Renesis Irons on 12a
The Renesis is the same composition as the 12A as far as I know (aluminum rotor housings, cast iron side housings). The tension bolts holds the whole package together.
06-22-06 | 05:53 PM
#27
Hunting Skylines
Joined: Apr 2001
Posts: 3,431
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From: Brisbane, Queensland, Australia.
Originally Posted by gmanuser
*read this*
it is very important to understand that althought they me the same demension they would seize, because they are made out of alluminum and you other housings are made out of cast iron from your 12a and by doing that you cause, 1. leakage, 2. seizure and most likely never be able to take apart engine agian, 3, warpage due to reasons 2 and 1
it is very important to understand that althought they me the same demension they would seize, because they are made out of alluminum and you other housings are made out of cast iron from your 12a and by doing that you cause, 1. leakage, 2. seizure and most likely never be able to take apart engine agian, 3, warpage due to reasons 2 and 1
06-22-06 | 06:54 PM
#28
Thread Starter
pistons do what?
Joined: Dec 2005
Posts: 93
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From: TX
Originally Posted by gsl-se addict
Yeah. I am just saying if you had the parts around. Not like the Renesis irons would be cheap either. If you are getting new parts, Renesis parts are often cheaper than the older 13Bs (such as the rotors), though. Currently there is a large supply of good used older 13B parts, but a shortage of used Renesis parts. In a few years, it will probably be more balanced.
79rx_7: You have to realize how all the parts are made to work together. The Renesis intake is tuned to work with that engine. It is where much of the power comes from. The intake won't work with 12A rotors/housings. Also, power is related to both torque and RPM. The torque in the Renesis is a bit higher than the other NA 13Bs, but not by a huge amount. Some of the torque increase is due to higher compression rotors. The major change is the redline. The higher redline, with an intake that can flow enough and is tuned, is what makes the majority of the power increase in the Renesis. The additional ports would offer you little or no power gains. As I said, they had a 6 port 12A in Japan, but the power is going to be less than what your 4port 12A can do. Yes, there are more ports, but the ports are much smaller. The reason for the 6-port setup is to have a wider powerband. Two of the secondary ports stay closed during low load/low rpm situations. This keeps the air velocity up and increases low end torque. At higher loads, the additional two ports open up for high end power. The 4 port engines are similar to having a 6 port with the additional ports open at all times (little less low end, about the same relative top end).
Having more exhaust ports isn't going to really help things. If you leave the stock exhaust ports in place, the exhaust gases are going to take the path of least resistance (the 12A ports), because the 12A is a single large opening and the gases don't have to exit the side and make several turns. Getting an exhaust manifold to work with that setup would be complicated.
Anyway, I think you are best off porting/modding what you have. You can add EFI, have rotors balanced/clearanced, ported, and so on and have a real nice NA 12A. Other options would be either the full Renesis setup (would be cool, but it would be easier, cheaper, and get more power from a TII setup) or some hybrid setup (S5 or Renesis rotating assembly, 4 port irons, FD housings for example). Many people prefer the 4 port engines because you can port them further. Also, for forced induction, the 6 ports offer no advantages (all the stock turbo setups are 4 port).
Kent
79rx_7: You have to realize how all the parts are made to work together. The Renesis intake is tuned to work with that engine. It is where much of the power comes from. The intake won't work with 12A rotors/housings. Also, power is related to both torque and RPM. The torque in the Renesis is a bit higher than the other NA 13Bs, but not by a huge amount. Some of the torque increase is due to higher compression rotors. The major change is the redline. The higher redline, with an intake that can flow enough and is tuned, is what makes the majority of the power increase in the Renesis. The additional ports would offer you little or no power gains. As I said, they had a 6 port 12A in Japan, but the power is going to be less than what your 4port 12A can do. Yes, there are more ports, but the ports are much smaller. The reason for the 6-port setup is to have a wider powerband. Two of the secondary ports stay closed during low load/low rpm situations. This keeps the air velocity up and increases low end torque. At higher loads, the additional two ports open up for high end power. The 4 port engines are similar to having a 6 port with the additional ports open at all times (little less low end, about the same relative top end).
Having more exhaust ports isn't going to really help things. If you leave the stock exhaust ports in place, the exhaust gases are going to take the path of least resistance (the 12A ports), because the 12A is a single large opening and the gases don't have to exit the side and make several turns. Getting an exhaust manifold to work with that setup would be complicated.
Anyway, I think you are best off porting/modding what you have. You can add EFI, have rotors balanced/clearanced, ported, and so on and have a real nice NA 12A. Other options would be either the full Renesis setup (would be cool, but it would be easier, cheaper, and get more power from a TII setup) or some hybrid setup (S5 or Renesis rotating assembly, 4 port irons, FD housings for example). Many people prefer the 4 port engines because you can port them further. Also, for forced induction, the 6 ports offer no advantages (all the stock turbo setups are 4 port).
Kent
You guys are making this thing out to be way more than it really is. What you have to realize is that the rotary engine is very simple and just because one has a little bit more displacement changes nothing, the 12a and 13b are the same engine. Think of a 13b as a stretched 12a, the same applies to the Renesis. You are making the difference between a Renesis and a 12a out to be as extravagant as a comparison of a 12a to a V8. As for the Japan 6 port, it was a bad design and should not be compared to the Renesis, the ports on the Renesis have much better flow characteristics than even the 13b 6 port so there is power to be had there. On to the exhaust ports, the stock p-port on a 12a is not a 'single large opening', just one of the side ports on the Renesis is the same size as the stock 12a port so there is much more area to get the exhaust out of the motor, also the side ports have been designed to flow just as good as a p-port so I don’t think there is any problem there. As for the rotating assembly, I never said that I wanted a high revving rotary, I just want the better flowing irons on my 12a and hopefully bank some big power. The fact that the Renesis housings will mate up wtih the 12a is worth a try .
Last edited by 79rx_7; 06-22-06 at 07:00 PM.
06-22-06 | 07:48 PM
#30
Thread Starter
pistons do what?
Joined: Dec 2005
Posts: 93
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From: TX
Originally Posted by gmanuser
the renesis is diffrent composition it is all alluminum casts dude i promise they did that to cut weight i looked at one the other day
It is indeed NOT all alluminum but in fact has iron side housings. This pic from Pineapple Racing says so
06-22-06 | 08:02 PM
#31
those exhaust ports look the same size but they must be better flowing otherwise why would mazda produce it when the 12a ports look alot more direct plus also the 12a exhaust ports can be made larger...
wheres the xtra 2 intake ports.. i cant see them??
wheres the xtra 2 intake ports.. i cant see them??
06-22-06 | 08:23 PM
#32
Rotary Enthusiast
Joined: Jan 2002
Posts: 975
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From: Puerto Rico Land Of The Fastest Rotaries
I noticed that the Renesis side housings are flat like the early versions (no grooves)...
Now let me see if I get this right... You want to use 12A rotor housings with the renesis side housings? Doesn't that make it a 5 port exhaust??? I would love to take a look at that exhaust manifold...
IMHO...I would just port the 12-A side housings and rotor housings... I've seen those little fu#3rs run in the 9's... Actually we used to run 12-A carb when the car was still streetable and ran 10:85 back in the days (about 8 years ago)...
Now let me see if I get this right... You want to use 12A rotor housings with the renesis side housings? Doesn't that make it a 5 port exhaust??? I would love to take a look at that exhaust manifold...
IMHO...I would just port the 12-A side housings and rotor housings... I've seen those little fu#3rs run in the 9's... Actually we used to run 12-A carb when the car was still streetable and ran 10:85 back in the days (about 8 years ago)...
06-22-06 | 08:29 PM
#33
I don't know the exact specifications of the renesis, but the advantage of the side port is that you have enough port timing to scavange the combustion chamber, while avoiding overlap between the intake and exhaust ports....I would venture a guess that if you wanted to do some extreme intake porting...or as extreme as you can go with a renesis plate, you would not have to extend your periferal exhaust port timing for the powerband to be effective at high RPM which would reduce your overall port overlap. This would improve your drivability at lower RPM with an extreme NA rotary....as well as if you kept the functionality of the axilary ports.
Just think of the advantages of not having to extend your exhaust port timing on ur high performance NA because of the additional flow of the side exhaust ports.
I doubt it would be the MOST powerful....I know this hypothetical setup woudn't be the MOST drivable setup...but you can have a really cool hybrid of both characteristics.
Being that the 12a is of smaller displacement than the 1.3 liter renisis, you're powerband would be at an even higher RPM. You might be able to get the RPM of a periferal port, or at least, a bridge port, while maintaining more drivability than the bridgeport
Just think of the advantages of not having to extend your exhaust port timing on ur high performance NA because of the additional flow of the side exhaust ports.
I doubt it would be the MOST powerful....I know this hypothetical setup woudn't be the MOST drivable setup...but you can have a really cool hybrid of both characteristics.
Being that the 12a is of smaller displacement than the 1.3 liter renisis, you're powerband would be at an even higher RPM. You might be able to get the RPM of a periferal port, or at least, a bridge port, while maintaining more drivability than the bridgeport
06-22-06 | 08:31 PM
#34
Thread Starter
pistons do what?
Joined: Dec 2005
Posts: 93
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From: TX
Originally Posted by Angel Guard Racing Team
I noticed that the Renesis side housings are flat like the early versions (no grooves)...
Now let me see if I get this right... You want to use 12A rotor housings with the renesis side housings? Doesn't that make it a 5 port exhaust??? I would love to take a look at that exhaust manifold...
IMHO...I would just port the 12-A side housings and rotor housings... I've seen those little fu#3rs run in the 9's... Actually we used to run 12-A carb when the car was still streetable and ran 10:85 back in the days (about 8 years ago)...
Now let me see if I get this right... You want to use 12A rotor housings with the renesis side housings? Doesn't that make it a 5 port exhaust??? I would love to take a look at that exhaust manifold...
IMHO...I would just port the 12-A side housings and rotor housings... I've seen those little fu#3rs run in the 9's... Actually we used to run 12-A carb when the car was still streetable and ran 10:85 back in the days (about 8 years ago)...
If you say those fu#3rs run in the 9's then with the Renesis housings I should be in the 6-7 range..... LOL thats good news tho, something to work toward
06-22-06 | 08:53 PM
#35
this has turned out to be a very very interesting thread
nice question
so this means you could run some smaller injectors and have a heltech computer setup...
either way you would have to make a custom intake for either carb or efi
nice question
so this means you could run some smaller injectors and have a heltech computer setup...
either way you would have to make a custom intake for either carb or efi
06-22-06 | 08:54 PM
#36
Rotary Enthusiast
Joined: Jan 2002
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From: Puerto Rico Land Of The Fastest Rotaries
I don't wanna burst your bubble but... You will not run 6's or 7's with an engine alone... My question is... Are you planning on using the 12-A rotor housing exhaust also??? Who's gonna tune that timming????
06-22-06 | 08:58 PM
#37
Rotary Enthusiast
Joined: Jan 2002
Posts: 975
Likes: 5
From: Puerto Rico Land Of The Fastest Rotaries
I have seen FD side housings on 12-A's but what you are saying you're gonna do is a thought that will haunt me for the rest of my days... Although I do wish you good luck but you are doing it the hard way believe me...
06-22-06 | 09:05 PM
#38
Thread Starter
pistons do what?
Joined: Dec 2005
Posts: 93
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From: TX
Originally Posted by Angel Guard Racing Team
I don't wanna burst your bubble but... You will not run 6's or 7's with an engine alone... My question is... Are you planning on using the 12-A rotor housing exhaust also??? Who's gonna tune that timming????
06-22-06 | 09:15 PM
#40
Rotary Enthusiast
Joined: Jan 2002
Posts: 975
Likes: 5
From: Puerto Rico Land Of The Fastest Rotaries
Well... remember that exhaust timming has to do with the exhaust ports... So if you have a regular engine and do a "shittey" porting job you could end up with a car that will not tune right... Take this into consideration.... There are 3 exhaust ports on the renesis which are located higher than those on the rotor housings of the 12-A... I just don't know how in the world that engine would even idle if it ever gets to start... And if you do cover the exhaust ports on the rotor housings what material would you use in order for it not to melt and/or literally devower the apex seals???? Just a few questions that pop in my mind at the moment....
About the gearbox... I have no idea, but it would not be hard to make a tranny fit in there... That would be the least of your problems...
About the gearbox... I have no idea, but it would not be hard to make a tranny fit in there... That would be the least of your problems...
Last edited by Angel Guard Racing Team; 06-22-06 at 09:17 PM.
06-22-06 | 09:39 PM
#41
Duct-tape fixes all
Joined: Oct 2005
Posts: 1,000
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From: Toronto, Canada
Why doesn't one of you guys call up Mazda tell them what you want to do, and see if they will let you talk to an engineer or something in charged. Heck they may even sponser you to do this, and give you an engineer to use. I think it would be worth the $3.00 call. What is the worst they are going to say... no?
06-22-06 | 11:05 PM
#42
Originally Posted by Angel Guard Racing Team
Well... remember that exhaust timming has to do with the exhaust ports... So if you have a regular engine and do a "shittey" porting job you could end up with a car that will not tune right... Take this into consideration.... There are 3 exhaust ports on the renesis which are located higher than those on the rotor housings of the 12-A... I just don't know how in the world that engine would even idle if it ever gets to start... And if you do cover the exhaust ports on the rotor housings what material would you use in order for it not to melt and/or literally devower the apex seals???? Just a few questions that pop in my mind at the moment....
About the gearbox... I have no idea, but it would not be hard to make a tranny fit in there... That would be the least of your problems...
About the gearbox... I have no idea, but it would not be hard to make a tranny fit in there... That would be the least of your problems...
What are you talking about 3 ports on the renesis....? isn't it 2 per rotor makin 4 total.....r ur talking about the hybrid 12a with 3 exhaust ports/rotor...
also what do you mean the renesis ports are "higher"......do you mean have later timing? rememeber the whole point of the side port exhaust is there is no(or very little) port overlap even if the timing may be later than that on a 12a...
Why not leave the exhaust ports...all 3 of them alone..and extend the intake timing later in the stroke on the renesis plates.....
06-28-06 | 07:01 PM
#43
Junior Member
Joined: Apr 2006
Posts: 34
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From: Pennsylvania
i could be wrong here but i dont think you can port out a renisis any more than it is, they are periphial ported from the factory so if you werent going to use stock ports it would be cheaper and easier to buy shiny new 12a periphial port housings from racing beat
06-28-06 | 09:27 PM
#44
Thread Starter
pistons do what?
Joined: Dec 2005
Posts: 93
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From: TX
Originally Posted by stupidturbo
i could be wrong here but i dont think you can port out a renisis any more than it is, they are periphial ported from the factory so if you werent going to use stock ports it would be cheaper and easier to buy shiny new 12a periphial port housings from racing beat
What are you takling about, the renesis does not have p-ports. I think you are getting your ports mixed up, a p-port is a single large hole in the rotor housing not the side housings, and also who said anything about porting a renesis, I want to swap the renesis side housings as is.
07-01-06 | 05:08 PM
#46
Thread Starter
pistons do what?
Joined: Dec 2005
Posts: 93
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From: TX
Ok I have found more out about this, it seems the only problem I would have doing this is the front side housing, the oil pump which fits on it has a different bolt pattern than all other previous engines and the pump itself is electric and runs off the ECU. I have tried searching for any info on the rx-8 pump but came up with nothin, none being sold anywhere. I will have to find one somewhere and try and mod it to either run electric at a rising rate with engine speed or convert it to mechanical somehow.
everything else should bolt right up including the 12a transmission to the rear housing, so no modification there.
Renesis pump pattern compared to 13b
everything else should bolt right up including the 12a transmission to the rear housing, so no modification there.
Renesis pump pattern compared to 13b
07-01-06 | 06:26 PM
#48
Thread Starter
pistons do what?
Joined: Dec 2005
Posts: 93
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From: TX
Originally Posted by blwfly
could get a plate cnc'd to go from renisis to old
or would it be to little room
or would it be to little room
I thought about that but I dont think there would be enough space and it would misalign the gear on the pump from the one on the e-shaft. Basicly its no go unless I can find the rx8 pump and make some sort of electronic controler to make the pump rise and fall with the engine speed.
07-03-06 | 07:23 PM
#49
Thread Starter
pistons do what?
Joined: Dec 2005
Posts: 93
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From: TX
Well I sent an email to mazda proposing what I am wanting to do and made the mistake of calling the engine a HYBRID between a renesis and 12a. So I got a responce from some tard in marketing, who went into a rant on how mazda is working with ford to create hybrid engines and electric powered cars. But on a more interesting note he said "We have conducted extensive testing on an RX-8 powered by a bi-fuel gasoline/hydrogen-fueled RENESIS rotary engine"
and then went on "Please understand that our engineering and product development teams are not in a position to assist a customer in creating/modifying his own hybrid vehicle. "
that bastard!
and then went on "Please understand that our engineering and product development teams are not in a position to assist a customer in creating/modifying his own hybrid vehicle. "
that bastard!
