who is running a semi peripheral port with there 6 or 4 port engine? might be doing it to my engine build. want to see how you liked it. good bad?

 

I'm also in process of building one,I already got the rotor housing done up for the semi.I'm using a fd motor and its going into my rx2,but so far no experience with running one since this is going to be my first time trying a semi p port engine.

 

I have FINALLY got around to testing semi p-ports. I stress the finally part because I've had them in the engine for almost 6 years capped off! I have a few customers on the fence, and needing some results before they went down this road. With that said- I LOVE SEMI P-PORTS. I set them up to be staged through mechanical operation. Basically once I go past half throttle, I have a cable start to pull the p-ports open. This works incredibly well. The transition cant even be felt even while opening them up at 1500rpm. The sound.... oh the sound. Take the V-tec, send it off for steroids and you will have rotary semi p-port induction noise. Fantastic. I will be doing extensive dyno runs, plots, tuning etc. soon which should help shed more light on the subject

 

i have a full PP 12A engine. idles @900, and basically drives like stock... with a carb and locked timing. i'm still breaking the engine in, but the tq curve feels like its totally flat, it pulls harder @2500rpm than a stock 12A ever does. its FUN!

semi PP should be better at low throttle and low rpm, so it might be better on the street.

only downside so far is noise.

 

I'm really interested in the whole semi-PP thing. Is it reasonable to think that one might be able to pass emissions with one (since it's a just a street port until the PP's open, and you could probably set them not to for the test)?

GTo: you're quoting 350 rwhp for you semi-PP... but I assume that's without the ports open yet?

 

Hey man, this sounds like quite the setup, could you give us a bit more info on this? or where would I be able to find a build thread or something similar.

 

my build so far is a s5 t2 irons and housings with my s5 n/a rotors.huge street port, exhaust port. im running pfc now with full tune on the 6port engine in the car. a semi pp port is safer than a full bridge. i spoke with racing beat on exhaust specs and they said, there street header full exhaust im using is fine. and that after a full tune maybe then decied on full true dual. though i would not be running a valve to open close the pp port.

 

i have several i build and use on my cars 3 rotor Semi port and 2 rotor semi port they work really great.I also make them for my customer,build a jig to do them for a few years now.

 

I do not see much of a issue with emissions (as you already stated). There is a bit of turbulant air while the p-port is shut. Which may result in some air/fuel dilution with exhaust gases. Sounds like a interesting project though. I cant totally quote power numbers just yet, but I can say 350rwhp was without any p-ports. There was some issues ecu related that have been corrected, so I am excited to see what happens now.

So far its still a very prototype setup. I don't have anything at all posted yet. Using this as development to finish a couple customer cars with faster results and best power (Christopher mostly).

Here is a quick rundown on the setup- 20b, "Circuit port", 9.7:1 rotors, nrs apex seals, balanced, dry sump etc. 90mm throttle body with our custom plenum box going to stock intake runners. 35mm triple throttle bodies feeding the semi p-ports. 10,000 rpm.

 

I'm loving my Semi p-port bridge. I drive it on the street and it actually behaves quite well. Starts easy and runs clean through the range on a Holley 650 DP in a first gen shell.

 

Yea that would be nice! I've had visions on the concept for years.

 

I don't understand how any kind of peripheral port is "safer" than a bridge, or how a bridge is "unsafe" for that matter, at least not until you get into huge ports that require going through the water jacket.

 

cause after time the bridge becomes weak and breaks and well boom. new motor time.

well i got all my info about a semi pp port. and everything i found is good. it is very tunable granted its not a big pp port. and power gains a very nice. and its drivable on the streets. in my case that doesnt matter since my car is a pain already to drive on the streets. my motor is in the works and should be done before spring. as the build comes to an end ill post pics.

 

Can we see some pics of the setups? Do you run the stock manifolds or custom? Obviously custom on the p-port side.

 

Ive seen some full p-ports with smooth 800rpm idles and good drivability. Most of the issues people seem to think stem from P-ports, is due them being used in race applications with only high-rpm power in mind. Youd have the same "problems" with huge side ports, bridges, j-bridges, etc.I firmly believe that if sized and tuned correctly and full p-port setup can have great drivability as well as decent gains in power. Im sure a semi-pport can work well, but it seems overly complex. How well do you guys agree with this? Logan?

 

i will be running stock mainfolds. the lower will be drilled and another intake runner will be welded to the pp port and merged to the side runners. my goal is to use stock mainfolds throttle body etc. since i have the pfc i want this to be as easy as a start and go project. the tune on the pfc is pefect for break in of the motor. then will retune. ill be stoping next month at jpr. will take pics then and start a build thread.

 

i was surprised at how nice the full PP drives once you tune the carb to give the engine what it wants. my idle is about 900.

 

My builder (From PR) suggested it a while back but the Semi p-port with a large street port is more reliable than a bridge or full pp and makes more power than a bridge. Right now the RX-8 has been sitting but I'll get more info for you this week.

 

where can I get semi pp LIM for 20B or Cosmo 13B? or can I mod my stock LIM to be semi pp?

 

you can custom drill the stock manifold. or try pro jay.

http://www.pro-jay.com/SEMI-PERIPHER...NIFOLD_c15.htm

 

Here is our prototype setup. Once I get more caught up, I will post the whole build process

 

Beautiful!!!!

 

oh please post a video of the semi-pp 20b, ive been looking for some self-touch material!

 

You know I've drawn up numerious examples and have always wondered how it would perform with the PP's NOT receiving flow from the orginal Tb's. That was before I started learning how to tune so now I can see how your set-up would work. I bet that set-up is loud as **** when they open. Do you think you have finally broken the 400rwhp mark? I'm finally getting ready to test drive my set-up but have been having battery and charging issues.


One more thing, did you notice a handling difference than before with your engine in it's new position?

 

I'd love to have an engine last long enough for that to be a problem

I've never heard of this happening in practice, just people theorizing. If it does happen, maybe it's just people doing very thin bridges with a lot of undercutting. There couldn't be much more side stress on the bridge than corner seal spring tension. I recently had an engine failure that involved the rotor smacking/grinding against the side housing and the points of hard contact weren't near where the intake port was.