You forget who you're talking about... why do you say it's obviously been filled in?

 

For a cheap street/strip setup I would like to try this:
Take a six port setup. and do some porting on the primaries. Have ONE tube of the manifold shared by the primaries. Next, take and peripheral port the housings with about half the size tube of what you would usually see on a p port. Next take some of those Pineapple 6 port inserts and put them in to where they stay open.
Next make a NOS setup that bolts directly over the 6 ports. The 6 port would have no part of the throttle body induction system. I would think you could bolt what would look like a block off plate over the 6 port with the NOS plumbed into the plate.
The small p port tubes would be the secondaries. How does that sound?

 

i dunno that doesn't look filled in to me

 

A lot of times the filling is resessed in about 1/4 inch or so. My motor though has flat filling all the way and is flush with the plate.

CJG

 

That's pretty similar to the setup that I'm looking to run with my N/A. I'm still doing research, but that's what I've been thinking (just now found the twin 50mm throttle bodies that I would need). I'm really curious though as to whether or not it's legal for the street, anyone know???

 

Street legal depends on how lax your emmisions laws are where you are at. One thing that is for sure is that this is not a practical street setup. (I assume you were talking about the picture of the peripheral port earlier?)
An all out peripheral port will not even idle under about 2500 rpm. A peripheral port is way too much for the street.

 

WRONG ! All out PP's idle better than very large street ports .... I know I have owned both : )

All out PP with rectangular intake ports (very large) with 51mm weber carb and 46 mm venturies idle 1100rpm all day long !

My street port with fancy fuel injection will only just do the same !

I repeat, no problem at all, do not let anybody tell you other wise, they are either full of **** or have never got one running right !

If you look back at the MAZDA FACTORY RACING manual for preparing the 12A Peripheral Port they recommend setting the idle to 1000rpm !!!!

This idling at 2+k is just ******* crap !, sure you can idle the ***** @ 9000rpm if you wish but there is just no engineering reason to do so !

The ONLY downsides to PP's are they are sensitive to back pressure, and they use alot of fuel in low load situations, everything else they are far far better at, that is why they are the ULTIMATE when you are talking about the Wankel Engine.

Just my experience from owning Peripheral ports (6 years)

Regards

Peter

 

That's news to me and I guess everybody else here in the states. Nobody I have seen is running pports on street cars here. If they are they need to post some pics. Do you have any pics of any street cars there running pp's?

 

We ran a PP around the streets of Memphis for a few years, and one friend of mine has owned a Racing Beat style AND a Mazda style. Both of them were street cars, and both of them idled around 1200-1500 RPM. They could've been idled lower, but they just sounded nice, and the tip in was a little better around there. The one I was around the most had the unstreetable 9lb flywheel, and the unstreetable 4.88 rear end. The car was registered in a county that didn't have emmission checks. It ran a 48 weber that I believe was opened to 51mm. The car had Mazda PP headers, dual presilencers, and 2 Hooker comp (almost straight through) mufflers. It was a little loud... but... it never seemed to bother us. The car really wasn't a dog at low RPM either, but when it hit 6500 RPM it felt like the hand of God was propelling the car down the street. Oh, and we drove the car to the body shop we worked at every other day for a few years b4 the car was turned into a full time SCCA endurance car. Need any more info on PP's on the street? It CAN be done; it's just rare. BRAAP BRAAP BRAAP. Spoolin can back me up on this one. He was around the car a lot too.
Don.

 

What kind of mileage were you getting? Did you ever run it on any 1/4m strips?

 

Damn PETER....

You remind be of those morons at MacDonalds, they say I have been cooking fries for 6 years, listen to me cuz I know best and your fries will never be soggy again haha. DAMN bro, just put out the info, dont be a dick.

Anyway! You power doesnt come on until 6000rpms, but I guess you forgot to mention that. This port is best used on a CARB engine. They are pretty much worthless in my opinion, UNLESS! you will be doing some heavy draggin, with HUGE power. Otherwise dont even both with this. It would break before the engine of the week..

M

 

Hey, The power can be tunned to come on at ANY rpm level you want !!! Not all PP's are the same, I did not forget to mention anything bro !

I just get sick and tired of read BS from people who have never had any experience in running this type of porting. I repeat, PP's ONLY downfalls are higher than normal (compared to side port) fuel consumption at low loads & high sensitivity to excessive exhaust back pressure, you can get a PP to have a wider power band + a much flater torque curve at ANY rpm band you wish depending on how you spec the ports and manifolds and assosiated hardware.

You should listen to the guys at McDonalds, you may learn how to cook fries

Dont like my advice, then dont read it !

 

It seems as though if it were a practical street setup, it would be used more often. The most often responser as to why they are not used is because they don't idle worth a **** and they are only good when you plan on running it wide open.

 

why would a pp necessarily have more fuel consumption and be more sensitive to backpressure?

 

You are right in that if it were the best street solution then everybody would be driving them, the facts are that for the reasons I stated they are no t the best solution for the way we drive our road cars, 90% of the time at low load low rpm.

They simply cannot be configured to use low amounts of fuel in these regions.

But they are streetable, and they do make power, and they are reliable, just they are not efficient 90% of the time. Which is bad if you are the one filling it up !

 

Which makes me wonder if you ran them as secondaries with street port primaries if you could get a pretty good street/strip setup? If they only kicked in after 5500 or so it seems it would work pretty well.
The subject does seem to bring out a lot of passion in people. Hopefully we can keep it as civil as possible. I know I have no personal experience in this area. I just like researching and getting lots of information before I attempt something that has had as much experimenting as pports have.

 

scalliwag wouldn't that idea be limited to the type of carburator you would be using. The secondaries would have to flow a heck of a lot of CFM of air compared to the primaries. I think that idea can be worked better with a fuel injected setup though. Can you imagine some sort of valve opening the peripheral ports at WOT and they firing up a nice set of bigger injectors? this could work. keeping low fuel consumption at low load rpms...

is it possible?

hey about the subject I have been reading it and I'm interested about it so if it's any consolation you opened my eyes on the subject.

 

I'm thinking injectors all the way on a Haltech, maybe even a Microtech system. It might work to have a big honkin' TB and butterflies in the port tubes. That runs with your idea of valving the pports.
It could sure be made to look really sweet if nothing else

 

I keep thinking of this but nobody seems to know. You dont need to run seperate butterflies, you can get very large (like up to 4") solenoid actuated valves for exhuast pipes that you could easily adapt.

The bit I dont know is what effect the small volume downstream of the valve between the valve and the rotor housing would have on the flow dynamics of the motor. Anyone?

-pete

 

Hmmm, I don't know. If you did use butterflies on the pports you could put them as close to the housing as possible.

 

The problem guys is back pressure @ WOT, if you can get a handle on this then you can use the benifits of porting overlap, wether it be large street ports, bridges, or Peripheral ports.

If you have too much of it, basically any system that will pass a noise test then you will not gain the benifits offered by porting overlap, infact it will be a hinderence to the point of making less power than a well tuned stock port or mild street ported engine.

This is the long and short of it, the problem for the last 20 years that I can remember is of noise control (aside from low load efficiency) if you are goverend by this, then it is pointless thinking of porting your rotary for increased overlap, N/A or Turbo.

I know this from alot of trial and error and later on analytical test. Basically for the street if you want it to be near legal with moderate noise, then you are facing an uphill battle with any type of porting you choose, I know it sounds over simplified, but you cannot get away from this fundamental problem when it comes to porting a rotary for performance gains.

 

I run one and i am here in the states. I live in WA. I run the pp12a in an rx3. Your right there arent very many of these here in the states that get run on the streets but then again there arent that many people that can tollerate the noise level and the gas money that it takes to run em. I will try and get some pics up but i am really buisy with college. Mine idles at aroun 1800 but thats just to keep the plugs from fowling.
Hey Rice Racing I private messaged you on here about 3 or 4 months ago with some questions. Did you ever get em?

CJG

 

Rotortuner, please PM me again, I had a few personal "issues" around that time and was not on the forum or e-mail much. All is under control now.

Sorry for not getting back to you.

Regards

Peter

PS: the coolest thing about a PP is the "bark" through the intake !!! The first time people hear this, is like WTF...The intake noise is beautifull I still have that memory deep in my head from my carby 13B PP.

 

Rice, Yeah that's why I was saying could you have the peripherals gated. So you run from normal ports up to a point and then open the peripherals. The muffler only needs to be good enough to shut up a normal port, because if you were doing noise testing you just wouldnt open the peripherals. What do you think?

-pete

 

Whoa, deja-vu. 'course, I think I was the last person to ask about this sort of thing...?

Just a thought about the backpressure thing... wondering about valving a cutoff to bypass the mufflers that'd open at the same time as the pports. Seems to me that might solve the backpressure issue without having a full time cop-caller system.

Vague brainstorming...