Defined N/a 20b semi p-port. 421rwhp
 

Perseverance---

: continued effort to do or achieve something despite difficulties, failure, or opposition :

This is the word anyone in the sport of n/a tuning would learn to live and love. Having no boost pressure, auxiliary injection, or even supercharger pulleys to play with, naturally aspirated is both difficult and also very rewarding.

With that said, here is our most recent shop car results! Using all learned knowledge over the years from my original ITB 20b, the good ol' 230wheel 1st gen "test mule" and many other projects, finally have the semi p-ports in action! Its a beta version, and really just the beginning. No rumors, no theorizing today. Just the findings and results.

The engine setup-
20b n/a, 9.7:1 rotors, CLR balancing, race rotor bearings, stock stationary bearings. circuit porting, and exhaust porting, semi p-port. Dry sump mazdaspeed front cover. Oil and coolant modifications.

Intake setup-
Stock 20b intake with custom sheet metal plenum and 90mm TB. 3 x 35mm individual throttle bodies for p-ports. 9 fuel injectors. Triple staging.

Accessories-
Racing beat front pulley, mazda comp waterpump pulley.

Exhaust-
Custom stepped inconel header, fully adjustable design. 3.5" main exhaust going to twin 2.75" pipe and dual center exit

Standalone-
Electromotive Tec3R ecu, and inductive coils.

Fuel-
ATL 13 gallon fuel cell, Walbro fuel pump, 550cc x6, and 200cc x 3

Dyno Video
http://www.youtube.com/watch?v=oXzuPuNWpXA

Dyno Charts

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Engine shots

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Car pics

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UNBELIEVABLE!!!!! Great job, the car sounds flawless! Great numbers and a nice big fat flat torque cure to boot!!! Congrats, all the hard work finally paid off!

Awesome!

You guys build some nice cars....your 1st gen, 13b s14 and now this

What numbers did you get without the PP open? Isn't that a new intake setup for the main runners from what you dyno'd in the past?

Congrats! I want one so bad!!!

Wow that's impressive! A real development.

The only thing I'd be critical of is the torque number—it's really low relative to the horsepower.

Thanks! Yes looks like the hard work was for something!

Its made 350rwhp 235 rwtq on the stock intake with a 90mm welded on. Which I found did not flow much better than a full stock intake. Later I modified the plenum the way you see in the pics. I did not however get a chance to dyno it by itself. I will be going back soon to see what it does alone. I estimate 370rwhp.


Thanks! I hear this a lot but its a big mis-conception. Any engine that can hold torque out to 10k is going to have almost half the torque vs horsepower. in fact at 10,504 by law of math, it has to be exactly half. Just like at 5252 torque and horsepower have to be exactly the same. At 241 rwtq its producing about 285 flywheel torque. using 3.9 liters displacement that is 73 ft lbs per liter. Some of the best piston engines (n/a of course) are making 75ft lbs per liter. So the torque is actually pretty darn good :)

are the side ports stock?

shoot i see circuit porting now... too late to edit.

nice man, real nice.

Great Job Guys, Looks and Sounds Wicked!

Wonder how this compares to the power SpeedSource is putting down in their 3 rotor Grand Am cars? They're running Pport motors, correct?

Fantastic Job

congratulations, Logan. i've been waiting for this day. it eclipsed my expectations. i trust this is not over and you'll be developing it even more with time. :)

:icon_tup: :biggrin: :icon_tup:

He,he, heeeeee!!

Fantastic! Seeing these numbers gives me hope that I may get close with my set-up. I won't be reving that hi as I'm not balanced for it yet. Great job Logan. You have really got something going here that will benefit any NA rotary enthusiast. After all these years, it's about time someone engineered OPENING semi PP's instead of the always open set-up.


Edit: Sounds like your PP's are opening just below 4K. Have you tried opening them later to smooth out the transition and improved bottom end? Looks like the semi's aren't really doing much till 5,300rpms.

I "heard" they made 426 to the wheels at a rule limited 8600rpm, I did not see this with my own eyes

(2-15 Mazda RX8 (Prep 2)
2-15.1 20B Cosmo three rotor (Mazda Spec parts). 2.0 liter, 9.7 compression ratio, 3-52mm throttle bodies, maximum of 6 injectors, maximum fuel pressure 4.2 bar, intake manifold is free. Maximum RPM 8600.)

Logan, are you able to close the PP throttle bodies completely so it can idle w/o the brap brap brap? also I see you have a tag, how much driving do you do? it must be FUN!

BigAl...

AWSOME, congrats on that achievement!!

Great Job and numbers

Good job guys! :icon_tup: No surprise though, I know you guys will get more power....

Well, I had wanted to stage them with rpm, but for time constraints they open mechanically. Half throttle is the side ports, and then past that the p-port ITB's will start to open. So on the dyno they are actually open from start to finish, 1500 on up. Torque was actually the same except from 4k-5k they had a little less. For the simplicity and no fear of a failing soleniod, I think I like this mechanical setup. The transition cannot be felt.

The semi p-ports are closed with anything less than half throttle. There isnt a brap, the large street ports definitely give a bit of a rumble though. Even the best ITB's have some air leakage, so there is a little turbulent air going through the p-port at all times.
I do a decent amount of driving. Have gone to a few track events, want to visit big tracks and do time attack and more. With the dogbox its a handful on the street, but I love it. lol

WOW. I could never have expected this great of results, congratulations to you sir. This should quiet up the N/A haters for a few days!

After I'm done with this FI setup for my 13b, this will be my next build. Nothing like being NATURALLY ASPIRATED!

Jeeeez a semi-port engine can make that kind of power??? wooow

Theories are one thing. Taking those and putting them into practice is another.

Game changer.... yes.

Epic.

N/A performance has just evolved.

Words can describe what you have done.

Nice work..

Need to ask why you write rwhp when the dyno paper says 421 on flywheeel.
421 on flywheel is somewhere around 370 on the rear wheels.