I've not seen a retangular hole saw. The rectangle are done cnc.. and that is big bucks.

 

I have access to a shop where I can do rectangle ports myself

 

Mazda uses a 46mm port RUNNER, just to make that clear. the ID of the tube you press/screw into the housing is 46mm ID. the actual port in the housing can be bigger or smaller. Mazda had an SAE paper about optimizing the PP engines for 9,000rpm. and they ended up with and Io/IC of 80/80, and a port size of 25cm2. they found that opening the port earlier doesn't help, as the rotor is in the way. Mazda's port is a D shape with the flat side on the bottom (opening) line.

see SAE paper 900032 "prediction of power output performance of the rotary engine"

as far as parts go, it could be pretty minimal, as even the Rx8 has a ~9000rpm fuel cut, and they didn't do much to do that! i would say to start with the Rx8 or FD engine clearances, and maybe you want the rotor tip to side housing on the big side. i would use the FD oil pressure regulator, to bump the oil pressure. if you can budget the FD/Rx8 stationary gears, they are hardened and multi window bearings. i'd use the 89+ tension bolts. you want the FC or later rotors, as they have the 9 pin retained gear. if you start with an FC engine, you want the turbo oil pump.

you're certainly welcome to balance the whole assembly.

apex seal choice is up to you.

 

Thank you for the info,I'm going to try to find that paper once I finish typing this up.

I believe I will be going with steel seals,I know I said carbon earlier,but I had a brain fart. I forgot carbon was for forced induction,and steel was high rpm usage.

I am looking to spend around 1k on the initial cost of peripheral port. I would like to keep it to one rebuild in one shot,I don't mind rebuilding,but it's my daily driver.


One question,I'm looking at turbo 2's on craigslist and I'm wondering if I can keep the stock turbos if I peripheral port it.

 

Actually its the other way around, carbon is NA only. Advantage is they are cheap and housings/rotors will get no wear at high rpm. Downside is theyre one piece so a bit of sealing is given up, and they wear quick.

Steel are also not too expensive but will be unforgiving in extended hi rpm/lean conditions. For occasionally hi rpm use with ensured lubrication they shod work fine in 2mm trim

The best are ceramics (nrs or ianetti), they wont come cheap but if you dont drop a nut into the inlet it will be the only set you buy normally speaking. They dont wear, nor do the housings or rotors. Basicly if all goes well the only thing you need to rebuilt the engine for are side seals.

In my housings the Od of the tube is around 67mm. Around .15mm negative clearance, so heat up housing in oven, put sleeve in freezer, slip it and it will never ever come out. For safety one could weld it briefly on the outside. Seal water passages with your favourite expoxy resin.

Port diameter doesnt really seem to impact midrange wot torque a lot in my experience as the shown dyno was with 52mm ports, 82 deg atdc closing. When flooring at 2000 rpm it will just pick up nicely and pull away.

The big factor that I think balances part load driveability and power will be overlap.

More overlap during vacuum in the intake will create alot of exhaust gas in the inlet stroke, causing misfire and stumbling.

 

lol, we've been over that. no you can't. you'd be lucky if it even ran at all with the stock turbo.

the peripheral port is like a piston engine with the biggest cam you can buy.

 

I haven't yet seen a piston engine cam that has the same characteristics.

 

Would it work with a bridge without busting components keeping in mind I want to spend about 1k on engine? Also,how much power could I expect from that if possible?

 

so you want to spend 1k, on your first PP on your only car? or do you have a back up to use as a if your main daily driver goes down?

firstly you're better of going with a bridge if your budget is 1k, you need a decent ecu to be able to tune this thing, and you're going to have trouble doing that for less then 1k... an old halteh e6k won't work well enough, or will it? seems like there is a setting you need to change and only comes on newer nicer ecus.
if you don't have to change the injector"timing" then a rtek for would work for timing and A/f adjustments. you can find those for ~400

even then a rebuild is going to cost at least 600 if you do just apex seals and the RA rubber seals kit.( thats leaving out side seals and bearings.)
also i dont recall if bridge ports like the stock FC manifold.. i know pj has the holley manfiold to keep all the runners divided that keeps the chambers from "talking" right?

 

no, the stock turbo is the bottle neck in the stock setup.

The 2nd Generation Rx-7 Resource

when Mazda's racing department went turbo bridgeport, they used TWO turbos that were bigger than the stock turbo

 

Why would it have to be CNC? CNC is for huge production runs of complex parts. You don't need a CNC to mill out two parts. That would be massively wasteful time-wise.

 

oh end mill.. still machine shop stuff.. a bit more then a drill press and a hole saw..

My bad.

 

Well if I went this route,it would be a smaller port, and I wouldn't want to be running as much boost as Mazda racing was,like around 10 pounds or so is my guess of what would be safe. It would just be kind of a fun factor to have a twin turbo car too,likely more practical than massive overlap pp.

 

I got a couple other questions I wanted to ask you guys.

What are the drawbacks to race clearancing rotors? if it was only good,wouldn't Mazda have done it from the factory?
also,I'm looking at an rx8 I could possibly afford, I haven't found a whole lot of info on the renesis engine except that people haven't experimented yet,anyone know of places I should look at for more info?
Again,thanks for the input

 

The rotors only need enough clearance so they don't touch the iron's or rotor housings. Any more isn't preferabele, it only exposes the side seals to the hot gases, and the rotor will move around more. I wouldn't want to run excessive clearance for no reason.

A PP on a RX8 renesis engine has been done, theres a story about it here:

Join5

 

Hmm,interesting article,it's odd,it produced the same hp that I saw on the only other pp renesis engine I've found,but the one I found,had a stock side port exhaust,but the one you showed,had peripheral intake and exhaust,but same hp.

Edit: here's the article
http://www.rx8club.com/series-i-major-horsepower-upgrades-93/peripheral-port-renesis-dynos-133479/

 

you don't look at things very thoroughly.. its the same engine.

the one john posted is linked in the thread you linked. there is just more info about it.

i'd also like to point out all the talk by the rx8 forum, and there leader "teamrx8" which has walked all over my ideas which i won't be sharing until success, but it goes along the lines of running side intake, side exhaust, at the same time as peri intake peri exhaust. don't ask........

if you want to pour LOTS of money( 10k ) at the N/a rotary devolopement your in the right forum. if u want cheap power for a potential car (be rx7 rx8 or 240sx). just get a 5.3 chevy v8 and don't bother with the rotary. you're in uncharted waters.

 

how come everyone sounds reasonable on the Rx7 forum, but completely inane on the Rx8 forum? there is something in the water over there...

you mentioned your idea here in a much more sane way, and it received much less fanfare. the complexity issue aside, i would suggest being able to switch the PP by load and not rpm, and then the PP should maybe be the main port when it isn't idling. those are just my thoughts after having lived with an Rx8 and a P port for a while.

 

Sorry I didn't notice,but I thought in the link I posted,they kept the stock exhaust side port,and the link you posted they had a picture with both peripheral intake and exhaust.

I am trying to stay away from an engine swap due mainly to the fact that even if I were equipped for it,my parents are appalled by the idea of am engine swap,plus the fact it's out of my price range. I did find an fb on craigslist with an ls1 mounted with a grannies conversion kit,but needs electronics,for only 1500 and my parents are not letting that happen. They're scared of It becoming a lawn ornament.

 

I mean for this post to be different from my last one,so don't harp on me for not just editing.

with reading that renesis engines use 13b housings with no exhaust cut into them,would that mean I could get a 13b,use renesis housings,and get the most efficient/best laid out peripheral? From what I understand the stock pp exhaust is too long,limiting power and causing exhaust heat,so a shorter exhaust stroke could give me a better setup,is that correct?

 

the plan (for the renesis PP) is to use 84 GSL 13b mid housing for idle, it has the least timing of any port( maybe too little), and i happen to come across one BNIB... that and the two outside ports being fed by a vary long yet tuned intake should yield great air velocity at lower rpms before the pp picks up, and yes i do plan to open the PP on a "power needed" bases as you describe.

im going to do a regular 4 port 13b one of these first, and if im satisfied i may not even do the renesis project at all.. i may convert a reni into a 13brew by welding up the exhaust ports.. but what would be for a turbo swap in the 400s range. thanks for your kind words, i take it you saw the thread on the rx8 forum?

 

Hey guys, I am looking at a 1990 turbo2 with 170000 chassis miles,and 65k on the rebuilt original engine but it doesn't idle well or go above 5k rpm. Sounds like a cracked seal? Is this engine going to be okay for a rebuild then good to go? or is the housing and or rotor likely damaged? Btw,I would be buying it for 3k, is this a good deal? He does have done aftermarket parts like rtek ecu and coilovers are the main expensive ones. No real poweradders.
Thank you for the input

 

 

You're sorta missing the feedback part of "critical feedback"
you don't do me or anyonbody reading this thread any good by not explaining your reasoning.