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To continue the discussion a bit, I seem to remember that someone had a Drummond build dyno'ed and it ended up under 200 rwhp. I will try to find that post if I can. It might be interesting to discuss further.
I think it was this one. I remember it being 199hp, but may be wrong.
Seems like this concept but using GSL-SE housings and deleting the Siamese port while retaining the stock intake ( at least no BP) could potentially produce even more power without having to rev quite as high.
Find a reliable way of blocking off ALL the Renesis exhaust ports , make a tuned twin pipe header and I think you would be onto a winner ..... !!
The reason why no-one is getting great results from hybrid Renesis engines is that they all seem to think.............. more ports = more better .
This is wrong, and if you understand why velocity is so important you will know why. Yet people keep doing it and wonder why they get sh*t results!
It has very little to do with the increased overlap ........ IMO.
edit: time flies and fuzzy memory on what year the engine swap occurred.
Classic intrawebz story fail; that was in 2012; a year prior to the aforementioned Drummond engine build and was the engine on they dyno that eventually failed and was replaced in 2013. Pretty sure it was just a warranty reman that was never all that great. Ended up puking oil, ticking SSV arm, etc. I assisted him with swapping in the Drummond engine after that. The superflow engine dyno graph is posted on the forum and below; it was mid-260 bhp at the flywheel, stock ports and internals, just precision blueprinted, finely balanced, and carefully hand built.
again, adding overlap to the non-overlap design configuration of the Renesis will only hurt performance potential.
… and yes, overlap matters for that very reason. The quickest way to kill intake velocity is for hot, high pressure exhaust gasses rushing into the early opening intake ports in the opposing direction, which results in killing the intake resonance that is an integral part of the zero overlap design configuration. It demonstrates how most people still do not have their head wrapped around the entire principle, how it works in total, and the performance sensitivity of it to such changes.
Originally Posted by kevink0000
I think it was this one. I remember it being 199hp, but may be wrong.
… and yes, overlap matters for that very reason. The quickest way to kill intake velocity is for hot, high pressure exhaust gasses rushing into the early opening intake ports in the opposing direction, which results in killing the intake resonance that is an integral part of the zero overlap design configuration. It demonstrates how most people still do not have their head wrapped around the entire principle, how it works in total, and the performance sensitivity of it to such changes.
If we all believed that............... the awesome high overlap rotary builds we see today would never have happened. It's just a matter of getting it right. One day someone will do it, and you'll be the guy trying to wrap your head around it.
no Brett, you again fail to grasp the totality of the differences, just as stated.
bought my first RX8 new off the dealership floor in April 2005 and still to this day have seen zero results for any Renesis engine with overlap added that even gets close, let alone exceeds, the best non-overlap Renesis engine output. The question is, why do you continue to refuse seeing and admitting to it yourself? Yet every time I’ve brought this particular thread up elsewhere, I’m accused of “throwing it in your face” or “being condescending” for having mentioned it.
If this works, then which is it? Well, because it doesn’t work and he well knows it despite that latest tap dance reply above to the person that revived this thread again. Yet still fails to understand that I’m only mentioning it as one of several examples of how the principles behind the subjects being discussed are not being understood and applied correctly. The light still hasn’t come on yet.
I’ll repeat myself again by saying that the barrier won’t be overcome until it can be accepted for what it really is rather than continuing to believe it’s being done as a personal affront. This prevents seeing and accepting the truth. Only those who truly want and seek the truth with a sincere and open heart can overcome that barrier and come to the truth.
Wrt the 2020 dyno above, it didn’t have the time put into to tune the AFR fully. It will make a few more hp if that had been done, but that’s not necessary because it’s not the goal. It’s the same basic result as all the others that have been built in the sense that they’re all in that general range of where they’re expected to be. This is not an experiment, not something new, not something different. It’s just a build and verify of the same thing that’s been done for the last 15 years or so. I don’t know exactly how many, wouldn’t surprise me if it was more than 100 or higher even. The experiments were all done in early-mid 2000.
Once built, the engine is first broken in on the dyno for approx. 8 hours using a specific break in procedure of so much time at xxxx rpm, then moved up to the next rpm level, until completed. Then if everything checks out it gets a power run as verification before being crated up and shipped out. That’s the only goal and these dyno sheets are all just that power run at the end. Once received, installed, tune verified, it can be immediately operated at WOT/raced. There’s no toodling around on the street babying it for 500 - 1000 miles and praying for a good result.
The one in the middle didn’t get quite as much money put into it as the other two. He’s a local guy with a street RX8 that wanted a good engine. He paid a good amount though; more than most people here by replacing major components just as I’ve explained on the forum many times, but wasn’t going for gold as on a competition engine. He got a very good result and while we haven’t spoken in 6 - 9 months he still has the RX8 with that engine to this day. Due to some life changes it doesn’t get driven much. Pretty sure he’d have told me if it was being sold.
So this same builder does offer porting; cleaning things up, maximizing where it matters, not adding overlap though, and he says the most he’s ever seen is about 10 bhp more. That’s it, completely maxed out. The downside is it’s harder on the rotor seals, requiring it to be rebuilt sooner and more often. Which sooner or later the side plates have to be replaced and ported again if that’s what the plan. I’ve testified to this over and over again on the forum as well, including advising people to not do anything more than a basic cleanup. My recommendation is to not even bother with that really, which the engines on those dyno sheets are all unmodified ports.
However, some most people just can’t let it go. Thinking they have something up their sleeves that the guy building pro rotary race engines in every possible porting, intake, exhaust configuration imaginable for a lifetime (now 83 or 84 years old) with every resource available at his fingertips somehow didn’t or couldn’t figure out. Ten years ago I got a price for a complete plug-n-play 340-350 hp 13B PP with custom everything including a fully tuned MoTeC ecu and it was over $40k.
That’a pro series (non-billet) NA race engine, just a typical build. Yet here I am just repeating myself to same thick skulls that likely aren’t going to be penetrated. Funny though, when we’re talking turbo it’s “just doing what’s practical and makes sense for the average enthusiast”, but for the threads like this, hybrid exhaust housings, 3-rotor Renesis, and other such not well thought out fantasies, then that concept doesn’t matter and is thrown right out the window. .
Want to be a knucklehead? Ok then, knock yourself out.
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bought my first RX8 new off the dealership floor in April 2005 and still to this day have seen zero results for any Renesis engine with overlap added that even gets close, let alone exceeds, the best non-overlap Renesis engine output. The question is, why do you continue to refuse seeing and admitting to it yourself?
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Thanks for the book.
You know what's funny ? We actually agree on a lot of stuff , mostly we just disagree on the fine detail.
In this case I would agree that what has been tried to date (including my experiment) hasn't worked. Or at least hasn't worked well enough to warrant the effort and expense.
But , I still believe there is a combo that will work. I outlined roughly what that was above . To date that combo has not been done 'properly' IMO. and I don't buy your argument as to why it wont work.
The world needs stubborn "knukleheads" to try the things that people like you wont. Otherwise we'd still be driving around in a horse and cart.
It doesn’t work for the exact same reasons the BP doesn’t work, which you already acknowledge the latter. Nobody ever advanced chasing things that obviously don’t work and could have been eliminated with some forethought. If you have to prove it out that far for it to finally be obvious to you like the BP, then ok. Have at it. I came to that BP conclusion before you ever did, and without ever having done it myself either.
Again, a wise man learns from the mistakes of others. I never said you weren’t smart, but question the wisdom of not learning from any other mistakes than your own. Which in this case would mean making the same mistake more than once. You’ll get there eventually though and I’ll be waiting in the shade to greet you.
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Again, a wise man learns from the mistakes of others.
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Plenty of 'wise men' grow old doing just that without ever trying or achieving anything themselves. Poor sad and miserable ...but oh soooooo wise ! lol
Kinda reminds me of a guy I met when I did a business mentoring program years ago. (Keith Cunningham ran it - you may have heard of him) . This one guy there was really clever , knew all the theory , had all the books , had done all the courses etc Most of us took the info and ran with it on pure faith, this guy wanted everything to be perfect before he would take a risk. So he he didn't do anything at all and as far as I know he still hasn't to this day. The rest of us did very well using the information all the while knowing there would always be a risk involved.
again, adding overlap to the non-overlap design configuration of the Renesis will only hurt performance potential.
… and yes, overlap matters for that very reason. The quickest way to kill intake velocity is for hot, high pressure exhaust gasses rushing into the early opening intake ports in the opposing direction, which results in killing the intake resonance that is an integral part of the zero overlap design configuration. I .
This does happen at low rpm and load and the effects are pretty obvious . But once the engine gets into the high rpms ...No ...............it doesn't. Otherwise my engine would make LESS power than stock and other high overlap engines wouldn't work at all!
If you are saying that, I'm not sure now that you fully understand why a Bridgeport Resesis doesn't work. You need to look at an engine where a BP does work and compare that to a Renesis!
It doesn't work because the overlap happens in the wrong place in the cycle, it's nothing to do with the design of the intake!
It seems as though you either misunderstood or are mixing up different parts of multiple discussions. It’s not the design of the intake manifold, it’s the intention/purpose of the design that’s being countered for that reason as stated. Otherwise the timing of it is exactly what I’ve been saying all along; due to the rephasing of the intake port position timing. I’m not even really sure what you’re trying to say and am not sure you are either.
You don’t have a stock engine, it doesn’t run as strong as an engine with the mods it has, should run. If it were larger it’d have more negative impact and vice-versa.
It’s not my intention to discount your experience. Data is only as good as the effectiveness of interpreting it correctly.
You want to see it in action at high rpm? Watch the video of the Renesis p-port Paul Lamar build way back when and pay attention to the inlet horns as it runs through the top end. It’s blowing major exhaust reversion out the intake. Just like I demonstrated plotting out a good engine dyno with unmodified ports against the p-port intake dyno results, it only exceeded the stock ports slightly over a 500 rpm range of the powerband and was negatively impacted mostly every where else. This is the same thing I’m saying over in the 3-rotor engine thread too that nobody is recognizing still.
So let me get this straight .... you are using a worst case scenario (HUGE PP intake) to prove what exactly? Does that prove that exhaust gas from a pp exhaust would go up a Renesis intake ? I think not.
WRT my engine ...there isn't another stock rx8 around that matches it .... that's real world ...your Drummond dyno is you hand plotting onto someone elses dyno...... that's fantasy world. I'm still not convinced they are great as you think they are .... let's see some chassis dynos against other stock good condition engines with similar mods.
Data is only as good as the effectiveness of interpreting it correctly.
Amen to that ! This is where actually doing something and evaluating the results trumps reading the interwebz and chatting with engine builders.
So let me get this straight .... you are using a worst case scenario (HUGE PP intake) to prove what exactly? Does that prove that exhaust gas from a pp exhaust would go up a Renesis intake ? I think not.
chose not to pursue it then, but am bored now, so to wit …
it only made 264 bhp @ 7400 rpm, a *huge PP intake* will make upwards of 350 bhp @ 9,800+ rpm(fact, by the same builder as my Renesis engines!)
what a person knows and what a person thinks they know, or the people upvoting them with likes think they know even less of, are not necessarily inclusive …
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chose not to pursue it then, but am bored now, so to wit …
it only made 264 bhp @ 7400 rpm, a *huge PP intake* will make upwards of 350 bhp @ 9,800+ rpm(fact, by the same builder as my Renesis engines!)
what a person knows and what a person thinks they know, or the people upvoting them with likes think they know even less of, are not necessarily inclusive …
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I don't have a dog in this fight, other than I admire and praise Brett for putting into metal what he thought would work.
Again, another attempt gives us a another data point, which is never useless.
The reason I am posting is that interestingly, this:
"(it only made 264 bhp @ 7400 rpm, a *huge PP intake* will make upwards of 350 bhp @ 9,800+ rpm(fact, by the same builder as my Renesis engines!)"
Is actually the same amount of torque in both cases. (give or take).
Last edited by kevink0000; 10-02-2022 at 10:35 AM.
I don't know if there is an argument here ..... I've conceded the mods were not a game changer already. In the meantime I'm just enjoying the braps and having an 8 that's slightly quicker than stock.
I only came back to the thread searching out something else, but really the PP port on those high hp 13B engines are not really that big compared to what had been used in the past
but agreed especially within the entire context of the Renesis intake/exhaust cycle difference from the 13B as I’ve tried to explain it multiple times. Which is why I also keep saying overlap port timing addition to the Renesis is never going to pan out in a positive way for most situations. There are still a few hybrid builds in progress though. So let’s wait and see how they pan out.
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if it in any way involves adding exhaust-intake overlap timing/flow then hopefully more time to thoroughly consider the ramifications of the Renesis intake port placement in ultra early phase of intake cycle will be given.
Because if I had to draw any conclusion right now it’d be that by and large this key point is neither understood nor even comprehended by pretty much everybody.
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if it in any way involves adding exhaust-intake overlap timing/flow then hopefully more time to thoroughly consider the ramifications of the Renesis intake port placement in ultra early phase of intake cycle will be given.
Because if I had to draw any conclusion right now it’d be that by and large this key point is neither understood nor even comprehended by pretty much everybody.
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Team;
Let me know if I’m reading you right.
Are you saying that because the Renesis has no overlap, it allowed for Mazda’s intake placement to open ultra early?
So, if any peripheral opening on either exhaust or intake were introduced, the ramifications would be that it would cause hot exhaust to revert in to the intake chamber and manifold having a negative effect on timing, back pressure, intake temperature or driveability, and it would be difficult to tune on the Dyno?
The Renesis was designed to be a Cleaner combustion rotary engine with similar
Power to that of the previous Rotary, right?
Mazda intended to block unwanted solids and gases from coming out of the exhaust by eliminating a straighter path for the exhaust to exit, right?
And anyone who tries to use peripheral ports to increase flow is wasting their time because it won’t amount to any significant gains to that of a well built fresh stock motor?
05-21-2021 | 05:35 PM
