Lithium

I was conflicted about it tbh, it looked much better than the out-going Garrett turbos however - if you compare his SR20 result with the SR20 result posted for an EFR7163 in the Borg Warner thread recently it leaves things looking like the G25-framed turbos may be overshadowed by an old dog.

Yeah, I've been saying for a while that all the noises I heard suggested that they intended on releasing the rest of the range - and have certainly not heard anything to suggest that doesn't still apply. There seems to be a fair likelyhood we'll see G-series "up to 1000hp", which presumably will mean up to around 90lb/min turbos.

Pretty much everything you said in your post in regards to the turbo match and compression are along the lines of my thinking, so I'm not going to write a huge wordy one - nice I think turbine flow on EFRs is often a scape goat for when EMAP spirals as the compressor efficiency rolls over on some of the EFR range. I've never seen a decisive result which shows any significant improvement in boost threshold either, and can't think of any convincing reason why more compression would directly drive the turbo harder by enough of a margin to give any significant gains. There are definitely improvements in torque from improved fuel conversion efficiency so it's a very worth while change as it also comes into effect off-boost. I suspect people put down the increase torque they experience when driving a car with more compression to extra spool, and realistically the fact the engine can accelerate the car harder will mean time vs boost will improve on the road - but that's likely more because the rpm have picked up more in the same time, more rpm = more exhaust flow = able to drive the turbo better so there is a response improvement, just the cause and effect are not as direct as some might thing

Yeah they are clearly an improvement over the GTX series, though if you look at the most recent result added to the EFR thread of the EFR7163 on an SR20 it makes it seem like there is more catching up to do to get to EFR status - granted the 7163 is probably the best performer "per pound" of the EFR range.

Nice data! Cheers for sharing, and imho there is room for a little more compressor with these hahaha - they should give them even just a mild update on the cold side

I had guessed that the power rolling over may have been partly necessity to avoid leaning out with the fuel pump starting to max out?

That's a really nice result! Still having boost control issues, though? The turbo should have more flow in it, which is a shame - but that is a massive delivery for an SR20! How does it drive?

That's pretty unlucky with the 7670 Not something you hear happening, the few EFR failures I have heard of have been overspeed / turbine wheel related 9180 on a 3.4 sounds like a real hearty combination though!

The funny thing is that G25-660 already has a hotside which is comparable to the biggest hotside available for the EFR7670, and compressor wise flows slightly better at all the points one would be likely to use on an RB25/26 if they were looking for a fast road car. Need more real world results to get a gauge of what spool is actually like, but I can't see any reason why despite seeming so small - a G25-660 is actually big enough to cover the needs of your typical punter building a quick road car

Looks like they've updated them!

Got some compressor maps for me?

Fark yeah, good call on mapping the 8474 in there - GET ON IT Borg. That would change the game if it delivered on that :o Also +1 on the G-series scaling. This stuff is all on paper, but imho the simple job of just compiling some points into one list kind of explains some of the things we see happening in practice on some of these turbos. The G25-660 with a .92a/r hotside could be quite a surprising beast on an RB25....

100%. One of the reasons I decided to break it down as often people just seem to look at the power claims or the peak airflow levels without considering the compressor efficiency. The EFR9180 doesn't really seem to be a turbo best suited to a setup which can flow a heap of air in it's own right, at least based off what I've done here it would indicate it'd roll over early if you treated it like a 90lb/min turbo and tried to flow that at relatively low boost. On the flipside, you could potentially shove one on a solid RB26 and crank a heap of boost through it and potentially make more power than you would with an RB32 with big cams capable of making lots of power without heaps of boost

And because people like this kind of thing, a loose translation of what kind of area these flow figures may convert to in dyno numbers if everything else is up to the task. Bare in mind, these numbers are not what I'd say are "on kill", but where the compressor is starting to really earn it's keep - they should have more to give, but the things start working harder to get there and you start moving more into "how optimised is this setup" territory. These numbers aren't a guarantee of what setups WILL hit using these turbos, it's what the turbos should be able to achieve working reasonably hard - but not too hard... and of course me making a bunch of assumptions lol. Turbo 20psi 25psi 30psi GTX3071R 339 352.6 359.3 GTX3071R Gen2 345.78 352.6 359.3 EFR7670 359.34 379.7 386.5 S257SX-E 366.12 386.5 406.8 G25 660 372.9 406.8 400 GTX3076R 400.02 413.6 420.4 Gen2 GTX3076R 400.02 413.6 420.4 GTW3476R 406.8 433.9 454.3 EFR8374 440.7 461 467.8 GTX3582R 474.6 488.2 501.7 Gen2 GTX3582R 474.6 508.5 522.1 EFR9180 501.72 535.6 569.5 GTX3584RS 508.5 542.4 569.5

Hi all, There have been all kinds of conversations on and off SAU about single turbo options for RBs (and other engines really) in the current state of the game and while I've not seen any evidence of compressor maps being inaccurate, different manufacturers use different ways to normalise and present the numbers, different cut off points, and different ways of estimating hp from compressor flow which can result in people expecting too much or too little from their turbos. I've decided to semi-roughly translate it all into an even measure and shove what I consider "the most relevant" turbos for most people who would be talking about turbo choices in here, and split the compressor flow potential they have at 20psi, 25psi and 30psi - using "65% compressor efficiency" as a cut off. Those are fairly familiar and reasonable reference points, and as you exceed 65% I view it that it's where the intercooler and hotside are starting to have to carry disproportionately more of the load to keep things happier. This is the "you're pushing it" zone, imho - even if it's not really maxing the turbo out. It seems to be a reasonable way of gauging them on a similar scale if you're going to being matching the turbos for real world performance. It may not be PERFECT but I think it gives enough of an idea of how they may compare, I'm pretty sure all these turbos have hot side options which are pretty close to supporting the exhaust flow needed these days - give or take, but some of the numbers here may explain a few interesting things seen.. Hope it's vaguely interesting reading Turbo 20psi 25psi 30psi GTX3071R 50 52 53 GTX3071R Gen2 51 52 53 EFR7670 53 56 57 S257SX-E 54 57 60 G25 660 55 60 59 GTX3076R 59 61 62 Gen2 GTX3076R 59 61 62 GTW3476R 60 64 67 EFR8374 65 68 69 GTX3582R 70 72 74 Gen2 GTX3582R 70 75 77 EFR9180 74 79 84 GTX3584RS 75 80 84

Yeah, hard to disagree with most of this. The last bit... I still need more data, and while I agree re: the choking engines - it seems quite a bit like the data is there, but Borg Warner have presented it in a way to make it seem "better than it is" They have mapped lines way past where compressor efficiency would be falling over, the "95lb/min" line which they so clearly mark for the EFR9180 is VERY misleading imho. You have to pay attention to the numbers, not just treat the right most lines as the target. I think there is a very real chance that the bigger G-series turbos coming out from Garrett could give Borg Warner a kick in the pants.

Yeah, next time I've got a dyno handy this will be worth a try to get a gauge of the NZWiring kit solution. To be clear, I've never debated that the crank trigger setup isn't the ideal solution *but* this data makes the difference look much worse than I expected... so far. Yeah going by the data so far it looks worse than I expected, albeit still would love to do this testing with something like NZWiring's kit.

These turbos are designed focussing on response for a power level, not max power level for a wheel size.... all the information is there to determine whether the flow will suit what you're trying to achieve, to make sure you are able to choose appropriately from that. There are plenty of cases where you can go up a size in EFR versus a competitor and still end up with better transient response and make up for, if not more than make up for the flow difference penalty you may have had using a size down.

Cool, yeah I hadn't done the math and just did a quick run through of my own and it does seem to add up with what you're saying - which is interesting as there is some pretty enthusiastic debate from some pretty respectable names about the likes of 12 @ crank not being enough etc... if your math (and the quick bunch I tried) add up then in theory there shouldn't really be too much error if you were to assume the crank velocity maintains a linear rate of change. I don't have any data on the realistic behaviour, though as you say... that would be VERY interesting. Still curious to see what you see if you maintain steady rpm at 5000rpm or so, just for interests sake - I've not got enough time to go fully through my math to make sure it's sane but it is starting to indicate that some things are overstated, which I guess explains how stock Evo triggering doesn't cause big issues haha. If that does work out as being the case, I am pretty surprised that the difference would be that big.

OK cool. To clarify, what I was questioning (to be clearly, not calling it out as BS - I more trying to analyse the data presented as it *is* good data but it'd be good to feel comfortable with the conclusion taken from it ) was this statement: I might be reading you incorrectly, you are only looking at a window on the cam disc - so checking it once every 720deg of crank rotation? And you are using that to gauge error between crank triggering and cam triggering? If so, then I'd be questioning your data if you DIDN'T see a big variation when the engine is not operating at steady state rpm... if you get what I'm saying? Hopefully this helps clarify what I am trying to get at, and at least we can get on the same page and work out how best to use the data - putting this kind of thing on the microscope is a worthwhile venture

OK, so what would happen if you compared a timing data between a car running the 36-2 and the 12-1 in exactly the same operating conditions?

Yes, I understand all this - this is my point. To try and get this on the same page, what do you think will be more accurate - 36-2 or 12-1 on the crank? What do you think would happen if you compared timing logs between both setups?

This is kind of the point I was getting at, the evidence you are presenting is partly comparing the ability to accurately estimate the crank position by comparing something that gets updated every 10 crank degrees versus something that gets updated every 30 crank degrees. Theoretically the error between the two should be negligible at steady rpm, but the error will increase the moment the rpm rate of change increases - it looks a bit like you selected a section when the engine was starting to go through a drag down after a dyno pull, which is much higher rate of change than the pull itself. And yeah, it should be more stable under steady state conditions which is why I asked if you can do that - it should mostly eliminate anything that may (or may not) be introduced by comparing 10deg updates with 30deg updates

Interesting data, thanks for sharing. It'd be nice to be able to separate any error which is introduced by triggering resolution - I don't have the time now to do the math to work out what (if any) meaningful error would be introduced via a combination of any signal filtering vs rpm rate of change. In your case there are 3x the amount of updates from the crank trigger as there are from the cam trigger in a given amount of time, which will create an increased amount of error even if there is absolutely no drift at the cam as the rpm rate of change increases. Are you in a position to be able do any more testing of this? I'd be interesting to do a brief steady state test at the higher rpm - ie, hold it at 5000rpm briefly to see the trigger variance.

Seems almost relevant