Lithium

Correct E35 max

Pretty sure around 26-27 psi

Here is a mate's 2.8litre EFR9180 setup doing some laps at NZ's time attack series - bonus loose moment at the end of the timed lap https://www.youtube.com/watch?v=3klPPfce7W0&t=2m20s

A quite relevant detail which seems missing here unless I missed it - what were AFRS doing? Tracking as normal? Did you ever stop and check the exhaust manifold by eye to see if it was glowing like could be expected under those conditions?

Yeah, glad you said that - I start rolling my eyes a bit when people make comments that "If it was a real 700+whp then it'd run xxxmph".... fact of the matter is dynos are just tuning tools and it's not that American dynos are happy, it's that MOST Australian dynos read lower than what pretty much everyone else in the world use unless they have imported a Dyno Dynamics dyno. 740whp sounds about right for high 130mph/around 140mph to me from the Dynapacks that I am used to, and sounds about right for what an EFR8374 is capable of. I'm guessing if this dyno reads like what I am used to then the turbo will be within safe rpm, JUST. Nice result, I look forward to hearing how it goes - E85 is awesome, tends to make the car feel better in general ... not just when tracing the target boost curve. Been good seeing this setup gradually be refined and start showing what the EFR8374 is capable of on a nice RB

Can you please clarify more here, I've asked how it drives - to put more specifically, you are basically calling the GTX3582R much of a muchness with the EFR7670. Everything I've seen anywhere else makes me strongly disagree with that sentiment, on the same engine and dyno the EFR7670 will fall over way before it and in the real world should be much more responsive. Again, all things being equal. Is the EFR7670 no more responsive than the GTX3582R to drive?

Ahhh you have a 2.8, that's a bit lazier than I'd have expected from a 7670 on a 2.8 then. Can you share your dyno plot? In all honesty, from everything you're saying it's really hard to not feel like asking you actually accidentally ended up with an EFR8374 haha. I know other people who have had quite conflicting results to yours, albeit with the .92 hotside

How is "400kw @ 17psi" lazy? You are showing 20psi before 3700rpm on a stock RB25 - right? That is not lazy if you are aiming for your power level, ignoring the fact this turbo would go >400kw. How does it drive?

Who is your tuner? Sounds like questions you should be talking to them about as that's who you work with an need to be on the same page with. I'd be content with a 5bar sensor, myself - I'd not want to be going over 500kpa one way or another. Just for sanity here, 32psi boost and 40psi are equal to 318kpa IMAP, 372kpa EMAP at 100kpa baro. I'm pretty sure @Piggaz said his EMAP peaked at 360kpa and he was getting ~122000rpm so loosely speaking the Matchbot numbers sound fairly on point. The EFR8374 with 1.05a/r seems a really really good match between compressor flow, turbine flow and response for a "nice" sub 3litre responsive RB setup - turbine inlet pressure is essentially starting to climb relative to inlet manifold pressure when you hit stonewall, so still "breathing" well while also not wasting turbine energy in the "transient" turbine rpm range.

Solid power and delivery for low mount twins near 500kw! Just for clarification, when you say "tested rear turbo feed and >10psi vacuum" - can you explain what you meant there? I've been REALLY keen to know about if or how much vacuum a high-pressed low mount twin setup is drawing at the intake as I have long suspect that the piping will force a restriction as required airspeed goes up and it will initially push the pressure ratio up quite high, meaning a lot of setups will go off the comp map before they necessarily actually reach their flow potential at atmospheric vs inlet manifold pressure... so choke earlier than they would. This would confirm that theory like a mofo. The next thing however, if that is what is happening - when you say 10+psi "vacuum", you mean atmospheric pressure (~14.7psi) - 10psi, or ~4psi absolute pressure? That is F-ALL. Like crazy low. The area of the map your compressor would be working in would be similar to if you were running near 90psi with no "vacuum" at the inlet

The power figure claims are pretty big, but Garrett tend to be pretty good with their turbine and compressor flow maps and they certainly indicate some impressive performance potential. On your typical Oz dyno I think of 500kw @ wheels as needing around 80lb/min of compressor flow when running E85, give or take - and so long as the turbine flows sufficiently to allow that. The G25 turbine wheel with all but the smallest option seems more than up to supporting that from what I've worked out and that is supported by the fact that Garrett are using the same turbine wheel on the much larger "G25 660" turbo. As a general rule of thumb it seems that your "decent" 26 headed RB needs near 30psi to make 500wkw assuming the Oz dyno/E85 combo, the G25 550s flow can flow ~48lb/min EACH at that level. That is a combined flow of around 96lb/min. If you managed a setup capable of utilising 90+lb/min of combined compressor flow then you are going to be comfortably north of 500wkw....

Actually I have a habit of understating things, but I might spell this out - I saw in your previous post you mentioned your "-5s". When I highlighted "ideal" setup, I would rate the stock location twin configuration as FAR from ideal - so if you are hoping to put G25-550s in the stock configuration then my response doesn't apply to that, at all.

I would say quite comfortably yes. Well and truly. I have bolded and underlined a VERY key word there.

Hmmm it can be done... https://www.youtube.com/watch?v=gECcCtlz-5c

That is huge! You're getting into brave territory pushing that much without any idea of shaft speed, but I bet the thing is fast as hell. The revs are likely to be due to the turbo limiting and partly the boost curve, if it stayed flatter it'd give a more "holding on to redline" looking power curve but realistically it's hard to compare with the RB26 as I am betting it's actually making WAY more power at high rpm than the 26 was still? Sometimes the "peaky" feel is a false economy when part of the reason it looks like it's not doing well up high is how much it is delivering so early is taking the shine off it. ~500kw at 8000rpm is pretty hearty! What pressure do you run in the tyres? Did you do good skids? Suspension setup etc etc should all come into it as well, but it really can be a mission getting a rwd off the line - if you did with that power though, it should be pretty damn fast

Not too surprised the GTX weigh a bit more, they have 11 full-height blades and as Mick said - a dense chunk of alloy with everything that doesn't look like a compressor wheel cut away from it. The likes of the FP HTA arguably are better if you are aiming for spool as they don't tend to have a higher blade count and tend to result in a similar-ish profile to the old blade/hub design but with less "fat" in each direction. I remember someone weighed the 59/82mm 82HTA compressor wheel and the 61/82mm Garrett cast GT wheel and the difference was 121g for the GT and 93g for the HTA. It's not specifically that it was billet, but it's the actual wheel design they could get away with by milling the wheel as opposed to using a cast. A lot of this is probably beside the point, the majority of the mass is in the turbine side - a lot of the spool is likely to come from the aero as opposed to the weight for the compressor in the grand scheme of things.

Very nice review! I drove this year back in 2013, before the sequential and before the EFR8374 and in all honesty - even then it was a high bar to set for "how a GTR should be" in a lot of ways. Prior to this we had many debates about twins vs single turbos and this was meant to open my eyes in terms of how twins were better, and I have to be honest.... it did surpass my expectations at that point, but while I felt I was a bit of a rude motherf**ker at the time being allowed to drive this mans AMAZING setup and still stick to my guns with the "but it'd be better with a nice modern single on it" line, I'm glad I did and I'm glad he moved on. I seriously can't really imagine what it is like now with the new gearbox and the EFR8374 on the roads he built it for. I have to admit that I get the shakes a bit imagining it doing what it was built to without a cage. But yes, even without experiencing the latest form - but yet again hats off to what you've built, Mr Pig. @BakemonoRicer - should give the EFR thread in Forced induction a bit of a nudge now you've lost your EFR cherry, it's probably beating a dead horse to death but there are still plenty of people who are dubious of the transient response magic of these things.

They did that with the Gen2 turbos and started saying "WAY MORE HP LOLZ" when a big chunk of the extra power claims for the Gen2s simply came from that. To be fair I suspect they are just aligning themselves with how much more power people are getting from the same airflow with more efficient engines etc etc, and no doubt if they changed the claims for the old turbos to align with it (ie, a GT2871R becomes a 520hp turbo, the GT3582R becomes a 750hp turbo and the Gen1 GTX3582R becomes an 840hp turbo) then no doubt people would start asking questions.

No no, Garrett have changed their new turbos to be 11hp per lb/min but continued rating their older turbos with 10hp per lb/min. They may as well have just made their dyno read higher for all their newer turbos Flow numbers make a lot more sense, you work out how much your engine needs - you pick a turbo from it and if you've done a good job - profit! It'll make what it makes on your chosen dyno.

Didn't think there was any argument about anything, I was just viewing my disdain for any turbo manufacturer making hp claims It has made for some very frustrating conversations in the past

Agreed, though 660hp @ engine is pretty optimistic stuff on petrol from that turbo

I think it's pretty much as retarded that they are claiming it at the engine. Wonder if we can put one on a good 5.9litre Cummins and hook it to an engine dyno shooting for 660hp and take Garrett to task for it when it doesn't, but the Borg Warner compound setup we shove on next does it without hesitation.

Yeah I was more thinking about the potential for a G30-range

How much of a rush are you in? The new Garrett G-series turbos may be interesting to hold out for....

Ftfy Also, bare in mind the 6266 turbine is the same one used on the 6466 and 6766 - so for all intents and purposes from the Precision range it is probably not really apples and apples with the 8374 turbine, and more comparable with the one on the 9180. I have in my head you already have a GTX3582R... I'm not 100% sure that it'd be worth changing unless you have a really good reason? What is the motivation for the turbo change?