devious12

So is it possible? Can a third rotor be added to the Renisis and how much would it cost? What other mods would you need to do?

I've searched and found nothing. I'm not talking about a 13B 3 rotor build or a cosmo, I'm interested in knowing if it's possible using the Renisis platform and with the side ports or if the third rotor would need to not have a side port to work properly.

Thanks for any info.

BaronVonBigmeat

Sure, you could attach a rotor to the front of the renesis.

Getting it to burn gas and deliver power could be a small problem though.

Frostee

cost would be large, cuz you would need to redesign the engine....

lurch519

it probably could be done, just by stacking another mid plate on either the front and back, then another housing, then another endplate. thats the relatively easy part. the hard part would be coming up with a new eccentric or crankshaft, though it may be possible to use one from a b20, then you would need to make up a new engine harness, redesign the intake manifold, and hook up a new ecu and program it, as well as integrate all the other things that run from the factory ecu. would be much much much simpler to just swap a 20b into the car in the first place, much like acosta motorsports in new jersey did.

acosta 20b rx-8 featured on mazda's website

TheColonel

So basically the short answer is "no" or "yes, but you'd be stupid to do so..." lol.

PaulieWalnuts

The short answer is anything could be done with the right knowledge, capabilites and money. I'm sure Rotarygod would gladly accept funding to research a project like this.

A 3 rotor renesis sure would be nice though. 360 hp natually aspirated. Giddyup

Photic

I had asked a similar question a while ago, although I was thinking about an extra 2 rotors, and have 2 ECU's (One for both dual sections) Maybe a split exhaust with 2 O2 sensors or something, but someone just straight up "No" so I let it be. heh.

shaolin

^^^That's a complicated setup. Fuel delivery would be a bitch.

devious12

Thanks for the feedback, I know Acosta did it but it was with a 20b (so I hear they were suppose to run that car today at Atco), I wanted to see the Renisis done like that. Forgot about that little thing... the eccentric shaft. Oh well, it's nice to dream, was just curious if it would cost more than say a kit like SFR's to do. 360 N/A would be more what I would want rather than FI.

lurch519

i had heard somewhere that people were either using renesis rotors on a 13b, or 13b rotors on a renesis, so you might be able to make the 20b e shaft work on the renesis, would be kinda cool to do something like that, but the engine management would be a nightmare

army_rx8

yaooooowza...that woudl be a head ache to set up. hmm by now i'm a lill curiouse

guitarjunkie28

there's a company that made an adapter to bolt 2 13b's together... that would be a LOT cheaper than trying to put a 3rd rotor on.

think about a 400 whp n/a renesis burning 87 octane

guitarjunkie28

well....2 of them, actually

devious12

So is that a 4 rotor that your talking about or just one rotor off the 13b with an adapter?

Also why can the engine use 87octane at that point?

Thanks

guitarjunkie28

no, it's literally 2 13b's bolted together.

devious12

I know but I thought the 13b had 2 rotors? I think I'm missing something.

And the 87 octane?

guitarjunkie28

the 13b does have 2 rotors... 2 13b's bolted together would in essence be a ghetto 4-rotor.

and why not 87? hell, i've run some turbo cars on 87 with conservative tuning.

shaolin

Ask and you shall receive.

2.6L 4 Rotor FD3S 500hp NA

http://members.dslextreme.com/users/erika/scoot.wmv
http://www.epoch-net.ne.jp/yasu/777/4re_001_b.wmv

Custom eccentric shaft, and individual throttle bodies along with a few longer bolts and a standalone ECU is whats needed...I believe...

guitarjunkie28

i thought we were talking about cost effectiveness...

the scoot 4 rotor is cool, but it'd be insanely expensive.
but one cool thing about 4 rotors (assuming the firing order would be 2 simultaneus combustion events) is you'd be able to control them with an e6k, or other cheap ems....just tell the computer it's a 2-rotor, then piggy-back the injectors and coils.

neit_jnf

for a side-port 3-(or more) rotor engine to be built, custom middle plates would be required. The Renesis has two larger exhaust ports, one per front/rear plate, and two smaller, merged into one, exhaust ports in the middle plate.

If someone made a middle plate with independent, same size side exhaust port as the front/rear plates and also with the corresponding intake ports, then a multirotor (3+) side port engine can be possible. Of course everything on it would have to be custom made, intake manifold with rotating sleeves if you want to keep the 3 intake ports per rotor configuration or for simplicity you could make it without the 3rd intake ports; custom eccentric shaft, custom tension bolts, custom exhaust.... and you'll need a full fledged stand alone like those used to control the 20B.

The side plates would be bigger so the engine will end up being longer and heavier than the 20B unless it's made all aluminum or even better magnesium-aluminum

cost? maybe bill gates can make it happen

rotarygod

That method would be fine if you still kept the firing order at 180 degrees by always firing 2 rotors together in a sort of flat plane crank type of fashion. However all of the 4 rotors out there run a 90 degree firing order. You tell an ems that you are running a 4 cylinder for a 2 rotor or an 8 cylinder for a 4 rotor. It would still work just fine. Granny's Speed Shop, who build the end to end stacked 13B based 4 rotor, did run the flat plane arrangement but only because they couldn't figure out ignition timing using the stock distributer. Since they were running carbs, that was the only problem.

Rotarian_SC

Yeah, it's quite expensive because you would have to design and manufacture a middle plate that allows the gas to escape. If you really wanted a 3-rotor I'd say it would be cheaper to go Acosta style and use the old 20B.

guitarjunkie28

i'd hit up the granny 4 rotor if i had the money... 450 whp, 450 tq on 87 octane :D