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As far as I'm concerned the ONLY thing in contention here is 435@11psi so:
"Then there is the fact that all previous posts in this thread suggest it needed 14psi to get 410ish whp (see my link above)..... How does that magically drop to 11 and then make even more power?"
Give me a satisfactory answer to that question........... please.
anyone, anyone ... Bueller?
let’s add another one to the hint-hint list; 493 whp REW @ 13 psig. Somebody said it has a cat converter and wastegates plumbed back into the exhaust but I can’t confirm that.
The point is that this fits right in with all the other examples. It’s all related to the same thing and right in front of everyone’s eyes to see.
does that mean you finally came to the satisfactory answer then? It doesn’t seem like it, because you keep explaining every example away dismissively.
Originally Posted by Brettus
Hope this one I mentioned above doesn't go the same way.
well three months later, any news?
which I came across a post in another thread from quite a few years back where someone said Ric Shaw tried it (NA only I think) and it flopped badly on the dyno. That was the only mention I ever saw of it, so can’t claim how factual it may have been.
The point is that this fits right in with all the other examples. It’s all related to the same thing and right in front of everyone’s eyes to see.
does that mean you finally came to the satisfactory answer then? It doesn’t seem like it, because you keep explaining every example away dismissively.
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I think it means that there are some results that I question because it doesn't seem logical whereas you accept every result as legit regardless.
Originally Posted by TeamRX8
well three months later, any news?
which I came across a post in another thread from quite a few years back where someone said Ric Shaw tried it (NA only I think) and it flopped badly on the dyno. That was the only mention I ever saw of it, so can’t claim how factual it may have been.
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yet if anyone questions your virtual results and data you go ballistic
but no I don’t just believe anything; this hyped up hybrid engine crap as one example, the people involved in all those results are well established. The results here I get and can see why they are what they are.
look, IT’S ALL THE SAME THING if you truly understand what’s going on. Starting to feel a bit embarrassed for you now, including not remembering your own posts and their context. Just because you’re hung up on all your RX8 experience and aren’t getting it doesn’t make everyone else wrong, lying, or deceived.
We went through this same thing over the mini PP engine you built. I think we’re well past the point now where you can try to convince everyone else that I’m the one who doesn’t understand.
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That's funny cuz I've always felt embarrassed for you ....... mainly because you can't bring yourself to argue in a non-condescending way.
As far as not remembering all of my 19500 posts ............ get real.
You can call it anything you want. You see this below; the one you question the most? You’re the only person questioning it. You threw up BlueTll’s 7670 dyno graph as a counter to it, like I had no knowledge of his. Yet he not only accepted the dyno below, he understood what you continue to refuse to either accept or understand.
You keep on about turbo size and porting with the dismissal responses, which demonstrates how it’s right in front of your eyes. However your dismissals then demonstrate how you’re not seeing it in these examples any more than in this thread that answers the question about how they made more power at less boost.
Again, the dyno below is the same thing just as the others. Again, your refusal to accept and understand is the same as in past threads. What you really don’t understand is that you really don’t understand what you think you do.
Again, the Renesis and 13B should be viewed as entirely different engines despite the things they share in common. The REW crowd gets the dyno below because they understand that engine. Again, once you put PP exhaust housings on a Renesis it’s no longer the same engine for the reasons already stated over and over again.
It’s not any different than taking the non-overlap header design and putting it on an engine with overlap; it demonstrates a complete lack of understanding of what makes them different and the theories relative to each different.
Originally Posted by TeamRX8
for those interested in learning and who are open-minded; more food for thought on what I’ve been attempting to explain and share ...
I wasn’t referring to the linked post you made above or your other old posts. It was the last comment you made here in this thread before I bumped it to add that example that you immediately dismissed again. You claimed to know someone building PP exhaust housing Renesis engine hoping to prove something.
Perhaps you were too busy reacting to have seen your own post immediately above mine.
Ok lets have your explanation then .... all I've seen from you is bluster so far! You seem so adamant about it's legitimacy and how I don't understand , yet you have failed to actually explain how it can be possible. Let's have it !
I questioned it because it flies in the face of every other result I've ever seen for that turbo. That, plus the engine (if I recall correctly) had nothing special done to it that would cause a different result.
To be 100% clear, I never questioned the whp numbers on that dyno (for the 7670) ...just the boost pressure they say it was at to achieve those numbers.
yeah, more like 16 years ... I often don’t hand things on the silver platter because giving someone the answer doesn’t teach them how to armchair use their brain
look, all the examples make power on low pressure. How do you make 600+ whp at low pressure on the same engine that made 400 whp at low pressure? More hp requires more flow through the engine. So why isn’t the pressure higher with more flow then?
maybe start by listing all the things that you think contribute to making boost pressure what it is.
Pressure is basically a measurement of resistance to flow.
Same pressure with larger ports equals more mass flow...and more power
Same ports with higher pressure = more mass flow and more power
Getting a huge increase in power at the same pressure means that your restrictions went down somehow...so if everything else remained the same there is no way to make sense of the increased numbers
Need to measure the pressure in the same place to compare... and anything that decreases flow will cause an increase in pressure. So restrictive exhausts will cause an increase in pressure and decrease in potential power.
This is hughly simplified but there is no way that physics lie....
Manifold pressure numbers and dynos are poor ways to compare 2 setups.
yeah ... I often don’t hand things on the silver platter because giving someone the answer doesn’t teach them how to armchair use their brain
Translation : you don't know (and don't understand the subject as well as you claim)
Originally Posted by TeamRX8
look, all the examples make power on low pressure. How do you make 600+ whp at low pressure on the same engine that made 400 whp at low pressure? More hp requires more flow through the engine. So why isn’t the pressure higher with more flow then?
maybe start by listing all the things that you think contribute to making boost pressure what it is.
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You don't seem to notice ...I'm not questioning every time I see high whp on low boost ....just a few specific examples. Like the one you posted above.
Here you have a relatively small turbo making great power .... nothing terribly unusual about that. Indeed it's been shown over and over that the same turbo makes that sort of power consistently. However :
1/All other examples show the boost pressure at around 20psi to achieve the same whp at the same rpm. (Using E85)
2/There is nothing to suggest that anything special or any trick was done to the engine to achieve such low boost.
3/You need a big turbo to get EMAP low enough to improve Ve with overlap.
4/You would need Ve to be over 130% to achieve that power at that boost.
5/This wasn't a big turbo ... EMAP likely around 2x boost pressure which has a NEGATIVE effect on Ve. (see 1)
6/Compressor is off it's efficiency island making a ton of very inefficient HOT air (see 1)
Below is taken from C.Ludwig's 7670 dyno thread in the rx7 forum :
Originally Posted by Ludwig
Below is the compressor map for the 7670 with plots for 16 psi (blue) and 20 psi (red) taken from our datalogs of MAP and turbo speed. As you can see, it just confirms what everyone suspected. The compressor is well on the small side for the rotary engine. At 8000 rpm at 20 psi we're well past anything close to efficient. On this engine, 8000 is well passed peak power anyway but even at 6000 rpm at 20 psi we're abusing the little compressor. I'm interested to see what the results of lowering the intake temps to a more reasonable level would be. That would allow the compressor to run more efficiently and move the data points to the left slightly. Going forward, once we get the ignition to cooperate and allow us to run more boost, we'll use the ECU to limit max turbo shaft speed and turn the boost up in the mid-range. So we'll end up with more boost in the lower revs with pressure tapering off at higher revs. The ECU has a turbo speed function that allows you to control the wastegate v. shaft speed. This was designed more for limited turbo size specs in various racing series and is very popular in rally. It just so happens we're also trying to maximize an undersized compressor and is just what we need. Of course, Geoff Raicer of Full-Race predicted this exact scenario a few years ago when this compressor was first being discussed. Listen to the experts!
I invite you to try putting 12psi and 55lbs/min on the above chart ... not pretty!
I understand what you’re saying, but it’s only a 12 psig loading and that matters for reasons you still aren’t grasping. Are you looking at the entire thing you posted or just looking at one small area of it with a telescope? You think they can’t measure boost properly? It’s the same thing as the thread subject.
You think Kyle Mohan can’t measure boost properly either? There are a number of things with doing it this way with a Renesis that I fundamentally disagree with him on, but what did I say about where it may possibly excel? Put a high flow, low emap housing turbo on it and it might make some serious numbers 6000+ rpm. To do that for mid-400 whp doesn’t make sense to me, especially for a street use RX8. It makes way more sense to do that with an REW without all the custom contortions.
the only person that’s ever questioned that particular EFR7670 dyno even once that I know of is YOU. Not the people with direct experience running this turbo in various configurations, not the rotary specific turbo & tuner vendor who has done dozens of them, not the shop who has installed quite a few (in different configurations) supposedly they had six 7670 installs total including this one at that same time period alone. Some of those only made low-mid 300 whp at same or higher boost, because the total configuration matters.
Again, if you have the eyes to see and the ears to hear, the differences between the earlier and later graph should be discernible. Some of it is actually discussed at various points, some of it is there in plain sight. I would suggest that part of the reason you’re missing it goes back to your small pp NA engine experiment. You flailed about seething in bitterness and hatred there the same as above and in other posts. There are fundamental things still not being understood is the nicest way I can put it.
here it is on the dyno, in the comments he says it’s 430 whp @ 13.5 psi, but that doesn’t really change anything from your perspective. It was half-bridge ported by ... Kyle Mohan
And the nicest way I can reply to you is to say ... that was not an explanation. Not even close to one.
Also ... just because I'm the only one saying it doesn't make sense, doesn't make me wrong. I've put together a compelling argument based on physics .... you have said it must be right cuz no-one else said it was wrong......... Nice!
And to add : you should know that high emap and overlap don't go well together so with a small turbo the 1/2 bridge is going to have at best no impact and at worst a negative impact on top end. The RX7 crowd know this well .... I thought you followed all that?
Also , minor point ...13.5psi is'nt 12 ...but if this was a bigger turbo ......I would believe 13.5psi making 420whp all day.
You flailed about seething in bitterness and hatred there the same as above and in other posts.
This is something you do, .... massively exaggerate my reaction. It shows me who you are and it's another reason I wont accept any gifts from you.
It would be correct to say ...I was disappointed with the result and pissed off by your condescending rhetoric.... that's the extent of it.
there’s no shortage of doing any of that from either one of us is perhaps where our view diverges ... and none of it really addresses why the results aren’t what they are on that particular build. Let me throw this out from your post above; maybe it’s not quite as ugly as you surmise it to be. Particularly wrt full E85, which you still seem stuck on believing has no benefit over E30:
Think I missed this one in the previous list of hybrid Renesis pp exhaust threads never to heard from again
Let me throw this out from your post above; maybe it’s not quite as ugly as you surmise it to be. Particularly wrt full E85, which you still seem stuck on believing has no benefit over E30:
Originally Posted by C Ludwig
The 20 psi chart was run with E80
Originally Posted by TeamRX8
You do realise there is temp. correction on dynos ....right ?
might gain a little bit more fully tuned, but pretty much the expected NA results imo
there will still be disputers and doubters who refuse to accept what should be obvious through a proper technical analysis, but that doesn’t seem to compute for video game generation.
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funny ... I deliberately didn't talk about the IAT. You just threw it out there without saying anything about it like that was some kind of majic answer. What a joke.
That’s not truthful, it’s just another one of your disparaging mistruths to present a deceitful narrative. If I had posted that response you’d accuse me of being the condescending person in the conversation again. You neither have the eye to see any more than the ear to hear, on multiple levels.
There’s no joke; it’s just you stumbling around in circles, in the wrong desert, in the wrong country. You’re so far off-base on every reply that it’s not funny at all.
Look, the only person who mentioned either temp correction or IAT is you. That the graph was run on E80 was not my point either. He was also another person who had no issue with the dyno results you continue to rage against.
“Are you a master of RX8Club, and know not these things? Verily, verily, I say unto you, We speak that we do know, and testify that we have seen; and you receive not our witness.”
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01-20-2021, 06:39 PM
