Lithium

It the weather is ok I'll be going for a strop in it next week, will try and get some kind of evidence of what it's real world boost threshold is like

I posted a graph a page or so ago It's kw at all 4 and not all in, he was aiming for 600kw and stopped there for pity for the transmission haha.

Ah yeah, 18Gs are one of my less favourite units funnily enough - not least because they are heading in the direction of 20Gs for lag and 16Gs for power... hence I figure you go either 16G or 20G, there is no worthwhile in between despite everyone going for the 18G for some reason. <edit: I see Cef33y isn't, though the same still applies but it's more understandable that it's got so little at 4000> Cool man, would love to see how that setup will go on a 20!!! There is a disclaimer I always give for EFRs, don't jump to any conclusions of how it is performing until you actually drive it

He certainly was, it's one of the fastest street cars in NZ around a track - though the car that won the "pro street" class at this round of superlap here is an R35 GTR with twin Gen2 GTX3582Rs that honestly looks another level compared to the R35s I saw last time I went to WTAC in Sydney, it was visible briefly at the start of the in-car footage but GTFO in a hurry.

I must apologize for the potato quality of this, unfortunately it's all I've got - but you still get a reasonable idea of spool, acceleration etc. This is an RB28DET with a 1.05a/r EFR9180 in an R32 GTR running on a Trust single gate manifold (from a T88 kit) on an E35 mix, 27psi. It's running a stock R34 GT-R transmission so he takes it pretty carefully on gear shifts, but it is making ~600kw @ 4 hubs in this video and hitting around 260kph on the straights here.

What turbo is that? I'm not overly impressed with the spool on this, have tuned a 50 trim T3/T4 on an RB20 which was hitting 20psi by around the same rpm. EFR7163 would destroy this thing in every which way, I'm pretty confident of that.

Nice Looks like it's waking up a bit earlier than the EFR9180, but also giving away a reasonable amount of flow - both of which being what you'd expect. It'd be very interesting to see how the EFR8474 goes if or when it comes out, seems like it could almost be the single turbo answer to this?

Nice! Is the R33 still cranking with the 7670? Out of interest the single EFR9180 on my mate's RB28DET is all in at about the same boost at similar rpm.

Garage 7 just posted this dyno plot of a GTX2871R on an RB20. 20psi at 4700rpm, 100kw at 4000rpm... no thanks.

Do you have any data on it? I often wonder if the front and rear ones work similarly hard or if there are situations one may end up taking more load than the other. I'd guess that more likely with stock location twins, but still curious

I am still interested to see more as well, There has been a lot said about them and I can see the potential but there is so little real world info I am treating it as unchartered territory so stick to what I have more an idea about. For what it's worth, the main issue I have with twins on GTRs is stock location packaging etc - any turbo is a single turbo for what it's worth. I would love to see turbine speed sensors on twins going into a common plenum. @Full-Race Geoff, have you guys done any turbine speed logging with the twins kits?

... sorry anyone who saw an update notification and had a precum....

PowerFC can tune for E85 (it's just fuel), but it will not do flex fuel.

On the topic of dynos which read higher than Dyno Dynamics, here is a result which may be of interest to people here. This is from a mate who had COMPLETELY maxed out his HKS GT2530Kais on his very nicely built and setup RB28 powered R32 GT-R. He wanted to hit 600kw at the hubs - figuring it would be enough more power to compete with people who were gapping him on straights at the track, but not so much power he should take a huge reliability tax from where he was already at. After picking mine and a bunch of other peoples brains he decided to take the plunge and go for an EFR9180 with 1.05a/r hotside and turn it up until he hit 600kw - as it turns out, it hit 608kw @ all 4 hubs at pretty much bang on the same boost as he was running with the GT2530Kais... so here is the before and after with no other changes other than the turbo and the bits required to fit it (Trust exhaust manifold from a T88 turbo kit, fwiw) and here is the result: The dyno was run in a "soft" mode as the huge amount of torque it was hitting was freaking the dyno out, so the 9180 run is actually potentially "less loaded" than the 2530 run which MAY have given it less time to build boost as well - you can still see a slight "loop" when it hits full boost and the dyno had a cry.

I'll be tuning an EFR7064 on a stock manifold RB25 in the coming weeks or so, just 98 but will share the result

Oh yeah I wasn't trying to sell the 16G again, was just sharing yarns - I know 18Gs are a fair bit doughier so from my sole twin scroll 7163 experience I would expect it to be substantially better than an 18G. In your case it sounds like the 6758 would be the way to go, but in the general sense I think the 7163 would be supernatural on an RB20 compared to what most expect and if I was personally sinking a bunch into one it is without a doubt what I would put on it.

Yay. You pretty agreed with everything I said, lets be friends But seriously, those two things are conversations me and some Nissan/tuning/turbo/rum enthusiasts over here have had come up a few times in conversation here and we feel pretty strongly that both probably represent the cost-effective, and then "ultimate" RB20 combo where usable power is a target. I'd have no hesitation suggesting an RB20 with a Sinco (6boost in Oz are the parallel) manifold, external wastegate and a 8cm TD05-16G6 with the 3" intake housing from Kinugawa (we know people who have bought them since the Mamba dramas and they still seem to be much the same) would blow away some stereotypes. I'd tentatively suggest that >250rwkw on E85 would be doable, and as I mentioned earlier... basically should be able to start building meaningful boost by 3000rpm in higher gears. An EFR7163 would be next level, >300wkw potentially and no issues keeping it on steam when into boost threshold territory. But yeah, if it's between a 6258 and a 6758 I wouldn't even consider the 6258 as a serious option.

OOPS! Good call ActionDan, sorry Piggy. If anything we should be talking about your low emissions cams and big laggy lightswitch turbo! Yes, that'd be appreciated in the correct forum

Exactly. Sounds a bit like you're arguing with yourself and declaring yourself the winner The setup needs to match the other parts, most would agree. I'm not aware of anyone fitting larger cams for low down power, though improved response within the target rev range... perhaps.

I think that is the point I've always made - I don't recall anyone ever saying longer duration cams pick up torque at the bottom, be interesting to see if you have any reference or if you are just winning a debate against a made up side If you can make the compromise (read: less VE) in a part of the rev range you aren't using then you just use the part where your VE (or "dynamic compression" as you're saying) starts building beyond what the smaller cams can provide, then you are always winning. You wouldn't use 288s and a Promod94 Precision for a GTR used for hill climbs, you wouldn't use 256s and a pair of -9s for Pro-class in WTAC and you wouldn't use VCam and an EFR9174 for Pro-GTR drag racing.

No, not at all. I am one of the people you appear to be mocking as I feel that the blanket "shorter duration is better" statement glosses over things too much.

This thread would make more sense in this forum: https://www.sau.com.au/forums/forum/8-forced-induction-performance/ Single turbos sound different to twins. Even single scroll versus twin scroll sound different, and then even between THOSE a lot comes down to the exhaust manifold design. It won't be so much to do with the brand of turbo, and a lot comes down to individual taste. Some like the smooth refined sound which result from equal length manifolds, some like they rougher/grumpier note of uneven length runners. What "sounds better" is very subjective, so really it's hard to know what to suggest as we don't know what you like or what yours sounds like. I've not heard a single turbo setup which is working right which I don't like more than twins. How do you find the 7064 on the RB26? I'd imagine it'd be pretty responsive

Wasn't that pretty much unanimous? Well the first part was, the second part would be a little bit of a blurred line. I can't remember the specifics of the thread but the Kelfords were an interesting cam and there was hope they'd be pretty cool and to be fair- without checking the thread I'd have hoped the compromise wouldn't be as bad as it sounds it was, but my argument is that the overbearing "any longer duration is bad, fullstop" is a bit misplaced, the trick is finding a match between the rest of your setup and how you use it. It's a shame they haven't worked as well as you'd hoped, I actually had some hope for them - would have liked to have seen them "happy" by 4500rpm, especially how Kelford marketed them.

I'm not actually sure, probably better talking to the people in your country on that one EFR6758 has potential to be pretty nuts on an RB20. I think it may surprise you, I'd not be overly surprised if you loaded it up from 3000rpm in a high gear you'd start seeing a LOT of boost early.

What manifolding would you use? Cams or anything? And E85, right? Also, just to answer something not asked - after experiencing RB20s and EFR7163s in person, I actually would personally use an EFR7163 on an RB20. I'm certainly not going to say it'd be a beast from "the basement" but I think the match would be extremely fun to drive. I think it'd "break the rules" about what you'd expect a powerful RB20 to behave like. From that comment you can no doubt see that I'd personally go for at least an EFR6758 In terms of the EFR vs GT2530, for what it's worth a mate went from a GT2860RS to an EFR7163 on his 3SGTE and the EFR gives away a little under 3000rpm but QUICKLY catches up, we saw 20psi before 3500rpm in 3rd doing a road tuning session... and again, that is the 7163. I wouldn't bother with smaller than a 6758 on an RB20, personally. You are never going to have great torque under 3500rpm, may as well keep turbine speed down a little and make a little bit of power for minimal compromise.