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Here is a recently registered patent from Mazda. two rotor with side exhaust and peripheral exhaust operated with valves, Patent 7159820 | IP Portal "IP Force" .
yeah, I didn’t get into reading all the details yet, but it appears to just be an update to the previous patent. The valve control on the exhaust ports being a critical factor.
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yeah, I didn’t get into reading all the details yet, but it appears to just be an update to the previous patent. The valve control on the exhaust ports being a critical factor.
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Valve control? Are they trying to achieve zero-overlap on peripheral exhaust to intake?
Got to tune another one of these hybrids yesterday :
Specs :4 port manual
GLSE housings pp exhaust ported
Intake ports all 4 bridgeported
MSP exhaust ports blocked at exit.
twin headers approx 1m long going to stock diameter from there back.
Power: as above, looks like a strong midrange with stockish top end (for a 4 port) but extended powerband past 7500. This dyno typically does read lowish - unfortunately the owner had nothing to compare it with so don't really know how good/bad it is compared to stock.
Braps : just like an old school
Got to tune another hybrid today. This time we put a good stock port on the dyno straight afterwards so is a good comparison to stock.
Specs of the 6 port hybrid:
New build
6 port with GLSE housings with the PPs enlarged.
All intake ports bridged.
Side exhaust ports blocked at the flange.
exhaust twin 2"ID pipes - unequal length then stock from there back. No cat.
Specs of the stock 6 port
Engine - stock with good compression
Underdrive pulleys
AEM style intake
Free flow exhaust system
Red line is the hybrid , blue line the stock port.
We forgot to properly calibrate the stock port rpms and it had quite small tyres so thats why the apv rpms don't align . With correct calibration I calculate the stock port would be at 202whp peak.
I will be posting something soon. Not metal, unfortunately, just theory, and not that it will be earth-shattering info, either. I know I have said that for 2+years. Just letting people know I haven't given up on this idea, since I have voiced advocacy so often here, I feel a responsibility to not appear to just drift away from that advocacy. Other things took precedence.
Last edited by kevink0000; Mar 19, 2024 at 10:45 AM.
Interesting, why are people even deciding to build hybrid renesis engines? It just seems worse overall.
I think it's because of the perception of performance that a 'brap' brings .... plus there haven't been enough comparisons like this to dissuade people.
Also : as I found with my own PP exhaust experiment .... there is some gain to be had with this type of engine if one is prepared to rev it higher.
Post #31, I know Mark has already seen this since he has posted on the thread.
If the renesis could somehow be put together to match this build, then I would say it would be worth it if someone currently needs a rebuild, they're going to be spending money anyways to freshen up the engine. I am guessing a 13b-rew in n/a form is more reliable on track compared to the renesis with its side exit exhaust ports. Who knows what the torque figures are on this 13b-rew build though, I would bet it's worse than a fresh renesis.
For an emissions legal plus registered in the correct state street car, the MSP offers exceptional performance and drivability for n/a rotary. As far as mass produced engines intended for public use, its hands down the best n/a rotary Mazda has ever produced.
To my knowledge, the only n/a rotary that will outperform the MSP would be a prepped race rew PP engine (or similar). There was a time I was going to purchase the engine below for my car, but thankfully I didn't go the race car route. https://www.rx7club.com/race-parts-o...k-cad-1131090/
I also recall a jdm n/a rew FD that was pretty quick around Tsukuba from what I remember. I tried digging through a few articles to find it but I don't keep up on what's what anymore. Maybe someone knows of the vehicle I'm talking about? I feel like if you can access the n/a records for Tsukuba you'll quickly find who I'm talking about.
ps - Super Street or Sport Compact Car magazine from '00s dyno'd FD stock and then with bolt-ons. IIRC it made 217 whp. Very healthy MSP makes >220 whp. Little food for thought. Here's a thread of similar tetsting I found on 7club. https://www.rx7club.com/3rd-generati...added-1104322/
Last edited by Federighi; Mar 21, 2024 at 01:35 PM.
Reason: for clarification
For an emissions legal plus registered in the correct state street car, the MSP offers exceptional performance and drivability for n/a rotary. As far as mass produced engines intended for public use, its hands down the best n/a rotary Mazda has ever produced.
To my knowledge, the only n/a rotary that will outperform the MSP would be a prepped race rew PP engine (or similar). There was a time I was going to purchase the engine below for my car, but thankfully I didn't go the race car route. https://www.rx7club.com/race-parts-o...k-cad-1131090/
I also recall a jdm n/a rew FD that was pretty quick around Tsukuba from what I remember. I tried digging through a few articles to find it but I don't keep up on what's what anymore. Maybe someone knows of the vehicle I'm talking about? I feel like if you can access the n/a records for Tsukuba you'll quickly find who I'm talking about.
ps - Super Street or Sport Compact Car magazine from '00s dyno'd FD stock and then with bolt-ons. IIRC it made 217 whp. Very healthy MSP makes >220 whp. Little food for thought. Here's a thread of similar tetsting I found on 7club. https://www.rx7club.com/3rd-generati...added-1104322/
I agree, the MSP really is Mazdas culmination of n/a rotary tech for street and track driveability, while making the engine more thermally efficient, hence the better emissions and fuel economy when certain pitfalls have been addressed. The vfad intake tech reminds me of the 787bs 4 rotor variable runner intake design, just a more dumbed down version.
I haven't followed really any n/a 13b-rew builds besides the select few on the rx7club, as a lot of them have been hidden with the passage of time since everyone wants to go the turbo route these days.
As far as I'm aware, he's the only rx8 driver utilizing the n/a msp doing sub 60's at Tsukuba, I'm honestly not even sure if turbo rx8's have taken down this wall yet as there's not a whole lot of drivers aiming for this target. He even mentions he can take about a second off if he runs racing slicks instead of street tires. While he's still seconds off of the fastest turbo FDs that run at Tsukuba, he's still posting times that many tuning shops have a hard time hitting with their FD builds.
As far as I'm aware, he's the only rx8 driver utilizing the n/a msp doing sub 60's at Tsukuba, I'm honestly not even sure if turbo rx8's have taken down this wall yet as there's not a whole lot of drivers aiming for this target. He even mentions he can take about a second off if he runs racing slicks instead of street tires. While he's still seconds off of the fastest turbo FDs that run at Tsukuba, he's still posting times that many tuning shops have a hard time hitting with their FD builds.
Yeah I know the car, I had no idea he broke into the 59's. Bravo! There are a few of those well prepped RX8's right at that mark over there. Awesome the platform still has enthusiasm and exciting times for sure.
hmmmm, could have sworn this was bumped recently 🤔
a couple more attempts are supposedly coming.
so the best turbo Renesis hybrid dyno we ever saw was from Mazdatrix/Mohan Racing well over 10 years ago. The never revealed much about the turbo specs, but 12 psig on full bridge Renesis with GSLSE rotor housings and a few other details that often go unnoticed though anybody can see them:
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and one reason I disagree with going that way; this FD3-REW
result from 2018
Originally Posted by Turblown
DNA garage built half bridge (ported by Mohan Racing - TeamRX8) 2 rotor FD3S with our cast EFR IWG 7670 turbo kit. 12.5 psi on E85.
The hybrid Renesis in particular has no bottom end at all due to overlap EGR resulting from the Renesis intake port placement being so far earlier in phase timing than the previous 13B engines coupled with the bridge porting making it that much worse. In general though, bridge porting with a smallish turbo is going to produce these kind of results with low boost, due to their limited flow capability coupled with less restricted intake flow path and intake/exhaust overlap increase.
The idea that you need a Renesis hybrid to achieve this result is mistaken, in addition to being that much more cost and effort.
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except it’s a fresh rebuild he put multiple thou$and$ into, the other is just a crap engine.
He’s doing it wrong on multiple levels though. It should be in the 175 - 185 whp range imo, but this idea is never going to pan out like most people think it will.
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Did KMR ever post a dyno on his hybrid build, or did that disappear forever? The NA 13b builds on the rx7club still seem to be the better options at this point for peak hp. Too bad that guy in the slow and indecisive 2nd gen build lost significant compression recently on his 13b-na build, it had some impressive numbers.
