Lithium

Not *as* suited as the EFR8374 I suggested - and only mentioned that because I thought you'd responded to my comment though OP has mentioned pump gas so gotta clarify some things as I may change that view a bit too haha. I'd prefer Sinco myself, I would look into Artec's cast divided manifold as well though there have been posts coming up suggesting that fitment may not be great so that might be worth keeping an eye on. My turbo suggestion was also assuming ethanol, you *may* need something different depending on what octane fuel you'll be running and how the dyno reads? You may need a "bigger" turbo than the EFR8374 that I mentioned if you're looking for 600hp @ wheels on say an Aussie Mainline or Dyno Dynamics rolling road dyno on say 98RON, but if you're going to be running on a hub dyno or Dynojet then it wouldn't be a problem.

Edit: Oops, I clicked the link to the thread notification thinking this was a response to my comment and said stuff explaining why I thought the G35 wasn't as suited to this situation and it could have looked like I was having a dig - and just realised you were responding to another comment. Ignore me!

Without being absolutely ridiculous about it, this is the gist of what I'd look into: - RB28 with VCam - Nismo intake manifold - If available a good T4 divided cast manifold. Smallest volume possible that is going to support 600hp, PROPER pulse convertor style thing - EFR8374 with 1.05 T4 twin scroll hotside - Good intercooler with minimal pressure drop and unrestrictive intercooler piping - Free-est possible flowing exhaust. 4" dump pipe off turbo - Run it on ethanol I'm wondering what I'm missing with people suggesting a G35 900, if there is a result or something I've not heard about I'd love to see it - from all I'm aware of so far that'd be a solid step down from an EFR8374 in terms of overall stand up/response if everything is put together and working right. Sure, capable of more power and go well for what it was but not "peers" with an EFR8374 in terms of responsiveness from anything I've seen so far. A G30 770 would be more comparable I'd have thought, and if I had seen such a setup I'd consider that as a possible viable alternative to the EFR8374 and would love to see how it would go - but I'm just suggesting unbiased and proven combos. At this point I'm not confident there is anything else that would compare that will safely hit 600hp and be as responsive.

Not to question this data at all, obviously very good input and context been given but I thought I'd add stuff from some data I've got for a car run in a hub dyno (these numbers are from a roller dyno that reads more like a Mainline/dyno dynamics roller than a Mainline hub) where we have pretty high confidence of no leaks etc. It's not for a G30 770 but should add some perspective. A mate's SR20VE with a Garrett Gen2 GTX3076R made 597hp @ hubs on E85 at 23psi at a bit of altitude, with 131,000rpm turbine speed. These don't have as efficient a compressor as the G30 770 and have the same max turbine rpm (around 145,000). Also gives a better lock on conversion of hub HP vs flow on E85 for a rwd on a Mainline prohub. If the are no leaks, the Pulsar G30 770 flows about the same as the Garrett version etc it seems like they shouldn't be at a point they are exploding at this power and I might go checking now, but I could swear others have made this power area fine already with them.

If you're not using throttle control for torque management probably not sooo much of a thing, but ignition cuts are pretty hard on stuff.... not necessarily something I'd totally expect to cause this kind of failure though. Cool yeah not familiar with the GPR so was just saying it in case it might be - and yeah with the GTR package there are ways of adjusting the boost targetting as well to avoid massive silly things from happening.

Haven't used the GPRP just something just occurred to me if you're using a package which supports torque management - I tuned an R35 using the M1 GTR package and one of the things that quickly got my heckles up was seeing the throttle pressure ratio data when trying to manage torque etc. Some competition level (Emtron as well) engine management systems that do stuff like this to ensure that you can control power delivery carefully but also have the turbo speed maintained so that when you want the torque "back again" without waiting for the turbo to respool can actually put a massive amount of load on the turbo if you're using e-throttle as part of the torque management. Like, huge pressure ratios and turbine speed - I'm not saying this is a thing with yours but its a thing that just popped into my head when @Komdotkom , mentioned "nifty stuff". If you are using e-throttle and torque management it's very much a thing to bare in mind, the conventional turbo matching stuff goes straight out the window when you start doing stuff like that as the transient situations can potentially end up operating the turbo in really strange places. Strictly speaking that can even be a thing if you go half throttle with a conventional throttle where the turbo is still targetting "full boost" and the boost control setup is able to maintain close to target, the turbo has to try and make up for the pressure ratio across the throttle as well and can end up working super hard - this is actually another reason why it can be sensible to reduce boost targets at part throttle. A small hint of this phenom is where some cars can go into surge conditions at part throttle. Pressure ratios vs flow get super odd.

Same. Do you have I2/I2 Pro? How familiar with the software are you?

Ah sorry, from some things you'd mentioned I assumed you were more comfortable with reading compressor maps. Nah, you're right against the edge. The red line I've drawn through the map is a rough estimate of where your engine may be operating in and it "stops" basically just at the max-rpm line on the right side of the compressor map. Touching that line doesn't mean instant fail by any means, but it does assume there are no outside factors meaning it has to spin harder and obviously I'm also just taking a punt so there is no guarantee that's accurate. Nice computer Maybe not necessarily quite a straightforward to work out the airflow the ECU reckons the engine/turbo are moving though it's definitely capable with I2 etc.

They've been out for a few years and actually a "joint" effort with (or FP say basically is a FP turbo that Mitsi liked so much they've sold as an OEM option) Forced Performance. They seem like excellent performers and are loosely FP Greenish from memory. They also happen to be "standard rotation" as they are an Evo X option

This is what I get when I have a quick go at Matchbot, let me know if it seems like I'm missing something. I'm "only" running it to about 7700rpm though as that's all your dyno plot goes to. Plausible that running it to 8500 could go further but it looks like your VE is going to start plummetting after 7700rpm so I'd not necessarily expect the compressor to need to do heaps more. What ECU are you running? You could look at logs to get a gauge of the estimated airflow. Here's my attempt at matchbot: https://www.borgwarner.com/go/N0YW5D

Ugh actually. Please hold, I'll just actually run the math properly and see where you're likely to actually be instead of guessing. Bbs

Ohh. I may have made a bad assumption with my previous post - I kinda glanced at the power and assumed your were running ethanol (which kinda assumes a certain airflow vs power conversion) which would make that power seem perfectly within the G30 770 capacity but actually, looking at the rpm and boost you're right... all things being "typical" your engine is likely to be breathing a heap more than that turbo would want to give at that boost. What fuel are you running on?

Argh also, I missed a point above - it seems that especially with the Pulsar turbos third party dealers seem to sometimes mess up orders. I've seen it (not directly experienced it, but definitely seen it happen to other people) where someone will order something like a GTX3584RS and end up with a GTX3582R, or a "G30-770" turns out to be a GTX3071R etc. If you had a GTX3071R or even GTX3076R or G30 660 and tried to run it like a G30 770 then there could easily be carnage. I've seen people run near 600hp @ hubs on the Pulsar G30 660 on ethanol so it can be done, but probably not super wise.

Seeing as it's a little ambiguous as to why you might be upgrading, I'll give some bullet point answers based off the two reasons you may be: Upgrading because you're assuming the failure is overspeeding: A G30 770, either Garrett or Pulsar version should not be overspeeding at this power level. It's leaning on them a little but should still be in a relatively safe place Any details on how the turbo looked/what broke and when? First time I've heard of a catastrophic failure with a Pulsar, can never rule out a manufacture issue with them (I know people who've had this with Garrett, Borg, Precision etc so Pulsar probably won't be immune) You can also overspeed the turbo without actually trying to make more power than it can support, if you have a restrictive intake or intercooler, or some kind of boost leak then there is the possibility that either the turbo is seeing a much higher pressure ratio than you'd guess based off when you see at the intake manifold - or alternately the turbo could be moving a heap more air than the engine is seeing, both causing it to overspeed while actually giving the engine less air than the turbo can provide if everything is working efficiently. Make sure there is no other issue with your setup that could possibly cause a premature failure, like oil feed blockage or something to that effect ^ Especially #3 and #4, make a seriously good effort in ruling out or identifying any possible cause there because you don't want to spend >2x the cost on a replacement turbo to end up with the exact same thing happening. Upgrading because you're levelling up: How much more power are you after? If you're happy with the power and response you had already, 590hp @ hubs isn't a heap short of what the compressor supports with those so going up an a/r may result in an underwhelming increase in power vs how much extra lag you get from it - imho the .83 seems like a good balance on the 770 even if it may hold it back a little at the top end of it's capabilities. Check out the 6466/G35 900 thread, someone has gone a 1.06a/r T4 Garrett G35 900 on their VCam RB28 and it's a lot laggier than this. There's no magic, if you have a bigger compressor, bigger exhaust wheel, big tubular manifold and larger exhaust housing then twin scroll is not going to offset the response at all.... but it will be capable of an extra 100kw @ wheels safely. If you are after an incremental increase maybe consider the 1.01 T3 G30 900, or if they have it a 1.06 T4 G30 900 - I'd wager that has a good chance of being a sensible in-between if you are concerned about response. It's unlikely that you'll be able to go up in power potential without some cost to response but that is one way that's likely to manage the impact somewhat. Just my thoughts.

PS part of why I did the above is so you can see your setup is likely reaching as high as PR 3.3

K, I've thrown some numbers loosely based off your dyno plot and what you've said into BW Matchbot. I've selected the EFR8474 compressor map because it happens to be an excellent match for what you're actually doing and also funnily enough Borg Warner doesn't have the Garrett data I used turbine flow data for the G35 900 with 1.01 hotside (as the 1.06 T4 isn't listen) to loosely match the turbine data. Very loose but should give a general idea of what EMAP and pressure ratio etc might be doing. https://www.borgwarner.com/go/3I1H4G

2.3PR is around 19psi boost at sea level if you have zero intake restriction - you sure you aren't missing a PR there?

Just to clarify, has yours failed or are you worrying about how risky you're playing it?

If you hate Precisions but like some of the "insane power vs turbo size" things maybe worth having a nosy at ApexTurbo, be super interesting to see something like one of their 64mm or so type units on an RB30. They seem to be getting results that seem impossible, even when you consider the latest Precision offerings... most significant Evo/Honda turbo records have already been picked up by things running ApexTurbos and one of the Honda guys "downgraded" from a bigger Precision turbo to a 62mm Apex to try and make it easier to get off the line and ended up making significantly more power at the same time, like they cracked 1000whp which is mad even on a US dyno without nitrous etc.

A Holset HX35 and a Mitsi TD06(/SL2) are *completely* different turbines - you absolutely cannot take what a Holset 10cm divided housing behaves like and try and use that to determine what a turbo with totally different housing and wheel geometry on both sides will do. May as well say they're both loosely based on circles so will behave similar. Hmmmm. I did write a post saying that the only ones I experienced were the bigger ones but decided to verify and there is every possibility I had actually been exposed to TD06SL2 20Gs when they had been referred to as simply "TD06 20G" so I'm actually going to have to not weigh in on that. The only thing I *can* add to the "maybe the SL2 doesn't add as much value as it's given credit for" is arguably the most famous TD06 aside from the TD06(something)-20G is the classic FP Green which was basically a 50-trim T4 compressor paired with a TD06H turbine, and had the reputation of outspooling and out flowing 20Gs of almost any combination... though this potentially brings the whole "compressor vs turbine matching magic" side of things into the discussion. Sometimes the result can't exceed or fall short of the sum of the parts. My memory also probably stretched here, but one of the best 20G setups in the entire RB kingdom was @Roy's RB20... I'm not sure that was an Sl2?

Good call on the altitude, I even thought briefly about that when I posted the comp map but so used to people living close to sea level that I didn't dwell on it... I guess there are a lot of areas people live that are high enough that the relatively "not high boost friendly" shape of the G35 900 map would mean it'd not be hard to over speed them when trying to make their rated power even at not a particularly high altitude. To add to that, there are a LOT of people likely running around out there with boost leaks. Like people think they've gone above and beyond if they've done a solid spanner check, or even smoke tested their pressure sides of turbo setups - before tuning where possible we'll try and pump 20+psi through the intercooler piping and the amount of times we've heard rushing air on a "nah it's definitely all sealed" setups is solid, potentially in the area of 50%+. I'd not be surprised if the reason a lot of the car's my little group have done that have ended up with "better than people expect" for the setups are if anything an indication of how many people are running around with undiagnosed issues. If you're one of the MANY people who are running around with a boost leak then yeah, turbine speed is the only way to be sure unless you pressure test it - I am certain some of the EFR horror stories come from boost leaks, they were basically booby trapped by having a selling point of coming with an internal BOV that just happened to often leak at high boost. Perfect. Re: Precision, yeah I've seen some data from people testing big Gen2 and NextGen Precisions and while the Precisions aren't the most "low inertia" turbos it becomes clear from the turbine speed stuff that some of the "magic" with them comes down to the fact they can actually tolerate a hell of a punishing. Like its not unheard of to have 76mm Precision turbos being run at speeds (as in turbine rpm, not tip speed....) that you should be starting to think about calling it a day with a G35 900 hahaha.

Ok, should have said that was your priority instead of response - a preference because you just like the idea etc is fine. So the TD06-20RX will basically make the power of a 25G but with the spool of a 20G. Turbine is the same so should have the same "Mitsi turbo" exhaust note you're probably looking for.

Are the Trust TD06-20RXs super super cheap? I'm not sure why you'd go a TD06 these days unless it costs almost nothing. From the perspective of someone who has been into RBs/turbos for over 2 decades now - I remember a time where TD06 20Gs were a wicked thing for an RB20/25. Like they cost less, were strong, and performed admirably (for a journal bearing turbo) against Garrett/HKS turbos which cost a lot more back in the day - a 20G would be a solid alternative to something like a Garrett GT3071R or HKS 2835 for sake of argument. That was around 20 years ago. In that time Garrett have since released a GTX3071R, then Gen2 GTX3071R, then the G25/G30 range of turbos - and there are budget equivalents semi-loosely based off all the previous things. This TD06 20RX from everything I can see is basically Trust finally upgrading the compressor wheel (but nothing else) to something comparable flow wise to the improvement Garrett did with the GTX3071R, a turbo that's been available for about 13 years now. If the year was 2010 and this turbo had just came out THEN (and at a sharp price point) then I'd understand threads like this coming up... but in 2023 I just don't have a clue why they'd be a thing anyone would consider. So yeah, short answer - it's something that will spool like a TD06 20G (a 400whp turbo from 1998) but is capable of around 10% more power. But a Pulsar GTX3071R (or the like) will probably cost less and do everything better.

I'm not aware of any "random" failures. I feel like I heard of people running into issues when going on a mismatch combo but it may be from this thread, or associated with the guys posting it - the general agreement at the time is that it due to overspeed which thanks to the more efficient G-series wheels etc it becomes a lot more likely than earlier Garretts so the idea would be to keep within the recommended "area" of these things. To get an idea of if 2bar-ish is a risk, the max wheel speed published for the G35 900 at PR3.0 lines up with around 79lb/min I'd not necessarily expect that line to be a "it asplode when you go past this point" level, but realistically the further you go from that line the risk climbs exponentially. Ironically the anti-Borg Warner silly people chuff at the idea of wheel speed sensors being a good idea as though they're the first turbos to be efficient enough to be able to blow themselves up if you let them keep pumping air, but this is why it's not a bad idea. It's worth noting at that map that it looks like compressor efficiency is actually QUITE solid still at the maxrpm which means it'll be super easy to overspeed one of these things, the common method of waiting until it stops making power easily is likely to get you way off the map if you're going for >2bar. The "next best" idea is estimating your airflow and picking where on the compressor map you land based off that and your intake manifold gauge pressure. My super bro-math way of estimating required airflow with a 2wd car on a hub dyno is relating lb/min to kw with a factor of 7.1.... so if you wanted to know what is a "safe max" point to push a G35 900 on E85 on a hub dyno at bar would be 79*7.1 = 561kw. If you pushed one to say 600kw you could also go 600/7.1 and find you're likely pushing in the territory of 85lb/min of air which is starting to get a bit up there but shouldn't be COMPLETELY insane. Ymmv as different dynos, different tuners etc will give different results A lot of modern ECUs support VE based fuel equations, and if the tuning is done competently (injector/fuel/charge temp etc settings all calibrated accurately) then the ECU will have a pretty good idea of the airmass getting into the engine as otherwise they'd not be able to command the correct injector flow to hit target AFR. If you have a Link ECU for example you can check a value call "airflow per cyl (estimated)" or something like that. If you get that value and throw it at an equation like "(percyl * 6 * rpm / 2) / 453.6" which takes the g/s airmass the ECU is assuming each cylinder it's getting and converts that to lbs of airflow consumed by the entire engine over a minute. I've found it to be relatively on point for cars I've tuned so far... this again should be <80lb/min at 200kpa MGP if you want to be safe.

Fairly sure I've already seen a bonkers NextGen 7275 result, trying to think of where. Could just be another Apex turbo result as those things are just mental