I've had this planned for some time, just waiting for funds, motivation, and a good enough friend to purchase machining equipment

Oh, and it would perform better for sure. Peripheral porting takes the most advantage of port timing vs. port size, gaining you the most VE. I would leave the side-port primaries stock, just cleaned up, keep the PP closing edge around ~60* to get the most of the power band, and oval it out like an exhaust port to gain volume without affecting timing. You would have a killer setup that IMO would kill a side-port config, cost much less (vs buying 2x 20B thick irons $$$) and come closer to rivaling a full PP with great drivability.

PM me if you want to talk about it any more...

 

LOL, yup I was thinking about it during KBBQ with a local friend. Pretty dead set on it now. It makes things sooo much easier. So basically dual stock primary ports with 2x ID1600 injectors in the stock primary position which will give me 3200cc's. So basically I plan to have a toggle switch like the one below which will activate the 2nd map on the Motec and open the butterflies for the semi-perry ports. At least that would eliminate any staging issues. I'll still try to get it to stage automatically but if I can't get it to work this will make it work with 2 separate maps activated by the switch.



thewird

 

http://www.precisionengltd.co.nz/rotary.html here you go guys

 

From Green Brothers...

$3850 4 rotor ecc shaft, f&r counterweights, rear nut, woodruff keys
$1800 2x center iron/stat gear mods – includes stat gear carriers and external oil feed tubes.
$1640 2x new FD center irons
$510 2x new ststionary gears
$520 4 rotor through bolt set
$200 4 rotor dowel set

$8520 NZD total = $7,055.40 USD

The rest is all 13b parts but since I want primary ports in the front and rear iron, I still have to figure that out. I'm looking into aluminum plates.

thewird

 

I think you're missing what I'm trying to say. You would eliminate the secondary sideports alltogether, and thus any kind of crazy aluminum parts or machining. Each rotor would be fed by 2 ports only, 1 sideport primary and 1 peripheral port secondary (somewhere in-between the size of a full PP @ 2" and semi-pp @ 1") You would devcon shut both front and rear iron secondaries and every other primary port. The peripheral secondary should transition by throttle input, anything over 50% throttle and it should be wide open along with the sideport to achieve the best performance. Just think of a full PP engine, but in addition to the full PP adding 1 primary port to each rotor, and reducing the size of the PP to suit.

Look over Logan from Defined Autoworks' thread about the 20B N/A semi-pp, you'll see that at full throttle, the streetported sideports alone did not yield really any low-end torque/power vs. the sideports + semi-pp together. The only real reason to transition the peripheral secondary @ 50% throttle is to get better starting, idling, cruising, driveability...

 

If you ever driven an RX-8, you'll know that the single sideport alone basically means the car is dead until 4k where the 2nd port opens. I don't think the car would be fun to drive unless that 2nd port opens if theres only one sideport. Wonder if there would even be enough flow to create boost on a big turbo. I think I'm gonna stick with 2 stock primary ports open at all times + the semi-peripheral. Maybe I'll have a talk with Logan anyway cause I still need someone to make the semi-peripherals as that is beyond me. I also think what applies to an N/A motor won't necessarily apply to a turbo motor in exactly the same way.

thewird

 

Hmmm Marco, we should talk. I have been working on some parts/ideas for exactly what you want to do.
A customer is interested in doing the same.

I'll pm you a bit later today.

 

That switch looks very familiar. I can't wait to show you guys what mine does.

 

Oh, do tell.

thewird

 

Goods and Services Tax. Don't know that you'd have to pay being out of country.

 

I'm not talking about transitioning by RPM, but by throttle input. Anything over 50% throttle and the PP and sideport are wide open at any RPM, which results in better torque/power across the board (as long as your PP doesn't close too late) I've done the same with my semi-pp 13B right now, I've set my 4-barrel throttlebody to only open the secondary & semi-pp butterflies at a little over 35% throttle, so initial throttle tip-in and low-throttle driving will still be smooth on the primary port alone. I'm going to keep my primaries stock, just cleaned up. Engine's not built yet, but that's the idea. I may even test actuating the secondary butterflies on an RPM switch and/or a boost switch to see if it helps improve power in lower RPM's.

Issues with spool and 4-rotor do not belong in the same sentence, LOL! And VE applies to any engine, all of the time, N/A or Forced Induction.

I'm sure if you work with Joe you guys will have no problem getting this thing up and running. I'll look forward to seeing it if/when you guys do!

 

The idea of running the semi p-port and secondaries on the secondary butterflies works. I have it that way on my street FB. However, I am losing out on the gains of an open plenum under the carb. I will admit that it is a pleasure to drive in town but I could have a lot more power throughout the mid-range if I did a plenum. BTW it will still brap and buck even with those ports closed.

Just my 2 Euro cents.

 

After talking to Joe, I might just try a primary port only 4 rotor and decide later if I need to go to the extreme of semi-perry ports. I'll be building the engine so no worries about rebuild costs

thewird

 

maybe a turbo car makes this a moot point, but you should try to go drive a PP car before you do it. they are more picky about the tune, but once the engine is happy, its pretty tame.

 

Man you guys make things sound hard for people.

four rotor side port is easy.
in order from front of the motor
Series 4 ('86) front iron(sec port for number 1 rotor)
series 4 centre(pri ports for 1 and 2 rotor)
12a tallport centre(sec ports for 2 and 3 rotor)
series 4 centre(pri ports for 3 and 4 rotor)
series 4 rear iron(sec port for number 4 rotor)

tallport plate can be ported to flow the same as the front and rear secondries and just have to machine water seal grooves in it.
building a couple at the moment and they make easy 900hp.
no such thing as over kill
basicaly tunes up like 2 '86 13b's
If you have a nice 450whp 13b street combo double it up to a 4 rotor and you'll have ab easy 900hp beast

we do nice dry sump kits for them now with billet pump bracket(suit Peterson pump),sump plate and drive pulley.

Brent

 

That's because you guys down their are the engineering geniuses when it comes to the bastard 4 rotor. Great point about the 12a plates but, most here would have never considered machining the water grooves. Matter of fact, haven't seen it done yet up here in the states other than the Racing Beat aluminum side plates.

 

Couldn't you get away with running pre-86 13b housings instead, with the watergroove in the rotor housing? you would just then have to fill in the water seal grooves in the 86 centre irons.

 

I've looked at the same set of options and I think running the stock front and rear ports and porting the mid plates should be enough. The balance my not be exact, but some custom trimming per rotor and the fact the airflow should be trying to equalize for pressure given it is compressed and I don't think it will be a huge issue. Under partial throttle you will have a variance in the flow, but under boost, the pressures should roughly equalize out.

My $0.02
-Trent

 

Trots, how about GSL-SE intermediate irons?

 

For $150 you can machine the grooves and have very close to equal flow,why **** around with old housings and devcon?cost more time and money and wont be as good.even with a slight difference in port flow you can see it in the egts let alone having a big difference,you can trim the fuel but if your spending the time and money building a 4 rotor you might aswell do it best you can with out spending any more money.

 

Maybe my project will help you think futher on this?
Feel free to ask silly questions there!

https://www.rx7club.com/old-school-other-rotary-63/tegheim-home-made-4-rotor-wolvo-project-892879/

Regards
Tegheim