Hello my name is stoo (fellow rotary head) and I have a question. From my understanding, there seems to be an issue with tubocharging in the renesis due to high compression ratios. So my question is this. Is it possible to CNC mill the groove larger in the rotar surface, to allow for a higher intake capacity, and if so; would it not make sense to lenghthen the groove on one side, changing the overall center position of the groove futher clockwise and angled to increase expansion effeciency? I would think the problem people are having is that they are focusing all of their effort on the turbo and engine management. this procedure would not only decrease the rate of effective additional compression caused my forced induction via lowering the tdc(effective) and increasing displacement it would also lighten the rotars as a side effect. futhermore, changing the angle and position of the groove 'could' effectively allow for greater tourque as the exhaust gasses would have a greater thrust angle. I think this product would sell like hotcakes, and as far as i can tell there is no patent or production. please give me a call if your are interested as i'd like to see it come to life. If it ever comes to life and it's origional....... that would kick ***.

 

another question I pose is this- how much of that rotar can be shaved..... I bet you could get a 10,000 rpm 1.8 litre screamer running at 10 psi if this was done right. wadda ya say 500hp renny on pump gas?

 

I'll wait for your results in doing this. Have fun.

 

pretty sure that it would have been done by now if it were practical .....

 

Uhhh - milling out the rotor will not change the engine's displacement. Secondly, the skin thickness of the rotor is not sufficient to further mill out the pocket without creating thin spots. RB does make a set of lightweight rotors but they are still 10:1 compression I believe. Lastly, you can turbo charge 10:1 compression just fine. Sure, it makes it harder to run higher boost, but moderate street turboing is quite possible. Just look at the new BMW 335xi.

 

The "rotars" are not solid, they are hollow and flow oil.

 

there is no way your are going to get a quarter of a liter more by shaving rotors. besides, the metal is too thin

 

YA NOW THAT I THINK OF IT... what was i thinking. still, i bet new rotar dimensions are more than just possible. I realize shaving may not be the answer, and that actually getting it done may be completely impractical.... but the fact remains, the answer to effective turbo usage is lower compression and i will not take no as an answer (even if it is for the sake of conversation) a complete rotar redesign maybe. I was looking around once and saw a set of race rotars that looked almost the shape of the mercedes benz symbol! the entire rotar edge was convex and it had the **** drilled out of it. so i agree, plan 1 negative response

and what about the direction the apex seals face.... what if they were tilted to flow with the grain.....

it's these essential internal components, i belive need to be modded before the renesis will be a hot little engine. -It is my favorite of all engines; so don't get me wrong- I just think the internals were designed with an economy factor and the compression issue was the result.... and yayayaya you CAN run a turbo and YAYAY it CAN be done right but ask yourself this, if you can get that far with this engine at x amount of boost imagine the amount of power you'd see if you could just push that boost alittle farther....

 

okay okay... how about this then.... obviosly you've seen the cross section renesis rotars then. (ofcourse the internal are hollow) but bear with me, inovation requires a good attitude and an open mind-

- it looks as though the it may be possible to intentionally mill out the center section of the rotar completely, so all that is left is the support braces that are left behind... I know this sounds crazy.... but then would it be possible to fab a new rotar face incert, possibly deep enough that it contacts the center ring that rotates aroung the eccentric shaft for support>

before anyone gets smart.... yes i know> week bonds, impossible to weld, but i don't care if it ever goes further than 300 ft for starts. I still think it can be done.

 

This can only end well.

 

I think this might be a troll... but I'll play.

Just give up... you might as well be developing a new engine if you're going to toy around that much. Unless you have lots of money and someone to help who knows more then it just wont be worth it.

 

Quote 1 - get a 10,000 rpm 1.8 litre screamer

Quote 2 - inovation requires a good attitude and an open mind

Maybe stop while you're ahead.....


S

 

You can't make apex seal grooves "go with the grain", the seal need to be able to move to seal the combustion chamber.

And if you took the rotor face down the hole for the eccentric shaft, how would you seal the side (your side seals would be gone)? It's not even possible, because your compression ratio would be below 4:1.

 

all rotors are shaped the exact same way....... provide pics/links and then this thread will get really interesting, troll(now which one of our guys is this?).

 

and you are where???? because only two answers might be legit..

and i bet you dont know either..

beers

 

You would be better off seeing if you can source rx7 rotors from the foundry before they are sent for machining if they are in a state where Rx8 seal grooves could be machined in or getting a foundry to recast the rx8 rotor with a deeper pocket. That just becomes a matter of money. Assuming you are looking at well over 400 whp in the end (where the compression would be an issue), what are your plans for the remainder of the drive train?

 

you are in need of some basic engineering classes my friend

 

I have come from the future. My timeline is from a parallel universe where the events as unfolded to me may differ from yours. In my timeline, the 8th gen RX-8 has 1.8L engines thanks to the work done by CrazyStoo. Do not doubt him. He is the chosen one.

 

*cue air guitar*

excellent.

 

You're missing a "d" right there at the end of rotar.

 

lol....uuhhhh, yes it will. You tuner guys are great.

I wondered the same thing Stoo. It would affect the power, and the boost capability for sure....just not exactly sure what it would do. Not sure why you guys shoot down innovative ideas, especially on an engine thats very innovative. I the technical stuff is too far over peoples head and its easy to make lame jokes.....never seen another group of people like this in my life. It reminds me of the "no the housings are not plated" thread....and I proved it 30 times over it was fact....LOL. Tuners crack me up.

 

No it won't. The displacement in an engine is determined by the area change, not static volume of the combustion chamber. For simplicity sake, take a reciprocating engine. Now take a 1/2" off the piston crown. The piston head now comes 1/2" less close to the cylinder head. It has drastically lowered compression. It has absolutely identical displacement because the piston head is ALWAYS 1/2" further from the cylinder head. The swept area of the piston remains identical. Regardless of combustion chamber shape, the rotor displaces the same volume. The Rx7 and Rx8 have identical displacements while having different compression ratios.

 

^what he said.

This thread has really brightened up my day. Thanks for the hilarity guys

 

The area is increased, which then increases the amount of air/fuel inside the combusion chamber. Rotaries are apples to oranges with piston engines.....

heres a link...
http://auto.howstuffworks.com/rotary....htm/printable

to narrow your search....

 

Yeah, because it's on wikipedia or howstuffworks it's true. The pockets on the rotor only affect the compression ratio, NOT displacement