Lithium

There have been a few failures, but not THAT common. A lot of the earlier EFR failures which are documented were actually more to do with the early build issues than actual overspeeding

Can't argue with that logic, be good to see how it goes!

You staying with the EFR party?

Lol! How is your car going?

I doubt the boom is that inevitable, I'm fairly sure a mate had that exact thing happen on his EFR8374 drift car after he first went to one and he just lost power and his heart sunk because of the stories about overspeeding - but then realised what happened, got it sorted and carried on. Car is still going strong. Worth avoiding, obviously - but not necessarily immediate death. Much the same as how you have people running around with boost leaks all over the place with stock ceramic turbo Nissans who never realised it. I guess not having the full load on the turbo MAY take some of the edge off?

How did you build your timing map, or where did it come from - and where are your weird mixture spikes? It's been a while since I've done an RB25 on pump gas but my gut feel is telling me that the timing numbers from 2000 to 4500 at light vacuum are really high, overadvanced timing can result in lean spikes and stumbles at light/transient load. If you are struggling with accel enrichment in that range I'd consider pulling some timing out around those zones to see if it gets any more sensible. Bare in mind piston acceleration from TDC (which is very dependant on rpm) have a HUGE amount to do with what timing you run. On the flip side (and not so much of an issue when in road-tune mode) your timing numbers on boost are pretty soft above 5000rpm. BTW, if you are who pulled the timing out from 5000rpm... if your intention is to keep it safe then you really shouldn't have bigger numbers below then, especially 4+degrees more!

Depends on which Vipec/Link you have - the G4+ generation allows either. 11.3 is quite a lot on E85, but maybe not so bad on 98

Please tell me you mean 0.9 lambda, down to .7x lambda and not 9:1 AFR etc

Sometimes a tuning issue can come down to fuel pressure or some external thing but there is every possibility it's as Dale says, the numbers the ECUs are crunching. There are bazillions of Links out there on RB25s etc which can rev without hesitations.

Interesting! Yeah I knew the turbine side was the same, which is HORRIBLE by the way but something got it in my head that the RB20 units were journal bearing too. Not too relevant, aside from the fact that it is dreadful how poor they were for how much money went into making them! They should have been the EFRs of their time!

What is the .83a/r twin scroll you are proposing to use? I am quite apprehensive about the whole twin scroll GT28 idea because I am unaware of a native housing for them, and have seen aweful results from people modifying housings meant for other turbines in the past - not to say it won't work, but I'm just wary... especially when giving away the divider space on that small a turbine. I'm not going to touch the "this will/will not work well" topic without turbine flow maps or any kind of evidence of performance on any other setup for fear of giving bad advice. I'd say the most accurate input would be that you'll be a guinea pig if you try it, though it has potential to be pretty epic. Really? I honestly was pretty sure that the RB20DET had a journal bearing ceramic wheel unit on it? If it is ball bearing then that REALLY highlights how much better the TD05s are, they are MUCH bigger wheels and flow and honestly weren't much laggier - definitely performed better than the ball bearing ceramic turbine RB25 turbos did on RB20s, which makes a mockery of Nissan/IHI's effort at turbo matching when you get a journal bearing unit designed for a 4pot behaving much better on their own engine. To be fair it's been YEARS since I drove such a setup, but while my R33 was in for work with the GT3076R I borrowed my mates S13 Silvia running an RB20DET with a TD05 16G on it, road tuned to 20psi and if are happy with the lag of a GT3076R (or ATR43SS2 ) on an RB25 in an R33 then an RB20 in a lighter chassis with a 16G is surprisingly tolerable. I'd love to know what a GTX2860R would be like, if they can spool even better and make the same power then I'd say they'd destroy a few ideas about what RB20s are like. Bare in mind they'll never be glorious at real low rpm, but 20psi before 4000rpm on any 2litre - even an RB20... and you get a very solid push in the back.

Cheers, glad you get what I'm trying to do - it's a bit hard sometimes online to put across where you're coming from. I think any of the options presented will work well... and on your note of the EVOs spinning the wrong way, just for interests sake EVO 10 turbos spin "the right way" and are twin scroll with decent sized housings on both sides. Good to know the Mamba turbos have held up, which ones are you talking about? Have been waiting for results to start coming through for ages and the relative radio silence makes one think that people could be either avoiding them altogether, they are getting results not worth speaking of or they aren't surviving - or a combination of the latter. @discopotato03 I understand, I was just trying to clarify these are all things that have been long considered and not just kneejerk comments. We are both pretty well researched.

Fair enough, was just suggesting an alternative which in ways is better suited to the RB20 - having a bit more turbine, coming natively with a T3 housing and not being too expensive. I'm definitely not saying the 16G is the best thing, though I am dubious of recommending a knock off DBB turbo until I have any indication that it's reliable etc. We know nothing about the compressor efficiency etc either, you absolutely cannot compare compressor sizes and assume "it's the exact same size" - blade angles, count etc will all affect spool and flow. You talk like I've not long considered all the variables, let alone have a good idea of the history or reasoning behind these things. Yes, I can compare the behaviour because we tried 16Gs on RB20s over ten years ago. Thus far they are the best turbos I've experienced on them, not that I've experienced a heap first hand- but imho they drive better than the likes of an HKS GT2535 on them. There are hardly any turbos you will find that allow an RB20 to start building good boost without too much work comfortably under 4000rpm and also make >200kw @ wheels on 98 or crack 250kw on E85.

There is a "normal" 16G which are why people underestimate stock EVO turbos etc quite often, can't remember the exact flow but it's barely over 30lbmin I think. The 16G6 is the "EVO" version of the 16G which is a more high performance take on It, they are efficient to much higher pressure ratios (presumably to be more suited to running with a restrictor etc) and are also often suggested to flow in the area of 40lb/min so long as they are in a housing which will allow it. I would strongly suggest the 8cm if you were to go that direction. Have tried them on 4AGEs and SR20s (the Kinugawa version with the 3" antisurge intake) And spool has been excellent and flow been more than satisfactory for those. Have only tried an EVO2 16G on an RB20 so small housings all around but better in every way than the typical RB25 upgrade.

I have been resisting saying so, but honestly - the Kinugawa TD05 16G6 with an externally gated T3 housing really shouldn't be overlooked here if you want an externally gated T3 option. They are a seriously underestimated performer - it would definitely hit your power targets in E85 and the response is very good with them, would be a really good match for a stock RB20 aimed at 20-25 psi max. Not saying it would be as good, let alone better than the GTX286x BUT after experiencing both GT28x and 16Gs on the same motors I really am not convinced in the price reward when there is the effort of going external etc is factored in etc.

Re-read that. f**k yes, if you can get a .83 T3 twin scroll GTX2860R and are keen to do E85 then absolutely do that. That would be mad. I don't have a working lap top so I am not inclined to do the math right now to guesstimate exactly what it would be capable of but I have quite a strong gut feeling that your 230kw+ target would be well achievable.

I will think harder about this... But fwiw after experiencing a 3SGTE with a twin scroll EFR7163 with a flange adapter so it fit the stock twin scroll manifold I was blown away. The thing could pass for stock response, one of the first topics me and "the lads" hit on was the amount of feelings you could hurt with that turbo on an RB20. I straight up reckon it would drive at least comparably to the ever popular RB25 upgrade, but with the ability of achieving your power target with change on 98. To be honest most turbos in that power range are going to be single scroll or a different flange but another turbo which did pop into my head immediately is the MHI/FP collaborated effort - the TF06-18K which was developed as a factory option ~50lb/min turbo for EVOs. They spin "the right way", make good power and seem to spool very well for the power they make. A bit like a turbo that flows more than a 20G and spools similar to an 18G at worst from memory. Just the first things that came to mind when I read your post but I will think more on it. I do feel a little that twin scroll may complicate where you are at a bit but will keep it in mind

I'd say. Enjoy this now it's finally really stomping from down low and has that snappy EFR response - do the intercooler when you end up getting used to the power and put the EFR8474 on

Not sure I'd bother tbh.

My gut feel is they're much of a muchness for flow, but the R595 would spool better

That is mega impressive, Not necessarily too surprising but still awesome that it is performing like that and it sounds like something that finally gives you the GTR experience you had been looking for. Long expensive and frustrating journey at times but finally there! Congrats on building a beast, hope there are many fun drives on The horizon with the new found power, response and general road manners:) cheers for the update, too!

Dammit. Wonder if there are any cheap flights over this weekend

That's decent! 145mph says a lot. Any word on when you get yours back/some dyno sheets with rpm on them?

Looks good, mate! In 2nd gear it looks like it's got GOOD boost by 3500rpm without trying too hard, and picks up hard when shifting in the 6000rpm range.

Dyno is just a tuning tool - the Gen2 6266 is well known in terms of potential, both from this car as well as on others, the 8374's abilities are also pretty well known. The engine is a healthy 3.2litre, running over 20psi of boost and the turbo is spinning at 120,000rpm peak (by choice) and is using ethanol blended fuel. It's fairly safe to say that the dyno number is academic, at a pressure ratio of 2.5 and 120,000rpm shaft speed that turbo is moving >75lb/min of air. Even on petrol that is going to be >750hp @ crank if all is running well, let alone if he gets E85 in the tank. There is every possibility the exact same setup on a different dyno with a different ramp rate would make more - even the same setup run "on kill" would on the same dyno and setup. I am very much looking forward to real world impressions!