Lithium

That's a very open ended question. For what power target and on what kind of setup?? Do you have the budget and inclination to do all the fabrication to do twin 550s? (it's not something you'd do on stock manifolds/location). It is the kind of setup which to justify would need a pretty solid engine spec, basically its a 1000hp turbo setup so expect the kind of lag that would come with one and expect to need to do the kind of engine and transmission development needed to support it. If you are looking at making the typical kind of power that people go for with low mount twins then no, imho it is not worth doing.

Nah, offline - but they have had good results making 4" exhaust flow well without being too loud so hopefully one of them will weigh in

Have just been discussing this kind of thing recently. Paging @Piggaz and @Mick_o...

I saw a post on Sinco NZ's Instagram page which made me think of you, how is your build going? Did you end up going Sinco for the manifold or is there someone else doing similar?

Can you post the dyno sheets as images?

When I first went to Oz for WTAC a few years ago I arranged to catch up with @Mick_o and @Piggaz for BBQ and rums and me and Mick were sorting out plans for the evening via PM on SAU. I could get 3 bottles of spirits in duty free so took an order for them for the evening shenanigans, and was somewhat bemused to be asked for a bottle of "Wild Spincter of the universe". I double checked he wasn't just joking around and he repeated "Wild sphincter of the universe, Rare breed. definitely." So yeah, there was a real awkward conversation with the customer service at Sydney duty free until it suddenly dawned on me wtf was going on. Bloody Australians haha

Finally, some testing of an EFR9280 and a whole heap of data from it compared to the EFR9180. Overall it seems really encouraging compared to the EFR9180, but it seems pretty conclusive that even the 1.45a/r hotside is too restrictive to support the huge flow of the new 74mm compressor on a 6 cylinder. The same car they stopped at 116,000rpm with the EFR9180, but with the EFR9280 they didn't reach 116,000rpm but got too much exhaust back pressure. Still, wouldn't be a bad unit! http://speed.academy/how-aem-performance-electronics-saved-my-900-whp-engine/3/?fbclid=IwAR31Gi1JxLfS38HAS9-CyaOwlcoNsqnxzwBHVXWtCfGhosCJhzY9-m1kvwA Also, a dyno plot from a 1.05a/r EFR9280 on a 2JZGTE:

To be fair it pretty much does what it says, so can't exactly knock it I was just amused as I was wondering what witchcraft they may have devised and it turned out to be a standard kind of thing that the setting usually has a much more mundane sounding name haha. So how long before you put it on a dyno and send it? It's definitely looking like a potent combo, and not sure if you've seen the kind of numbers people are getting out of these turbos - but it could surprise some people

Ahh ok, pretty standard - just never seen it called "quick spool" before. Definitely a handy strategy for bringing it up near target quickly, slightly early "cracking" of the gate definitely has a tangible affect on spool.

Nice, that is decent! Legotech doesn't have charge temp estimation? Curious to know what "quick spool" means in this instance, what kind of strategy are they using?

Oh, wow.

I don't know of any results for them so sorry, can't help you directly - but the eyechrometer reports that they look to be aiming for making more power from a setup that you wouldn't be restricted by the stock manifolds anyway... and I can't see how they'd help response at all, so it'd be quite a bit of expense with the possibility of no tangible improvements.

Last part of the Garrett part#, and it gets a bit garbled as people use some of the turbo naming incorrectly at times when comparing them. The GT2860R "-5" is part # 707160-5 The GT2859R "-9" is part # 707160-9 The reason the part number helps to know is that you end up with the right housings to bolt into the stock location.

Still haven't seen anything to suggest that twin gates really do anything useful, have been waiting for something to click it into place for so far all the single gate setups I've been around seem to perform comparably to twin gate ones - both in response and boost control... so I clearly wouldn't have doubted yours would be fine

I don't think the path is necessarily significantly more torturous than your typical I4 or I6 single turbo exhaust manifold, it may seem exaggerated by the length of the things. The firing order is still evenly spaced (funnily enough) so equal length/timed headers are very possible, in fact the later ones run them factory so the pulse timing is not really a factor. Yeah agreed on the T1 damper, as I said earlier I was already raising my eyebrows at the claim- again the temperature isolation alone makes them worthwhile still even if the smoothing doesn't change the delay versus signal processing.

Not sure if we are on the same page or not regarding spool, I'm not quite clear on what you are saying.... but I think runner length means a LOT in regards to spool. Subarus should be able to spool like Evos and SR20s if runner length didn't matter. Alas we have immediately gone to the T1 dampener so can't comment on unsmoothed signals. I have to admit I chuckled at the "because electronic filtering causes a delay" thing but I am not certain that they would both be equivalent. Either way, the dampener also serves a purpose in regards to temperature isolation so worth using

Almost completely different kettle of fish compared to the low mounts on RBs tbh. Gets rid of a few of the huge fails about them haha

My comments relating to this I tried to make really clear was to do with transient/spool conditions, but even then the pressure is actually not as steady as it sounds like you'd expect - also if you want meaningful EMAP logging it is worthwhile running something like this: https://www.t1racedevelopment.com/product/gt1r-emap-kit/

Definitely on a similar wavelength. Look up "pulse converters" in regards to manifold design - especially in patent applications etc. There is some irony in the amount of effort that the aftermarket have put into making pretty tubular manifolds when OE manufacturers have highly qualified people with massive financial backing designing things, and decide they know better. There is naturally often space/reliability/other factors often at play, but then there is still more method behind the madness which is factoring performance into things as well than credit is given - at face value it may look too agricultural but actually the reasoning can be brilliant. There is quite a bit of data out there in SAE papers etc if you dig deep enough. Also, while pondering on this kind of thing - check out the AMS AlphaX exhaust manifolds which are used for >1900whp R35 GTRs....

Lol truth (aside maybe for the need for twin gates), however quite a few ideas being bandied about here apply to designing any manifold.

I am still thinking on it, but at this stage I think it's wildly overestimated in many situations UNLESS the lengths and/or the amount of pulses you are collecting can result in significant interference at the collector. When you have a group of 3cylinders merging into one on a 6cylinder you probably almost have to try to make that an issue. The path they follow and the merge itself are probably more significant factors, and it just ends up convenient that making a nice merge involves bringing the separate runners around from different directions and bringing it in evenly. Basically, I would put equal length as a pretty high priority if there was going to be any chance of high pressure pulse overlap at the collection point, otherwise I'd lax quite a fair bit and focus more on making the exhaust maintain as much energy as possible between the exhaust port and the turbine - which really is why we try and avoid interference at the collector in the first place.

Weeeee a big math session and I missed out!!! lol I assumed it was a wording issue as opposed to actually literally referring to mass flow past a given point - by definition a flow rate is past a certain point, having a pipe length involved in that wouldn't make sense unless as @GTSBoy was essentially covering... you are taking into account external factors which could influence the flow. I think friction/pressure ratios etc are beyond the cope of this conversation. Well I thought so before haha. I interpreted the statement (and I still feel that this is more relevant to this topic tbh) as effectively the rate that the manifold could be filled based on the current flow rate of the exhaust, I guess an equation to describe it could be something like "FillRate = volumetricflowrate / manifold volume". The reason I feel that is more relevant in this situation is that the gas flow through a manifold is extremely transient, when you are talking a 3>1 manifold on one of these things you are going to have a VERY inconsistent concentration of gas through the manifold so when a new EVO event happening you aren't going to displace gas at the turbo flange at the same rate the gas exits the exhaust port. I feel like this kind of thing is key to building drive pressure which will have a very significant effect on response - which I feel is one of the major things we are trying to optimise with this kind of thing.

So what benefit do you think there may be in having a lower flow rate? And yeah, very interesting stuff. Hoping we can try some stuff out with a design on a car we're doing, but the problem is there won't be any comparisons - it will just be part of an overall setup so hard to know what will contribute to what.

Hell yeah, honestly the amount of things I wish I had the time money and skill to put together and try because there are PLENTY of commonly accepted routes which I feel like could potentially be improved on - but would not push for people to try, or try myself without having more certainty. And just for trying to see what happened haha. Not just velocity, but essentially yeah - it does. This conversation could get very big very quickly, and no doubt the line between knowledge and opinion can start getting blurred but my 2c on that particular comment is that you shouldn't control velocity with runner length, the longer the runner the more time the exhaust has to shed energy. When "tuning" a steady flow rate through a pipe you usually adjust the diameter of the pipe, the length usually has more to do with synchronizing events and balancing up other factors involved with managing the bigger picture.

Hmmm not sure how the runner length would affect the turbocharger's efficient speed? Some of those other things I can see interacting with each other to a degree but compressor efficiency and optimal turbine speed I don't really see the runner length doing much. I very much understand choosing things which deliver sound etc that you dig, though... like realistically nothing is ever going to be perfect performance wise so if there are things which are going to make it more fun to you then by all means. Does my head in when people try to justify their preferences arguing until they are blue in the face when "I just like it this way" is a perfectly acceptable reason for choosing their own mods I am pretty sure I didn't say exclusively heat. A lot of it is theory but I feel there is quite a bit of reason to assume it has plausibility to it - not least that we have data already provided in this thread showing very carefully designed and nicely built manifolds with smooth curves and nice merges showing that it would be generous to say that it didn't gain... realistically that's probably charitable when I would guess in some instances like this if the "stock manifolds" result was the "after" in the comparison then it could have been arguably called a great success. Like anything it will come down to various variables, what the target is etc. If I had seen these headers before this test with what I've seen now (excluding this test) before this test was done and asked what would perform better overall I wouldn't be confident in much other than the tubular ones would likely sound cooler....