Lithium

You're not the only one. Quite keen to see how it goes down the 1/4, assuming that will happen?

It appears the software only shows the area of the graph the power and torque curves actually hit - so instead of starting at 0 and going up to the most torque you'd make, it starts at "106". The result of this is that you are zoomed in as much as possible to your power and torque curves without losing any data, so what would appear to just be little wiggles in the curve have been magnified up to be huge sharp jolts. If you got Excel and plotted the points on the graph into a spreadsheet and then made a 0 based graph off it you'd probably find it APPEARS a lot smoother. Dynapack dyno software does the same thing, and whenever I have posted a graph people have questioned the tuning because of the bumps they can see - but its actually because the dyno software is set up to give you as much usual information as possible

Yeah I guess I could have said that but decided easier just to say you can't, much the same as technically you can't use a solid piece of alloy as a head without a bit of modification

Yeah I guess I could have said that but decided easier just to say you can't, much the same as technically you can't use a solid piece of alloy as a head

I have a Garrett GT3076R, I posted a pic earlier in the thread of the engine bay to give an idea of what I need to work around. I'm not 100% sure of the point of your rant, but basically I got given a 4" inlet POD filter for my birthday a few years ago after mates got sick of me procrastinating about doing something to my car and told "You have to use this now" My plan is to make a full shield around the pod filter, and make a decent cold air feed from where the stock intercooler was. In NZ there are no laws about what kind of air intake system you are or aren't allowed, so legality is of no concern to me.

What power range exactly do you mean? Check out this site - possibly a bit out of date but has some listed: http://t04r.com/turbos.php These days there are neat things like the Garrett GT4088R and GT4094R, and in NZ there was or is a IHI RX8 which is an ~1100hp really flash thing.... they are basically used on indy cars.... that'd be interesting to see on a Skyline haha

No, you can't mate up the RB20DET head and RB30E block - but (I may be corrected here) I'm pretty sure you can use your loom and ECU with the RB25DE head. I assume you are using an aftermarket ECU for this?

Dunno about you but I have a 4" intake and a filter to suit, its not gonna fit in there without chopping stuff. I had an intake like that with my old Honda and it worked superb though, and in that size (~3") you I am pretty sure AEM did a fitting which basically blocks off the air flow if a restriction appears - ie, filter submerged.

What do you consider a proper pod setup?? Or a naked pod setup?? My pod filter sits where the stock airbox goes but has no shielding at all. Yet.

Awesome, thanks for that. Bonnet up or bonnet down?

Cheers, I guess that detail is what we are after and is going to have to help the situation What I'll endevour to do is get before and after on the dyno and see what happens. Abu - thanks for the input though the example you give sounds like it doesn't assist what we are after, unless you did the runs with the bonnet down?? What I am talking about is when the bonnet is down and you run the risk of heatsoaking everything... I'd like to know how much can be gained by going from an exposed pod in the engine bay to a decent cold air setup.

That looks nice and tidy to be honest - could you tell any difference with it?

To dredge up an old post - this topic is something which has caught my interest after a bit of a dyno session I had with my car this weekend. I (stupidly) didn't think of popping the bonnet, but was a bit perplexed after I realised that despite tidying a few things up with my car I had actually lost a couple of kw instead of gaining - despite the boost curve looking better and the shape of the curve looking much nicer. Not to mention the car actually feeling better on the road than ever before.... I had 3 runs within the space of about 2 minutes, each successive run making about 2kw less on a car which is usually like clockwork. Air fuel ratios nice and safe, boost level consistant, and had just done a compression test finding all cylinders having healthy compression. It only occured to me AFTER I got the car off the dyno that this is the first time I had ever dyno'd the car with the bonnet down since going to a bigger turbo etc, and for those who haven't seen the video - things get quite toasty under the bonnet of my car: My car would be quite hard to do a cold airbox with, though I am a fan of that modication nonetheless. I hadn't bothered with it due to lack of motivation and the fact so many people don't run one and say "Thats what an intercooler is for" and the fact my engine bay is quite busy already but logic has it that the less the intercooler has to do, the better. I know with my old naturally aspirated Honda with much less power and underbonnet heat I made a 10kw @ wheels gain from changing from an unshielded pod filter to a nice cold air intake, so there are definitely applications for it. Anyway, its over a year on from the last post on this thread - does anyone have any back to back comparisons of before and after such a modification... or should I document my expedition into doing this with before/after dynos etc? This is the area I'd need to fit a box around Cheers, Dan.

That is a fairly good point in the case, cheers DP - I can accept that as an advantage of the twins.... though in that instance more to do with the actual twins than the difference between twins and a single. Something like an RX6R would be nifty to get a hold of and see what it can do.

Ohhh I wouldn't go that far, I just got back from having a drive with my .82a/r GT3076R boosted R33 S2 and I really don't look back - so much fun

Thats pretty easy: HKS GT2530 Compressor: 47.7mm inducer, 60.1mm exducer Turbine: 53.8mm Inducer, 47.0mm exducer If you were to double the area of the wheels, the inducer and exducer equivalents would be: Compressor: 67.5mm inducer, 85mm exducer Turbine: 76.1mm inducer, 66.5 exducer Garrett GT3582R Compressor: 61.4mm inducer, 82.0mm exducer Turbine: 68mm inducer, 62.3mm exducer The trick is with the GT2530 it has double the amount of material for the equivalent surface area, seeing as it has two wheels - that is weight and also space not taken up by air. I'd imagine that will (aside from fluid dynamics which are beyond me but must come into effect when two compressors are trying to pump in the same path) compromise some efficiency. There are definitely advantages to the twins, but I'm yet to be sold on them making them better than a matched single. I'm still learning stuff, but can't help but think that the tight housings they put on GT2530s etc must strangle them a bit compare to the relative large housings you get on GT3582Rs. A GT3582R I am very sure has a LOT more housing volume than a pair of GT2530s, which is maybe part of the reason why they aren't as punchy as you'd imagine compared to the GT2530s - but also why they can push enough air to warrant a conversation about them?

I realise this, but I can't show you a graph to demonstrate as there is no easy way of doing so. I can and will try and endevour to get some evidence of how a GT2530/GT2860-5/GT3582R car all compare as I get sick of speculating on this topic - and hearing what are often unfounded opinions supporting one or the other way of doing things. For what its worth some of the fastest track cars in NZ are EVOs running GT3582Rs on 2litre engines, I've been in one myself which with full interior and pump gas temporarily (until a full competition car at the same event) took out the course record on a tight hill climb event. If a 2litre engine running high 300awkw on pump gas on one of these turbos can be highly competitive on a circuit I don't think the response is going to harm a 2.6litre. As I've said before and you seem to ignore, the GT3582R GTR I have driven comes across as overall more responsive than GT2530 cars I have driven - Cube's example of GT2530s from 4000rpm assumed they take off from those revs on an RB26. They don't, if you do that from 4000rpm in 2nd on an RB26 it fluffs around for a bit before it does much. A GT3582R while it doesn't leap straight onto full boost either will give you a pretty decisive push in the back and then charge up the road, I can't argue it TOO hard but I really remember feeling more impressed at how the GT3582R responded than how disappointed with the GT2530s I felt. The reason I focus on 4000rpm is if you keep the GTR I talk about on the boil (ie, race track revs) then whenever you floor it the thing takes off like something with its arse on fire.

GT3582Rs are WAY more responsive than T04Zs. Cubes, that response you talk about is going to be hard to improve on. No matter what turbo you have it has to accelerate up to speed. The fact yours spools way earlier and has the same kind of response indicates to me your car is WAY punchier. Strictly speaking up to a point you may not get a lot more response beyond a certain point, and clearly there is around a 1000rpm area where yours has to be more responsive as it can make more boost in that rev range? Also while I have you, you know how your car spools the GT30R - and that GT35Rs are the next logical upgrade (laggier, but not hugely so), and you are just running a basic internally gated setup on a stock exhaust manifold - do you not find it strange that someone has claimed that GT2530s on an RB26 is more responsive than a GT35R on an RB30?

I understand that what you say above is consistant with the popular belief, though 99.9% of people that say this stuff has never actually driven a GTR with a GT3582R, and wouldn't be surprised if a good percentage who repeat that rule haven't even driven a car with GT2530s to realise exactly how laggy they really are. For what its worth, the car with the GT2530s has to pretty much clip the 7500rpm limiter it has at the drags to launch without bogging - the car with the GT35R will smoke all four tires if it launches over 7000rpm, only needs 6000rpm to get a clean take off. The GTR running the GT3582R on the road feels better from 4000rpm than the GT2530s I have driven, I believe it has better overall response. I still maintain that rule of thumb comes from people comparing big singles which outflow the pants off a pair of GT2530s with GT2530s. Maybe I need to sort out a camera and make a response clip between a twin GT2530 and a single GT3582R and see if observers of the clip can pick which car is running which turbos

I'm fairly sure a pair of GT2530s will have more mass to accelerate than a single GT3582R.

I have disagreed with you before and you've made out like I didn't know what I was talking about, and I realise you have a LOT of experience with Skylines but I don't know what the full story is with what you are claiming above - maybe something was wrong with the RB30DET setup or maybe something else!? Either way, there is no way in hell a decent RB30DET setup with a .82 GT3582R turbo on it is laggier or less responsive than an RB26 with GT2530s. I've been in and/or driven all the setups you describe including an R32 GTR with a .82 GT3582R and the GT3582R on the RB30 monsters a GT2530 turbo'd RB26 everywhere. If you rolled both setups side by side from 2500rpm in 3rd gear the RB30DET / GT3582R car would be gone by the time the RB26/GT2530s was starting to think about getting serious. Its been a while, but the way I remember it the GT2530s did seem to "windmill" a little happier than the GT35R on an RB26 at driving around town speeds but as soon as you started getting into it the thing would charge into life and get out of dodge. I swear than the GT35R on the R32 GTR I have driven is the least laggy near 350-400wkw setup I have driven overall. This isn't the best comparison but it will give an idea - the plot from two cars tune on hub dynos, the one with the GT3582R (the one the dyno plot is actually for) is running .82 a/r turbine housing and the run was started at 3600rpm. 4WD was used for the run, and the car was running 20psi with Tomei 260deg cams. The blue line I overlapped from another mate's GTR which was running more mild (possibly stock?) cams on 22psi with the fuse pulled - running straight RWD for the dyno run. The GT2530's setup was started at 2000rpm, giving a little more time to get the turbo up to speed. Probably worth a mention as both the GT3582R and the GT2530 runs were done with quite quick "ramp rates".

Very nice - look forward to seeing how this comes out. Are 272s big enough for an 850hp odd turbo?

Awesome, congrats on the buy Go to photobucket.com, look for something like "join" and click that, follow the instructions and away you go. Its very easy to join and use and costs nothing.

I have a larger Garrett GT3076R with a .82a/r turbine housing and the only thing making my car not great for doing that kind of stuff is the clutch I use. A GT2835 would be absolutely fine for daily driving, I'd say it'd be nicer to drive than the stock turbo which is an annoying POS to drive with its irritating hiss and complete inability to make any real torque or power despite the fact.

Yeah well fortunately mine is tuned at a pretty safe ~11.6:1 on BP98 so what keeps me happy on "normal" fuel keeps me well well entertained with E10 in there. I am pretty tempted to try a back to back dyno comparison with 98RON E10 and conventional 98 actually, I'm adamant there is a reasonable difference.