Lithium

Shit, that's pretty decent - nice work Edit: What was responsible for the speed readout on the video? A bit odd that it got you at a peak speed of 161-162kph when you trapped at 108mph lol

I'm not sure what car this is?

Tbh it's hard to know what to say in response to this as you haven't actually specified your aims. You've mentioned response, and mentioned power, but not really what you are looking for. Andrews video really didn't give much info on response, stamping the throttle in 2nd at mid rpm with a car with a sequential gearbox doesn't tell you much. It didn't seem like a lag monster, but what can you really tell watching a video - especially when the video isn't showing a boost gauge or tacho? Fwiw from the little I've seen and the fact that he's basically said its laggier than a GTW3884R (which would be lucky to be over 20psi by 5000rpm) and the fact that the pulls in the video start at an rpm and a gear where it's going to rev out reasonably well even with almost no boost initially it's really hard to draw much from, I'd not be surprised if a 6870 didn't give anything perceptible away. With so little information out I'd be deciding between an EFR9180 or a Precision 6870, both known quantities - the 9180 if you want more response or a 6870 if you want more power. People seem to have been having issues with poor quality housing castings with the EFRs so I am dubious of them atm, so the Precision arguably may be the best option - unless you are keen on taking a punt on the likes of a Xona Rotor XR9569S, the family of which seem to be given some epic results. There are a couple of RBs in Oz due to be running with those in the relatively near future, I'd keep an eye out for results on those as I suspect they could be impressive.

Agreed. The driving seemed pretty decent to be fair, and realistically that should be the best indicator but it would have been nice to have seen a pull in a gear where it doesn't go so fast that you can't tell what's happened - 3rd gear with a boost gauge or something that is meaningful when you aren't actually in the car would have been good, but not having that isn't necessarily being dodgy so much as I know myself that it can be hard to remember what will be helpful when you are out thrashing. The fact that no dyno/boost plot or overlay without calibrated rpm is a LOT more suspicious. That seems like the obvious thing to share if you are happy with the results, or what you'd omit if you really would rather not show it. In regards to the smaller housing, Andrew has mentioned a few times on FB that he'd rather they had a bigger turbine wheel - seems a lot like they think exhaust back pressure is an issue and would probably explain why they didn't bother with the 1.01 in the end. To be fair, the issues didn't seem to be ones which would affect spool. The fact that they pushed it hard with the 1.21 with no filter does make it seem like this must be the upper realms of this turbo in a street(ish) setup.

This is from the blue DC2, right? I was told that this is running an EFR9280 now, and that this comparison is comparing the EFR9180 with the EFR9280.... in fact, if there are no crossed wires then there is a pic of this car on the Full-Race FB page saying it has an EFR9280 now

Jesus, so many ups and downs - hope the journey starts going a bit smoother. This pic stood out to me, Bilsteins are so diverse in their ability! Here are mine before they went in my R33, over 10 years ago:

There are a lot of things I could say to this glorious demo of building a strawman argument, but the most obvious would be - what exactly are you doing in this thread if the sheer mention of 1000hp clearly triggers your fear response?

Actually curious about this myself, I don't profess to know heaps about F1 but I do understand they had a fair bit of R&D and weren't running the worst engine management - all things considered they made small high revving engines survive quite epic power levels fairly well considering

I don't agree, and that's not just because there is a clear difference between being smart and being wise The beauty of modern ECUs, turbos, cams etc etc is that you can build an engine capable of producing 1000hp by nudging the boost up to the level required to make that power - but having that there as an option as opposed to the default mode. For sake of argument, a 1000ish-hp capable single EFR9280 setup on an RB30 would be much much more usable on the road even if running at 600hp than your classic popular 600hp low mount twin setup on an RB26 - and there isn't much use for 1000hp in most situations. If I was building a fun GTR street toy I'd realistically build it like that, a responsive 1000hp capable setup that I rarely ran at such a power level because realistically - even 600hp is nuts on the road, but use 1000hp for the old drag day/chops at roll racing type stuff. Naturally you'll still have a shorter than normal life, and there will be more likelhood of niggles etc... but there are plenty of people crazy enough that it would be worth it.

Good luck, very interested to see how it goes and if it ends up much different to the other quite smart folks who have invested a lot of time and money in trying to make stock location twins work well at higher power levels - I have seen and been involved with enough projects to know that just because no one has "cracked the code" doesn't mean that someone won't come up with a way around it, and it'd be pretty cool to see some cunning solution which works well so please to update on the approach and the results. No matter what the outcome I can't see how it wouldn't teach someone something

Is this a trick question? I am not aware of ANY stock appearing low mount setups making a legit ~600kw @ wheels "all boost". I'd imagine that if it was easy then by now it would be way more common to see setups like that, or there'd be a few hero cars making even close to that. Realistically people seem to hit a wall WELL before that power level, not matter what size turbos they squeeze into the stock location. Here's probably one of the most "full effort" low mount twins setups I am aware of, twin GT-RS with all the fruit etc - not sure what the low mount twins 1/4 mile record is now, but this held it for a while: https://dsportmag.com/the-cars/this-aussie-rh9-r32-gt-r-does-more-with-less/ The GT-RSs only fall slightly short of the GTX2867Rs in flow, mid/low 40lb/min versus mid/high 40lb/min and the same turbine wheel and housings.... so should be pretty indicative of efforts people have needed to go to make in the area of 500kw.

It is a bit of a shame Motec left the GPR packages quite basic considering how powerful they are, it sells the platform very short. You really shouldn't have to change to an Emtron to get what you need from it - though I love how well sorted Emtron are out of the box. Just for interest if you (not sure if you meant developing a custom package, or getting a pre-existing one) or others didn't know, there is a GT-R package for the Motec M1 which is very very capable: https://powertune.com.au/2019/07/12/m1-nissan-skyline-32-34-gtr-rb26-package/ Car sounds like it is going very very well, and I agree with the Dragy - we have a couple and have used them for similar testing/tuning. I look forward to seeing how it goes once you hit the strip

Achilles 123S are a pretty decent street tyre, a GTSt I tune almost hit 11s with "only" 123mph trap speed and very gentle launches because he was having axle tramp issues - doesn't sound that great, but ~12.1 in a RWD Skyline on 18" street tyres isn't too shabby even before you consider it still had some traction in reserve if it weren't for the tramp.

Ohh he finally did one with a bunch of data, I've followed him for some time but in the earlier days there were just lots of random driving vids and pics and stopped checking the updates - some pretty good data in that one! Rolling on in 5th (with a 6speed) from 3100rpm had 20psi by around 3800rpm from what I saw which isn't amazing spool without context - but for a 105+lb/min compressor that ain't messing around!

In all honesty, I'm split on this - and because I am not certain one way or another I am leaning towards the side of conservative. I've spoken with numerous other tuners and a number of them swear that EMAP goes up significantly with a turbo setup even if the turbos aren't run harder, though I've not found anyone who actually has EMAP data to quantify this theory. One of the builds I tune actually has maxed out it's turbo setup, and we have a solid nitrous system on it and EMAP logging etc with the intention of checking where the back pressure is (we already know we've maxed the turbos out, but want to quantify what's happening). What we like the idea of is that instead of running it to ~40psi where from all the data I had at the time (EMAP setup have only just been installed) we might be able to dial the boost back to ~35psi where things are not fully tapped out, and then use nitrous to top it up back to the power we are at - which is a level where we are keen to cap it due to engine/trans strength. The theory is that we MAY be able to drop EMAP significantly while making the same power for the reasons you basically are eluding to, you don't need the same drive energy as the compressors aren't providing the "air" so the gates can bypass the rest. The frustrating thing is that we, and others I know who NOW have the hardware to confirm this just haven't had a chance yet to collect some data - and it seems that in our case, and others (as often ends up being the case) the turbo setup may just end up being upgraded to something more efficient to drop EMAP at the same level... which is a solution, but means I don't get to learn what the effect the nitrous will have. 400hp worth of nitrous is a LOT though, and I guess one variable to consider is if the wastegate(s) will actually be able to bypass enough....

Given the turbos you are coming from I doubt that the 1.45 will be a problem for you. It's naturally going to have more lag than a 1.05, but given you are looking at running a bunch of nitrous I think it's probably necessary. @Piggazon here has a 2.8litre with a 1.45a/r EFR8374 and that is very impressive on the road, I am sure a high compression 3litre wouldn't be worse.

Yep, and to add to that - the first graph with the huge torque figures is because the power and torque figures are as read from the hubs/hub speed. When you put a Dynapack dyno into "flywheel" mode it divides the measured torque by the final drive ratio loaded in, which brings it down to something more representative of what the engine is making after drivetrain loss (at least when TCF is set at 1.0, so no torque scaling). An additional feature is to "correct for flywheel power" which is really nonsense which boils down to multiplying the torque by whatever the TCF is, and naturally power is boosted as a result of this. My preferred use of a Dynapack is to have it in "flywheel power" mode so that you can get a realistic gauge of the torque the engine is generating, but leave TCF to 1.0 so you are just seeing the SAE corrected figures the dyno is generating.

What's the setup?

Hey mate, sounds like a fun build Some pretty ambiguous or open to opinion comments in there so some background on what you've had and where you're coming from would help. Your previous "big turbos" you've had, what are they are what kind of power have you made with them? Is this the same engine spec as you used with them? It'd be good to quantify what an acceptably responsive turbo would be for you, and what "too small" means - as an EFR8474 should be fine on a 3litre depending on how much work you're expecting it to do. What is the pre-nitrous power target? Also, a 400 shot of nitrous - I see you like to party. You may need to be very sure you have enough hotside to support the inevitable exhaust gas flow which is going to result from this combo

... they also rip on US dynos for "reading high" yet come out with stuff like this, claiming 800+hp from setups which just can't make that kind of power - then post times which don't match the power and make a bunch of excuses. I remember when they had a couple of serious drag Skyline builds where they were making big power claims but not running as quick as lads down under they even went so far as to claim the drag strips were downhill here and if they ran here they'd be faster lol

Do you have any specs on the boost control solenoid you are using? What frequency are you controlling it at?

Dan is a very powerful name. I can only imagine what it'd be like to be an Action Dan.

Waiiiiiiiiiiiiit. I'm completely wrong here, I've assumed you're the same ActionDan who was on numerous NZ car forums and moved to Oz and is now on numerous Oz based forums - though now you said "Say what?" I notice you are in Vic, whereas he is in Perth. Well f**k, all this time I've thought you were him ahhaha. My bad.

I am a Honda man from way back, and will own more I suddenly remember at this point that I first encountered you from Toyspeed NZ hahaha.

Real mixed bag in there, why did you get rid of the 40th anniversary? Also, RB20 180SX is a hell of a fun combination - one of my favourite cars I've spent any time thrashing was an S13 with an RB20DET running a TD05-16G and 20psi up it and a mad screamer pipe, so so much fun. Mine goes a little something like this: 1987 Suzuki Alto 1989 Honda Prelude Si 1992 Honda Prelude Si-VTEC 1985 Toyota Corolla FX-GT 1997 Nissan Skyline GTS-25t 1988 Mitsubishi Lancer GLXi (soooo economical and unexciting) 1992 Honda Prelude Si-VTEC (mad regrets for selling the first one) 1981 Toyota Cressida 1997 Ford Fairmont 2004 Honda Saber 25V 2007 Mazda Axela MPS I think I've peaked.