Lithium

GCG/XTR sell "GT3076Rs" with a .70a/r compressor cover and ATPTurbo sell a GT3076R-WG (actually, do they still sell these? I can't be bothered checking) runs a T25 rear end with trimmed GT30 wheel and a .70a/r comp cover. Both I believe are TO4S...

I have never heard of such a beast. What does the id tag on the core say it is? Any pics of the compressor cover?

Its the anti-surge housing. My GT30R does it too: http://www.youtube.com/watch?v=ClXcNtAMJjg

Enough to have a lot of fun I'm glad people in this thread have more sense than in others talking about GT3076Rs... they're an awesome turbo for an RB25

Simon Dudding ran his first 8 on the pick a part RB30

Which is?? Assuming it doesn't include a custom gearbox or bigger displacement?

After reading various turbo threads from Oz, I am truly perplexed. Maybe you should all get XR6-Turbos or maybe Supercharged V8s!! I've driven my mates R32 GTR with a .82a/r GT3582R and its building boost in the 2500rpm range and by the time you reach the revs the stock turbos have reached full boost the thing is pretty much ready to hit warp factor 9. It DOES have a big turbo feel below 3000rpm but phooey. You don't buy a GTR to show how good it can tow.

. Funny you should ask, a mate of mine's car is on the dyno right now. It is running a forged 26 with 260 degree cams and a .82 gt35r. Just at the early stages of tune but I can tell you with a .6 bar spring the wastegate is open before 3500rpm. Intention with it is to have a really streetable low 11s car with possibility of tens leaning on it. We researched before choosing it and couldn't find anyone running it so hope we are right!

So long as it has a thicker headgasket and a good tune it should hold on for a while. I know a few around here who have done them - not sure how it'd relate to the dyno referred to here but the cars in question were running high 120/low 130mph trap speeds.

Really?? Are you sure - I most definitely haven't heard of that. The 1JZGTE was twin and ended up with the single turbo CT20B if I remember rightly, which seem about comparable with an R33 GTS25t turbo from all I've seen.

Are you wanting over or around 600hp @ crank? It will be a lot laggier being that its quite a bit larger size, very cool/impressive looking turbo though. If you are "just" looking for GT35R type power have you considered something along the lines of a Precision SC61, a T3/T04S from ATP, an HX35/40 etc... quite a few cheaper plain bearing options out there.

I assume you are looking at 600hp @ wheels? Because a GT3582R will do 600hp @ crank quite happily. GT4088Rs have been used on RB25s and RB26s with .81a/r rear ends and aren't too laggy for their size, definitely better suited than a T04Z for a RWD turbo street car looking for the 600hp @ wheels power area from what I have seen. If I even lost the plot, its where I'd look.

Definitely agree re dyno print outs not showing the full thing, however showing my car bogging and recovering and destroying an R32 GTSt with stock turbo even by the end of first gear has to indicate somehow how quickly the thing builds? I think the GT3071R would be brilliant, and a bit better than the GT3076R for streetability. On the flipside its nice knowing I have 270rwkw and can EASILY go way past that. I think people are describing of GT3071R/GT2835s what I get with mine, ie - can hear the turbo spooling at minimum throttle in the 2000rpm range cruising around town. Throttle behaviour is very NA, etc. I'd *LOVE* to have an opportunity to drive a GT3071R and GT3076R turbo'd car back to back and see the difference actually. If you are SURE you don't want more than 270rwkw, and can live with changing turbos if/when you change from the mindset of "My car is at the quick end of a mildly modded car" to "my car is at the slow end of a well modified car" or are pretty sure you won't change to that mindset then the GT3071R is the one

As said / shown before - outright boost threshold the GT3071R seems to have nothing over the GT3076R. MAYBE (you'd have to go in both back to back) the GT3071R might have better part throttle behaviour, but I am serious when I say mine is really really nice to drive. You can tell its down on torque below 3000rpm but who drives hard there and expects to go fast aside from people with 5000rpm redlines? Got a vid on youtube of a run from the drags this weekend where I managed to badly bog a launch with the .82a/r GT3076R racing a fairly mild R32 GTSt, gives a reasonable impression of how it pulls from low revs in 1st I think:

Haha just because thats what we're both running is by far not because we "needed the .82 to make that". I don't have a boost controller, I am running completely off the actuator and was just loading up preload. If I went any higher it was going to start creeping - it made the 270rwkw REALLY easily. It would have made quite a bit more but we put more fuel in to make it run ~11.6:1 to keep the motor understressed relatively speaking. If/when I get a boost controller and following how easily the car gained power when we did things, I expect it to crack 300rwkw without too much stress- just a bit more boost. People have made over 300rwkw with the .63 BUT it'd be a yuck way of doing it.

The most powerful stock bottom end RB25 I have been in/come across is this one - has cams and thicker head gasket, stock from HG down. Made 450rwkw (~600whp) on a pretty high reading dyno though I reckon it'd run over 500whp on most sane reading dynos. Here's a video of it running a 10.6 with full interior, pump gas and a set of drag radials: Trap speed etc seems not the best, but they were being a bit gentle with the gearbox etc - remember, all stock bits.

Agreed. I did expect a better threshold (mine almost looks better) from the GT3071R but still on the road the 71R should feel better. Same with GT3076R vs GT3582R, the lag doesn't SEEM hugely different but GT35Rs start feeling quite weak on RB25s - you need to really give them some beans to get going.

LOL, if you are worried about that then you shouldn't be looking at up to and over 300kw @ wheel turbos On the road its really not as bad as it looks, if you think it looks bad. Remember RB25s are WAY under turbo'd stock. 12psi at 3600rpm is better than a stock turbo'd RB26DETT will do, and the RB25 comes in a much lighter car - makes it that much more streetable. With a "laggy" .82a/r GT3071R or GT3076R you'd out accelerate a stock turbo'd GTR from low revs, then it will catch up because your tires want to liquify.

The only stock standard GTR I went in was really really disappointing. Was running stock boost, stock exhaust, stock everything - I struggled to believe it.... I had a semi-wanked up NA Honda which was pretty comparable in acceleration (dodges flames). The new owner of the otherwise mint R32 GTR trucked on and did a full service, got it a very unrestrictive full exhaust system, pod filters and an electronic boost controller for it and ran 1bar of boost. He was pretty happy with it and told me I should come for a drive to see if I thought it was better - to be fair I didn't have overly high expectations after how horrid it felt before. Seriously, the thing lost traction when it hit full boost in first and had my whole hearted attention from that point forward. It felt like it was designed to be like that... like Nissan would have liked to have done it from factory but knew they shouldn't, so set it up so you really HAD TO.

This will probably be a useful reference, shows how the boost builds...

Interesting to see that it hardly seems to build boost any quicker than my .82a/r GT3076R on an RB25! This is from my dyno tune:

I believe that at the level I am currently at, my turbo has nothing over a .82a/r GT3071R - but a GT3071R would have a fair bit over mine in terms of streetability. If you are confident you aren't going to get bored with 250-260kw, then I think you are on the money. My car is perfectly streetable, and even at the "underutilised" level it is at the moment I think it would be really really good on a track. It has an exceptionally predictable power delivery, once the thing is past its boost threshold the thing leaps into life as soon as you get on the throttle. A GT3071R could only be better It is nice knowing I potentially have another 100hp @ wheels of flow without changing it if I want it without adding any lag or changing it though....

I'm all for seeing a decent medium sized single on an RB26. A mate of mine is actually first firing up his R32 GT-R running a built RB26 and a .82 GT3540R on it - probably bigger than a TD06 25G but the same kind of idea.

Yeah me too. For what its worth, you really can't feel any of it on the road. All passengers etc perceive it as just building up and having strong power all the way through, the only "weakness" is that the thing doesn't go straight to 15psi and hold it. If it did that it'd be so much more solid, nonetheless there are definitely gains to be had by removing that slight dip. The plan is next year to go to a built motor etc and then give it some boost and revs, this tune was just to get it safe and fun to drive - not to hunt every last hp For what its worth, I gave it a run on a rolling road dyno for fun and the dip wasn't anywhere near as extreme.

The fuelling on mine was nice and consistant, and the timing is all fairly sensible though we / he didn't play with the VCT point. The tuner is a very accomplished tuner, he tunes some NZ GTR who went over to Australia last year and turned a few heads.