So apparently it's quite easy to make your own peri housings, just drill a big hole and press in an aluminum sleeve. And I suppose drill/tap holes for the manifold.



What is done with the ports in the side plates? Obviously filled but with what?



Are there intake manifolds available or would that be strictly custom?



How much power would a guy be looking at out of a 13B? 12A?



J

A **** ton of power. But not too streetable from what I've heard.

na 13b's will make about 320hp, streetable is relative, but the pp is gonna be a little hardcore for a driver.



mike

13b n/a's will make 320hp for just the peripheral porting job? https://www.nopistons.com/forums/pub...DIR#>/ohmy.png

would be a weekend car then . . . if i actually did this . . .



hmm could just dip into the elevens https://www.nopistons.com/forums/pub...#>/biggrin.png



J

i drove a big bridge port rx3, and you could drive it to work, but i'm not sure you would want to.



mike

what is undriveable about a bridge port? I always hear "rough idle" and such, but I haven't read specifics.



and what about bridging the 5th and 6th ports...affect driveability?

I heard they have bad low end that is what makes then not so streetable, and they are loud as hell..

WTF?Peri porting is easy?Thats a first.Not streetable but still.For a weekend warrior that would rule.

Easier than what I thought it would be - mainly in the $$$ department, as apparently you don't really need to buy custom or factory peri housings, you can modify regular housings.



Bridging the 5th and 6th port is the other thing I was thinking about, and might still do - that would be totally streetable. Just wouldn't have nearly the power.



mmm



power



https://www.nopistons.com/forums/pub...1047683894.gif peripheral



Anyways - back to filling the side housing ports, and finding manifolds . . . ???



J

a bp is very drivable, but each brap (you know brap brap brap brap), rocks the car, it wants to buck at part throttle under 5k rpms, other than that, the bp got mid 20's mpg on the freeway, it has more low end torque than any other na ive driven, and it was quiet



mike

Here is how Racing Beat does it:





J

yeah, but you have to worry about port timing too



mike

Check out some of Judge Ito's posts. He has a semi p-port/bridge he is putting together https://www.nopistons.com/forums/pub...DIR#>/ohmy.png

Besides the Peripheral intake opening. A P-port engine offers more intake timing then a bridgeport. Basically the P-port engine is the biggest camshaft you could install on a rotary. Intake on a p-port could open sooner then a bridgeport and close later then a bridgeport. But because the engine has a huge overlap(Intake and exhaust ports opened at the same time) keeping a steady low Idle is kinda of hard. And because the the intake ports are so huge, it has an effect on air velocity(air velocity is slow) and reduces low rpm torque.. Some low rpm torque could be regained with a custom intake manifold.

does it have to have the overlap (from exhaust and intake being open at same time) to make most power, or could you give the pport diff timing and still make gobs of power?

or the always nice semi-pport, just use a near stock sideport for your primary and pport as secondary, maybe the center housing so you only have 3 runners going to the intake manifold, one for each pport, and one for the center housing feeding both primarys.

run 3 individual TB's, actually, just use the stock Throttle Body.

ooooooh god im overloading with ideas!!!!!!!

the nsu wankel spiders idle nicely at 800rpms, they have a small port though, and it uses a 2 barrel progessive carby, the first stage is really small, the second is big



mike

yeah, theyre small ports with reasonable port timing. but still all pport.

ito, you should try to make a semi-pport N/A, that can be driven daily. see if you can get 300hp N/A streetable, lol. thats a challenge

VWs have carbs like that, erm i mean throttlebodies

Ito, check your PMs on RX-7 Club. https://www.nopistons.com/forums/pub...#>/biggrin.png

couldn't you make control unit to control a smaller pipe that's inside the big p-port one that opens up below a certain rpm and closes the big intake?

huh? I got confused reading your reply. Sorry

I will.

Yes Mike, the smaller the p-port the less intake and exhaust overlap the engine has and a smoother idle can be achieved. On a large Peripheral intake port and a large p-port exhaust there is some serious intake charge being sucked right into the exhaust stroke.. Is called SCAVENGING..

So what is the best port size and timing?



(and still nobody knows what to fill the side ports with?)



J

Thats the thing, best port size for what? With a pport you can make power high in the RPMs (i've heard around 13,000RPM and so), yet the 787b had its redline at 9,000RPM because it made all of the power, torque, and fuel efficiency it needed at that redline and below.

And the old NSU's were street legal pport only cars, that idled and drove like regular cars.



So it's just like an intake cam, how wild do you plan on being?

if you read the rest of the bible, errr racing beat manual, they recommend using devcon (plastic steel) for filling the intake ports. its a 2 part epoxy that mixes up like JB weld and you pack it in the port (please, no perverted comments) and smooth it out about 1/8th of an inch stepdown from the side housing surface. VERY crude attempt of showing you what i mean:



surface of side housing \/ opening of intake port

--------------------------------_______-------------------------

where to stop devcon at/

I see, I suspected something like that. I should actually get that Racing Beat catalogue already but I'm allergic to spending almost $30 for a catalogue (by the time it gets to me).



I will have to study this timing issue in detail it seems.



J

yeah thats one of the hangups to a diy pp housing. that and the labour time to actually do the machine work+a new rotor housing is not much cheaper than a new pp housing



mike

I would think that JB weld, or some sort of high strength epoxy would work. Or weld in and machiene the weld flat?



BTW i like this thread.....i'm learning about streetability on baby bridgeport motors..which is what i want to do with my vert

I run a 13B peripheral Port on the street, i have racing beat housings,a 51 IDA carb, and some carefully placed exhaust.The tuning is the key.the engine has great power below 7500 rpm,but from there up to 11,000 is like adding NOS,if you run an aluminum flywheel,it spins up really quick.i use the stock turbo flywheel for running at the stip,and the light one on the street.there is nothing like the power of a pport.e-mail me at pportnossp,and we'll talk.

all i 've ever heard of using is devcon. that is what everyone is using for filling side pockets and such....

I'm new to the group, but have had a desire to build a rotary drag car so I have some questions on peripheral porting. To give a little information on my self,I have a small plastic inject and machine shop, I also try to do things as least expensive as possable as far as money going out, plus I like to tinker. Is there any info on where a peripheral port needs to be cut? Also why couldn't you directly inject your fuel into the housing to eliminate the fuel lose out the exhaust?

Richard