Lithium

That's what you're meant to do, line them up on the chart - you also need to fill the compressor efficiency cells out with the efficiency values that line up with the dots on the compressor map. What should essentially happen is you get a general thumbsuck of exhaust back pressure etc. Not super accurate but you can build a loose picture of things. Worth mentioning that you probably have bigger cams/better VE than the default numbers in matchbot, and it seems that you're revving it to at least 7500rpm so probably should update the rpm scale to suit the max rpm at least. I had a super fast rough fiddle with the settings, take with a grain of salt but I'd guess slightly closer to reality for your car currently: https://www.borgwarner.com/go/JMZZ59

I should have been more thorough with my response on the "EFR9280 doing 1000hp" I actually know someone who has cracked 1000hp @ hubs with an EFR9280 on an RB32. It was running a 1.45a/r hotside at the time and EMAP was STILL unacceptably high.... and that's a big step up in housing over the 1.05a/r - so imagine how bad that would be? I understand the next logical comment could be "Well why not run the 1.45a/r then?". The 1.45a/r on a EFR9280 adds significant amount of lag. Like 400rpm on top of maybe the extra 300ish you'd lose in spool going from a 9180 to a 9280. The 1.45a/r EFR9280 acts like a BIG turbo, does crack 1000hp but does it basically completely tapped out and big EMAP when run on an RB32 and you're likely to be looking at full boost getting up near 5000rpm... the combination just starts not really making sense imho. I realise the Rigoli 4G63 makes 1000hp @ hubs in time attack form but you gotta remember that it's on a 2.2litre engine that will run like 45psi to make that power, the 3litre is going to be running in the area of 15psi less boost to try and move the same amount of air on a compressor map that is happier at higher boost levels - basically the 3litre is likely to have similar or higher EMAP with significantly lower IMAP, which doesn't do great things for encouraging air to flow cleanly through an engine. I am a fan of the EFR range but the EFR9280 is one of my less favourite of them just because it isn't "quite" right - at least on RBs IMHO, though if you're "only" looking for 900hp range then going that with the 1.05a/r hotside should give a nice jump in power potential over the 9180 without pushing it too hard and losing too much response. If you're looking for 1000hp+ then it really is probably time to start looking at things which have turbines which are more enthusiastic at that kind of power level.

Another thought here. So I've spoken to people with "similar" engine specs to you who had or do have 9180s on them and you really shouldn't be running into that much of a tapped out situation still really. Like its going to be pushing the compressor a bit, but it sounds like you're potentially dangerously tapped out right now. They've been able to push boost levels beyond what you're seeing so even ignoring the power levels, anecdotally speaking they're probably getting at least as much air into their engines as you are - I'd definitely try and rule out this kind of thing before you spend serious money. One of the guys who I know who runs an EFR8474 had a sudden drop off in performance and pressure tested it all and it came up fine, however it turned out that the Turbosmart "internal BOV" got a bit of grit in it and was jammed open. The trick is it didn't show up in the boost leak test as it leaks straight back into the compressor cover.... so it won't really show up as a leak in a smoke test as it's not leaking to atmosphere, but it WILL actually be effectively a boost leak in use if something like that happens. The stock EFR recirculation valve is also known to just leak even when it's "working" at higher boost levels, so that could also be a possibility. If you haven't already, I'd try and make sure this kind of thing isn't a possibility.

The WGDC not having an effect on boost definitely suggests she's getting pretty tapped out. Bare in mind again that doesn't mean there's not more power if the engine is able to "do more" with the air its already moving, whether the tune is soft or whether you could get more on a better fuel. Your plans sound solid anyway, though I'd be pretty cautious about things with the turbo seemingly tapped - if it's being pushed that hard there IS the potential for significant overspeeding to be going on which isn't ideal at the best of times, the EFR turbine isn't the most tolerant. Re: The 9280, I don't know anyone running one "hard" as such. Jesse Greenslade is at around 890hp @ hubs on E85 at 26psi last I heard. I don't know if that's tapped out, I suspect it's not: I know of someone else with a RB34 running an EFR9280 as well, they hit 925hp @ hubs on E85 and it definitely had more in it. They were "only" after 650kw (870hp) max anyway, the swap to the bigger turbo was more about making the power easier while not losing response over the old turbo - as opposed to actually making max power. Based off what I know with that one all signs suggest it's got plenty up it's sleeve but I don't know how much. I suspect the 1.05a/r hotside will start struggling if you go for 1000hp @ hubs, and the 1.45 adds QUITE a bit of lag - anyone I know who has run it has swapped to the 1.05 on the 9280 so far. Imho if you have your heart set on making 1000+hp @ hubs without being ruthless I'd consider looking at the likes of a Garrett G40-1150.

He's got a solid sized Hypertune intercooler, would hope that's efficient. I did just realise that boost is tapering back to 22-23psi which drops the pressure ratio a bit, and also raises questions of if the tuner had a reason for it and also would partly explain the power rolling off harder.

Right my last posts I tried to do hastily on my cellphone and the posts ended up quite messy - so I've waited until I have a spare moment to properly read your post and try and give you a bit of a clearer picture of how some of this works. Firstly - you ask if because your head flows more you need less flow? Nope, it doesn't work that way. lb/min is basiiiically a combination of how dense the air is, and the volume that is shifted. Increasing head flow increases the volume of air that your engine is capable of moving, the only way to increase the amount of air that goes into the engine without increasing the actual corrected lb/min on the map is by increasing the density of the air (ie, cooling it) before it goes into the turbo. The volumetric efficiency thing is why I mentioned above that I wouldn't suggest a 9180 for a bigger engine with a big head like yours as an option to make >600kw @ wheels because that big capacity and decent ability to move air at lower boost levels puts it in an area that the turbo isn't really likely to be at it's happiest. Secondly, in regards to something about you 82lb/min assumption which hasn't been addressed (sorry I rushed my last responses) - you really can't assume that you're moving 82lb/min of air, there just isn't the data available to accurately estimate that. There could be every chance that your engine is actually moving MORE than that.... and that's because of a key thing we always need to consider when choosing turbos, fuels etc and that's BSAC or Brake Specific Air Consumption. That's basically how efficient your engine is at making power for a given amount of airflow, and the variability of this between setups is why I'm always non-committal about predicting exact power levels for a given engine setup. BSAC relies on a number of things, but the ones potentially most relevant to this conversation are the fuel and how hard the tuner pushes the tune on that given fuel. I highlighted your point that the tuner didn't need to put a lot of timing into her.... I'm not quite sure how to interpret that and am not going to make any assumptions (and am certainly not criticising it) - just sharing some things to consider here. These 10hp per lb/min type guidelines is clearly assuming the engine is operating with a certain amount of efficiency. Here's the trick, if the tuner has been told "don't go past 560kw on the stock gearbox" and found that the car has made that power at safe boost without needing to run a lot of timing then they could be WELL justified in saying "Sweet - Tune is safe as houses and it's making the power my customer wants, ideal!" and leave it there. Here's the clincher with that, a "soft tune" could easily pick up another 10% more power with the timing optimised while still not actually being overly aggressive. On top of this, you could arguably pick up another 10%+ more power over a tune safely optimised on pump gas by tuning it to make the most of E85. Just for a thought experiment, lets assume that with a full optimised (but safe enough) pump gas tune you can make 10hp per lb/min, but your current tune is giving away 10% of that power due to being soft, and on E85 it'd be able to make 10% MORE than on pump gas. Optimised pump gas: 820/10 = Needs 82lb/min of air to make 820hp @ engine (like what you're assuming) "Soft" Pump gas: 82lb/min x 1.1 (for the 10% worse BSAC because of soft timing) = 90lb/min of air So based off those assumptions, what would happen if you are actually running super soft timing and it's moving 90lb/min of airflow? Optimised pump gas: 90 x 10 = 900hp @ crank Ethanol: 900hp x 1.1 = 990hp @ crank Caveat: I am NOT saying this is the case, but it could be an option - and again, it's no criticism of anyone... it's just the kind of thing you need to factor when looking at this kind of thing. So, if we assume you're off the map then there are a couple of things you need to bare in mind. Firstly, as your compressor efficiency "runs out" the intercooler has to do more work to cool the air down and the turbo needs to do more work to move the same amount of air, which means the turbine needs to do more work to drive the compressor which drives up exhaust back pressure. If you had exhaust back pressure and turbine speed data it would not surprise me at all if back pressure was getting a bit wild, and turbine speed is creeping up near the magic 116,000rpm EFR9180 max compressor speed limit. So, if these assumptions were correct - what would happen if you went to an EFR9280? You go from being well off the map to suddenly being at ~64% compressor efficiency which is HAPPY. Your exhaust back pressure will plummet, which will actually increase your engine's volumetric efficiency, you will potentially actually move MORE lb/min for the same boost level, your intake temperatures will drop and you'll pick up a significant power at the same boost on pump gas and more significantly, you have quite a bit of headroom to make more power if you turn the boost up. You'll also lose a few hundred rpm of boost threshold of course, on the same token @GTSBoyhas been referring to velocity at the compressor inducer - that same drop in velocity can make it take a bit longer before the compressor starts operating efficiently, and result in a bit more lag. You don't get a lot of stuff for free, unfortunately. Feel free to question anything I've said there, but hope it helps paint a picture of the kind of things that can be going on and why I often ask lots of stupid questions when suggesting turbos and also when trying to work out what could be going on - also why turbo speed and exhaust back pressure sensors are SUPER useful when optimising big setups like this.

Actually, just noticed that the TCF is set up for estimated flywheel power. Hmm it does seem a bit on the low side for this turbo, I would be checking for other issues in the setup if you haven't had it boost leak tested etc Edit:sorry missed it's on pump gas. Nevermind, this is big power for this turbo on pump gas. As above, it's one which works better at high boost - I'd normally aim for 500-550kw absolute max at the hubs on pump with one of these. Yeah, you'll need a bigger turbo if you want bigger numbers on pump - probably bigger on both sides... I wouldn't be aiming for an EFR for 1000hp on 98. E85, fine. Really 1000hp you should be considering a better fuel regardless of what turbo

There could be other things going on as well but you are definitely at the upper end of that turbo. The 9180's compressor efficiency is better suited to running at higher boost levels, I've generally suggested people who run them not run massive head specs if running an RB with one so they "need" more boost to make their power and run in a happier zone. It is a bit surprising it is getting so hot still though, it shouldn't be THAT bad I wouldn't have thought so I'd be weary of possible boost leaks or something like that. A turbo speed sensor pays off a lot in this kind of situation - but again either way a 3.2 with a big head IS going to choke at modest boost on this turbo, there is not going to be a massive amount more power on the table no matter how you look at it. These are a very good turbo for something that came out 13 years ago - will still be not super easy to get something which makes more power without giving away response but a lot of what you're seeing here is how the engine and turbo need to suit each other very well to get the best results - some setups will make the same or more working the same turbo less. Borg have since released the 9280 which would sit in it's place and walk away from this power level with minimal impact. Already know a couple of people running 3.2-3.4 engines making around 700kw at hubs with them on the 1.05 hotside but it would give a bit away in the lower rpm- but pretty much anything capable of making more than this will.

That's kinda funny, that kind of thing has been said in the past (SAEJ1349 correction results in lower readings than some others, all legit - just different effects) and while the hub dynos do read higher still usually, the difference is NOT as much as people like to convince themselves. It seems to be less of a thing that comes up now that hub dynos are being used more in Oz as well, people realising that it isn't automatically +100kw or whatever. But yeah as you say, just a tuning tool afterall - you gotta use the data in context for tracking sensible expectations and improvements.

Nice, if you haven't yet - hub dynos ftmfw, I have no idea how guys have been struggling with rolling dynos for so long and it's nice seeing Oz workshops etc getting over the ripping on Kiwis for using them because they read high and joining the dark side. Steady state and repeatable tuning is so good, especially knowing that unexpected "not the gains I was expecting here" etc question marks can be linked to issues as opposed to wondering if it's just to do with tyre/roller interfaces etc. The numbers will be a bit bigger than non-US roller dynos but that's not what it's about. Look forward to seeing what this thing does on send, it is a cool setup and definitely got some potential. Good luck (y)

Depends on the block you're using. When tuning RB30s I use an unmodded M8 Bosch donut in an M12 hole in the block (same as 2Js) using one of these thingys: https://www.efisolutions.com.au/knock-sensor-conversion-stud-m12-to-m8 With RB25/26 I *have* used a combination of drilled-to-M10 donut sensors and they've seemed alright, alternately have just had an M8 and M10 bolt welded back to back to make up a similar adapter stud to the Toyota one you use on RB30s and JZs.

Ah nice, yeah solid result. Hp ratings are so frustrating, who knows what conditions they're defining for making that hp etc - even if they can't do compressor maps it'd be lovely if they could say "Flows up to x lb/min at x boost" kind of thing a bit like that excel datasheet I compiled for a while for different turbos where the info was available. The .84/6266 combo seems like it'll be a nice one on a 2.6 anyway, look forward to seeing how it goes

With >600kw from the 6466 I'm guessing that's a hub dyno, in which case I'd say your goals seem super realistic. I'm kinda hoping to see mid 500kw area without being silly on the Gen2 a bit with E85 on the hub dyno I use and 400kw easily on 98ron. I'm not 100% sure about the Gen1s as the 6466s really overshadowed the hell out of them when they came out (and lets be real, the 6466s were basically a game changer when they came out and are still not easy to beat in terms of how flexible they are in terms of power, response and what they work on) but I doubt there is THAT much difference so again, feels like the numbers should be realistic.

Some of the tribal "rah this turbo brand" or "rah that turbo brand" does my head in, especially where people give "advice" which is pretty clearly actually based on their biases. Ironically a build I'm involved with is also centered around a divided hotside Precision PT6266 Gen2 on a "true" split pulse cast manifold and we're going to be using it on a 2JZGTE. The owner had been convinced to upgrade to an EFR8374 when his car had pretty bad lag issues which were actually nothing to do with the turbo itself, and it didn't have a lot of miles on - like yours I expect it will be a super effective street setup which will probably surprise some people in terms of the power and response it's capable of. Half the time the issues the bigger name turbos have are to do installation or how they're matched to the engine they're on. I've seen some turbo speed data on how some Precisions are used on bigger builds and it's amazing how far into "overspeed" territory their compressors stay efficient - imho a certain amount of their reliability reputation is effectively them being a victim of their own success in that fact. Aside from you know, the likes of Tilton and RP968 but they are pretty much having their own private WTAC battle half the time so I guess don't count.

Yeah pretty level stuff. Thought I'd throw in that the Xona Rotor range of turbos that use the UHF turbines are also an interesting "modern" generation turbo which due to design pretty low inertia vs turbine flow as well. Funny you mention the EFR casting issue, I half blew the whistle on that here as much as I'd potentially be viewed as biased towards them. I just want people to be aware of the goods and bads of things so they can make their own choices and people spouting misinformation to suit their bias is going to be called out - as you also do There is a chance we're at that "things are looking better" now, but either way it's a shame there was some reason for concern relating to QC as you do have to be wary of that kind of thing - and it's a shame when the likes of the EFR8474 are pretty much the best thing you could put on an RB that you're pretty keen on partying with in terms of the whole cake-and-eat-it-too of usability and power making potential and if QC is going to be a problem it may not be worth the risk. At the very least at that price point you SHOULD expect decent build quality. I know quite a few people who have run 8474s and 9280s over the last couple of years and haven't heard anything recently so maybe some hope there? In closer relation to this thread topic while following on from the EFR 2.5ish yarns - ignoring recent history of QC (I'll ask people who have been using them and report back for better or for worse) a mate has an EFR8474 on his stock stroke "man cam" RB26 and despite the huge cams it makes full boost in the low 4,000rpm range, "lights up" boost wise with minimal provocation under foot - its super super lively for an RB26 with *any* upgraded turbo combo, and makes ~530kw @ hubs on BP98. Power is still hanging >500kw at 8500rpm, so it's kinda like having an 90s'ish spec RB26 build in terms that from 6000-8500rpm the dyno curve and sound are reminiscent of a T88 equipped RH9 car *but* if you're side by side with a -5s or Garrett GT35 based turbo GTR at 4000rpm and put your foot into it.... the Garrett fellow is going to be watching tail lights before you even get to the party revs, at which point you'd need an even laggier Garrett option to try and make the numbers to keep up with.

Wat. Lets just break this nonsense down shall we: 1) I don't know anyone who has actually broken an EFR directly, I *do* know plenty who have run them off the max compressor speed. 2) ^ You read that right, the "failure" warning is misattributed to a magical turbine speed limit but the actual max speeds published are to do with compressor max speed - there is no max turbine speed published for the EFRs. If there is a turbine failure, the thing would have been WELL past the max compressor speed so whoever has put the car together has f**ked something up if they've got to the point the EFR fails due to turbine speed. 3) Taking the top two points into account, you're basically saying "Sure the EFR is a way better performing turbo than the Garrett GTX equivalent, but if someone is incompetent with the match and installation there is a remote chance the EFR will fail sooner than the Garrett." Basically the EFRs are better. But get a Garrett if you have legit concerns that you are an idiot, it will also fail if you poorly match it- but you might have a longer grace period to work it out.

Haha. Not the most serious suggestion by a long shot, but felt like it'd be an amusing one to throw in the mix because you were seriously considering twin T67s. I'd call this about the equivalent to a T67 while being a little bit more modern. Similar wheel sizes, similarish frame, similar lag, look pretty cool, have T51R mod as an option, and they are pretty much the only turbo in the territory of what you're looking for with published compressor maps that will actually retain compressor efficiency at >40psi and capable of making a fair bit more power: https://agpturbo.com/borg-warner-s257-sx-e-57-61-12769095003/ You'd go the .83 vband hotside (well, I'm *assuming* that it would be the most space compatible). I know you want .6x but you're looking for max flow and the Borg turbines like a decent a/r, having a quick play with matchbot suggests that at 40+psi you're going to be pushing even the .8x hotside.

On what kind of dyno? Hubber? Dyno Dynamics? Dynojet? A/r doesn't work like that. At this stage I'm assuming you're looking for 60-70lb/min per turbo which would roughly match up with a 7685. Will have a ponder

What is your actual power target? Choosing an exhaust housing a/r without any consideration for the rest is odd, you could end up making an unnecessary compromise unless there is a tangible reason for deciding on the a/r before you have even decided what turbos you are using?

Oops! Sorry. Yes, that. Though I do like the idea of two solid sized turbos, a huge meaty power delivery AND revving to the moon which is how I got sucked into the off topic bit. Would love to know more detail on what @Butterswas talking about re: dyno plot, I know the exact detail / plot itself may not be available... I'm guessing it epitomises the description you gave there? @khezz, when you're "keeping it on the boil" etc it can be surprising how shit a power delivery can be used to make a car go fairly quick. One of the cars I tune runs an over-cammed (imho) 4EFTE head in a Toyota Starlet running a stock Toyota W58 gearbox. The engine doesn't start to really trap useful air until around 4500rpm, but the block/bottom end setup is not safe to really run much over 8000rpm so basically ANY turbo you put on it is going to be laggy as f**k but you don;t even get to rev it to the moon to make up for it. When I first got involved with it the thing was running a Turbonetics turbo which wasn't full boost (~23psi) until around 6000rpm (later after gearshifts on the strip) and still managed to run a 10.7 @ 130mph, driving the absolute shit out of it - but that's basically not making full boost until somewhere between 6000 and 7000rpm on the strip and only revving to 8k with a 1.5litre engine. He ended up putting a G25 550 in there to make it a bit easier, and we ended up with full boost at 5300rpm (remember the engine doesn't really start even driving the turbo until after 4000rpm, so that is a VERTICAL dyno plot lol) and way better transient response... brought it down to 10.5 @ 133mph at the same boost/similar power, and most of the improvement is just because of response, and that's him being less brutal on the gearbox. Seems off topic, but the moral of it is you can go surprisingly quick at the strip with a rubbish power delivery even without flatshift or a sequential transmission - that Starlet has a woeful power delivery and still does solid 10s without a huge amount of power. Clearly improving the delivery helps, and it would go much quicker with a better transmission, but still be a dog for anything else. The point is 1/4 mile times are pretty much the worst measure for how nice a car is to drive.

Firstly, I was responding to your conclusion "extra brownie points for doing it in series", I had no issue with the concept in sequential. Second, you wouldn't run a Lysholm as the first stage - unless I'm missing something you cannot move more through the compressor than it can flow by itself. You'd need a significant bypass to allow a 90+lb/min turbo to be able to move all the airmass it needs to achieve ~1000hp, and if you're doing that kind of bypass then it's a sequential setup. With a multi-stage compressor setup you run the biggest compressor first and use the smaller ones as pressure ratio multiplier, you've increased the density of the air going into them so they don't need to move a larger volume of air than they are able to. If the Lysholm was able to support 90+lb/min then there is no point running the turbo at this point. Now for my other comment, I have to admit I stuffed up my math - more because of rushing it and mis-juggling the numbers than anything else. To give an idea of why I thought that... I assumed 65% adiabatic efficiency for a twin-screw (I think this is VERY fair) at pressure ratio 1.5 with 24c pre-compressed air temp then you end up with 84c outlet air temperature. If you WERE going to compress this by a PR of 2.0 using a typical centrifugal compressor without intercooling it first then you'd end up with a second stage temperature of over 200c. Where I messed up my calculations was that I had a brain fart with the "final density" calculation and ended up effectively treating it like you needed to cool 207c using 84c ambient temperature - not 24c, so that ended up with a MUCH lower air density in the intake manifold... 88lb/min mass flow "conventionally turbocharged at 30psi" became 73lb/min at the same "boost level" and made it look like a fail, but actually it's not that bad at all. It would actually "only" fall down to 85lb/min.... so still less dense than single stage but you're right, non-intercooled between the two stages wouldn't be a game changer. That aside, I prefer the idea of a regulated 2-stage turbo setup for spark ignited small displacement/"moderate boost level" engine than a compound supercharger/turbocharger setup.

That's more like I would have expected It is a pretty cool idea but you do really need to intercool between each stage otherwise the air density becomes rubbish and as such the second stage becomes a lot less efficient and you don't necessarily end up with the results you could while also having mechanical drag added to it... But the general concept is awesome

Very interested to see where it ends up That'd be a good result!

Ahh, yeah sometimes hard to tell with tone Meaningful boost by 5500rpm isn't inconceivable, though full boost at 4000-4500rpm - I'll have something to learn if your setup manages that, unless you've missed out mention of nitrous or that the turbo tweaks include changing to much smaller wheels etc 😮 In saying that, I've been involved in brain storming for a twin setup for >1000hp @ hubs hoping for full boost around 4000rpm on a 3litre and we have hopes that it's achievable but that's getting pretty cunning with the overall setup - from what you've said you're not getting up to the kind of mischief we're planning

I wasn't trying to talk you out of them, just making sure you did appreciate that it would be super laggy (I never said they won't spool either) - not just a bit lazy. I'd call that realistic, not negative. Fwiw, something measured using no-lift-shifting and generally being used at full throttle/max possible rpm isn't the best metric for what it's going to drive like but yeah. Anyway, you sound like you are pretty happy with the compromises - as I said at the start, I love the old school JDM drag "style" and look forward to seeing results (you don't ACTUALLY get to see what this kind of combo dynos like etc very often at all) and videos... miss this kind of build, and keen to hear it.