Lithium

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...

Nice work man What tyres etc were you using?? How do you find the GT35R overall?

The hot side is quite different on a GT35R I'd imagine, its definitely a bigger wheel... why do you want the surge slots? Tial did a GT35R with a GT30R looking cover, though if you are going for a decent upgrade and want the nice whistle etc etc why don't you just trend set and go a GT4088R? They are pretty awesome turbos, there are some nice twin scroll manifolds out there and you're not going to have to upgrade in a huge hurry. You can obviously tolerate a bit more lag and obviously the amount of power you made with the GT30R wasn't enough, so do it right I have a secret agenda of course, I want to see what a GT40R would be like on a R33.... but meh

IS THAT ALL ITS GOT? My bad, I must have confused it... man its coils aren't a virgin anymore Thanks again for that, man - quite a weight off my mind though still have to find out exactly what part is causing it if I'm to not spend $1k on splitfires or whatever they are Thanks everyone for the input given while sorting this out

Nice work, is it S362 or bigger? Going by that dyno power and trap speed I am guessing it was tuned on a hub dyno or something?

I'm going to try a different ignitor first, I have tried other sets of VN coils and it made no difference to the problem so not sure that its the actual coils.

To help with the investigation, I swapped out the wasted spark setup for a stock COP setup from a 100,000km+ S2 R33 and went out for a general cruise - it didn't skip a beat. We're going to try a pretty much unused Link 3-channel ignitor in the wasted spark setup and see what happens there, if it still plays up I have a good mint to just get a set of Splitfire coils and be done with it.

So when is this bad boy going to hit the strip? And on that topic, why on earth has GAS2JZ not hit the 1/4 mile either? That would be fricken cool to see

Agreed with all other comments, there are threads for Africa on whats needed to reliably get around that power. A GT-RS will do 250+kw but is working quite hard to do so, the GT3071R (if just cracking 250kw is all you need) or GT3076R path (for cracking 300kw) would be the way to go. There isn't such a thing as a GT3564R that I am aware of, a lot of people have been understandably mistaken into thinking the second two digits represents the turbine a/r (ie, 82R = .82a/r) but it actually represents in most cases the compressor wheel exducer size. A GT3582R with a .63a/r turbine housing would also be a viable option but the GT3076R with a .82a/r will do the same with possibly slightly more response down low.

Can you guys confirm that you downloaded the map from the ECU and found that everything looked completely normal, not to mention everything adding up on the wideband when road testing it when it was playing up?? I would have thought that if the data pulled off the ECU is correct, then the data IN the ECU should be?

Gah I do actually have a suppressor in there, oh well back to the drawing board

Thats quite interesting, thanks I would have thought that kind of thing would show up when we downloaded the MAP and also datalogged using the PCLink software? Its been brought to my attention that Link recommend using a 2uF noise suppressor between the coil pack's positive feed and earth with a wasted spark setup, which I do not have. I'm not sure if that could possibly explain some of the issue, or if it would be just to eliminate general noise from the system?

Yeah its the same revs in every gear. The ECU doesn't do anything if knock occurs, its not that clever unfortunately

The car never made it to Oz obviously, but it finally did some shake downs with its new engine/suspension/wheel & tyre changes last weekend and was straight back in the 7s with plenty more in it by the sounds: