Lithium

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.

Yeah, it's hard to know how much the lag was from going from the 1.05 to the 1.45 housing - but realistically a setup which previously was OK with the 1.05 housing on the 9180 would need the 1.45 if it was going to be leaned on, so in that kind of setup it is a factor worth counting in I suspect. 50kw or so is beileveable, that's more or less what happened in the case I mentioned as well - except when you are talking 10-20lb/min more flow you'd realistically be hoping for the potential for a lot more than 50kw. It's still a really good improvement in it's own right, and the guy I am talking about is happy with the results - it is a monster now.... but so far for the most part the power increases don't seem to be matching the advertised flow increases. Perhaps hot side? Or perhaps people just not winding them up?

One of the chaps I know went from a 1.05a/r 9180 to a 1.45a/r 9280, in all honesty I was slightly underwhelmed by the results but it actually seems like the tune was not fully aggressive etc - its on a drift car and the main aim was to bring EMAP and turbine speed down while running the same kind of power as the 9180 was so it was never run on kill. It made 700kw @ hubs at 28psi on an RB32 on E85 and was a few hundred rpm laggier than the old 1.05 EFR9180. From memory it was around 110,000rpm turbine speed and not full MBT timing, EMAP was creeping up by this point (it was already past 1:1 on 24psi) , and is noticably laggier apparently. It went from under 620kw @ hubs to 650kw on the same boost (~24psi) so definitely breathes easier.

Nice result, thanks for sharing - it drives me insane that the Mainline logo often overlaps the plots, but you can see that it is comfortably at 20psi by 4000rpm which is very solid for a ~400kw turbo setup on an SR20, definitely better than what I've seen EFR7670s do on them which is very good going.

G30 diagram: G35 diagram: Interestingly the core centre to turbine outlet are 100.5mm from the G25 to the G35s, and the turbine inlet to turbine outlet centreline are 70mm across the range as well. Seems like they've gone to lengths to try and make it easy as possible for any unit from the whole range can drop into the same location

I've asked for boost graphs, will pass anything on if it becomes available but not particularly high boost afaik. This is from the UK so it's on petrol, and will probably be Dyno Dynamics "flywheel" mode. Can probably find out about the v-band dimensions from dimensional drawings on Garrettmotion

Looks that way, boost for boost. The G30-770 compressor flows about 10% more efficiency for efficiency - give or take depending on where it is so on kill that difference should be able to be quite a lot better, and the .83a/r G30 turbine flows about comparable to the 1.01a/r GT30 turbine combo so this definitely is like going up a size in compressor flow and exhaust flow while losing no response.... which can actually end up feeling like an improvement in response given the extra flow all other things being equal. So far the G30-770 is looking like it's real promising

Here's a dyno overlay of a GTX3076R Gen2 with .83a/r hotside overlayed with a G30-770 with .83a/r hot side on petrol at the same boost level. This is on a stock RB25, so more a comparison of how it goes psi for psi within the GTX3076R's limit versus outright potential - which is worth noting that the G30-770 with .83a/r hotside is on paper very similar flow wise on both hot and cold side to an EFR8374 with 1.05a/r hotside:

Eeesh this thing is going to be nasty, good luck sorting the rest out - look forward to seeing what it does

Just happened to roll in here and find this, I like it! My 2c, I'm not 100% sure how it would pan out in reality as there is so little info out there on it - but I would be inclined to put a GReddy intake manifold on it. It may cost a LITTLE low down torque, but it is very unlikely to be a problem if tuned properly afterwards - it won't be enough to offset the gains you've had in other areas and still be torquier than it had been previously and more importantly... you want to make more power, with an NA car you don't have the benefit of boost etc so stretching the torque curve further up the rpm is a massive necessity if you want to increase your powerband and make bigger numbers. I think there is a really good chance that getting the likes of the GReddy plenum on there, which is a unit known to pull the torque up the range a bit - would give you a more rewarding power delivery and generally open it's lungs up a bit. The cams won't be able to do their best work with the stock plenum sitting on there imho.

That is a very very nice looking car, sir

Cheers for clarifying How did the S369 and the 6870 compare aside from the Borg not smoking? The G42 should be quite interesting, definitely a bit of a step up!

It had a 6870 on it previously, from memory?

OK that is what I wondered - the old "way off the map" trick is a prime cause for soaring EMAP. The "choke line" from Borg Warner is around 117,000rpm for the S369SX-E - as you start drifting further off from there compressor efficiency will go ballistic as the wheels need to spin way harder to try and move any more air, so the wastegate has to close to try and keep boost going in and you just get raising EMAP and it tries to drive the compressor to get air it really isn't meant to shift. Whether all that air was getting to the engine or not you were WAY off the compressor map, so trying to reduce EMAP by trying bigger exhaust housings etc would have been band aids to the issue. Don't suppose the airflow model you were using gave an estimate of the airflow it reckoned the engine was getting? Wonder if there is a chance there was an airleak or something, or does that power figure match up with 90+lb/min of airflow on that dyno?