Although some think it is going to be too dificult, due to the fact the exh passes through the motor mount, a long primary header used to make excellent power gains on previous rotaries. what do you think power wise can be attained? I am wiling to make an educated guess at 8-12 whp as the factory log manifold sucks and only helps emissions. I hope to be fabricating one after delivery(3rd allocation), but it wont be carb legal but will be fun =)
Has anyone seen anybody prototyping one? I am willing to guess Racing beat is. but anyone else?

Kyle Lancaster--Double Agent Salesman

 

Re Amemiya is currenlty making one... Here is the link http://www.re-amemiya.co.jp/sub_win/rx_8_88.html

 

Yeah, each rotor has 2 exhaust ports.

 

one for each of the main exhaust ports, and the two secondary exhaust ports are combined into one pipe (i guess since they are smaller)

 

...jeez, that RE-A body kit kicks ***... that is hot stuff...

it's nice to see that their header leaves a lot of room (at least on the flange) for opening up the intermediate housing ports a little and port matching to the header... i really love the incorperated baffle there... marvelous :D

 

didnt superstreet or sport compact carsay there wont be any headers for this car.

 

I don't exactly know about the design of the siamesed exhaust port but doesn't adding that baffle restricts the port's area to half its size? Wouldn't this effectively reduce flow through this port and force it to the main exhaust port?

 

It looks like they were wrong :D


Since here's a pic of the header from RE-Amemiya's site (linked above)



Now.. if it is smog legal... that's a different story...

 

A design flaw that I see in this is the location of the O2 Sensor bung. I'd have put the bung in either the pipe coming off the center, or after the collector.

With a little bit of EE, it would be possible to put 2 O2 sensor bungs in, one for each rotor... the EE work would come in combining the signals from the 2 sensors into an input the ECU could read. If I remember correctly, they are wide band O2 sensors, which are quite a bit more complex than the old lambda sensors on the FD.

The advantage of this would be loging each rotor's performance, so matching power-outputs on each rotor could be done. . . I'm not too sure if something like this has been tried before (Wideband tuning on a per-rotor basis) but I'd love to try it!

 

Could somebody please care to comment on this?

 

I would like to believe upward to 20+ HP can be gained for 3 reasons:

1) Rotaries like to breath (don't know if it's a much the case with different port locations) and so they typically respond better to exhaust modifications than a recipocating powerplant.
2) The factory design looks like it really comprimised HP for torque
3) High rev'ing engines typically respond better to improved breathing

 

not really... what's happened there with the siamesed port is Mazda's feeding two secondary exhaust ports out through one external port... because there is almost continuous overlap between the exhaust pulses, and a half-baffle in the intermediate housing itself, this extra baffle on the Mazdaspeed header actually gives you more leeway as far as porting the exit from the intermediate housing goes (it's sorely needed).

 

I was a little surprised to see the divider at all, but they have obviously done the testing and found that it works ok.

I would have thought that it would have decreased the effective area of the exhaust runner too much, but without actually have seen the exhaust ports in person other than a few dodgy pictures, to see how much volume they will flow it is hard to make an accurate judgement.

I think having the centre ports going into a single pipe is good for scavenging reasons. In the old school motors (hard to believe a Gen III RX-7 is now old school because of the engine!) the exhaust ports were peripheral, so they were open basically all the time meaning pretty much a constant flow of exhaust gas through them, obviously with a much stronger initial pulse as the port opens.

With the side ports, the exhaust ports are open for a shorter time, and basically never at the same time for front and rear rotors. So having the centre exhaust runner common would promote exhaust scavenging as the first exhaust pulse would be ending as the second port was about to open.

With then a more contant flow of gas through the centre pipe, the outside pipes upon merging, would also be advantaged by the scavenging effect the flow of gasses from the centre pipe, so it should all work very nicely, in theory!

 

That is slick looking. I am not an expert about headers but it is easy to see a well constructed one. It is a nice clean design and those welds look top notch.

 

what size piping do you think that is?

 

Looks like about inch-and-a-half to me.

 

I think it's also there so the opposing rotor doesn't get blasted with exhaust gases.

 

Those headers look the treat. Can't wait till us Aussie guys start picking up on everything you guys have learned!

 

hymee that is the best avatar I've seen yet

 

Thanks mate.

I had to cut it down heaps to meet this site's requirements.

Here is my "full" version

I ripped from a cool animation that can be found here

It is pretty cool!

Cheers,
Hymee.

 

does Re Amemiya have an english website? or a link on their main page to one? if there is one, i can't find it