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Lithium

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Lithium last won the day on November 20 2019

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About Lithium

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    Rank: RB30E

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    Wellington, NZ

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    2007 Mazdaspeed Axela
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    Mr Lith

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  1. This kind of thing is why I asked all kinds of questions trying to ascertain where you were wanting to go, as you didn't put that across with your original question. The fact you were asking at all, and the fact you highlighted that it would be on pump gas, used on the street and sitting at around 700whp most of the time suggested that you might be quite concerned about the "around town" part of the rev range. Realistically if you are concerned about the 8500rpm part of the rev range then you have to be willing to sacrifice some of that bottom end, which it sounds like you are now - hence we've moved on and a couple of us are telling you to go 76mm Precision Different people like different things, and this is why people are silly to make out like there is one size fits all - there will be people who will shake their head at the big cams and big turbo discussion for a street car that is going on. Hell, it is not the way I'd go personally BUT I understand that different strokes work for different folks. I've seen that Real Street video misses this kind of point entirely to me, in some ways it shows how the 68mm is way better for the street - or that the 72+mm is where you are transitioning into something which is more of a drag/hp hero car. It dulls the car down on the road, but is much faster if you're keeping it on the boil... IF you have the build to keep it on the boil like that. A 72mm+ turbo that does everything at the top end is not going to be the perfect thing for someone who might want to be able to accelerate hard without dropping 3 gears and / or using rolling antilag to make a quick burst of acceleration happen.
  2. Phwooooar going to be pushing it, maybe on a hubber? No maybe what its going to be pretty damn saucy, in that size range I don't feel like there is a Precision turbo that response vs power is going to be a worth while change from what you have.
  3. What is your power target? I feel like I've said a few times that the 3576 should be capable of more than some may expect, or do I not count as an SAU internet mechach00ner?
  4. I don't fully agree, sadly. And given I'm the one that started going on about these turbos ~12 years ago its hardly that I'm biased haha. There has been some pretty good conversation for, against and about from one side or another and it is still fairly frustrating that the conversation has been going for 12 years and there is still pretty f**k all data on them. I don't blame people for having doubts.
  5. At THAT kind of level, yes EFRs have their place, as with Xona Rotors and Garretts.. The 6466 and 6870 are beasts as well, but I only really lean to them as being "the best" until you are looking at over 1000hp - realistically it seems that as much as you get people talking about EFRs being fragile, smoky Precisions seem more common than broken EFRs. Why not stick with your Garrett? They should have heaps more in it.
  6. This! I was gutted when the trolling started in my original thread which ended up with it being locked, now there is near 12 years of quantity over quality to browse on the topic - I'd take an obscene bit of pride in starting the longest running technical handbag fight on the interwebs!
  7. No worries. Based on what you've seen there, and if you've got the setup to hold it - I'd write off the G42-1200, the 7275 as well as the EFR. I personally would go the Precision 76mm over the Garrett 79mm as well, the Precisions are just so proven at this kind of level on this kind of setup... just such a known quantity for offering a good balance of compressor flow, response, and backpressure. If you haven't seen this then find some time to have a watch over it, it is very relevant to this discussion. The TRC R32 GT-R runs an RB32 with a Precision 7685 Gen2.... Out of interest there are people running Xona products in Oz, Cartel in Oz (https://www.cartel-aus.com/product-category/turbos/xona-rotor/) sell them and have a few people running them to good effect. They're also pretty proven in the US, but there are levels which different brands seem to have focussed on and the area you are looking (single turbo comfortably making >1000whp on a 2-4litre engine) is pretty well covered by Precision and I'd not suggest anything else. The Xonas are best at the "700-1000whp per turbo with epic response and not epic backpressure" kind of deal - to the level that cars running them often are matching or beating things with bigger peak power numbers.
  8. Hi sir, this definitely feels like it could be wide open aside from the fact you seem to have stated the "1100hp GTR" thing as an absolute requirement. I'm going to do my normal annoying thing and respond to your question with more questions, and bring in some philosophical yarns about it - not to talk you down as that might not be needed, but just in case they are things you've not thought about. 1) What kind of dyno are you looking for "1100whp" on? Making that on a Dynojet in the US or a hub dyno anywhere vs making it on a Dyno Dynamics or even Mustang rolling road dyno are two quite different things. We're talking the possibility of needing to make 15%+ more power to measure "1100whp". 2) Given that dyno numbers are so all over the place, do you have an idea of how ACTUAL fast you want it to be? Have you experienced a car which would do sub tens, or driven a "BIG turbo car"? 3) What kind of transmission are you going to be running? If you are going to be running a clutched/h-pattern gearbox predominantly on the road I'd definitely be biasing the more punchy things versus hoping for a full 1100whp personally. I guess you are using a few cubes, but it can be pretty amazing how much boost you lose in shifts if you don't have no lift shifting or anything like that when using a large turbo.... there is probably a zone where if you are going to have some mechanical sympathy that a more responsive/lower powered turbo will be as quick or quicker EVEN on the 1/4mile. I'll leave those questions and be interested to see what you say, but to give a general feeling from what you've said so far - what I'd go for if I were in your position: 1) If the 1100whp target is important and you are using a sequential/auto and especially if you have the option of no lift shifting when you are in race mode - I would actually go Gen2 7675, or even 7685. The amount of lag you step up to when you try and aim for a legit 1100+hp starts blurring a bit, and if "crazy power" is important to you then you're going to want more anyway. People don't seem to sit with 7275 sized turbos for too long, once you go past the solid 68mm things people just end up unhappy until they've gone ~76 from what I've seen. If you really want 1100whp, just go straight here imho... don't f**k around. 2) Of the options you've provided, if the peak power isn't THAT important but you want it to be fast then if it were me and I wanted something that 90% of its life it was on 98 and road use and especially if you're using a more convention transmission etc then I'd use an EFR9280. I don't think it will make 1100whp on E85, it may fall pretty well short - but it will be very fast, and very usable. I'm not super blown away by what I've seen of these though, like I'm not certain that they are any better an option than the best 68mm turbos out there which makes me hesitant to suggest them given the price, intolerance to overspeed, and less than ideal packaging which brings me to: 3) If I'm answering #2, but casting a wider net to options you've not mentioned so that I'm just answering "this is what I would do in your shoes". If it were ME then I'd go with a Xona Rotor XR9569S. This is not because I have enough data to prove that its the best choice, or even that I am necessarily 100% sure that it is. It's more that I have a hard on for Xona Rotor right now, I feel like the best 68mm turbos (so the Precision 6870 deserves an honorable mention here) offer a real nice in between for being a fun street turbo but also the potential to be real world FAST... often nipping on the heals of things running the bigger frame units despite being down on peak power, especially where conventional gear shifting is involved. The Xonas are something different, very unique turbine wheel which have amazingly low EMAP for their size, very good transient response, have a TiAL v-band flange which is easier packaging and potential upgrade path wise I think, and you're not likely to make peak numbers any higher without going >70mm. The two quickest A90 Supras in the world right now (well, last I checked) are running high 8s at >155mph with these turbos on 3.2litre straight 6s without nitrous - peak numbers aside they can make for a proper fast car but something that would be still really fun and real world fast "just" running on pump gas, you'd not need to have E85 and be revving it to the moon to be making it seem worthwhile. In regards to the twins, imho you would have to REALLY want to go that way specifically. PMC's G25-660 RB28 does seem like an epic combo for the power to be fair - probably the most impressed I have been with a twin-turbo RB setup that I can think of but as you said yourself, a lot of expense and not a very flexible point to build on if you decide you want to change in future. Just my NZ2c
  9. The trick is there seems to be a trend of this from the few black series EFRs I've seen results in, at least one tuner I've spoken to has decided it's a back pressure issue but this data doesn't suggest that to me. The trick is I don't know where to go with it beyond the possibility that the compressor map or something about the data is not accurate which I'm not going to leap to concluding. If you follow the compressor map the line where 116,000rpm sits hovers over 90lb/min until about PR3.2 which I would be surprised if it is reaching that high, but never know. Fwiw Gen2 GTX3582Rs fall fairly short of 90lb/min on the compressor maps and cars have made more power at the hubs than this on E85. Not hating at all, I would prefer an 8474 over a GTX3582 but there are things I still have some question marks about
  10. Nice! Awesome to finally see some data on the EFR8474 looks really solid in terms of what the data is saying about it - I'd be happy with that EMAP at that power. What is odd though, and seems to be a bit of a trend... where your IMAP is, and where your turbine speed is lines up with 90lb/min of compressor flow. Do you reckon you're making the power you'd expect when your compressor speed and boost level suggest you are pushing at least 90lb/min of air? This is part of what I've been told from people who have tried black series EFRs, they aren't getting the numbers they were expecting before they run out of compressor speed but perhaps the expectations need to be adjusted? And yeah, the back pressure comment was about people looking at making use of the >100lb/min rated compressor flow of an EFR9280 - so closer to the 1000hp @ hubs territory, unfortunately I don't have first hand data so much as just going from people who I'm spoken to who have used them.
  11. The power target would be helpful with this discussion Generally speaking, most people I know who have tried the EFR9280 have not been particularly blown away so far, exhaust back pressure seems to be a thing - especially on bigger engines... if you're going to do it then the 1.45a/r hotside is the only option I'd consider. The G42 1450 is definitely going to flow better but also most definitely comes at an impact to response, in fact one of the guys I know went to a G42 1200 from an EFR9280 and that delivers power in the higher rpm better but even that turbo added reasonable lag over the EFR.
  12. Most Thursday nights I have a low key group of car mates who meet up and yarn in Lower Hutt, there are 2/3 Skylines as regulars but its really just across the board (@Looney_Head included) - welcome to pop down sometime if you want. PM me if you are interested and I can let you know details, watching the weather for tomorrow night as it looks borderline atm haha
  13. So far the only "modern" twins setup that I've seen which has generated a result which gets one thinking is the PMC/Integrated Motorsport R34 GT-R which makes >1100hp @ crank on G25 660s. It's laggy as hell, but has a wide (like 6000-10000rpm?) power delivery so there is a bit of a swings and roundabouts thing going on there - you would NOT use that for what most are looking for with twins, not least because it's not stock location but instead some wild fabrication involved. I don't expect there to be any major development with stock location twins as turbo tech isn't really the primary hold up, it's mainly packaging limitations imho... which is a lot of why I'm so pro-single on an RB. BTW, this thread is hilarious to look back over.
  14. I'm not so surprised about the G30, but I mentioned the G35 - which is what this discussion is about.
  15. SOOOO much this. Fun detail if you are paying attention, at PR 3.5 the G35-900 has 0 compressor flow advantage over a Gen1 GTX3582R and it drops back rapidly from there. A Gen1 GTX3582R is probably capable of more power reliably and arguably with better response (for equivalent exhaust housing size) than a G35-900 on a 4cylinder.
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