Lithium

I would be interested in seeing that if it ends up on youtube

Sounds almost like he'd have been happier with a GT35R I'm pretty sure that power would be achieveable with 25psi on race gas, and in my experience a GT35R feels a bit more lively underfoot than a pair of GT2860-5s.

Thats unfortunate, it has been done time and time again and all going well I'll hopefully be able to post a plot for another one in a month.

T67-25Gs make some big power...

Search function brought up crap loads of info you lazy bugger, the only reason I am showing you a thread is it came up on the first page of the quick test search I did to make sure I wasn't going to tell you off for no reason. For christs sake, it takes less time to search that it does to start a new thread people!!! http://www.skylinesaustralia.com/forums/Re...l&hl=gt28rs

I believe the classic famous FPGreen turbo is a 50trim T04E compressor wheel mated to a Mitsi hotside - they flow a bit better than the 20G and by all accounts have a really good power delivery. I wouldn't expect a night and day difference but maybe another 20kw or so wouldn't be out of the question.... its a bit hard to tell for sure, but they certainly seem to be able to make cars go well.

So there are Skylines (RWD presumeably?) aiming for 6s in Oz? Will be interesting to see... I know there were a couple of tube cars in the states running RBs - if I remember rightly one with a GT4788R and one GT5591R so they are clearly aiming for huge numbers with but all has been quiet for the last year or so on those builds.

Simon who? Its some SAU member's one, can't remember his username. There is a Simon in NZ who has a Stagea with a T04Z on it which is also much laggier/weaker down low than any dyno plot I've ever seen for a GT35R - but it makes good power, of course. The overlay above is the only decent reference of one in comparison with a GT3582R though - do you think its better or worse than usual?? Its consistant with what I've seen overall - all things being equal, the GT35R is invariably a fair bit better spooling than a T04Z and the T04Z is capable of more up top. Its not too surprising, as the T04Z is like 6mm larger on the inducer, bigger turbine, and older design - I'm not sure what magic people think they have which would make them spool similar to a GT35R. Hell my mate who has a GT35R on his GTR can launch the thing at the drags at 5500-6000rpm without bogging, if it launches the way guys with low mount twins like GT2530s need to he just fries the tyres through 1st - and T04Zs are laggier again than those. Go figure.

Does the tuner use an EGT probe, or even better do you have any way of measuring intake vs. exhaust manifold pressure? There is the possibility that badly dialled cams could cause such an issue. Another option if you have lost power everywhere... are you actually using the exact same dyno as last time, or has anything such as wheels/tyres changed? Silly questions perhaps, but I know most Oz tuners are still using old rolling road dynos which seem to be finicky/inconsistant at the best of times. Also rule out the possibility of air leaks etc, is it at all laggier than it was before?

If he has scaled it, it looks like he has given the T04Z the benefit of the doubt as really with the amount of boost the GT35R is creeping up to in the midrange I'd expect it to surpass the T04Z at those rev ranges, though the T04Z will no doubt edge it out before and after those points.... shame about the "funny" boost curve as it doesn't do the GT35Rs strengths over the T04Z justice, even in shape of the curve. Its still pretty blatent how much better it spools, though.

Because while the GT35R has a lower power potential makes a reasonable amount less power, it is MUCH better in terms of spool. Here is a dyno comparison of a GT35R and a T04Z on very very similar engine setups and boost levels: You can see the GT35R is starting to fall over though the T04Z setup with 270deg cams might have a bit of a breathing advantage as there is no other rational explanation for it to be making more power through the midrange on less boost.

Still soon or do you have dates in mind? Its been soon for a while now

No the compressor and exhaust wheels (for 56trim versions) are exactly the same.

Isn't the 94mm compressor used in the GT4094R a lesser trim to the GT4294R, possibly making it a bit less of a "bad combination"? Something I find interesting is that the compressor maps I have seen for the GT4088R imply that it falls over quite a bit when you start going over PR ~2.5 or so yet there are cars making really good power on 30-40psi with them. Am I missing something? I've trawelled through and for dyno plots of Supras (our closest equivalent that DO have plots for them) running GT40R and so far haven't seen any which stand over equivalent setups running GT3582Rs, whether its because no one has pushed them to their capabilities or if they just can't flow sufficiently to suit a big motor. Maybe someone has and needs to share their results still

There is a chap on some Skyline forums (might be on this one) called Rockabilly who runs a GT4094R and is running ~700hp on a GT4094R - the GT40xxR turbos on RBs is something I have been trying for ages to get good info on. There are plenty of EVOs out there running >600whp on them though, with impressively good response - the T04Z/T67BB/whatever people call them are "So pre-2005" these days haha. Vid of FullRace showing off one of their GT40R setups.

You mentioned this dropping off on gearchanges thing, thats a bit weird - was it more than one car that you have experienced this dropping off thing with GT35Rs? I've been in cars running .63 and .82 GT35Rs on RB25/26/30s and once you are in the "happy zone" they have always come on nice and hard and certainly no falling over in gears - wonder if what you have experienced there is something a bit different.

Damn mate thats a big turbo you have there, and pretty good spool for a turbo of that size too - probably got more in it

"GT3566" sounds like its moving closer in the direction of a T04Z than a GT3582R. One of my mates made 1bar by ~3500rpm with a GT3582R and a 6boost manifold on an RB25 so 20psi by under 4000rpm with a cammed RB26 and a good manifold could be conceiveable. The 4300rpm 20psi 370wkw setup was with a first ever effort manifold made in the garage and probably gives a fair bit away to things like 6boost/Fullrace manifolds.

Probably because they are the laggiest turbo for the power they make and the cost to obtain them and I'm not sure HKS even make them anymore so the odds are that one you buy will be many years and kms old. GT3076R as stated, is ftmfw

Nice, I really look forward to seeing how that goes - it may well surprise a few people. Is that something that might be happening soonish? This puts into perspective how useable and potent a GT30R can be, running 470whp (350wkw) on pump gas in a FWD Honda in the US - remember this is a MPH speed, these little bursts of acceleration would have to be in 4th and 5th gear.... so light car or not thing engine is really making some power and torque:

Who on here has both maxed out a .82a/r REAL 56t GT30R (most of the ones in the dyno results thread aren't or are only on 1-1.3bar) or even better, on race gas? I said that number in reference to guys maxing the turbo out on C16. In this list you can see a few cars running FP 3052 (basically a GT3076R from Forced Performance) doing around the 10s at >130mph in Eclipses which weigh >1300kg, or basically R33 GTS25t weight but with 4WD transmission loss. You'd need a few hps to do that in a street car of that weight.... http://dsmtimes.org/times.php?Page=1

Correct Honda and EVO guys have been getting >500whp/low 10s out of them for years now.

It sounds laggier than my GT3076R to me, and a GT3076R will make 530whp if it were tuned on a suitable motor with 85% ethanol blend - as well as spool a bit better.. Be very interesting to see a dyno plot of that car.

I'm guessing thats on a 3litre? Unless there is something I've not heard about (in which case a dyno sheet with boost plotted on it would be very nice) that you can do to bring them on harder, I find that VERY VERY VERY hard to believe. If you can make a T04Z do that, I'd love to see what you can do with a GT35R! Also on the dyno we use, a setup identical to wrxkilla's made 370wkw @ 20psi with full boost at 4300rpm - sounds like the dyno he ran on is quite conservative.

As I said, GT35 and GT30 are completely different hot sides. Trim is just the ratio between inducer and exducer - the fact that the GT30 and GT35 are both 84trim just means that the GT35 could well just be a scaled up version of the GT3076R turbine wheel, or something like that. I very much know what you mean by the GT3076R induction sound There are people around the town I am in who think my car has a T51R on it. GT4088Rs do it very nicely too...