im deciding on what to do wit my 7. im looking into all type of engine swaps for my car but i do love my rotary and want to keep it n/a. i know go turbo as every one says but im going to get another car for that purpose and want to keep the n/a in the 7. does any one know the power out puts for a periphial port engine it will be fuel injected when or if i do the motor. standalone and all that other good stuff. i want to have a bad *** n/a. any info is greatly appreciated. if i do the motor it will be fully built race style. thanks .

 

I'm guessing 300-330hp
Are you serious about using a P-port on the street?
MFR housings or homemade?
I made my own for the racecar, have'nt tested them yet.

http://www.wankelkim.net/rx7/fb/portchoke2.JPG

 

yes the car will be driven on the street from time to time once the car is complete its jst gona be kept as a collectors car. mfr? sounds familiar where are thay located do they have a site or number i can call. the pics you have are nice.

 

MFR = Mazda Factory Race, no website.
Peripheral port is far from streetable, powerband is insanely high up the revs.
Plus you will need the oiling system to keep up with 9000+ rpm's. Did i forget to mention the NOISE You WILL get pulled over alot

Stick with a bridgeport, it will make plenty of power if done right.

 

I'm interested in seeing what Peejay has to say, as he seems to be a big proponent of the p-port.

I just read in an old thread (digging through the archives) a post by Peejay saying "if you're at low load, you want sideports (at any rpm); if you're at high loads, you want p-ports (at any rpm)." Something I've been thinking about: p-ports seem to have the advantage of better, more direct flow, but I would think that the path required by having side ports would result in a better mixing of the air/fuel mixture. So pumping losses may be higher with sideports but the actual combustion should be more stable. Of course, I have no idea whether or not this is correct, but it seems what would be natural to me. If anyone else could chime in about this, that'd be great (as I haven't done any real testing).

 

Why not do smaller peripheral ports? They don't need to be race-sized like the MFR and some homemade ones I've seen on various websites and such. The NSU engines had modestly sized p-ports stock. There was one with comparible HP and torque to the R100's 10A back in the early '70s. They each had something like 100 peak HP, but the NSU made it at 7k while the R100 was closer to 6k.

Imagine a 7k HP peak on a modestly sized p-port with 13B rotors. I bet its low end driveability would rival most street ports and probably some half bridgeports. It would most likely beat a full bridge for streetability.

 

Bridgeports make no less exhaust noise than a P-Port....INTAKE noise is a different story.

 

You have it backwards. The Mazda 10A was 100hp at 7000rpm, the NSU Ro80 had 120hp at 6000rpm.

Peripheral port increases torque at a given RPM. You will have more top end, more mid range, and more bottom end torque except for below about 2k.


A street port would crap all over a P-port for driveability. Drivability means you can idle the thing and drive at low throttle openings. You know that brap brap brap at idle? Imagine trying to cruise at 30, 40, 50, even 60mph with the engine going buckbuckbuckbuck. It's not pleasant. Downshifting makes it even worse, since it decreases the load on the engine. You need to *upshift* and bog the engine down, because it is increased load that smooths the engine out. We had my small port P-port running at 7k out of gear and it was still all stuttery Note that the NSUs were only available with torque-converter equipped semiautomatics (think aircooled VW "Auto Stick Shift" type unit) specifically to make low-load driving more pleasant.

I have customers who drive "hairier" engines than a mere P-port rotary on the street. But they have eight cylinders so they don't buck, they just spit and snarl and make all sorts of badass noises. Most of 'em have nice loose converters too...

 

ive seen an nsu spider idle, burrrrrrrr brap burrrrrrr brap

they have really really soft engine mounts