Lithium

The turbo(s) have no idea which gear its in... a turbo won't spool differently just because a different gear is engaged, the rate the dyno allows the car to pull through the rpm will be the real teller. EFR6258 is ~400hp rated I thought? Makes it comparable with GT-RS/Garrett "-10s" and given it looks like its full boost around or after 5000rpm, comparable to them in spool as well?

The boost leak would cover a bit, but they both still come on pretty late for their size

Nothing to write home about at this stage, need more rpm/boost to hint at capability

Nice! Sound much different revving out?? So when are the new injectors and tune coming, and what boost are you going to run it to? Time for a new low mount 1/4 mile world record?

When is it actually making full boost?

IDEALLY you have an ECU like a G4 Link, and can get real fussy/fancy with it. Roughly how I've gone about it: A) Set NVCS off B) Tune ignition/fuel maps as you normally would C) Create 4D ignition/fuel maps (I use rpm vs MAP like the base maps) to engage on condition of NVCS on, set NVCS to on D) Map 4D ignition/fuel maps as you normally would E) When satisfied you have got the NVCS off and NVCS on maps optimal (in my experience NVCS likes more fuel and more timing than when off, at least for parts of the rev range) - set the switch points to suit the best of both worlds F) Have a faster car with the same peak power...

Much of the GTX/EFR stuff I've posted is comparing between different turbo setups on the same dyno and car to give relative gains or losses

This dyno BS actually really puts me off this forum, seriously. Open your fkn eyes, its just a tuning tool - the number is the number it read, if there was a median point for how "all dynos" of all types would read for the same car.... Dyno Dynamics read well below it so are far and away from being the definition of realistic readings. If 320-330kw was more realistic on that particular dyno used, it would have made it - Dynapacks are very consistant. Who gives a shxt if it would make 320-330kw (assuming certain tyres, wheels, tyre pressures, that traction is there, and what shoot out mode they are running) on some old rolling road thing. A relative gain is still going to be a relative gain, so lets focus on helping this lad find it.

I found ROUGHLY 10% difference with NVCS on VS off on the same boost level, if you make a few more psi at 4000rpm then thats going to exaggerate that difference. 10% more power anywhere is pretty big..

Nice power I saw you mentioned lack of low end when you posted in the dyno results thread, Nistune don't support VCT right? Coming up with something to get around that (or just upgrading to a G4 Link/some other good aftermarket ECU) should get you bringing boost in a few hundred rpm quicker and making a good amount more torque for the same boost level if you haven't got it engaging already.

Been ages since I've had both next to each other, but the compressor wheel design looked a bit different the way I remember it - the S1 had a twin blade thing going on whereas the S2 looked a lot more minimalist, the way I remember it. There could have even been a slight difference in size but it was a long time ago and I've pretty much lost interest in the OEM units

None whatsoever, not for lack of hunting. After seeing the results for the EFR6758, a pair of the buggers would be terrifyingly potent on an RB30!

There is some parallel dev I suspect, Cosworth were working on them before ANY options were available. And cheers for posting the link, I had been having issues with my browser and ended up with a "CBF, do it later" moment. I figured I'd said enough to give the proactive googlers something to hunt for

Very interesting results showed up for an EFR6758 being used part of a new bolton kit for Chevy Cobalts, they ran it up to 35psi on E85 and it pushed out 540whp on a Mustang dyno - which are one of the harshest reading rolling road dynos out there, by reputation. It made over 500whp on 30psi, and had 35psi (internally gated) by 4100rpm on a 2litre. Pretty impressive stuff!

Yep - HT were having clutch issues through most of the weekend from what I heard. Still 7s by both cars in a weekend is very cool.

There is no authority on whats high or not But yeah, DD seem to on average read a little lower than a Dynapack - so its fair to say its a solid 15-20% more power than yours... so its fair to say its a turbo which is theoretically capable of full boost by around 4000rpm on an RB25 and make near 420wkw on E85 on a Dyno Dynamics dyno? This was with a .63a/r hotside, too....

Wasn't your 410kw on a hub dyno? I could be wrong, but I had that in my head. I've never seen >600whp on a Dynojet from anything smaller than a GT3582R before.

Holy crap - 614whp with a GTX3076R on E85:

Holy hell, damn you Aussies! I'd love to be able to see this Good luck both teams on bettering your PBs, there could be history made this weekend! Looking forward to what HT's new record will be

I have often wondered if the 6boost (or other decent merge collector manifolds) have the same fantastic exhaust note with twin scroll or twin turbo applications as they do 6>1?!

All open housing, internal gate I believe. That was on 21psi on a 2litre 4cylinder on pump gas - that will be by no means the limit

Haha true - thats a very impressive time off a 1.9s 60ft, mid 10s car on a good run, for sure

Totally, though the same would apply to the GTX turbos too. The big plus is the TS EFR also comes internally gated. I am pretty sure the wastegate is plumbed back in with those examples. Also for some fun, a Type-R Integra running pump gas with an overlay from 21psi runs done with a GT3582R (orange dotted line), EFR8374 (blue line), then EFR9180 (orange dot/dash line):

5.2s reaction time? Did you fall asleep?

Thought I'd share some results from another forum - I think most people here are on-to-it enough to understand whats going on so I'll keep my observations to a minimum: The guy doing these tests (Jeff from Perrin Performance in the US) commented that he was a bit thrown by these results, as the "seat of the pants" impression was that it actually outspooled the GT3076R and GTX3076R turbos he had tested previously on the road, and felt generally more responsive and quicker to recover boost on gear changes - while on the dyno with a steady state rpm increase it appears overall more comparable with a .63a/r GTX3582R in spool and somewhere between the .63 and .82 GTX3582R in flow. He compared a datalog he did with the GTX3076R (green) on the road with one of the EFR7670 (red) and found that even though he went WOT slightly earlier in the GTX3076R log the EFR7670 matches it for full boost at the same rpm and time stamp - meaning it had boost built the boost and climbed rpm in a shorter period of time, aka faster boost threshold My impressions so far from this test are that the EFR7670 in terms of dyno results is going to be most comparable with a GT3582R that spools slightly faster, but it appears than on the road it'll actually drive more like a "fast" GT3076R. Its worth noting that these are comparing T3 open housing turbos all around, the Garretts are all externally gated while the Borg Warner is internally gated. A twin scroll Borg Warner EFR7670 could potentially be completely insane on an RB25DET after seeing these results, I reckon.