Stole this from another forum....Engine is running in a drift FD in the UK... thought a 3rotor with side exhaust ports wasn't possible? http://ausrotary.com/viewtopic.php?f...72b617cdc82d24

 

Fricking sweet!!!!!

 

Its 5.45am and im sitting here tring to figure out this motor... wouldn't this be a tuning nightmare because of the irrigular ports in the middle housing?

 

I guess only time will tell.

 

Interesting.
I wonder if it would'nt be better/more tuneable, with peripheral intake ports.

 

Sooner or later I knew some one would do a 20B-MSP engine.

Excellent stuff

REgards

 

That is bad ***!

I would love to see the numbers on an engine dyno.

 

Huh, interesting... end plates look like the ones from the 4-port automatic, right? Maybe with that and some work on the intake ports on all the plates, it'd be possible to... well equalize the flow and timing moreso anyway.

 

Sweet!

I don't know if its a problem on the renesis, but what about the heat/exhaust in the irons? I've seen na rotary's w/ glowing hot exhaust pipes.

How well do the irons take the heat? or expell it?

Awesome motor tho!

 

I wonder what they did to support the e-shaft in the middle?

 

It's a short shaft motor so the intermediate housing(s) should have staionary gear/bearing setup.

 

It's possible but you technically will have a problem with uneven exhaust flow. The only real issue is that the center rotor would have to share two smaller exhaust ports when compared to the front two rotors. On the stock engine, the center plate shares two exhaust ports for the front and rear rotor while the front and rear plates would have the larger exhaust ports. For this configuration to work evenly, it would really need to have a thick 20b style center plate to allow for the center rotor to also have the one large exhaust port. Either way, I'm glad someone is finally trying this. With no overlap in the timing, this engine could possibly pass an emissions test with a large cat.

 

The exhaust isn't water cooled.

 

oh happy day! i knew it was a matter of time. yes, the middle rotor's exhaust flow will be in question, but hopefully things will trickle down in time and several heads can come together to effect a solution.

would give a quarter of my left nut to hear that thing breathe ...

 

So it would seem to be a good idea in theory, but maybe not so much in real life due to the porting?

 

The exhaust porting issue all depends on if the engine is built with a re-engineered larger center housing to equalize the exhaust port flow. The above engine was built in a more economical way with parts that already exist. So anyone can build it. The above engine will work. It just wont have the ideal exhaust flow. Truthfully it may not be much of a factor. Example.....if the slight restriction only causes a loss of 20hp, I don't think anyone would really complain. The real nice thing here is we do have an engine we can compare it to. GToRX7 had a similar 20b set-up with pp exhaust that made 345rwhp ITB's and mild porting. Either way, it will be really nice to see what kind of numbers this engine gets.

 

Interesting look ... for a second I was going to say its a 4 rotor before nothing the intake and seeing only 3 inlets and then had to take a closer look to note that its a sideport exhuast.

 

There may not be an issue with a slight reduction in hp from the smaller ports, but the problem is tuning the engine. You'd need to instrument it up the wazoo because at very least you'll need to tune the center rotor differently than the front and back rotors. With the center ports from the middle sharing exhaust runners with the end rotors, you'll have no way to easily tell what the center rotor's doing because the EGT's and AFR's as measured in those runners will be a mix of the end rotors and the middle rotor. You'd have to try to figure it out by comparing the front and rear runner measurements with the center trying to guess at what's really happening in there. So that's 4 EGT probes, 4 widebands, datalogging for them all, a Standalone capable of tuning each rotor seperately for fuel and spark. Not cheap and not the easiest tuning project ever.

Would probably be cheaper and easier to just make a custom center plate.

 

i hear dat thing run

 

links down, dammit.

 

There are no issues with the exhaust porting.
The car is now running up to 7000 rpm and is pulling like a train.
I keep wanting another 2 gears in the box,we are using an RX8 box with 6 gears and a 4.1 final drive.
Regards
Carl

 

Since I have actually built the engine and tuned it i can say that it is very good and I have not driven an N/A engine like it.
This is what the RX8 should have in it.
It has lots of low down torque ,but still wants more and more revs.
Zero overlap of the inlet and exhaust ports helps with exhaust evacuation.
The car has not been on a dyno yet,but I can say that it pulls harder than a modified FD RX7 that is still on stock twin turbo's running around 330hp.
Regards
Carl

 

What 20B is the SpeedSouce Rx8 running? I thought it was an MSP style.

 

I think you will find that whilst it is called a Renesis 20b it is actually a Peripheral inlet and exhaust port. Mazda are trying to cash in on the Renesis name.
Regards
Carl

 

here is a pic of the engine bay.
It still needs a tidy up.
Car has had a shakedown run yesterday on track,and is able to compete comfortably with 600hp Skylines.