting close to there peak performance (i stopped tuning mine at 500rwhp as it had std internals and r34 is a brand new motor and is only running 15.8psi at 510rwhp) make you wounder what is posible from it at 20psi plus and some cam timing.(Garret australia tells me the turbines are good for 2 bar but i doubt the actuators would hold that). I personaly dont think i would go past 10.8mm lift and around the 260 to 270 deg depending on application (but with the extra lift you need to do a number of head mods , cam cap retaining studs upgrade, valve springs upgrade , lomb clearance machined to state a few. So the question is will you gain much from larger cams from these turbos ? most likely not over the simple poncam combination, so valve for money it most likely not worth the effort. pete ps does that answer what you wanted to know

twin gt2560r are the go last car i put together with these turbos and small cams and pfc made 510rwhp at 15.8psi with raser sharp throddle responsive the only reson it was tuned down to under 16psi was it madent had the new nismo pump fitted yet (it made 524at just on 17psi) and was boarding on the limit of the std fuel pump. as stated earlier you can get gt2560r ~$2500 and add ~$1000 for pfc and about $300 for rb20/25 afms ,~$700 700cc injectors sard your in business. You'll make 400 to mid 400's with out cams but through a good set of cams in the mix and you should be aroung the 500rwhp. I personally haven't seen a better on the street combo than this for all round performance(responce verse out right hp) my 2c

you guys get over the whole "must have been in WA thing" as a whole state shouldn't have to pay for a few peoples sins std injectors good for around 400rwhp or 300rwkw but that is maxing them out and not advisable if you want reliability (700cc sard injectors are cheap and run beautifully with pfc) pete

the lap of Nurburgring is awesome (but the rest is a bit lame) r34 gtr existing corners at 160kph and the thing is stepping out on him and scrumming on race rubber. I just want one (900hp from memory) pete