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Back in 2005/06, I was aware of a 270 crank hp stock port 6port renesis in my area, and the normal, with a good quality n/a peripheral tuning, was 6ports at 245-250 crank hp.
Then you could add all those tricks to get the power down and you had a very zippy ride, wpc bearings, lighter wheels, better tires, gearing, diff etc etc.
THat was then when you had access to well built strong compression engines. Now with these getting older, I don't know.
the is issue is stock-port vs peripheral port, not stock engine.
I only brought up that the dyno from my own original factory stock engine (zero internal modifications from Mazda and about 20,000 total miles mostly on the street being the point) indicating 221 whp on a Mustang dyno is posted on here from back in 2008 to counter that “it’s a Mustang dyno” point. Fwiw, 187 n-m = 137 lb-ft
. 2005 Mazda RX8, original factory engine with ~20,000 miles, TeamRX8 CAI, header, & exhaust, Cobb Beta tune
This hybrid is a hand built, blueprinted engine with peripheral port housings and the comparison is against a hand built, blueprinted Renesis engine without porting. There was an entire race series from 2004 to 2015 using these hand built and blueprinted Renesis engines that were then sealed to prevent tampering. Some of us are very familiar with them, but most have no idea at all.
Some of the statements on here aren’t just from not being informed, they’re outright untruthful and intentionally dishonest words and feelings …
These are a few different stock*port* Renesis data points; engine dynos (bhp), chassis dynos (whp), different fuels, etc. The thing is, we can dyno race from here to eternity, based on my own experience comparing the video to fixed reference points and overall feel of speed, unless it’s hampered by excess weight then it’s not that fast imo: . . . . . . .
The problem is that no one has solved the biggest problem -- Side port exhaust.
Team has already pointed out countless times on nearly as many platforms if the exhaust has too many flow paths any hope of scavenging is destroyed, and with it any hope of achieving (N/A) results superior to what an extremely well built stock port renesis is capable of. The ONLY potentially relevant advancement as it pertains to the viability of the n/a hybrid renesis concept is a solution for the permanent deletion of the Side/Siamese ports.
Honestly it would be easier to fit an RX8 front cover on an REW......but....I have an R3 so I'm stuck with the S2 front iron, so I hope someone figures it out.
no, there’s an intake port part of the issue as well that you and pretty much most other people fail to recognize still.
I appreciate your input.
Even with said intake port issue remaining, that hybrid engine still produced better numbers than 99% renesis engines and that was with an awful (for n/a power) 5 port exhaust configuration. It would stand to reason that with a peripheral only exhaust setup those results could be improved, by how much exactly?.....who knows? Potentially enough to at least justify further R&D into ways to mitigate the drawbacks on the "intake port problem". Fabricating intake setups isn't terribly difficult to do, however the refining them to achieve desirable performance may take some time.
Conversely, lets say you could snap your fingers and solve the intake port problem tomorrow, what kind of results do you think you would see pairing that with a 5 port exhaust? As far as I'm aware, no one has come up with a viable solution or even a prototype for resolving side port exhaust problem, and doing so is a lot more difficult than simply grabbing some tubing and a welder to make an intake. How many people have the tooling or resources to even attempt such a thing?
I stand by my assertion that the side exhaust ports are the more difficult, and thus more pertinent impediment to progress.
you can’t and I still contend that no, it doesn’t make within 5% of the best Renesis engines. That doesn’t even consider all the cost and effort to go in that direction. Why wouldn’t you just do what it takes to have the best Renesis engine instead than do all that with a excessively complicated 5-pipe exhaust, motor mount to account for it, etc.? Most people can’t even handle getting a 3-pipe Renesis exhaust manifold built. Every time I point out one of the keys to getting a turbo fitted properly on Renesis is to get rid of the factory motor mount on that side of the engine, all I get is “it’s too much trouble and hassle to address”. You just can’t make up this level ironic hypocrisy.
What you need to do is go back to the Mazdatrix/Kyle Mohan thread and read it through again to see and understand where they started and then where it ended. It never was any good, but certainly a lot worse at the start. That was 3 - 4 years worth of effort by knowledgable, experienced rotary engine specialists putting way more financial backing into it than you’re going to find around here. Yet again, if you did your homework then you know some others spent more than that and where are their results?
again, it’s not just one or the other, it’s the combination and the same reason it doesn’t work on the exhaust side is part of the same reason it doesn’t work on the intake side.
the best way I can explain it is that people see a piece or two, but due to various misunderstandings they can’t see and put the whole puzzle together. One of the misunderstandings is that overlap is a power builder. It’s not, it’s just a side effect of what is the power builder; filling the chamber. Except the chamber isn’t being filled if exhaust gasses are overwhelming and flowing in the opposite direction against the clean intake air that the chamber needs to be filled with to make power.
On a Renesis the full primary intake port opens at 3deg ABDC. This is substantially different than the earlier engines, even heavily ported ones, and the only reason it works on the Renesis is due to not having overlap. Once you add exhaust overlap the only thing that comes close to that is a peripheral intake port. Except just like on the exhaust it doesn’t any more have a single intake port than it does a single exhaust port.
Nobody is grasping the physical reality of that situation. Those multiple intake ports are all connected together at various points, but lack the effective magnitude of momentum of a single intake port because of the additive effect of the losses. Yet in addition to being less effective than a peripheral port it still has all the same considerations that a peripheral port has as far as the things that work negatively against it. Yet it also has all the negative issues of a Renesis as well.
It really makes no sense at all to go down that path. The people who went there gave no consideration at all to the things I’ve pointed out in detail attempting to explain why it won’t work. Nobody is evaluating on that level. They just think throwing parts at it will result in magic. There is no magic; either the law of physics support it or they don’t. Even if you block off both the side exhaust ports and the primary intake ports, this introduces other factors that are going to require more effort, finances, and difficulties to overcome.
Even the high power 13B NA PP engines are not a cheap endeavor. Those engines built for serious road racers, by the time they have the intake, exhaust, fully tuned ecu, the engine itself, etc. those are over $30k entry cost. Then you have the entire rest of the car to build out to support it properly. That was actually quite a few years ago the last time I saw one of those engines priced out fully.
Honestly, most of the people on here have no idea about much of anything really. Just ideas and things they heard and saw, not real understandings or experience.
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looks like perhaps you overlooked this recent one as well, which has filled side exhaust ports per your previous assertion, kind of missed the 5% mark by a little bit …
you can’t and I still contend that no, it doesn’t make within 5% of the best Renesis engines. That doesn’t even consider all the cost and effort to go in that direction. Why wouldn’t you just do what it takes to have the best Renesis engine instead than do all that with a excessively complicated 5-pipe exhaust, motor mount to account for it, etc.? Most people can’t even handle getting a 3-pipe Renesis exhaust manifold built. Every time I point out one of the keys to getting a turbo fitted properly on Renesis is to get rid of the factory motor mount on that side of the engine, all I get is “it’s too much trouble and hassle to address”. You just can’t make up this level ironic hypocrisy.
Go take a random sample of 100 real world renesis engines and that hybrid makes more power than 95 of them. While your experience may differ, and you have provided dyno results to show that it has, the VAST majority of people do not have a renesis making over 200whp on any dyno, much less a mustang. If you throw out the Drummond Star Mazda engines, how many achieve 210whp, much less 220whp? I actually studied your header thread and ultimately concluded that buying an aftermarket tubular header was a waste of time and money. I agree , the excessively complicated 5-pipe exhaust does more harm than good....but if anything that would seem to make a stronger case for the potential viability of the hybrid concept.
What you need to do is go back to the Mazdatrix/Kyle Mohan thread and read it through again to see and understand where they started and then where it ended. It never was any good, but certainly a lot worse at the start. That was 3 - 4 years worth of effort by knowledgable, experienced rotary engine specialists putting way more financial backing into it than you’re going to find around here. Yet again, if you did your homework then you know some others spent more than that and where are their results?
As their setup was turbo and built for road racing I didn't really see a ton of information that would be applicable to building an n/a setup, other than of course using GSL-SE housings .
the best way I can explain it is that people see a piece or two, but due to various misunderstandings they can’t see and put the whole puzzle together. One of the misunderstandings is that overlap is a power builder. It’s not, it’s just a side effect of what is the power builder; filling the chamber. Except the chamber isn’t being filled if exhaust gasses are overwhelming and flowing in the opposite direction against the clean intake air that the chamber needs to be filled with to make power.
Wouldn't a more efficient exhaust setup work mitigate this effect? There is no scavenging or exhaust tuning with a 5 port exhaust, such things could be introduced with a peripheral port exhaust could they not?
On a Renesis the full primary intake port opens at 3deg ABDC. This is substantially different than the earlier engines, even heavily ported ones, and the only reason it works on the Renesis is due to not having overlap. Once you add exhaust overlap the only thing that comes close to that is a peripheral intake port. Except just like on the exhaust it doesn’t any more have a single intake port than it does a single exhaust port.
Nobody is grasping the physical reality of that situation. Those multiple intake ports are all connected together at various points, but lack the effective magnitude of momentum of a single intake port because of the additive effect of the losses. Yet in addition to being less effective than a peripheral port it still has all the same considerations that a peripheral port has as far as the things that work negatively against it. Yet it also has all the negative issues of a Renesis as well.
If by "connected together at various points" you are referring to the stock intake manifold, couldn't one use an ITB's or Carbs to help aid intake velocity and chamber filling?
It really makes no sense at all to go down that path. The people who went there gave no consideration at all to the things I’ve pointed out in detail attempting to explain why it won’t work. Nobody is evaluating on that level. They just think throwing parts at it will result in magic. There is no magic; either the law of physics support it or they don’t. Even if you block off both the side exhaust ports and the primary intake ports, this introduces other factors that are going to require more effort, finances, and difficulties to overcome.
Agreed, magic doesn't exist, but I'm interested in these "other factors" blocking off the side port exhaust would introduce....
Even the high power 13B NA PP engines are not a cheap endeavor. Those engines built for serious road racers, by the time they have the intake, exhaust, fully tuned ecu, the engine itself, etc. those are over $30k entry cost. Then you have the entire rest of the car to build out to support it properly. That was actually quite a few years ago the last time I saw one of those engines priced out fully.
Honestly, most of the people on here have no idea about much of anything really. Just ideas and things they heard and saw, not real understandings or experience.
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No one is talking about building a full PP dry sump race engine with a Motec, so while probably accurate those price quotes aren't particularly relevant. The main appeal of doing anything with a renesis is simply cost, there are tons of parts and motors lying around, for cheap an if there is more performance potential to be had using these otherwise garbage parts, it would be nice to know. Obviously building the initial test mule(s) will be more expensive, but like anything IF it pans out then cost can be reduced to some degree as more are built. Maybe it's not possible? Maybe those star Mazda engines are the best anyone can hope for using a renesis as a base? I don't pretend to know the answer, but would very much like to find out.
Last edited by sharingan 19; 05-22-2022 at 04:56 PM.
looks like perhaps you overlooked this recent one as well, which has filled side exhaust ports per your previous assertion, kind of missed the 5% mark by a little bit …
no, he was going to suggest it to his friend that has the engine, but you don’t really need a dyno when there’s the reality of time vs speed in 2nd gear per the video
I’ll trust in that reality more than any dyno, any day … the same goes for the other one in this thread. It’s there for anyone to see, yet plenty don’t.
you misperceive plenty yourself, as per the previous reply, I’m not going to bother addressing those things.
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so another thing is that the Singapore hybrid Renesis must have a 5.125 rear gear installed. Because the shift points don’t match up with the indicated speed until that ratio is accounted for. It may be listed somewhere, but I can’t recall ever seeing it if it was.
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So ......... I finally got to tune one of these hybrids myself (In collaboration with Mark Haynes who built the engine)
*SSV operational set to open 3800
*VDI inoperative
*APV inoperative .... fully open
*Semi PP intake
* PP exhaust plus stock Renesis exhaust ports
*Freeflow 3" exhaust system
*Stock coils
*Stock intake/maf setup
*Old worn out GLSE housings used
*Renesis rotors
*Balanced rotating assy
*tuning stock ECU via Mazdaedit
This dyno compares a race prepped stock Renesis (red lines ) with freeflow exhaust with the hybrid described above (purple lines). Torque at top, whp below.
Comments :
This hybrid was definitely a budget build done as an experiment . Compression is likely less than ideal and I'm sure more could be done to maximise the setup but it does prove what many of us suspected.
1/huge loss of low down power
2/Small increase in power up top .... potentially larger than what is shown here but certainly no more than another 10-15whp.
3/It pulses like an old school rotor and other than the low down power loss runs pretty well on stock ECU.
So ......... I finally got to tune one of these hybrids myself (In collaboration with Mark Haynes who built the engine)
*SSV operational set to open 3800
*VDI inoperative
*APV inoperative .... fully open
*Semi PP intake
* PP exhaust plus stock Renesis exhaust ports
*Freeflow 3" exhaust system
*Stock coils
*Stock intake/maf setup
*Old worn out GLSE housings used
*Renesis rotors
*Balanced rotating assy
*tuning stock ECU via Mazdaedit
This dyno compares a race prepped stock Renesis (red lines ) with freeflow exhaust with the hybrid described above (purple lines). Torque at top, whp below.
Comments :
This hybrid was definitely a budget build done as an experiment . Compression is likely less than ideal and I'm sure more could be done to maximise the setup but it does prove what many of us suspected.
1/huge loss of low down power
2/Small increase in power up top .... potentially larger than what is shown here but certainly no more than another 10-15whp.
3/It pulses like an old school rotor and other than the low down power loss runs pretty well on stock ECU.
So, the difference between dyno and dyno 2 is only the PP exhaust?
So ......... I finally got to tune one of these hybrids myself (In collaboration with Mark Haynes who built the engine)
...
Comments :
This hybrid was definitely a budget build done as an experiment . Compression is likely less than ideal and I'm sure more could be done to maximise the setup but it does prove what many of us suspected.
1/huge loss of low down power
2/Small increase in power up top .... potentially larger than what is shown here but certainly no more than another 10-15whp.
3/It pulses like an old school rotor and other than the low down power loss runs pretty well on stock ECU.
Worth the doing to validate theorized results, but having done so ... it seems the value is novelty, and applications of sustained ~7k rpm and higher.
The Mohan engine has the APV barrels pulled as well. In theory it will flow less with them in and then likely make less peak power. Which it likely won’t matter regardless with semi PP since those aren’t valved. Even with the potential gain of a full-on build I don’t see it having more output than the best Renesis can do.
The 5 port exhaust is ok for turbo, but it's doing no favors in an n/a application. Waiting on someone to figure out how to delete the side port exhaust altogether. Always nice to have an additional data point though; thanks for the update!
Waiting on someone to figure out how to delete the side port exhaust altogether.
This is the setup I'd really like to see done properly :
*stock Renesis Intake ports ...with some massaging in the right places
*stock intake manifold with tuned valve timing
*blocked off side exhaust ports
*PP exhaust
*Tuned length headers
I think it would match a stock Renesis down low and do better up top than the above setup.
This is the setup I'd really like to see done properly :
*stock Renesis Intake ports ...with some massaging in the right places
*stock intake manifold with tuned valve timing
*blocked off side exhaust ports
*PP exhaust
*Tuned length headers
I think it would match a stock Renesis down low and do better up top than the above setup.
My thoughts EXACTLY !!!
The stock RX8 intake is huge (relative to previous rotaries) and well designed. I'm sure it's got more in it, but side ports aren't going to pull it out.
This is the setup I'd really like to see done properly :
*stock Renesis Intake ports ...with some massaging in the right places
*stock intake manifold with tuned valve timing
*blocked off side exhaust ports
*PP exhaust
*Tuned length headers
I think it would match a stock Renesis down low and do better up top than the above setup.
It simply won’t; especially down low, but then we’re right back where this all started. I understand why people think this, but it just won’t have that outcome due to things that have already been posted/discussed that still either aren’t understood or are just being overlooked/not fully considered by the people concluding otherwise.
As I went into detail previously in Taiwan hybrid thread where the side ports are filled/blocked, the intake valves are functional, etc. and then also provided logged data for comparison demonstrating how the performance isn’t there; the Renesis porting is not readily duplicated in the earlier 13B plates and when the mods are made to bring it closer to the Renesis porting on those engines, then the bottom end becomes even worse. Because they don’t even compare down low to the Renesis in unported form. There really is a general disconnect with most people on the overall understanding of the two engines.
I again respectfully put forward; despite the similarities, they’re essentially 2 different engines wrt the the intake and exhaust cycle processes. And they aren’t going to play nice with each other when combined together which to date has been proven over and over again. I do regret stating it as such, but suggesting that the bottom end will match more or less demonstrates the overall misunderstanding of the situation.
This might as well be us all going back in time 15 years and me trying to explain to everyone else why a multi-tube header offers no power advantage to a Renesis. It’s essentially the same thing wrt how people don’t fully understand what they think they do. Theory only works when properly applied.
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As I went into detail previously in Taiwan hybrid thread where the side ports are filled/blocked, the intake valves are functional, etc.
Edit : didn't read that properly .... thought you were refering to the Malaysia one. ....Were there ever any dynos done on the Taiwan one ...can't see anything in the thread ? https://www.rx8club.com/rx-8-discuss...inside-273410/
As far as your contention that it can't work goes , I do understand and agree with a lot of what you say on this . However, your THEORY that the PP exhaust with a properly tuned header system wont play nice with the Renesis intake is still just that ... a theory. IMO
I've played around enough with these engines to understand one thing ..... Until you actually try something..................... you can't be 100% sure of what will happen.
you’d be 100% sure with the proper understanding; again people just aren’t putting it all together properly. Just like I said in the linked thread above; opening the whole port at 3° Pri and 12° Sec is not comparable to a 13B BP and a 13B large street port won’t get there. As also stated from the beginning when I went into all those detailed explanations and diagrams in various past threads; this combo puts it into a PP realm under all the wrong circumstances and conditions.
In summary, this cannonball is never going to fly without being shot out of a cannon.
…. but I’m otherwise done with it and am not feeling any more inclined to going back and engaging in all the same basic arguments that were made on the other subject in 2007 again either. Because it really is just the same thing all over again for me.
Anyone with something to prove should quit with their own maybe, possibly, and could be’s to instead show us all how it’s done. Without that there really is nothing to stand on from that viewpoint in light of the numerous examples now indicating otherwise. Just because someone think’s it has potential means less than nothing when weighed against the actual facts in hand to date.
I did a lot of analysis on the track footage video for the Malaysia example. It doesn’t pass the muster imo. That’s all I need for my own affirmation. When you actually have something more than hope, dreams, or virtual gamer thought processes that defy the law of physics then please let me know.
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As I went into detail previously in Taiwan hybrid thread where the side ports are filled/blocked, the intake valves are functional, etc. and then also provided logged data for comparison demonstrating how the performance isn’t there; the Renesis porting is not readily duplicated in the earlier 13B plates and when the mods are made to bring it closer to the Renesis porting on those engines, then the bottom end becomes even worse. Because they don’t even compare down low to the Renesis in unported form. There really is a general disconnect with most people on the overall understanding of the two engines.
I again respectfully put forward; despite the similarities, they’re essentially 2 different engines wrt the the intake and exhaust cycle processes. And they aren’t going to play nice with each other when combined together which to date has been proven over and over again. I do regret stating it as such, but suggesting that the bottom end will match more or less demonstrates the overall misunderstanding of the situation.
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I just wanted to highlight this for Extreme Emphasis for future readers and those who struggle to grasp the benefit of the Renesis engine, and why putting so much energy into chasing peak horsepower if futile, People really downplay the advantage of the low end performance the Renesis has over all other NA 2 Rotors.
and also note... I spend far more time reading, then I do sharing my own opinions here, I'm sure my post count can reflect that. Sometimes this is very beneficial as its easy to get trapped in your own opinion once you voice it...
While reading through the forums in the time I've been here, going back in threads all the way back 04'.
There is about 10,000 times more evidence that supports Porting a Renesis does NOT work, then there is that it DOES.
There is also about 150 times more evidence, that a blueprinted stock port Renesis, is superior in just about everyway, in power, longevity, and versatility then any type of Ported Renesis. You could take it so far as to say any ported 12A/13B when you expand what makes an engine "better" beyond peak horsepower.
I've see alot of banter about the "95 Percentile" of RX-8s which meet a dyno, and how those 5% of cars isn't fair/realistic to use in comparison. And It's important to remember, especially now, 95% of RX-8s are poorly maintained, poorly modified, and often also have notably heavier wheel/tire combos which suck wheel power on a dyno like no other, There's the significant amount of owners who are unaware of the effect of not disabling traction control when getting on the dyno.... Ontop of 75% of RX-8's hitting dyno's have a malfunctioning/non functioning AIS
I don't think Wheel Dyno's are credible in general for really deep diving into engine building, of any type. Far to many variables, and it's much easier to inflate or deflate numbers. An Engine Stand eliminates the possibility of alot of those variables which means a much more controlled environment, and usually the operators are far more experienced in just about everyway...
The dead horse Team has been beating about the Renesis and its lack of overlap, we have really started to see in Piston Engines in the last 5 years. There is a uncanny similarty to the engineering Mazda did with the Renesis in the late 90's to early 2000's and the Engineering that is being done on alot of Piston engines now - Mainly I am referencing the engines with "Single" port Heads, which have integrated exhaust manifolds. Many of the more experienced, and talented engine builders/tuners have had alot of success abandoning base engine principles and rules they used/practiced for decades (especially in regards to camshafts which has a significant correlation to what is done with porting a rotary) when it comes to these engines Naturally Aspirated, and they have had some pretty incredible Results. One of the most interesting being a relatively stock K24Z which has a single exhaust port from the head that made 355hp on Pump 93 octane... This particular tuner found very quickly chasing ridiculous amounts of overlap, and aggressive valve timing was not the answer to making power on this engine.
This is not me saying that the Renesis has some secret hidden horsepower we just haven't figured out how to tap, because I don't believe that. I think Mazda knew exactly what they were doing with the Renesis, and its pretty much tapped out from the factory once you go beyond uncorking the exhaust, and building a premium blueprinted example.
Last edited by blackmount; 08-29-2022 at 10:20 AM.
02-05-2022, 07:35 AM
