tommis85

Are you talking about turbos on identical engine types because if not then capacity and rpm's and so forth would also play a great roll. Like, for example, the GT35 and T04z function a lot better on stroked Rb26's as they have higher capacity.......close capacity to the 3.0L on which they're meant to run very well on. I think you also mean: "you could get a properly setup T04z making power nearly as early as a poorly setup GT35...." ???? (the GT35 is smaller than the T04z). But yeh, I think you could add the size and shape of your intercooler piping and core to the list as well. The more corners and restrictions you have in the how intercooler system from start to finish, the more lag you will have although this would only be very noticeable when you compare the BEST design (similar to V mount) to the absolute WORST design out there!!! Dump pipe / elbow piece etc behind the turbo would also contribute I guess. Induction system into turbo inlet.....hi-flow filter vs factory paper element filter etc. Oh, and if you have some cold air or not....partition/cold air box and snorkle etc. That's just some things I can think off... ;-) To add to the mix in this thread, I'm going with a GT3040/76r on my stock-stroke GTR. I'm chasing good response and power but am not using twins. I've been wanting to go with a GT35 or T04z for a long time but I want to keep the response.....not to mention that, with the bigger turbos you'd want to be using external gates which don't fall under any of the mod plate codes (something which is a must these days, especially when you drive your car to the track) If I weren't so concerned about the legal side of things (having been to court and all) I'd be going for a nice GT35 setup.

Rezlo, I wouldn't mind checking the video out as I too am tossing up between a T04z and a GT35. Maybe you could post it up on youtube? My email is [email protected] Cheers, Tom EDIT: yep, I'm hating already! LOL

Guys, After doing a lot of reading on this site I think I may have come up with a nice turbo to suit my power goals and budget. I'm thinking of going with the internally gated GT3271 which really appears to be a nice mid range application for the stock stroke RB26. What do you guys say? From what people have said on here, this turbo should have nice results. Thanks, Tom

Yeh that would be good if I could make it down there. Well, 300awkw equals about 402 horses at the wheels. My GTR being stock probably only puts down about 220 horses at the back after the other horses that make up 280hp have had their legs cut off in the transfer case. So yeh, 400hp at the wheels would be quite a step up indeed!!!! Hopefully I'll have my new turbo(s) by then because I definitely won't be racing with them again - it's just a bit too risky with 13y/o ceramic wheels!

Ah ok yes that makes sense. Looks nice (and expensive!) lol So, with twin scroll you can safely go for a larger ratio of 1.06 while without the twin scroll you shouldn't go over .82 and possibly use the 0.61 to 0.62 sizes OR, even step down by a turbo size? What would you say it would be equal to (sorry, I'm not too good with compressor maps - am about halfway through the Garrett Site 101 to 105 on turbo sizing) LOL - gotta start somewhere haha! I've never had to do this sort of research before as I've never had to upgrade nor had the money to do a big conversion like that.

Ok excellent...well, maybe, just maybe, it looks like that I have narrowed my turbo choices down quite considerably. I guess I'll have to run a external wastegate with this one which I was trying to avoid as I'm a tightass I'll get onto my mechanic and see what he can get in for me as far as twin scroll goes. If the turbo is twin scroll then how does it perform at the high end? I guess it has the 1.06 rear for that so it shouldn't choke the engine one single bit, or? How does the turbo kick in? From the graph it looks like it's a nice gradual curve as opposed to a T04 non-TS style thump?

Correction, it's 0.82 lol, so none of the ones I listed

Juggernaut1, So those results in the above post are with the 3582 running a 1.06 ts bum end? I agree - that sounds like a fun car to drive indeed! So, judging form the graphs, I'd be safe to run a .83 or 1.06 on my RB26? Sorry, I think they come in either .8 or .83 - I'm not on the Garrett site at the moment.

Mate there are just too many choices and opinions. Maybe I should just do what most people do and that is: A. do the research to the best of you ability and then buy a turbo and "build and tune the engine around it" B. tuck your tail between your legs and buy a set of twins and conform with what is a GTR. ....and have some money left over to put into other areas like suspension and cooling etc. But seriously guys, thanks for the help and thoughts and opinions. Gives me, and all those others that just read this thread, plenty to think about if they're on the same upgrade path.

Ah Michael this is a small world indeed. Can't miss a car like yours and I don't know why it didn't click earlier. I got plenty of footage of you taking it sideways around the corner leading onto the straight. I don't think my GTR would have had much on yours - you were going quite well. Last time I went they also had passenger rounds at the end of the day so maybe I could come for a spin and see what a GTR is meant to go like!!!! Actually Michael, I'll probably have to get in touch with you seeing that you race at the same track as I do and also with, what I believe is a non-stroked 26?? Will have to see how you go when it's all ready! Might help me in deciding on what to get for mine as right now it's a back and forth between 30 and 35 As for legality, I'm going to contact Queensland Transport and see what sort of regulations they have for twin to single turbo conversions and mod plates. Usually it's simply a matter of staying within the mod plate code and complying with safety and emission standards....which is important for me and it's a daily driver and not a track car like Michael's.

Maybe we can get away with our turbo mods if we also install a donut deep frying machine under the hood? My mechanic says he can put a mod plate in for the turbo conversion. I'll ask him what the plate code actually covers and what is excluded. ...stuffs me too, most of their laws are beyond me. Where I live we pretty much have convoys of heavy trucks passing through billowing emissions into the air, brakes hissing and turbo's spooling and surging on gearshifts. BUT, if they hear one little hiss come from a car you'll have the entire population of cops get redirected from their domestic disputes, robberies and Donut King's to hunt you down!!! Yeh lets not turn it into a single vs twins thread....lets just keep it single orientated as the thread starter has started it off as ;-)

Discopotato03, That's all fair enough. While I was trawling through the Garret site I came across that very same turbo series. GT32. Seeing that people say that the GT30 series may be a bit smallish and is only limited to "that" much power and the GT35 being a bit biggish, how would you rate this GT32 series? On a 26, would it be a good average for single turbo upgrade? Well I have the quote for the twin upgrade pretty much ready to go - I only have to give my mech a call and he'll get the turbos in etc. I just want to spend a week or so getting feedback on singles before I do anything. ....that is the other part I've been fearing. I've had my fair share of run ins and court hearings and so have now ended up with my fully stock GTR. If you plumbed everything in correctly, made sure everything is heat shielded as per legislation, filtered and not vented to atmosphere....would it all be legal? Also, my mechanic said they can supply a mod plate for a single upgrade which would all be good or? You can make a single upgrade be totally legid and legal, right? From what I know, you're not adding anything to the car it doesn't already have (which is the beauty with GTR's)....you're merely improving the car.

I'm pretty much just weighing up the two options. I've already explored the twin upgrade to the finest degree. Now, I'm looking at the twin to single option and seeing what people have done, their experiences and how their results compare with their goals and hopes etc. So yeh, all the above has been very helpful...

Roy, Yes that was the first option I explored and had it fully quoted down to the last Banjo fitting that may need to be replaced It came to around $3800 including a couple of dyno-tunes. In that case I would have been running a set of twin bolt up 2560's or which ever ones were the modernized N1 size units. Yes you're quite right with the price comparison. Yes, one of the other mechanics I consulted had the same reasoning. If it's a GTR it should stay twin simply because a GTR has a twin setup. Personally I believe that the whole twin setup was something big during the era but these days, with refined manufacturing processes, you can get single units that have the same, if not better, performance than the 13 y/o ceramic jobs. It's just a matter of finding one lol out of the millions of choices out there. Back then, the only way you could get blistering response was with a set of very small ceramic exhaust wheels....literally next to no lag. I just like the idea of one medium frame unit. Easier to work on, maintain, less congestion and less complicated.

Paul, They may all be fair and good but I think that you may be comparing this to your stroker? The more posts I read (and dyno graphs I see) the more laggy the T04z seams to be. I sort of agree with Mike's comments above: It appears that you have to do all these things to make the big T04z perform and have the characteristics of a smaller turbo more suited to the 26. I'm sure that with these mod's to the T04 it would come onto song quite nicely but why do all that when you can just run a smaller turbo that will run nicely straight away. Paul, with my stock 26 I'd probably have to run the 0.61 bum end everywhere and maybe (MAYBE) use the 0.81 if I'm game and totally steer clear of the 1.00 (I'm not into drag racing anyway - I could buy a VL for that)

Juggernaut1, Yeh I'm just looking at the GT30 options in Turbobygarret at the momment. Yes you're correct with the number of options you get with this series ;-) According to the site two of the GT3071's come with a specially made rear end with a internal wastegate which is also excellent (although they don't sell the actuator with them but I guess you'll just have to get one from somewhere else). I'll have to run these past my mechanic and see what he can do for me. Well I race at QR (queensland raceway for those who may not know) and if you google the track you can see it has quite some tight corners but also a nice front straight. So, you'd have to set the car up for that but also Morgan Park in Warwick which is quite a different track again. I'm thinking that you'd have to bias the car to windy/cornering performance and hence, you'd also assume that the GT30 series would be best??? If only you could take them for a test drive!

Mike, that's very true. Right now I'm seaking input from everywhere I can on what turbo to upgrade to. My mechanic is doing his research and I said that I'd see if I can find some info on SAU and then compare. So far there's been some excellent threads, like this one. Yeh, it does seam a bit stupid and wasteful. Maybe I should be investigating sizes in the GT30 to low GT35 region instead, where, GT35 would probably still be too big?

LOL at the last couple replies! The last point despite the humour, is actually quite legid! I'll also have to revise my "wage" size so I can upgrade the whole car to take that power I think for now I'll go with the one size smaller turbine lol! I've been lucky to buy a stock GTR so I know what turbo response is all about. I've never experienced response in a turbo'd car like I have in my near mint condition R33. In saying that, I wish to be able to keep the responsiveness if possible so going for the T04 probably isnt the best choice. If you tallied up all the turbo recommendations in this thread I'd say that the GT3582r would have the highest count? Or? I think from what people have said in here, this turbo would be a good average unit to go with....not too small and not too big and just a bit laggier than the stockies or twin upgrade. BUT....then, you'd think that even a GT3582 would be too big for it for it with my power goals and track use. You want to be able to pull away nicely from those tight corners! I've heard GT3071's mentioned a fair bit for both GTR's and GTST's...would these perhaps be a better choice? So far, I have my choices rounded down to a GT3071, GT3582 and T04z twin scroll with 0.61. The last two would also be more expensive as they require external gates. TOO MANY CHOICES!!!! HELP!!! lol (sorry, my coffee has just kicked in)

Yeh, you' think so. Especially if you went for the twin scroll etc like KB240RB pointed out.

Yes the .61 with twin scroll would be the ultimate for a 2.6L engine....seeing that normally, the T04z is more ideally suited for a 3L motor. With the .61/twin scroll you should be spared from real bad lag....maybe it'd start to spool at say 3700rpm or so rather than 4000??? Public Enemy, do you run those other two turbos on a factory 26?

Hi all, I've read this thread from start to finish and I'm quite impressed by it's content. Nice work everyone! I too am looking at upgrading my factory twins to a bigger single to make between 400 and 480hp (just gross estimate for now). The first turbo I had recommended to me was a T04z which is why I read this thread back to front. A lot of you say it will run OK on a stock Rb26 but a lot of you also say it's much better for a 3L engine and would be quite laggy on the lesser 2.6L. However, one thing....what if you rain the T04z with a .7 bum? How would that go? You think it'd spool a bit lower than 4000rpm? I agree with one of the comments above that if you go to all these length of setting up a single unit then you should go for bigger figures. I was leaning towards the GT3076r but am wondering if you'd be better off with the 35r as above. Just too many options out there - if only you could passenger in the car that has the turbos....04, 35r, 3076 etc But yeh, if someone could comment on the bum end ratio of a T04z that would be awesome. My mechanic suggested 0.7 as mentioned before....what do you all make of it??? Cheers Tom PS - yes, I have considered a set of 2560's which would be far cheaper and less of a hassle. A lot of people have asked me why I just don't go with them so yeh....

Yeh that wasn't too bad an effort at all people - thanks for the info. Off course people out there can still add to it, but so far it's already a pretty good reference for anyone tossing up between the twin and single turbo options. For those people who are reading this, my mechanic has quoted me a maximum of $3800 to get two GT2560's fitted not including a couple of dyno runs for tuning etc. These turbos should give me very similar performance to the N1 units. If you go for this option it leaves money that can be spent on other bits and pieces needed for track events like oil coolers, brakes, tires and possibly suspension although this is not half bad in the GTR in stock trim.

Saliya, Thanks for all that info - very well set out! All your points are so valid, especially your first and last ones and yes, rough estimates/quotes have put the cost for a single turbo conversion around the 7 to 8 grand mark - but that's with a slightly expensive mob here in town. To be honest I think that for me the best thing to do would be to upgrade my twin's with a set of modernised N1 style turbos, ie, the 2560's. They will bolt on directly and all you may have to do is replace some banjo fittings if required. In all honestly it would be cheaper to buy some poor bastards GTR with all the work (not just turbo) already done on it - but then you never get the experience the feelings of it being all your own work etc as you upgrade step by step. If I was to upgrade with a set of twins I'd be able to run a even Bar everyday wouldn't I? I'm thinking that the stock support systems (fuel, iginition, AFM's etc) should easily be capable of running 14 to 15 pounds and from memory, the 2560's are rated all the way to 17-18 pounds max (to be confirmed lol!) Obviously I'd want to get some dyno tune runs in before and after to make sure that it's all working properly. But yeh, from all the discussion above and from what my mechanic has told me, it'd be best if I went with a twin upgrade with new, modernized turbos of roughly the same caliber with the main reason for doing so being to replace the inferior ceramic time bombs that could, even at stock boost levels, blow up at any time depending on how you treat them. Tom

Unique1, Well, thanks for the discussions above. That's exactly what I was hoping for - to uncover some more areas on it and maybe hear from people who've done it. Chances are, that I'll most likely go for a set on twins (GT2560's for similar response, or GT2860/disco potato for big twin upgrade).....but this would only be to guarantee very similar response on the track also because it will only cost me around $3800 minus the dyno tune's. I've been in a mates R33 GTST with a fully worked engine running 418rwhp with a GT3540 (i think from memory) and wow, the thing howls. These turbos don't 'woosh' or 'whistle', they HOWL like a bloody jet engine and once it does kick in it really throws you back. Quite violent, because of the lag period and then the lurch when it builds up the 18 odd pounds. So yeh, the sound and engine bay looks associated with medium to large single unit are pretty awesome in my opinion. Also gets rid of some of the clutter in the engine bay and is all very easy to access compared to a set of low mounted twins. Yeh I know what you mean there. With a PFC included, the single conversion will set me back at least $8 to 9000 I reckon...probably less the more time you spend shopping around or even doing the work yourself like some people on here. I've had my chance with serious car mods - my previous cars were a Mitsubishi Cordia and R33 GTST and both went a lot harder than my GTR went when it was stock, but they didnt come close to the GTR's stock handling!!! No way. But yeh...I put in many thousands into engine mods and re-builds and am now wishing that I put all this hard earned money into the GTR instead - with the same style and type of mods in would be seeing well over 500hp. (engine rebuild with forge's, ignition system upgrade, fuel pump and lines, turbo upgrades, exhaust and induction upgrades, gearbox......you know, all that stuff that could have seen so many more horses when put into the GTR!) But that's an old story lol - don't wanna bore you with it. Ohwell, what can you do hey? I sold them cars and now have a clean slate but don't know if I want to spend that heavily again. I also know, from experience that one thing leads to another with cars even when you limit yourself at the start.

Hi (00 \SKYLINE/ 00), Ok, looks like we have some differences in opinion above but that's excellent. It generates more problems and ideas for the conversion which makes sure that as many things as possible are covered before I fork out the big dollars. Up to point 4 or so is excellent, that confirms a fair few things then. However, my opinion differs in these points: 5. If I was to run a turbo that's even half the size of the ones you recommend I highly doubt that I would be running it on more than 1 Bar. Chances are that on my factory support system I'd be running it on a mere 12-13 pounds to start off with due to it's much higher air flow volume (efficiency) than the tiny stockos on there. I'm thinking that if I ran something in the GT30-35 range at 14 pounds it would be equivalent to running the stockies at 17-18 pounds as far as efficiency goes. And that's a lot on stock motor. 6. the car will run as hot as I drive it. I generally drive quite peacefully. On our track days, the engine temp didn't budge from half way and that's on 13 pounds...the only temps that did sore were the oil temp so for that I will need to get decent oil coolers. I'm amazed by how well the radiator works in these RB's....but yes, oil cooling must have been left out by Nissan. 7. yeh this area is open to opinion from everyone. So many turbos to chose from but what I want is to retain drivability which means that boost should come on at around 4000 (a bit higher than the stockies) and not at 6000 lol. That's pretty rough haha - I've seen plenty of youtube videos with big turbos, doesn't look very driveable especially on the circuit. But yeh, I dont think I want a turbine that big - not on a little 2.6L anyway. Them things are the size of soccer balls lol! The thing is I've seen plenty of very nice GTR track cars with singles in them and they pull out of the corners like crazy. They pretty much bounce from corner to corner so yes, with a nicely sized turbo (or custom turbo) you can get some very decent response for track racing (which I do - which is purpose of car etc). I would like to have both nice responce from the turbo but I also want it to be there all the time when flying down the straight where on this one, you can reach about 220-240km/h in Porsche GT3's. So yes, I don't want the turbo to run out of puff because it's too small or has incorrect ratios. I might yet go my twin upgrade option...but I want to fully explore both paths. Twins go exceptionally well and new modern small turbos get awfully close in response to the tiny little ceramic jobs from 13 years ago. But as I said, there are some awesome single setups out there that would blow the pants of my GTR on the track haha! Unique, I'll answer to yours shortly...just have to duck out. Thanks heaps for sharing your knowledge with me so far - very muchly appreciated!!! Cheers, Tom