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so here’s another one that likely won’t end well based on what I can see and hear so far
filled the side ports with molten zinc, unfortunately it becomes molten at 700*F, which he conveniently explains away as no big deal, it will never get that hot.
the one thing he may have going for it is that it’s at least a big turbo (China GT45), but a bit dishonest in the usual youboobtube glorying about it like it’s his unique idea when it’s pretty clear where most of his ideas came from. He did get rid of the OE mount entirely, but I question if the two water pump studs that support the engine will hold, but if it holds then kudos for that. However, if you have the ear to hear then you can recognize everything I posted on the port timing/overlap issues.
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Bah ... I'm sick of your BS .... you claim to know everything but say nothing of any consequence to back yourself up. I'm done.
but to address another mistruth posted about me; all I know on this is the same thing all the other people who accepted it know. The very same people you keep trying to use to make points against it with. How does that not even click in your head? It’s simple really.
The only reason you won’t accept it is because it involves me. Even if I point blank state the reasons, it won’t be accepted by you. Everybody can clearly see that. You’ll continue to scream and bawl at the top of your lungs, throw your rattler on the floor, and kick the slats out of the crib until the well after the cows come home.
Not worth commenting on your silly post above till you actually make a valid point .... If you can manage that ... I'll carry on the discussion .
you’re mistaken if you think your carrying on of the conversation represents any value or purpose for me. If anything, it only keeps you from continuing to demonstrate your mistaken assumptions and not so well formed beliefs.
You want some points? Here are a few:
- you don’t really understand volumetric efficiency as well as you think you do.
- you don’t really understand in totality what is actually going on down in that area of the compressor map as well as you think you do.
- you often can’t see what’s right in front of your face.
remember in your G30-660 thread where I had to explain the turbine flow comparison relationships to you? This is the same thing, just a different series of points. I handed that one to you, but on this you’re going to have make the effort to dig yourself out of the ditch you’re in ...
Point - people can’t see what’s right in front of their face.
Here’s what was originally posted on the compressor map image, except I blocked out the IAT note for clarity:
and here’s what I posted after with only a “just throwing this out” comment (also blocked out the IAT note):
It wasn’t thrown out as a “majic (sic) answer” as claimed in an exaggerated reaction, but rather was intended as a possible starting point or two for someone with the eye to see, that they might find their way ...
Only at 12.5 psi the compressor efficiency will be around 10-15ish points down (60% vs 45-50). Factoring that in gives you close to the same charge temp at 20psi as at 12.5.
Well again; it’s not you against me, it’s you against everyone else including me. The same everybody else you tried to use in your examples against it. That’s still not clicking in your head.
It doesn’t say what efficiency is down there; you made an assumption it’s that low, what if it isn’t? You suppose it’s that high of a charge temp; what if it isn’t? Are there other factors involved that might change that? What would/could those be?
Originally Posted by TeamRX8
... was intended as a possible starting point or two ...
because you’re still not seeing the full picture, you’re too focused on one point again just like you were on IAT earlier
let me say it again; it’s only 12.5 psig of loading.
what do you think that means exactly? or what other influences are related to that?
it’s running that low of pressure out to 55 lbs/min; what does that really mean in terms of loading?
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Well again; it’s not you against me, it’s you against everyone else including me. The same everybody else you tried to use in your examples against it. That’s still not clicking in your head.
Doesn't really matter ...if it doesn't make sense to me , I'm going to question it . The same way I've done for the past 15 years on this forum. With time and results proving me correct more often than not. I wouldn't have got to tune over 100 rx8s with all manner of modifications using the stock ECU nor produced the results I have done with my own car if I had taken that 'sheep' mentality.
Originally Posted by TeamRX8
It doesn’t say what efficiency is down there; you made an assumption it’s that low, what if it isn’t? You suppose it’s that high of a charge temp; what if it isn’t? Are there other factors involved that might change that? What would/could those be?
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Correct, it doesn't say. All I have to go on is notes from turbo manufacturers saying efficiency drops "rapidly" beyond the 60% line. I was being optimistic with the 45-50 estimate IMO. But you have to agree that as you move further away from the published data on the map (to the right of the 60% line) ... efficiency decreases ... Right ? And that being the case .........with the 7670 running at 12psi and 55lbs efficiency is LESS than it would be at 55lbs and 20psi.
Originally Posted by TeamRX8
it’s running that low of pressure out to 55 lbs/min; what does that really mean in terms of loading?
Please clarify what you mean by "loading".
To me ...there is only one bit of info we have about this that could possibly explain why boost is only 12.5psi when all other dynos of the same turbo with the same fuel and similar setups require 18-20psi plus to make the same power. And that is ................ the bridgeport.
However , my understanding is that to make overlap (eg ... a bridgeport) work on a turbo engine you need EMAP to be at least on par with if not less than IMAP. If we don't have that results will be at best on par, and at worst ...worse. Am I wrong with that statement?
There may be something else happening that explains it like ICE cooling the charge air ...maybe ...but we don't have any mention of something like that. So my best guess would be something like ...someone sat on the boost gauge hose.
Or................... it just got reported wrong. You know ...**** like that happens ALL THE TIME ...right ?
However, you believe that out of all those people, of which more than a few have extensive experience with the EFR7670, that every single one of them is overlooking it and you’re the only person who thinks to question it? It’s not a Renesis engine either. As I’ve stated before, despite the similarities, an REW might as well be a completely different engine. The number of RX8s you’ve tuned is not as relevant as you think and is likely more a part of the issue of why you don’t understand what those other people do.
Those people you think are overlooking the obvious have extensive direct experience with both the engine and turbo, no contest compared to your armchair opinion for that particular combination. That’s why you tried to use them as your examples, right? Again, it’s not clicking in your head. You talk about all the points in various bits and pieces, but you haven’t put it all together. That’s also likely why it doesn’t make sense to you. As with the little PP experiment, the incorrect ideas, concepts, and assumptions get mixed and matched up in the wrong combination. Except that happened because it all made sense to you ...
Since you like to estimate generalities so much, what do you think emap is and why?
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However, you believe that out of all those people, of which more than a few have extensive experience with the EFR7670, that every single one of them is overlooking it and you’re the only person who thinks to question it? It’s not a Renesis engine either. As I’ve stated before, despite the similarities, an REW might as well be a completely different engine. The number of RX8s you’ve tuned is not as relevant as you think and is likely more a part of the issue of why you don’t understand what those other people do.
Those people you think are overlooking the obvious have extensive direct experience with both the engine and turbo, no contest compared to your armchair opinion for that particular combination. That’s why you tried to use them as your examples, right? Again, it’s not clicking in your head. You talk about all the points in various bits and pieces, but you haven’t put it all together. That’s also likely why it doesn’t make sense to you. As with the little PP experiment, the incorrect ideas, concepts, and assumptions get mixed and matched up in the wrong combination. Except that happened because it all made sense to you ...
Since you like to estimate generalities so much, what do you think emap is and why?
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Firstly ...I wasn't trying to relate my rx8 experience to the REW ...you seem to misinterpret why I even mentioned it.
And sure ..they have more experience and I respect that. But I also know that sometimes people don't question things because ...they didn't think about it or simply didn't care to comment. I do the same on here ............. All the time. You are possibly the most prolific poster on numerous threads here so I guess that's hard for you to understand.
EMAP is going to be somewhere around 20psi ............. that's off matchbot assuming a very low restriction exhaust/intake/intercooler, which being a race car, is a reasonable assumption to make.
What do you think it will be ...and why ?
I do have some news ..... the owner has upgraded to an 8374 and will be dynoing the same car, same engine, same setup, same dyno in the next month or so. The comparison should be ...very illuminating! Wanna guess the power at 12.5 psi ?
While I think about it .... you keep bringing up the PP thing. Kinda looks like a petty point scoring exercise to me.
no, it’s not any news because it’s right in front of anyone’s face who is looking at it; it’s the same people you’re now arguing against over on RX7Club trying to explain why you’re not seeing it right.
The other thing is not a dig. It’s just an example to make the point of where something went wrong and why. I told you the same thing there about how your view was wrong and you assailed me for questioning your thought process. That was well before you got to the end result. I’ve been wrong plenty, more than anyone else on this forum likely. Not really sure why I keep having to telling you this over and over. I was wrong on this very thread topic back in the day. I came around to realizing why it won’t go well in general. People still argue against it and we see the NA result in the one recent video, yourself too until the last several months or so after many pages of wrangling over it like we’re now doing over this.
matchbot is not an end-all on everything, just as Elliott told you and also me too previously; you don’t fully comprehend the VE aspect among a few others. Again, it’s all in front for anyone to see on why it makes same or more power on less psi in this very thread. People just aren’t seeing it.
so back to loading. What is the lowest loading on a turbo? When the compressor discharge is blowing to atmosphere, right? It flows easily without much backpressure at all on compressor or turbine . You demonstrated for yourself here and on RX7Club that you’re just not seeing the logic of this. The engine flows so much air with so little backpressure that the actual work of the turbo is significantly less. Even if the charge temp is equal to when it’s at 20 psig (not saying it is, just using your own statement) the low boost engine is actually making more power than the 20 psi boost engine. It’s also making more power than the same engine at 28 psig and less charge temp too. So how is that posdible?
look at it this way; somebody might look at the compressor map and think; “hmm, I’m way out of the efficiency range. Oh wait, all I have to do is restrict the compressor discharge with an orifice so it has 20 psig at the compressor, but then the manifold boost pressure is only 12.5 psig”. The problem with that though, is now the turbo is loaded with making 20psig at the compressor with the resulting emap backpressure. So emap would be high as a result and working against the low manifold boost pressure. So I’d suggest to you that the emap is lower than either you or matchbot are comprehending.
so let’s take it to the next level, using a recent example. Most people assume if they have XX psi and XXX IAT in the manifold that when the intake valve or port closes the pressure and temperature of the volume in the engine before the piston/rotor begins to compress it matches that. In reality it’s not. Per the previous example I just used about backpressuring the compressor so that it falsely forces a higher pressure. In reality, that example is most engines, it’s just a matter of where the orifices/restrictions are between the compressor discharge and the chamber before the engine compresses it. It’s not just pressure, but IAT as well because what IAT is at certain points can’t be measured. With FI, the IAT on one side of a restriction isn’t the same as the other side of it. If the restrictions are after where the measurement is then you don’t have a true measurement. Like say, downstream in the manifold or ports.
so how does the same engine with the same turbo make the same power or more on less boost pressure? If done properly, removing the restriction(s) that are backpressuring the compressor and forcing the turbo to carry a higher load resulting in more emap. It’s not that simple, but is the basis for it. The compressor map used for your example that I highlighted and reposted the one corner from also stated “stock port”. A stock port REW requires a lot higher pressure to flow that amount of mass, and a resulting higher turbo load, higher emap, etc. The efficiency somebody thinks is there, well it really isn’t due to other factors not so easily recognized. A half bridge is also a huge exhaust port too, remember when I note it was ported by Kyle Mohan, the same person doing this Renesis hybrid?
and look I’m writing this out quickly off the cuff, so some things might not be stated quite right, typos, etc as it were written out in advance and edited over a long period. Just trying to get the general gist of it out because I have real work that needs my attention. Because hopefully you’re now at a point to start seeing it a bit clearer, even though you probably still are in denial to some degree. This is essentially what all the examples demonstrate in a general way; high flow & low boost pressure, you just have to comprehend why that is. Which the most recent example I posted and got this all started again is an EFR8374 on low boost pressure making around 580 whp as I recall, somewhere near there. That was right in front of your face too, the one you replied, “so what?” to and now have asked me to make prediction on. 🤔
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Firstly ... thankyou for finally making the effort to explain vs your usual 'i'm clever and you aint' BS. If only you could do this more often ..there wouldn't be all this nasty arguing. Instead we'd just be having a good discussion.
After reading that ( a couple of times ) I'm seeing where you are coming from. Thing is, I understood most of what you are saying all along and only disagree on some of the detail. I understand how a big turbo and overlap can be a wonderful thing. I just don't think the same applies when the turbo you are using is too small and inefficient.
I also don't think there is any 'free lunch' as you are suggesting. There are certainly ways to extract more for less ..... one being the twinscroll manifold that harnesses pulse energy early in the rpm range, but that same effect isn't present at peak where we are discussing.
It takes work to turn a turbine , there is no getting away from that whether pressure on the compressor side is at 12psi or 20psi, pushing 55lbs of air takes a lot of work. It would take about 6psi less turbine backpressure on 12psi than 20psi ............. IF.............. compressor efficiency was the same.But efficiency is going to be significantly lower (meaning similar backpressure) at 12psi on this example! That is physics well understood by turbo manufacturers like BW. And they have created a program to calculate that ..... the fact that results don't always work out, is more due to the guy doing the inputs not having enough data vs incorrect calculations.
I think we both agree that EMAP being higher than IMAP is not going to get good results with high overlap so this argument boils down to only one thing :
How much backpressure will be present!?
I say ...................unless there is a majic sweet spot on the compressor map that BW doesn't know about ...EMAP is too high to get the overlap working well enough to get that result.
otherwise you’re as great of an accuser as your are a hypocrite-doer of all those things you love to use as your excuse to do them.
remember when I said there was something I thought was being overlooked, even at RX7Club, and you assailed me on that? Yet here you think you have something over everyone there on this, but nobody there agrees with you. Did you ever even look at the link of the shop that built it and review what they do there? Again, you think nobody there has the same level of awareness as yourself, just like you think is the case on RX7Club too? But then you have all that experience with this particular turbo and engine configuration too, right? “One set of judgements for me, but not for thee” is more like it.
The reason I disagree is because my feeling is you still don’t fully appreciate and understand the other dynamics involved particular to the rotary that Matchbot doesn’t account for. I keep noting to you that the rotary modeling there is not accurate. I’m not saying that it can’t be manipulated to produce the numbers you want to believe it should spit out. Rather, that’s GIGO imo.
the thing is; why are we going on and on over this one example and also these incessant railings expressing outrage over me?
it seems to have been forgotten what the actual topic is and what it was that started us in this direction; that being the Renesis hybrid and it also then making similar power on less boost
I’d like to again suggest that the core theme of everyone else is doing it wrong, or can’t measure boost properly, or realize and detect some mythical problem, or run a dyno properly, and so on is instead a manifestation of incorrect beliefs and understandings. It seems as though those things are held on to with such loyal certainly that there’s a refusal to even consider otherwise. Perhaps even greater than that, is an insatiable desire to prove me wrong and somehow put me in my place is more central and of importance than anything else about the actual topic itself.
Hopefully now there’s at least basic understanding on how a rotary engine that had an output at one boost level, could then later have a similar or even better output on a lower boost level. Because if you’ve been paying attention at all on how this has progressed, one of the things done now is they’re porting it to the absolute extreme including the peripheral exhaust housings. Which I commented on just how extreme the overlap on it is previously and when I mentioned about it “leaking like a sieve” that was then railed on over too. It certainly outflows that REW engine on the exhaust side at least. That’s also why it has almost nothing below 6000 rpm. Again, I’d rather have that REW setup, but what do I know?!?
Just the same, there was at least one other thing they did that I’m dead certain that still isn’t being recognized despite being right out in the open. When you’re convinced something isn’t possible or shouldn’t matter though, then the eye to see it is going to be lacking.
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so after several years of touting up how great their custom hybrid engine build was going to be, apparently they found out otherwise . Now what they’re calling a Hybrid for the new direction is retrofitting a Renesis front cover to REW irons and housings and maybe some Renesis internals. In other words, an REW conversion...
this hybrid exhaust port housing idea is never going to pan out in NA mode for sure. I don’t really foresee an REW based NA engine being any better than an NA Renesis either.
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I forgot to post this screen shot near the end of the vid, couple of heavy-hitter turbo RX8s listed on the dyno record list on the shop wall; Kyle Mohan’s 20B Turbo @ 731 whp, etc.
another one that appears to have been flushed down the loo; think I posted the original engine build link from France before on some thread here, but came across a French RX8 forum thread on it. Right near the end it said the car was returned for a problem and that the company who built it changed and never did another one. Born 2012 - Deceased 2015.
Never heard from again as best I can tell; was being tuned with an Adaptronic, GTX35 turbo, custom stainless steel tube fabricated UIM (probably did more harm than good). Vids of it on the dyno but never any graph, just the usual vids toodling around on public streets … 😑
01-30-2021, 04:28 PM
Because hopefully you’re now at a point to start seeing it a bit clearer, even though you probably still are in denial to some degree. This is essentially what all the examples demonstrate in a general way; high flow & low boost pressure, you just have to comprehend why that is. Which the most recent example I posted and got this all started again is an EFR8374 on low boost pressure making around 580 whp as I recall, somewhere near there. That was right in front of your face too, the one you replied, “so what?” to and now have asked me to make prediction on. 🤔
. Now what they’re calling a Hybrid for the new direction is retrofitting a Renesis front cover to REW irons and housings and maybe some Renesis internals. In other words, an REW conversion...
