Lithium

It definitely is interesting enough to make me wonder how it'd compare with the likes of the BW EFR8374, Precision 6262 and the HTA3582/HTA3586 (I suspect it fits somewhere in between) - oh to have the funds and means to do a shoot out between some of these units!

Nice result, looks like a bit of a beast so far - be interesting to see how it goes with the bigger injectors! What kind of price would this kind of thing be going for?

This isn't really a specific twins versus single thing, its comparing three turbo options which aren't really comparable. The first is the "GT2560R-9s" which are the ultimate response twins of the "last generation" of turbo tech I guess you'd call it... they flow ~30lb/min each (60lb/min peak flow combined in a perfect world). The next is the EFR6258s which are the smallest of the EFR range and ever so slightly larger physically than the "-9s" but arguably similar in response due to design and better materials, and are rated to flow ~44lb/min each (88lb/min peak in a perfect world) - so while they are fairly close in size to the -9s, they are a newer generation and essentially targetting a way higher power level. The reason you can't get a closer flow match with twins to a -9 or even -5 setup is basically there is no EFR small enough to do it. The last is the EFR7670 which is rated to flow around 64lb/min all by itself, so is essentially the closest match to the -9s - still capable of flowing more but is an all bells and whistles current generation turbo, nice core, twin scroll option, TiAL turbine wheel, better aerodynamics etc. so is like the equivalent of a size down in single turbo speak - but able to still outflow the -9s. If you are from the mindset that -9s are the ultimate "driving" turbo on an RB26, then an EFR7670 would probably be eye opening.... better response and moving the power potential that bit closer to -5s.

The single is smaller, more responsive than the twins. 6258 are capable of heaps

A single EFR7670 would however be more responsive and make more power than -9s

They don't do twins that small, EFR6258 shouldn't be far off in response but would make a crap load more power

Yep - it makes pretty hearty power before 5000rpm considering it's capable of cracking 900whp/670wkw!!

Finally found a result for an HTA3794 on an engine a bit closer to the RB world in displacement and behaviour - someone did a "budget" high power build with an Audi A6 using one on pump gas, following mods: Stock 2.7 with more than 100k miles only upgraded with IE rods (stock piston) Running stock 2.8 heads (no 2.7 hardware) they were OEM factory rebuilt units. Rs4 intake with 75mm BBk throttle body Custom Single turbo HTA3794 034 IIc standalone Tuned by Dynodoc Aem water Meth Spool actually looks not really any worse than a T04Z from what I can tell, and these turbos are known to be able to make much more power than this on E85 - can clearly tell that it's not struggling with flow looking at the dyno plot, too. A built RB30, E85 and hearty boost and I reckon one of these things would be almost scary

On what fuel? Any more info?

Are you another Kiwi? We only have E85 at two pumps in NZ that I am aware of. There are guys who bring in Sucrogen E85 (works out as like $3 a litre) and we've used this on flex fuel cars: http://www.trademe.co.nz/home-living/cleaning-bins/other/auction-634702052.htm

I missed that 450+kw bit, is that just crack 450kw - or 450-500kw? Shouldn't the -5s get there (even if "just over 450kw") on E85?

I don't know if I missing something here, but I'm actually not sure how you can call the Link not proper flex fuel - especially with the amount of full flex fuel cars running ViPEC/Link ECUs there are running around. If you mean having a predefined table that makes life a bit easier for the tuner, and has the potential to promote laziness then sure... that's all good, but I'd not say that it means that the Link isn't proper flexfuel. You realise those scalars are just a thing to make the maths a bit easier, and more of a tuner aid that outright functionality - and arguably are a starting point as opposed to a thing there to mean that you don't need to tune properly? IE, I'd never load a base tune into a car and let someone thrash it without confirming. Those scalars can be merged manually really easily and used in a Link as well, you just don't have the separate scalar table with magic numbers in it so it might cost you an extra 4-5 minutes (generous estimate of how long it would take me to calculate out about 10 numbers and plug them into a table) if all the tuning you were going to do was a pump gas tune, an E85 tune, then rely on magic numbers to fill in everything in between.

What is your power target and how much lag can you live with? Your description gives little to work with, I am guessing stepping up in power is the target but how much - and how much less streetable can you handle?

Seems like a totally flawless victory to J.E.M. (and the original poster) really - congrats OP, and thanks for coming back and confirming the outcome

Very nice, got to be happy with that - looks like a much cleaner power curve, can only imagine the rest of it is tidier too. Very solid power

I love this magical "RB25 specific" stuff. Turbo has NFI what engine it is attached to, sure - there are some combinations which will suit each other better or otherwise but for the most part that is bigger picture turbo/engine/part matching stuff (ie, tuning in the bigger picture). Comparing two large turbos on an engine not good at spooling turbos and allowing one to start at 1500rpm and giving that turbo 4.6 seconds to reach 4500rpm (Hypergear - assuming the 9 second run Chequered uses still applies) versus one which starts at 2500rpm and allows it 3.1 seconds to get to 4500rpm (GT35R) proves that the Hypergear turbo can build more boost by 4500rpm if it's given 50% more time to do so. Out of interest, the GT35R is actually hitting full boost 3.7s into it's dyno run after starting 1000rpm later, versus 4.6 for the Hypergear. How they'd both compare on the same start rpm and ramp rate, who knows. A question which hasn't been asked so far - is that an actual Garrett GT3582R, or an ebay-type "GT35"? I'm starting to wonder.... and if that's the case, save your money and keep the stock turbo.

Strength hasn't been the issue, he wants more torque down low which making then motor stronger is not going to help

Oh yeah, I expect that the HTA3582 would have a pretty big flow advantage over the stock FG turbo... Or even an edge over the normal 3582

Beat me to it, GTScotT :-D Comparing response between the HTA3582 and a HTA3586 is not like comparing with a normal 3582 Cheers for sharing that juggernaut, good info. Any thoughts?

In what way? Needed a little wastegate porting but after that it performs excellently, well at least the T25 version does an I expect it would be virtually identical!? Power and boost from the T25 version of the exact same turbo on an SR if you didn't see it in the Kando thread

Like this? http://www.ebay.com.au/itm/Kinugawa-Turbocharger-3-Anti-Surge-TD05H-16G-w-T3-8cm-V-Band-Internal-Gate-Hsg-/281161079416?pt=AU_Car_Parts_Accessories&hash=item4176819a78#shId

Thinking back - I am actually really impressed with how the run of the generic Kando TD05-16G turbo worked on an SR20 a mate has done... checked over dyno results on a NZ Silvia forum and it produced better spool than ANY turbo setup on any other Silvia on the forum, and went over 250rwkw without even trying (17psi, stock motor & cams, E85). Going by the initial results the TD05 would give 2/3rds of f-all away to a GTX2863R in any respect (16G6 = 42lb/min vs GTX2860R = 42lb/min vs GTX2863R = 44lb/min - all full boost between 3500rpm-4000rpm on an RB20 at a guess) for half the price, you'd just need to do a little bit more than basing it off an HKS hotside.

Try and convince FP to sell you a DSM Green without housings for cheaper and get a Kando T3 internally gated TD05H turbine housing and a Kando 16/18G anti surge compressor housing - then get it milled to suit? Too hard? GTX2860R, or even 63 would work very nicely as well - actually.

Best solution really - especially when he wants full boost before 3000rpm! Not that he should NEED it. In reality I would have no issue thrashing around a small well matched turbo on a stock RB20 for lols. I reckon a 68HTA (or even a normal TD05-16G) would be great on one. Fixed that for you I put that down to driver

Old pic from when I was tuning an RB25 R33 - black line is with fuel/timing dialled in with VCT off, red line is fuel/timing dialled in with VCT on: Looking at over 10% more power through the low/mid-rev range with VCT on