https://www.rx8club.com/attachment.p...1&d=1365724970
https://www.rx8club.com/attachment.p...1&d=1365724970

 

I'm going to guess that the plastic content of the exhaust port is too far out of spec.

 

this is how i found it.
NOW WHY is there communication between rotors??
The space is located at the top lip of the centerport insert--plastic tie just slipped thru--a little tight--but its there.
Sorry for the bad camera pics

 

huh?

 

I'm not very knowledgeable on the insides of the RENESIS, but I seriously don't understand the point of this lol

 

There is a plastic zip tie in the exhaust port of the center iron. Presumably melted into place? Plus, one end of the zip tie is sticking out of one side, the other end out the other side. And there isn't supposed to be a passage between them.

 

i'm surprised you could even make it out. the **** just looks like a blurry mess from a crappy cell phone to me.

 

What is being said here is that: There is a hole that goes through the exhaust ports from front to rear rotors and its being pointed out by the zip tie. The question being asked is: Why is there flow between the two rotors?

It wasn't that hard to grasp.

 

and the answer is? this is almost popcorn worthy.

 

"I couldn't figure out the torque specs of the exhaust port, so I zip tied it instead and figured that would work"




?

 

He hit it on the head. There is communication between the two rotors. So when one rotor is exhausting--it is blowing a small amount into the other rotor--i am not sure of the timing of it all.
That zip tie is NOT melted--it is sticking through part of the opening between the two rotors.

It seems to me that should NOT be there! Why put a wall in the insert to separate the flow and then leave this open?

no doubt about it to me --the centerport needs some massaging.
They are crappy pictures.....best I could do at the time.
I will try to get better ones up.

 

Ah, the zip tie is for demonstration.

At a first guess, minor EGR effect?

 

https://www.rx8club.com/attachment.p...1&d=1365805045

maybe better?

 

this cant be a good thing

 

It's insignificant ...........................

 

Was it ported?

 

No. It was not ported.

Brett with all due respect man--the way I am thinking any port to port leakage has to be of some significance? Especially for us boosted guys.
To me --eliminate the backspace, smooth it out and fill in this hole may help a little with centerport efficiency?
It probably would not be big --but every little tweak does help.

 

It's been something that was discussed many moons ago. There was a Japanese header that was made with a divider to try to separate the two ports. I don't remember anyone spending the $1000+ for that header. I believe someone tried to weld a piece of metal in the center of the exhaust port. I don't remember the results of this.
Ray may remember something about this discussion. I think it was when we were first discussing long tube headers about 8 yrs ago.

 

If one rotor is in its exhaust stroke and the other in any other then wouldn't the opening actually increase exhaust flow?

 

Well .......................remember that i have tried a sleeve in there that had a lot of the center plate cut away and gas was free to go from side to side . Results of that test showed zero difference .

 

Zero difference? I thought your car became more responsive once you replaced that plate?
Maybe I read it wrong?
I dont understand how port to port leakage cannot affect anything.
Shelldude--you dont want exhaust leakage into the other rotors chamber.

 

I'm not sure if I want it or not... apparently Mazda does!

 

dude ... get a better camera, cell phone camera is just ...

I use Canon 7D ...

I see what you mean by now

Its not a big deal I think.

 

You mean KnightSports.

I was gonna get it IF (big IF) I can get the RX-8 I want here. Yen is much cheaper now so I don't see why not ?

According to Knight sports, they said when u separate the port, it even out the pulses and the result is higher power (slightly), Racing Beat actually did have something like that during their R&D, but they found no real benefit over it (very very little) and it cost an arm and leg for mass production. so they released the 3 runner header they sell right now.

 

No you misread it OD . I Thought that was the issue and that is why i swapped it out and put the stock sleeve back in . But that changed nothing and so I had to put the lower response down to the bigger compressor wheel.