I'm kinda new to the RX8 and whole rotary concept. About how much back pressure does the rotary need to make optimum power? If any at all.

 

11.5

 

Repeating, not just .5

 

thanks

 

Brettus, is that 11.5 psi, lbs/sqin, newton meters, or gargefarks/ft?

 

engines, not just rotaries hate backpressure.
Now talk about exhaust volume, speed, pulses, scavenging etc and your question may start to make sense.

@riwwp: i read garagefarts/ft... time for new glasses?

 

I love how he took the number as an answer without even a unit of measure. Shows that he really knows nothing about the term other than how to spell it.

Once he educates himself on the term, he can come back and find out that this isn't a piston engine, so everything he just learned is useless.

 

As I understand it, piston or rotary, no engine needs or wants backpressure.

Edit: bse50 already said that....my bad.

 

Correct.

 

BSE is quite correct . 11.5 garagefarts/ft is the optimum .

 

Well considering I've been building V8s for nearly 7 years now in my free time, and also work on and off in the maintenance bay working on HMMVW's for the army I'm sure I really don't. But I guess that doesn't matter. Forgive me for trying to learn this engine.

 

I aim for 4 metric sheep/hp^2

 

I have zero problem with someone trying to learn. Anyone can back up my reputation there. What I don't understand is IF you know what back pressure actually is (since it's a misnomer) AND are attempting to learn how a rotary engine can be affected by it, why did you approach the question that way, and then apparently accept a response that could not possibly give you the starting point you were looking for?

Take whatever field you are knowledgeable about, and then assume you have someone that comes to you and asks you a question about what you know, but asks it the way you asked the question here. How would YOU respond?

Take a good look back over your opening posts. If you really know what backpressure actually is, how could that question give you an answer that is usable? So, even if you didn't mean it that way, we can't see that intent, and make the assumption that you have no clue what you are doing, and are yet another kid walking into the river without being able to swim.

Which we see.

Every.
Single.
Day.


So approaching it this way kills any motivation for us to assist you in your self education.

So maybe you would like to try again?

 

Well I understand why yall were sarcastic, I have to deal with younger soldiers who don't know much. I'd guess a better way to ask my question is I'm planning to make a custom exhaust for my 8 and I'm trying to figure what diameter piping I need to use, if I need to put any extra bends in the piping or keep it as straight as possible.

 

As big and as straight as possible. No scavenging for the rotary. Dump to atmosphere is technically the best possible in terms of power, but the noise can be ... painful.

 

That's what she said !

But how many garagefats/ft ?

 

Depends on the lunar bean per mile consumption rate.

 

unbolt the exhaust mani and remove everything that is connected to it. free flowing and saves weight. might want to remove the hood also and buy some earplugs