Lithium

DIN is just a different standard, SAEJ1349 was first put together in 1980 and is slightly more conservative but ultimately it doesn't seem like there is any good argument that I know of to use it instead of DIN - especially if you have been using DIN numbers since Dynapacks have been used? They are happier when set to DIN (hell, they're happier when set to SAEJ1349 so makes it seem all pretty academic) than Dyno Dynamics still, which doesn't bother me as Dyno Dynamics read so low that comparing them with almost any popular dyno around the world is broken. The dyno is just for tuning, who cares if there is a dyno somewhere which reads higher or lower if you're just comparing to the same configuration? Straight "SAE" I can understand the argument against, the corrections seem to go a bit weird at higher ambient temps and the results come out excessively inflated whereas DIN vs SAEJ1349 seems like a 2% or so difference from memory, versus 10+% between a Dynapack and Dyno Dynamics.

Ohh. That should be fun. You just bought it? It's probably an HTZ3076...

I've not seen this thread, hate seeing nightmare stuff like this going on. So a couple of questions - how does the car actually drive on the road? Does it feel excessively laggy in the real world? What kind of rpm does it start building boost at all (ie, start pushing a bit) and when is it "getting serious" in 3rd gear from a low rpm pull? Next thing, if I read right - you've found that this car has had "lag" issues all the way through? Like you've change manifold, turbo etc and it's STILL laggy and drops boost hard? What fuel are you running? And out of interest, where in the world are you? A sinco manifold is unusual in Oz I'd have thought.

Dude, this is the COMPLETE OPPOSITE of results. This is for sharing results, not asking what it should make. Get it tuned, share the result and then we'll all know the answer If you want to discuss the setup or how well its matched or should perform, start a suitable thread.

I assume you are talking about the manifold. Love the Turbo Killer avatar btw

While I can't say for 100% sure, I doubt it's a fuelling issue if the car didn't start running leaner when the issue came about.

The fact the tune hadn't gone leaner would suggest it's less likely to be a fuel delivery issue which is one of the causes for this kind of thing which I've seen. To cause THAT much sensitivity at that low boost and requested timing would need to be quite the fuelling issue, not something that would be too subtle to pick up even if it was only one cylinder - imho. The other thing (and probably more common cause for this type of stuff) is triggering issues causing the effective timing to fly way off requested timing. Either make sure the wiring to the CAS is good, or if you can find someone with the same type of CAS then maybe try swapping them over - or anything else you have the tech to do to rule that out.

Agreed. The 7163 would be the smallest I'd put on an RB25 and honestly, aside from the fact that it'd drive like a small turbo it is NOT that small. People have already gone ~350rwkw on Dyno Dynamics on E85 with them, from memory. EFR7163 or bigger on an RB25, for sure.

Haven't experienced one directly, a couple of mates have played with them and rate the hell out of them - anything I said would be anecdotal. They certainly don't look to have the boost threshold of the EFR7163, if I had to say then I'd say they start feeling a bit more like a big turbo but some seriously good response once past boost threshold like the whole EFR range. Fwiw back in 2011 I was intending on getting an EFR7670 for my RB25 with a 1.05a/r T4 hotside, I ended up bailing on the idea as I lost enthusiasm for a few reasons (not least how long it took BW to get production moving properly :/) but I was hoping for a similar drive under 4000rpm to my old GT3076R but particularly from 3500+rpm that it'd start REALLY getting perky and building a gap in both response and flow... hoping the setup to be capable of another ~50wkw peak power. I still think that's not unrealistic and really it'd have potential to be on of the best possible turbo matches for an RB25 which isn't intended as a drag car, I reckon.

My money would be on the EFR7163. It would be a pretty crazy thing, imagine less lag than your GTRS with more power than a 56 trim GT3076R.... I'm guessing that'd be not far off the mark

Hi Adrian, long time no speak. So for transparency on this one, I'd been dubious of the EFR7163 - tbh some of the dyno plots I've seen for them have not been that convincing and I'm still not quite sure what that is about (I have since seen very convincing dyno plots too - so maybe they were setup issues!?), also the very large trim compressor wheel thing made me feel it was more to do with managing space and maybe turbine speed than actual real world performance improvements. I did wonder if they were going to end up being somewhere between a 7064 and a 7670 and tbh I've not experienced either of those two turbos first hand so maybe it could be possible that I'm underestimating what they'd be like as well - but for now going off what Geoff Raicer has said about the 7163 it feels like the wise choice is that he was onto something when he raved about them when they first broke cover. I'm not going to eat my hat about being cautious about them though, better that than tell everyone the new best thing is here with absolutely no evidence and turn out to possibly have given out terrible advice The best data I have on the EFR7163 was from sitting in the passenger seat of a Celica GT4 running a stock 3SGTE with an .80 twin scroll EFR7163 with some fabrication done to pair it up to the stock GT4 twin scroll manifold. Attached is some plotting of boost vs rpm for a pull in 1st gear, 2nd gear and 3rd gear. In 1st it was hitting ~20psi in the high 4000rpm range, 2nd it was between mid/maybe low 4000rpm depending on when the pull started and 3rd it was comfortably hitting 20psi by mid 3000rpm. With enough time and loading in 3rd we were actually regularly seeing 1bar barely over 3000rpm lurking around in a 50kph zone, as can be seen here. I think compared to what we had in the 90s and early 2000s the EFR7163 could pass for a stock turbo on a 2litre engine, it may have been ever so slightly more doughy than a typical T28BB (my natural comparison when thinking of a "decent" stock turbo from a 2litre turbo car of our era) under 3000rpm but once you start getting into the boost threshold range of the EFR7163 (3500+) on the 2litre the EFR actually started felt as good if not better. I think one of these would be crazy on an RB25. Without having experienced one first hand I'd have been dubious, when you consider it's 57mm inducer compressor rated at near 60lb/min of flow. I daren't predict how one would drive on an RB25 but from my impressions with the GT4 I would not hesitate to say it'd be MUCH better than anything I've ever been in when aiming for the type of performance "we" like. That is nice road manners and something that won't be a stupid mismatch at any kind of boost which the stock motor is happy with on 98 octane. The most recent big turbo RB25s I've been in have run GT3076R and ATR43SS2 (both journal and DBB) and they are not in the same league of spool. You wouldn't need to get the logs out and trawl them to work out what the comparison is, I'd put it out there that you could potentially do a casual drive around a city block without even going WOT and you'd have a pretty good idea, if that makes sense?

@Full-Race Geoff would probably be the best one to hit about about that I have no idea

I think it's not necessarily that it's not working right so much as being a lot more careful to ensure that whatever they release is on point and works best - not putting all eggs in one basket and also not throwing out a product before everything is "in place" like last time, I think they're trying to learn from last time and do a better job. The fact that they already have compressor maps should suggest they aren't pissing around. I have my concerns about the huge trim wheel BUT I have also experienced EFR7163s (which I was similarly concerned about, they have a similar sized inducer to EFR7670s and GTX3076Rs) first hand and they spool better than a GT2871R.... so Borg Warner aren't newbs, and I wouldn't rely on conventional wisdom when you have something that is pretty outside of convention - we can but just wait for real results. Something worth noting with that compressor map and indicates where this should be relevant to the interests of Skyline guys/everyone who have been worried about the risk of overspinning these turbos. If you look at the 2.8 pressure ratio line at the 75lb/min area which is more or less the common and sensible area to stop pushing harder with an EFR8374 on an RB, the old EFR8374 is >111,000rpm so both compressor flow and max safe rpm are starting to get close. The prototype compressor map shows it as under 104,000rpm, you could push the same setup up to 80lb/min and still not be working the turbine as hard. It is good to see Borg Warner still developing these and can't wait to see a new product emerge.

Unsure why you are speeling like I think otherwise, I clearly agree - I simply pointed out that Garrett had made a little more effort than usual to the turbine side which is interesting but not hugely encouraging under the circumstances, it still looks like a mess but maybe just not as bad as it initially looked. In terms of the 1.22a/r hotside - it's clearly a necessity if people want any hope of getting near the flow the 84mm comp wheel can supply, I think that housing really would be the only option for anyone seriously wanting to use this turbo. They have supplied the flow map for it so there is no need to wonder about the fairydust factor, it flows almost as much as a GT4088R 1.06a/r divided hotside which has been proven to support some reasonable power levels. I expect it will make a fair bit more than your run of the mill GTX3582R on an appropriate setup but I think its still Garrett showing they are losing touch and clutching at straws. Will will find out fairly soon, there is someone putting one on a 2JZ drift car already and probably will be running soon. EFR8374 is a 6264 in Precision talk, 64mm turbine exducer.... Not sure quite what you are getting at by your high capacity engine tiny capacity on high boost ponderings, but if I assume I know what you are wondering about... the compressor flows at it's best at ~22psi on a very efficient setup, any more than that and it starts flowing less so if you hope to making "1000hp" you have to do it at 22psi. The turbine side is undersized, the more restrictive your hotside is the more pressure you build on the turbine side for a given amount of exhaust flow. For sake of argument (and pulling numbers out of my ass just to clarify the concepts) an EVO running a GTX3582R at 500awkw may build 40psi of turbine inlet pressure but probably running 35psi to achieve that power figure, so the exhaust side in that instance is 5psi higher pressure than the intake side which doesn't cause a huge issue. The bigger the difference across the engine the more "interested" the exhaust gases are in hanging around the engine as the intake side is lower pressure and the gases just want the easiest way out.... this effect drops VE and can start negatively affecting your ability to make more power for obvious reasons (ie, the cylinder volume holds more and more useless hot gases than clean air/fuel mix). That brings on to the mismatch - if you want to aim for the peak flow levels of a turbo whose compressor is at it's best at 22psi, but the same turbine can cause 40psi of exhaust pressure trying to support less power than the new compressor can make.... you have a HUGE pressure difference across the engine and basically start sacrificing displacement until you can't make more power or something even less appealing happens. Hope that makes sense, or at least wasn't way off what you were getting at

While my reactions were the same and I still ultimately agree with you (Garrett changing their hp "rating" standard to be more generous while kind of makes sense in the current climate seems VERY conveniently times), I have to add that I just discovered that the GT3584RS actually has some kind of new fancy turbine wheel which a/r for a/r flows a bit more and the 1.22a/r options flows a metric shittonne more than a normal 1.06a/r T3 housing. That turbo could prove to be a bit more interesting, yet.

Yep, agreed. Aside from the GTX3584RS which looks like it's not really great for anything.

This would be probably the most interesting to most people involved in this thread, I'd suspect - looks quite nice for an RB25: https://turbobygarrett.com/turbobygarrett/turbochargers/gtx3071r-gen-ii

Very nice gains! How does it drive with the new cams by comparison? Dyno sheet is suggesting much better spool - 60kw more at 3500rpm is quite a difference haha. Who make 268/272 VCT compatible cams, too?

This is all awesome input, cheers for sharing it. Again - this stuff will only be scratching the surface, too.

Haha you're very generous, alas I actually made up a bunch of variables with that example and I'm not going to argue a rule of thumb otherwise - I just made up a theoretical situation which would/should function the way I hypothesized if such a cam existed. The main reason I posted was just to try and highlight there is much more going on when changing to a different spec cam than just "losing response" as an all encompassing thing - it comes from people focusing on a specific rev range. I nearly don't know enough about how cams etc etc work to just glance at a spec and tell you how it's going to work on a setup, but I also suspect I have more of an idea than your average punter so one way or another I think this discussion is the blind leading the blind - but it's interesting to compare ideas and experiences to see what comes out. I very much look forward to how Simon's car comes out with the Kelfords, I've been wanting to see a set of those tried for AGES and you can't really argue with real world results - for better or for worse.

OK, sorry - that makes more sense, yeah we're probably closer to the same view than I thought however you're still ignoring a few variables which can influence things.... though you aren't specifically saying "250deg for EVERYTHING" that I know of so possibly not relevant Now we actually see there is a fair bit more overlap (hurhur) in how we're looking at it - and keeping with the NA view on things to keep it simple, I don't think I agree fully with the "just for up shifts" relevance - at least for my example. 3000rpm isn't upshift territory, that is actually often in the normal driving around zone - well below boost threshold, so realistically where the car would often be driven. Yes, there is a sacrifice in response at very low rpm where if you are modifying to the point you need more head flow and have a bigger turbo then one would think of that area as not too relevant, so long as you have matched the cams and turbo to appropriately suit the rest of your setup. That is the case with everything though, a bigger turbo makes the boost threshold come later AND transient response can become doughier - the hypothetical case I gave here will also bend the torque curve upwards like that too but without the transient response issue. The kind of thing you are saying is what I'd expect with huge drag spec / NA race motor cams, but the likes of Kelfords 270s won't be aiming for that kind of thing - at least I wouldn't think so. I personally think if I'm using a car as a fast road car/track car then I would rather a car that stands up better from 3500/4000rpm and is still perfectly drivable below there as well as making more power everywhere above there, than making a car slightly more grunty and build a little more boost at "potter around town" rpm. It all comes down to matching the parts to what you are doing. Something to ponder in regards to your dyno pull example, yes - I agree the smaller cams are likely to build a bit more boost from 2000rpm but what is easily overlooked is how little air is moved at those rpm and realistically if you have a turbo that isn't going to be fully on boil until after 4000rpm then the "extra spool" is not going to be a huge deal. If you are at 3500pm and we assuming you have the same VE there at 2000 then you are moving 75% more gas at that point with all things (including boost) being equal. That won't be happening, though - even mild cam engines will have substantially more VE at 3500rpm so you have much more than 75% more gas, so what happens there has a MUCH bigger influence on how the turbo is driven in the real world. Now imagine my hypothetical cam example - I'll be ultra silly about it and pull numbers out of nowhere, lets say little cam gives 85% VE at 2000rpm and 90% VE at 3500, and big cam gives 80% VE and 95% VE at those respective points on a 2.6litre. At 2000rpm the small cam could be moving 2210lpm of air, the big cam could be moving 2080lpm. At 3500rpm the small cam could be moving 4095lpm of air, the big cam could be moving 4323lpm. Basically the difference in flow (/ perhaps ability to spool a turbo?) is 250% more with the big cam at 3500rpm versus the small cam at 2000rpm. If you play with dynos, try doing a run starting at 2000rpm with a lead in time of 4 seconds and then another run with the same car starting at 3000rpm with a lead in time of 2 seconds - odds are reasonable that, depending of course on ramp rate etc the boost curve for the run starting at 3000rpm will look more flattering despite the 2000rpm run getting heaps more time to try and spool the turbo up as the sheer exhaust energy pushed through the turbine in that 2 seconds will be much more than the 4seconds at 2000rpm. Any edge in engine flow you can gain with a turbocharged motor which doesn't rely on boost can pay big dividends as it tends to feed back on itself, the more you flow into the turbo the faster it can supply even more flow and so on. A stroker is a foolproof way of doing it but if you can increase VE at useful rpm then that is also very cool but again, there will always be trade offs. The very aggressive ramp rates to high lift with a short advertised duration which some people use is one way of trying to minimize the trade offs and to be fair it is pretty effective in a lot of ways, but it's not "for free" either. Anyway, apologies for the huge post - I wrote the first part last night and my computer reset itself to do updates just before I sent and I felt more like spewing ideas on this morning's commute.... finding an interesting thing to discuss when I have 2 hours on a train each day is temptation I struggle with resisting.

Was a little sad to read this post. You are usually one of my favourite guys to read posts from, both paying attention to what others have to say and also a bit more thoughtful/wise about what you say. None of us here are expert enough to pull a trump card and state what the correct answer like that, and seriously I'm bewildered you feel you can launch into a topic and effectively say "no, this stuff is not that complicated. More advertised duration makes a car laggier and worse, end of." I am no expert but I have been around and played with enough to know that when playing with this kind of thing that making that kind of generalisation is folly, I can't say I know enough to know what will work or how things will compare as again by my own admission it's something I am far from an expert on and there are wayyy too many variables involved to even try. General rules of thumb are one thing and often work but that's for general estimation, not the rules that all of physics have to abide by to keep things simple for us to compare - as nice as that would be. As a thought experiment ... you say longer duration makes the engine work better with more rpm... purely hypothetically but what say you have an engine which makes full boost at 4700rpm with a 240degree cam and change to a set of 260degree cams of similar peak lift where the threshold of working worse to working better than stock is around 3000rpm - are you suggesting that despite the motor being able to pump air better above 3000rpm and assuming the engine is not running turbo(s) that are choking the motor at that point that it's not going to yield torque / spool gains from the resulting VE improvement despite the gains starting to happen well within boost threshold?

Yes! I remember having an extensive debate on this topic with people from here ages ago, just looking at advertised duration tells so little of the picture - if you're throwing advertised duration with no consideration for lift, the cam profile itself, lobe separation angles, where the valve events occur relative to the piston position, other modifications etc then you're not really commenting on something you know enough about to make an authoritative statement on... ESPECIALLY if questioning someone like Kelford Cams whose cams are sitting in the engines of some of the fastest time attack cars in the world, among other things. There are always trade offs somewhere, but making a sweeping statement about how a car is going to perform regardless of displacement, stroke, compression, porting, manifolding, turbo choice, cam degreeing etc based off longer or shorter duration >.35mm lift is rather silly.

+1. And again, anything you use to estimate "power" is going to be "estimated engine horsepower", not hp @ wheels - and I know from experience that often the calculated results often get heavily question because by nature of how crazy low Oz dynos read the crank hp results which get calculated if done correctly are often much higher than people expect from typical @ wheels readings on a Dyno Dynamics. A thing no one has mentioned here is fuel as well, if you treat the % duty cycle of x size injector = hp described above for 6 cylinder turbos and are running E85 you will get very optimistic results

More or less - MPH really is more accurately an indicator of "how much power the car gets to the strip". You can't go near 150mph without having a lot of power, the reason I posted those is that those trap speeds have been done with an EFR8374, 9180 and twin 7163s respectively and if nothing else I was hoping it'd stop dyno arguments and put more focus on the fact that these turbos result in *ACTUAL* fast cars with easily accessible power for their claimed flow rates. A lot of the people who question the performance of these turbos are looking at the wrong things for comparison, and arguably these turbos are NOT actually for them as in all honesty - if I was building a drag car I would not use an EFR, it's a waste of the tech and the effort to get it working. Go straight to a Precision and enjoy more lb/min per mm of compressor inducer and just crank the boost to way off the map and in most cases the turbo will choke before grenading due to overspeeding. They are comparatively simple to work with for simpler uses by often (but certainly not always) simpler people. The EFRs are a different beast, I indicated this at the start of the first thread I created on this and still maintain it. It's basically a motorsport level turbo available for the masses and has certain compromises in cost and tolerance in order to allow much better performance if you are willing to put the effort into correctly matching your setup and spending the time and money getting it all together and working properly. From what I can tell and have experienced with these, the turbo matches aren't to get the max lb/min per mm of inducer or whatever, it is to provide an airpump which will make the engine it's attached to move as close as possible to the target airflow as quickly and easily as possible. A smaller turbine or compressor "small side" does not promise this every bit as much as a bigger turbine or compressor small side clearly doesn't automatically mean more flow. Selecting the turbo and setting it up may require a bit more thought than throwing a Precision Gen2something on and pondering whether to use springs or gapfill in the wastegates for setting target boost, and it may be wiser (but certainly not necessary if you've done everything right) to monitor turbine speeds to ensure things don't go out of target but again... this kind of thing has been par for the course for a LONG time in high end motorsport. You are just able to reap the benefits previously exclusively available to people who thought nothing of spending 5 digit sums for their airpumps, but also some of the obligations resulting in using highend materials in order to get the nth degree of performance from them. Owning very high end equipment doesn't make you a very high end operator, so results may vary when people buy these things. For the people with doubts about these turbos, a few things to consider: How many people can you find who have moved from low mount twins, Garrett GTX/Precision singles, or other turbo combinations to EFRs and raved about it? Now how many people who have owned then decided to move to Precision/low mount twins/Garrett GTX etc when there is an EFR to suit the results they are looking for?