rotarygod

This is just what it sounds like. This is a Renesis that has had peripheral ports cut into it. The side intake ports are no longer used. The side exhaust port configuration is retained. We've been curious about it. Here it is.

The results are very interesting. As predicted, power does go up. However it isn't anywhere near what a peripheral intake and exhaust engines can do. It is interesting to note how much the powerband changes between 19" in length and 22" in length. Look at what rpm it makes more power than the stock engine.

http://www.rotaryeng.net/RX8PPB-Stock-RX8.jpg

http://www.rotaryeng.net/RX8PP264a-Stock-RX8.jpg

Here's how they built it:

http://www.rotaryeng.net/Welded-steel-p-port.html

tajabaho1

263 for PP? well, the graph does make more power, much faster than the stock even if the peak hp is a little disappointing

rotarygod

It should be pointed out that the most powerful periperpheral ported engines make their peak power up over 9K so this may actually not be that bad.

The 19" runner graph shows power being greater than stock above 6100 rpm. That's pretty high. If you look at the extreme left though it implies more power below 5000 rpm as well. If the tuning trend could be extended down lower, it would probably make more power between about 3500-5000 rpm as well. That is assuming that these runs didn't just start at 5K but rather the graph does.

rotarygod

Here's a dyno of a conventional all peripheral port (non Renesis) engine with 24.5" long runners. A shorter runner setup should be more powerful. This shows a peak power level of about 245 hp which is more than the shorter (22") intake runner p-port Renesis.

http://www.rotaryeng.net/Weber58-24....yno-curve2.jpg

This implies that the peripheral exhaust port is still superior when used with a peripheral intake port. I'd tend to agree as you need to have similar timing characteristics between intake and exhaust port to get full potential.

rotarygod

Here it is on the dyno at Mazdatrix:

http://www.rotaryeng.net/Idle3.wmv

http://www.rotaryeng.net/Standoff3.wmv

rotarygod

????? You are contradicting yourself.

MazdaManiac

iTrader: (3)

Wow, that's a lot of work for 60 HP.
Does it idle?

rotarygod

You just said those sheets are wrong then you said you trust it far more than others.

Floyd

Thanks for the post RG! I'd never actualy seen a peripheral port before

rotarygod

It's idling around 1300 rpm. Here in Texas your car needs to idle below 1000 rpm to pass inspection. This engine is also using a carb and not fuel injection so there is probably some power to be had and a lower idle that could be obtained.

tajabaho1

I +1 on that

and from what I've read on here, PP renny = not safe with turbo.......so......wtf

rotarygod

Actually they do cross at 5252. The stock dyno lines are hand drawn in for rough reference only.

zoom44

its the problem with the graphing not the results. they are not scaled the same, ray.. we see that allot with dyno plots

flyboi1121

dang... hp goes up but so does tq. for someone who isn't rolling in cash, this is well worth it if u already have the engine out or replacing one... but to pay for labor for all that mmm~

zoom44

not to mention that some renesis' with just a smart rebuild and masterful tuning have seen 262 on an engine dyno. so the Pport seems hardly worth it

rotarygod

Good luck trying to make this work with the stock ecu. I guess it could be done. You would need a new intake manifold though. It's not something I'd do to my engine. I'm still convinced that the all side port rotary is the perfect street combination.

TeamRX8

iTrader: (25)

well it's BS from the sense that the PP exhaust was modified extensively in other areas, so it's hardly a relative comparison to a bone stock Renesis for the point at hand

RacingDynamcs

How are you still convinced??? It makes very little power when modified in N/A form (compared to previous gen) and it doesn't run any better than the old 13b's.

rotarygod

Look at it again. It doesn't have a peripheral port exhaust. It's all side port exhaust. Only the intake ports are peripheral.

Keep in mind this engine isn't for a car. It's for an airplane. He only cares about what it does at 1 particular rpm and doesn't need a big powerband.

tdiddy

I always thought the exhaust ports were more of a restriction than the intake ports? I understand that there is power to be had by improving the intake ports but couldn't we see a larger increase in power from exhaust porting?

Forgive me as I am not well versed in porting and its pros and cons...

rotarygod

They are. There's more to power than pure static flow numbers. Many people don't understand this.

TeamRX8

iTrader: (25)

aaack, my bad, guess I don't see any need for doing such on the intake as opposed to the exhaust

sideways oval would be better than a round port IMO, harder to make though

I know who he is and what he's doing, not impressive at all considering those are flywheel #s

rotarygod

Those peak power numbers aren't impressive if all you are looking at is the peak. Look at what rpm those peaks occur at though compared to engines that make more power and it really isn't bad.

RacingDynamcs

And its not very good for the kind of port that was done.

rotarygod

How many other peripheral intake, side exhaust port engines have you seen? I stated earlier that it was lower in power compared to an all p-port engine. It should be. The exhaust port timing is all wrong in relation to the intake timing.