Lithium

Is it worth it is all relative. Going to an EFR would be an expensive exercise with the amount of refabrication required. Getting a Gen2 GTX3071R without the turbine housing would be my first choice in your situation, swap the cores and sell off the GT3076R (or something?). The Gen2 GTX3071R should improve both response and spool somewhat as well as give you 7-8% more flow than a GT3076R - at least on paper. You haven't said what you are making with the GT3076R, but hypothetically speaking if you are currently up around the 360wkw area than the GT3076Rs seem to start hitting a wall, you could stand to get closer to 390kw with better spool - and that is starting to get into the area where the GT30 turbine with a .82a/r housing starts crying "enough".

Yep. At a guess it would be just over 360kw at wheels on a Dyno Dynamics on its all in boost, a .82 housing would allow more I would say - with still decent response.

Since the tune this car has done 2 hillclimb events, the first one it came second overall - the second one it won outright. Here's a clip from it's first timed run at the first hillclimb, he's able to cover large parts of it just using 3rd gear... at times getting quite low in the rev range and still being able to pull quite briskly out of corners which I thought was decent for a reasonable flowing journal bearing turbo.

I remember there being some conversation about these things years ago and they seemed like a viable option from their international reputation etc, but not that many people in our (NZ/Oz) neck of the woods really wanted to be guinea cops so results are quite thin on the ground. I never recommended them as the range at the time of this thread was ultimately based off replicating Garrett T-series wheel designs which guarantees results representative of an obsolete design. Anyway, over the last few years Master Power have started designing their own wheels - complete with flow benching them and supplying compressor maps etc, a couple race cars which I tune have been using their 59mm billet "R595" turbos but with moderate tunes which aren't going to do them much justice so we've treated them as an affordable reliable thing that "just works", though one of the guys did some changes and wants to hit the strip at some point to shoot for a solid 10 so I was instructed to "wind it up" so did just that and was pleasantly surprised - so figured it was time for a thread bump The performance related stuff is a stock (aside from head studs, rod bolts and head gasket) R33 RB25DET, FReddy intake manifold, Sinco exhaust manifold, Master Power R595 with .63a/r T3 exhaust housing, and a 600x300x100 Fenix intercooler - it's running on E85. Here are the details for the turbo in question: Here is a compressor map and details for this particular unit: Compressor: 59 inducer, 84mm exducer, 49Trim Forged CNC Aluminium Turbine: 59mm exducer, 70mm inducer, 71Trim 12 blade Core: MP350 360 Thrust, LI journals, Water cooled And the NZ supplier we've used so far: http://www.frantik.co.nz/MasterPower-Turbos.html And the result - I kept winding it up until I started encountering hints of any restriction coming into play and it was at about 23psi where it started getting a bit "over it" so this is getting near "all in" for that exact combination. On 1bar the thing opens its gate in the low 3000rpm, its opening here at around 23psi before 4000rpm - it's the best power delivery I've seen on an RB25 making this kind of power on this dyno, and it's quite up there in general I think. Thought this may be interesting, so far they've seemed reliable enough etc though I've not really had too much exposure other than these two guys and a made running a slightly smaller one on his Honda. They've all "just worked" so far, and we've been pretty impressed with the response for a cheap (~$1000NZD) turbo but getting an indication of the power they can deliver has made me think they maybe shouldn't be completely overlooked.

That's much more like what you'd expect to see, nice work - must be huge fun to drive now! Not that it would have been shabby before, but..

Yeah that's probably reasonable, unless there is some big issue with traction or something.

People debate a bit about better, but I feel there is a strong argument that hub dynos offer less variables affecting the final result - so when comparing with other hub dynos the numbers should be pretty legit so long as the same correction method is used. In terms of yours, just tell us your first thoughts after you give it a cane. You've done a fair bit of driving on the 6266, the power isn't likely to be insanely different - could be more, could end up being less... but keen to know what you think of it when its done I'm sure you'll call a spade a spade despite the likes of me, Mick and Piggy leering at you hoping you'll like it haha

Awesome, keen to see how it goes - good luck Just as a reminder, you are on a 3litre, still VCT and some kind of drop in cams? You have gone the 1.01 T3 hotside?

What would matter to me most is a comparison against something I am familiar with. To me personally Dynapacks/hub dynos are WAY more meaningful than Dyno Dynamics - I have to do conversions and take into account the fact that supposedly semislicks result in different readings to "hard tyres" etc on roller dynos, and that SOME Dyno Dynamics read different... in addition to the fact that I am just generally used to what makes what on a Dynapack. I have been tuning using Dynapacks for around 8 years now, and playing with cars which have been tuned/dynod on Dynapacks for 17 so a Dynapack versus a Dyno Dynamics is like comparing speaking English and speaking French to me. I'm sure the same would apply to most of you, and that's the value of sticking with a given dyno/dyno operator if you can. The dyno I actually tune is the same computer as what was used for the first dyno day I ever went to back in 2000, completely irrelevant but still kind of relevant - I can compare a run I did with my Honda Prelude from 2001 with the first Skyline I tuned on ethanol in 2009 with twin turbo V8 300ZX I'll be tuning in the near future, and get a realistic gauge of how their engines all ACTUALLY compare And to get it more to the topic, here is a dyno plot of a S14 with a high compression/ported/E85 SR20DET with a 1.05a/r EFR7670 "all in" on the same dyno (tuned by Prestige's tuner, not me). This should work out as around 414rwkw on a Dyno Dynamics by the conversion I usually use

Yes, this definitely happens. With rolling road dynos even the exact same setup can get different results with different tyres, or different ways of tying them down etc. That's one of the reasons I am not a fan of them pesronally. Ironically, the highest reading dyno I know of (won't mention names) in NZ is a rolling road dyno... I have no idea what they've done to get the readings they get but it's insane - but it's repeatable enough to gauge comparisons so I guess it suits the purpose, at least so long as people don't believe that their car with a much higher figure than anyone else with the same setup is actually that much more powerful. Lol Pete, touché Yeah, the fact the tyres aren't a solid link means there is less wasted energy - not to mention having to spin the wheels around etc. It's also a thing which makes the data more precise and therefore it's much easier to trust the data you are getting from the dyno software. If I had more money than I had anything to do with I'd have a Mainline hub dyno

Different methods used to measure power and different calculations for correcting the results to try and eliminate influence by conditions on the day. As a result there are totally dynos which read higher or lower figures for the exact same setup, but in most cases it's not to try and pull the wool over people's eyes- naturally competitors will suggest otherwise if someone else's dyno reads lower than their own though sometimes that claim is actually bollux. I think those workshops who continously tell customers their dyno reads low (or otherwise) are the worst - just be straight up about the result and what it means in context. Sooner or later it's going to become clear if the car is fast or not so why let the dyno dictate that? It's just a tool. Fwiw the dyno I use to tune reads on the high side compared to average and you can't get more straight up than I am about what is going on - for better or for worse. It happens to be a tool I have the privilege of getting to use and I love the fact that there aren't tyres involved to add an extra variable to try and track and control when trying to repeat conditions when tracking the effect of changes

What GTSBoy said - but to add here, there are different kinds of load bearing dynos... an eddy brake dyno is one of the options (which the Oz manufacturers use). Dynapacks use a hydraulic brake.

Twin scroll not an option

Guessing that meant .83? 4800rpm sounds realistic for stock stroke and 24psi, not bad given the flow potential tbh... be interesting to know more. At that rate it'd be very usable on a 3litre

I wouldn't hold my breath, @whatsisname is one of only about 3/4 people I've seen any indication of using one for ANY car in the world right now and he has been really quiet so it's hard to know how long his build will be, this kind of thing often can take ages from the point the turbo arrives but will let him comment when he shows up It's very early days from the turbo release and Borg Warner and Precision turbos are ultimately more known and desired in a lot of ways - and the Garrett is actually the more expensive option to a degree so they may not become very popular unless the results come out well. I have to say, I'm pretty impressed by the Gen2 GTX3582R which has a 66/82 compressor instead of 67/84.... as it turns out @whatsisname's decision to take an early punt could pay off as on paper it looks like his setup could be one of the perfect matches to what it wants, so potentially could make for a very good result.

+1, will be very interested to see how it performs in practice. This is potentially a REALLY good choice for an RB25, especially if you have some other nice supporting tweaks to the car What supporting mods, and fuel will it have?

I'm so far relatively impressed with the Gen2 GTX3582R, met a lad with one on his fresh RB26 build at a track day I was at on Monday - running a 1.01a/r twin scroll T3 hotside on BP98. I don't have much info on it, but I did see a dyno plot at the track and it was near 200kw by 4000rpm and made 460kw @ rear hubs (I'd call that around 410rwkw if you can't understand hub dynos) on 21psi. It had a beautiful power curve for that level, with peak coming in at just after 7000rpm but holding >450kw all the way up to the 8000rpm they ran it to. It seems like Garrett may have managed to go to a 66mm inducer without sacrificing too much in the way of response, and clearly have managed to do very good things for flow. The car had quite a happy wee anti-surge whistle too, a bit less low-key than the Gen1 GTX - I have a soft spot for that noise so a good thing in my books haha.

Has 135mph in his sig

In what sense? Count? Pitch/profile?

Awesome, looks like a chunkier frame than the old T04S hot side

To add to that, I'm warming to the GTX3584RS - it looks like the 1.22 housing is enough, and as I suggested the other day it looked like the 1.01 may not be too bad for what you're looking for either. Looking forward to seeing results!

Haha yeah absolutely. I guess I should elaborate on where I am coming from, and I guess it's all extrapolation but historically the Garrett hp claims were a realistic indication of that turbo could do on a typical pump gas setup - so they basically used "hp @ crank = lb/min x 10". A GTX3582R became around 750hp being a 75lb/min turbo, the old school GT3582R was good for around 650hp with its mid 60lb/min compressor, 520hp for the GT3076R etc etc. That kind of ended up being something of a rule of thumb and quite a few people treat Precision and FP turbos the opposite way, if you are wanting an estimate of their peak flow then you go "lb/min = hp / 10" - so the PT6262 is a 73lb/min turbo, the PT6466 is a 90lb/min turbo and the PT6870 is capable of over 100lb/min. For my thumb-sucks I found that 10hp per lb/min was probably conservative and realistically it was probably closer to 10.5 for GOOD (ie, BP98) pump gas on a good setup, or 12hp per lb/min for E85. These are all pretty loose, obviously compressor maps don't have a flat choke line across all pressure ratios and even then atmospheric conditions, tuning, transmissions, dynos etc all are variables so I just use it to gauge things. If you treated the Dynojet as reading 78% of the engine power, or a "22% loss" for 4WD (yeah I know it's not that simple, but bear with me) - then use my calcs to estimate the lb/min per turbo required to make those power levels, you get: Garrett GTX3584RS x2 = ((1649hp / 2turbos) / 12hp.lbmin) / 78% = 88lb/min Precision PT6870 x2 = (2029hp / 2turbos) /12hp.lbmin) / 78% = 108lb/min All pretty airy-fairy, but it usually seems to be in the right territory. Fwiw I use ~70% for Dyno Dynamics, so I'd be not hugely surprised if I saw them do something in the range of about 550awkw and 677awkw, but I'd never say "This is what they'd make".

Indeed, and a GTX3584RS is rated at 1000hp. Going by the all in result for the twin 1000hp, 2200 Garrett hp = just over 1800whp on that dyno

That thing is a pretty top spec build, 4.4litres with all the fruit, to be fair! The thing here is 43psi is ALL in here, they completely maxed the turbos out to achieve this. And on the same dyno, unfortunately obscured curve but Gen1 GTX3582Rs on a 4.1 with 40psi: Worth noting that an R35 has gone >2000whp on the same dyno with Precision PT6870s

Sweet, that's good to know - I'm always cautious setting expectations on those dynos, people have gone >1000whp on other more popular breeds of dyno but its hard to know how to convert.